Automobile Emission Control-
The Development Status,
Trends, and Outlook
as of December 1976
a report to
the Administrator,
Environmental Protection Agency
prepared by
Emission Control Technology Division,
Mobile Source Air Pollution Control,
Office of Air and Waste Management,
Environmental Protection Agency
April 1977
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Automobile Emission Control -
The Development Status, Trends, and
Outlook as of December 1976
A Report to the Administrator
U.S. Environmental Protection Agency
Prepared by
Emission Control Technology Division
Mobile Source Air Pollution Control
Office of Air and Waste Management
Environmental Protection Agency
April 1977
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Table of Contents
1. Introduction 1-1
2. Conclusions 2-1
2.1. Conclusions 2-1
2.2. Discussion of Conclusions 2-5
3. Development Trends 3-1
3.1. Emission Control Systems Containing 3-Way
Catalysts Are Receiving the Most Effort 3-1
3.2. Improved Fuel Metering Systems Continue to
Receive High Emphasis 3-7
3.3. Significant Use of Electronic Controls
Appears to be a Relative Certainty in the
Next Few Years 3-9
3.4. Non-Catalytic Engine and Emission Control
Technology is Also Showing Some Interesting
Developments 3-11
3.5. Catalytic Developments Other Than the 3-Way
Catalyst Are Also of Interest 3-13
3.6. There Are Indications That The Space Required
For Emission Control Systems May Become A
Future Problem 3-14
3.7. Turbocharging as a Means to Increase Vehicle
Performance Is an Active Area 3-14
3.8. Diesel Engine Development Continues to Receive
Emphasis - But the Development Work on the
Diesel's Problem Areas Does Not Seem to be Receiving
the Intensive Effort Which May be Necessary to
Meet Stringent Emission Standards 3-15
3.9. The Efficiency at Which Development Information
on Emissions Related Subjects Is Reported to EPA
May Be Decreasing 3-18
4. Fuel Economy And Cost 4-1
4.1. Fuel Economy 4-1
4.2. Cost 4-31
5. Driveability 5-1
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Table of Contents (con't)
6. Unregulated Emissions . ; 6-1
6.1. Sulfuric Acid . 6-1
6.2. Hydrogen Cyanide (HCN) . 6-27
6.3. Ruthenium Emissions 6-38
6.4. Ammonia 6-40
6.5. Polynuclear Aromatic Compounds (PNA) 6-44
6.6. Diesel Particulate Emissions 6-53
7. Individual Manufacturer Reviews 7-1
7.1.1. American Motors (AMC). . 7-1
7.1.2. Chrysler . 7-27
7.1.3. Ford 7-52
7.1.4. General Motors (GM) 7-^94
7.2. Independent Developers 7-150
7.2.1. Bendix 7-150
7.2.2. Robert Bosch 7-160
7.2.3. Dresser 7-176
7.2.4. Engelhard 7-182
7.2.5. Ethyl 7-198
7.2.6. Holley 7-204
7.2.7. Matthey Bishop 7-210
7.2.8. Questor ....... 7-217
7.2.9. Universal Oil Products (UOP) 7-223
7.2.10.. Walker 7-226
7.3. Foreign Manufacturers 7-235
7.3.1. BMW . .- 7-235
7.3.2. British Leyland 7-241
7.3.3. Citroen 7-255
7.3.4. Daimler-Benz ....'..... 7-257
7.3.5. Fiat 7-281
7.3.6. Fuji Heavy Industries (Subaru) 7-286
7.3.7. Honda 7-289
7.3.8. Mitsubishi 7-295
7.3.9. Nissan (Datsun) 7-309
7.3.10. Peugeot 7-330
7.3.11. Renault 7-335
7.3.12. Rolls-Royce 7-341
7.3.13. Saab 7-347
7.3.14. Toyo Kogyo (Mazda) . . '. ." : . . .7-363
7.3.15. Toyota ; 7-368
7.3.16. Volkswagen (VW) 7-404
7.3.17. Volvo 7-432
Appendix 1 Al-1
iii
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SECTION 1
INTRODUCTION
This report is a summary of the current technical status and development
trends in the automobile emission control field. This report has been
prepared for the Administrator of the U.S. Environmental Protection
Agency (EPA) to inform the Administrator and other interested parties of
the current status in the emission control technology area.
This report contains a summary and evaluation of the development programs
of automobile manufacturers and other organizations involved in the
development of automobile emission control technology.
This report does not contain projections of future air quality, analysis
of future air quality requirements, or any other air quality studies. A
detailed discussion of these topics is available in the literature.*
The period of time of interest for this report is the 1978 model year
and post-1978 (1979-1985) time period. This time period is considered
as a range related to the current deliberations by Congress on the Clean
Air Act.
Most of the information in this report came from manufacturers' res-
ponses to a request from EPA. Most of the responses from the manu-
facturers were received during December 1976 to February 1977, so the
information pertains to the period of time around the end of calendar
year 1976. The specification of time to which the data relate is
important in an area like emission control technology, in which progress
is continually being made.
* Air Quality, Noise and Health, Report of a Panel of the Interagency
Task Force on Motor Vehicle Goals Beyond 1980, March 1976.
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Copies of the responses submitted by the manufacturers are available for
public inspection at the EPA Freedom of Information Center at the EPA
Headquarters Building, 401 M. Street, S.W., Washington, D.C. A copy of
the letter request from EPA and the date of receipt of the responses are
included in Appendix 1.
Other data used in the preparation of this report were: a) 1976 and
1977 certification results, b) 1978 Part I applications for certifi-
cation, and c) the technical literature.
This report is the sixth in a series of.,reports on the same subject. The
earlier reports were:
y
Automobile Emission Control - A Technology Assessment as of December 1971.
Automobile Emission Control - The State of the Art. as of December 1972.
Automobile Emission Control - The Development Status as of April 1974.
Automobile Emission Control - The Technical Status and Outlook as
of December 1974.
Automobile Emission Control - The Current Status and Development
Trends as of March 1976.
The nomenclature used in this report for emission test results and
standards is a triplet abbreviation. In this shorthand notation for
example, the 1975 Federal standards of 1.5 grains per mile hydrocarbons,
15 grams per mile carbon monoxide and 3.1 grams per mile oxides of
nitrogen are abbreviated 1.5 HC, 15 CO, 3.1 NOx with the understanding
that the dimensions are grams per mile. Similarly, a vehicle that
achieved 0.2 grams per mile hydrocarbons, 2.2 grams per mile carbon
monoxide and 0.22 grams per mile oxides of nitrogen on a given test
would be said to achieve the levels of 0.2'HC, 2.2 CO, 0.22 NOx.
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The current emissions standards are thus:
1977 California: 0.41 HC, 9 CO, 1.5 NOx
1977 Federal: 1.5 HC, 15 CO, 2.0 NOx
1978 50-state: 0.41 HC, 3.4 CO, 0.4 NOx
When urban, highway, and composite fuel economy data are available, they
are added after the triplet notation as MPG , MPG, , and MPG respectively.
A specific note on nomenclature should be mentioned here. This report
uses both the nomenclature "dual catalyst" and "3-way plus oxidation
catalyst" (3-way + ox cat), to describe certain types of emission
control systems.
Both systems use two types of catalysts in series. The dual catalyst
system has historically been one in which the first catalyst has been
optimized for control of NOx. The 3-way plus oxidation catalyst system
has been one in which the oxidation catalyst has been added to the
system in order to oxidize HC and CO that otherwise might be in excess
of the standards. This is especially the case for CO with 3-way catalysts.
The way that the systems operate during the emission test and recent
developments have caused the distinction between the two systems to
become less clear.
Because the NOx catalyst and the 3-way catalyst both are the catalysts
closest to the engine, it is preferable to use them as oxidation catalysts
during the cold start portion of the test to hasten catalyst warm-up.
Therefore, HC and CO conversion efficiency and catalyst stability under
oxidizing conditions are important for NOx catalysts as well as 3-way
catalysts. Secondly, the desire to reduce ammonia emissions and the
need to optimize for fuel economy has led to a requirement for more
precise fuel metering for dual catalyst systems. This point also adds
to the similarity of dual catalyst and 3-way catalyst systems because 3-
way catalyst systems also require precise fuel metering.
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Therefore, because of the start-up system requirements, and the fuel
metering requirements, it might be said that there is little difference
between the two system types, and they could be combined into one.
However, for the purpose of this report the distinction is made. Three-
way plus oxidation catalyst systems typically have a platinum/rhodium
composition and could potentially be a'candidate system without the
oxidation catalyst at low HC and CO levels. Dual catalyst systems can
have a variety of compositions for the NOx catalyst including base
metals. Because the dual catalyst calibration of air-fuel ratio is
generally richer than stoichiometry and thus the NOx catalyst does not
oxidize HC and CO after warm-up, the NOx catalyst alone is not effective
in controlling HC and CO emissions to the required levels.
In time, the differences may vanish altogether, as development continues
and the systems with superior performance are more clearly identified.
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SECTION 2
CONCLUSIONS
2.1 Conclusions
Based on a review of the available data, EPA technical staff have
reached the conclusions listed and discussed below. The conclusions
apply to the time period (Spring 1977) in which they are made. In the
field of emission control technology, rapid changes in progress can
occur. These technical changes can be positive, i.e., anticipated
improvements may be achieved and even surpassed. These changes can also
be negative, i.e. , concepts that had shown promise in initial testing or
on a theoretical basis may prove out to be less attractive when examined
in more detail. Additionally, new developments may arise which can
cause changes in the direction or emphasis of development programs and a
possible dilution of the effort targeted toward demonstrating compliance
with future emissions standards. Examples of developments that have
occurred or are occurring are: (1) legislative imperatives such as the
fuel economy standards of the Energy Policy and Conservation Act (EPCA),
and (2) technological issues, such as the effects of the gasoline
additive MMT on emission controls. Therefore, the conclusions listed
below may need to be altered if changes in progress occur or if new
developments arise.
Conclusion 1
The currently applicable standards for model year 1978, 0.41 HC, 3.4 CO,
0.4 NOx, cannot be met for model year 1978.
Conclusion 2
The issue of when more stringent emission standards can be met was
specifically addressed in this report. The following table lists
emission standards and the model year in which they can be met,
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based on the following assumptions.
1. Emission control is the single constraint. Fuel economy,
cost, performance, driveability and other considerations find
their own levels.
2. The automobile industry knows what the standard will be by
June 1977.
3. Market demand must be met.
4. All effort is directed toward attainment of a single standard.
Additional requirements to meet other standards in preceding
or succeeding model years can dilute the industry's effort and
could change the estimated dates shown below. This means that
the table should not be interpreted as a set of emission
standards versus time, it simply indicates the earliest dates
at which the standards are expected to be achieveable.
5. All 0.41 HC standards assume a methane exclusion.
Emission Standard Earliest Model Year
0.41 HC, 9 CO, 1.5 NOx 1979
0.41 HC, 3.4 CO, 2.0 NOx 1979*/1980
0.41 HC, 3.4 CO, 1.0 NOx 1981
0.41 HC, 3.4 CO, 0.4 NOx 1982
* With a delay in the introduction of new models.
Conclusion 3
The fuel economy performance of a vehicle at any emission level is
strongly influenced by the type of technology used to control emissions.
Emission control technology, better than today's emission control
technology, has been and is being developed by the automobile industry.
Use of such improved emission control technology, given the time to
optimize the systems for both fuel economy and emissions, can result in
the attainment of future emission standards with no adverse impact on
fuel economy. Use of improved emission control technology in conjunction
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with other technological changes planned by the automobile industry to
improve fuel economy can result in significant improvements in sales
weighted fuel economy of future model year fleets over the 1977 model
year fleet.
Conclusion 4
With the technical approaches now under consideration, there is a
significant difference between systems targeted toward 3.4 CO and
those targeted toward 9 CO.
Conclusion 5
The octane improver fuel additive, MMT, is beginning to appear in motor
vehicle fuels in significant concentrations. While there is considerable
uncertainty over its impact on catalytic emission control systems, there
is sufficient cause for concern over reports of deterioration of engine-
out hydrocarbon emissions and catalyst plugging. The manufacturers are
especially concerned about impacts upon the emission control systems
targeted for the statutory HC level.
Conclusion 6
The study of emissions of currently unregulated substances continues to
be an active area of investigation. New areas of potential emissions
have been identified, specifically, transition metals and rare earth
elements that are used to promote the emissions performance of catalyst
systems.
Conclusion 7
The adoption of a non-methane hydrocarbon (NMHC) standard, equivalent in
stringency for reactive hydrocarbons to the statutory total hydrocarbon
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standard of 0.41, has the potential impact of increasing the industry's
capability to comply at this level. Methane is non-reactive and thus
difficult to control with catalytic technology. A NMHC standard also
has potential fuel economy, system complexity, and cost benefits,
depending on the actions taken by the industry.
Conclusion 8
The rate of progress in the development of emission control systems to
meet future, more stringent emission standards appears to be at about
the same rather slow pace that was evident last year; Some changes in
emphasis have occurred, however.
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2.2 Discussion of Conclusions
Discussion of Conclusion 1
Virtually all automobile manufacturers are planning to meet emission
standards of 1.5 HC, 15 CO, 2.0 NOx for model year 1978. These emission
standards are the same as the emission standards for model year 1977.
In their responses to EPA, most of the automobile manufacturers indicated
that their plans for model year 1978 were based on the 1976 Conference
Committee Report on amendments to the Clean Air Act. That report had
emission standards for model year 1978 of 1.5 HC, 15 CO, 2.0 NOx. Even
though the changes to the Clean Air Act contained in that Report were
subsequently not adopted by Congress, the manufacturers' position
appears to be that the intent of Congress was to adopt emission standards
of 1.5 HC, 15 CO, 2.0 NOx for model year 1978, thus they have based
their plans accordingly.
Because the plans of the manufacturers are targeted toward meeting 1.5
HC, 15 CO, 2.0 NOx for model year 1978, there is little possibility that
emission standards much different from these levels could be successfully
implemented for model year 1978. Even for a relatively lenient standard
like 0.9 HC, 9 CO, 2.0 NOx, for example, some durability vehicles would
have to be rerun, calibration and system modifications for each data
vehicle would have to be reexamined and possibly redeveloped, new or
additional supplies of certain components might be required which are
not now planned for. All of this leads to the conclusion that there is
not now enough lead time to do anything significantly different from
what the manufacturers are already planning to do for model year 1978.
Discussion of Conclusion 2
Estimation of the earliest dates that more stringent emission standards
could be achieved from a purely emission control technology standpoint
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is' provided in the table below. While such estimates are important they
are of limited value since the automobile industry is faced with other
important considerations, the principal one being fuel economy. A
discussion of each of the standards considered follows:
Emission Standard Earliest Model Year
0.41 HC, 9 CO, 1.5 NOx 1979
0.41 HC, 3.4 CO, 2.0 NOx 1979*71980
0.41 HC, 3.4 CO, 1.0 NOx 1981
0.41 HC, 3.4 CO, 0.4 NOx 1982
* With a delay in the introduction of new models.
0.9 HC. 9 CO. 2.0 NOx
The 0.9 HC, 9 CO, 2.0 NOx standards could be met in 1979 with good fuel
economy, but considering the desirability of having standards in force
for at least two years, the optimization of technology at this lenient
emission level could slow the development of improved technology,
especially 3-way catalysts. However, considering the fact that MMT will
be used in the certification durability fuel for the first time in 1979
there would be less technical risk at this level than for more stringent
HC standards in that year.
0.41 HC, 9 CO. 1.5 NOx
These standards are numerically the same as the standards for California
for model year 1977. While extension of technology developed for
California to Federal application might seem at first to be relatively
straightforward, there are differences between California and Federal
certification protocols that complicate the issue somewhat. The most
important difference is that for model year 1977 California permitted a
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durability vehicle to line cross.* That is, the straight line fit to
the data may exceed the emission standard anytime during the 50,000
miles of durability mileage accumulation as long as the emission data
vehicle's emissions, projected to 50,000 miles do not exceed the stan-
dards. For Federal protocols, line crossing of the durability vehicle
is not permitted. This difference has important implications because of
the ability to meet stringent emission standards depends almost totally
on the ability of vehicles to have good emission performance at high
mileage. In fact, maintaining emissions below the standards for 50,000
miles has been the most difficult task industry has faced in meeting
stringent emission standards since the 1970 Clean Air Act amendments
were passed. Therefore, the California experience is not directly
translative into projections of compliance with Federal emission standards
that are numerically the same.
At emission levels of 0.41 HC, 9 CO, 1.5 NOx, the pollutant presenting
the most difficulty is HC. It is a long way from 1.5 HC to 0.41 HC as
far as control technology and the difficulty of compliance are concerned.
This is especially true when the relationship between HC emissions and
fuel economy is considered. If the emission control system does not
have the capability to control HC adequately when spark timing is set
for good fuel economy, compromises may have to be made in spark timing
calibrations (more retard) that can adversely affect fuel economy.
Time and effort are required to develop emission control systems to meet
0.41 HC while retaining good fuel economy calibrations. This is borne
* California allowed line crossing to avoid the need to require
manufacturers to run a separate durability vehicle for each engine
family to be sold in California. Thus 1977 California vehicles are
in most cases simply recalibrated 49-state vehicles. California
has advised EPA (letter dated 2 February 1977 from Thomas C. Austin,
Deputy Executive Officer-Technical GARB to Benjamin Jackson, Director
Mobile Source Enforcement Division) that it does not recommend allowing
line crossing for 49-state vehicles.
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out by the experience in California where fuel economy of the California
fleet has lagged the Federal fleet (on a equal model mix basis) by 1-2
years largely as a result of the less than optimum systems and calibrations
used to meet the more stringent California standards. This extra time
is a consideration that leads to an implicaton that the 1980-1981,
rather than 1979, time frame may be a more attractive date for the
application of these standards of 0.41 HC, 9 CO, 1.5 NOx.
The adoption of a non-methane hydrocarbon (NMHC) standard would make the
compliance task at 0.41 HC less difficult. However, the effect is small
compared to the reduction required from current Federal standards.
The 0.41 HC, 9 CO, 1.5 NOx standards would tend to encourage the devel-
opment and introduction of 3-way catalyst systems if these levels are
followed in succeeding model years by lower NOx standards. This is
considered important, since many of the systems that will be used to
meet emission standards more stringent than 0.41 HC, 9 CO, 1.5 NOx will
contain 3-way catalysts, and the 0.41 HC, 9 CO, 1.5 NOx standards permit
the phase-in of this type of technology.
0.41 HC. 3.4 CO. 2.0 NOx
While these standards could be met in the 1979-1980 time period, they
might not result in an orderly phase-in of 3-way catalyst technology.
The 3.4 CO level will be difficult to meet with 3-way catalyst systems
in the near term, and the 2.0 NOx level offers no real incentive to use
the 3-way catalyst for NOx control. The systems used to meet the 0.41
HC, 3.4 CO, 2.0 NOx standards would more likely be advanced oxidation
catalyst systems. These systems would be similar to current Federal
systems but would utilize larger, more efficient oxidation catalysts and
some form of air injection. If standards more stringent than 0.41 HC,
3.4 CO, 2.0 NOx are eventually going to be required, and assuming systems.
using 3-way catalysts will be used to meet these more stringent standards,
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then it would appear that the 0.41 HC, 3.4 CO, 2.0 NOx standards would
not encourage the phase-in of the type of technology that will eventually
be needed.
0.41 HC. 3.4 CO. 1.0 NOx
These standards could be met in 1981. However, as was the case for 0.41
HC, 9 CO, 1.5 NOx, more time may be required for the development by all
manufacturers of systems that meet these standards with good fuel economy.
The standards of 0.41 HC, 3.4 CO, 1.0 NOx could more reasonably be met*
in 1982-1983, following two years (1980-1981) at 0.41 HC, 9 CO, 1.5 NOx.
Two years is considered the minimum number of years that emission
standards should remain constant. This gives manufacturers time to
optimize the systems, because the standards are not continually changing,
without excessively stretching out the time for getting to more stringent
standards.
The most difficult pollutant to control at the 0.41 HC, 3.4 CO, 1.0 NOx
level will be CO, if 3-way catalyst systems are used. The addition of a
downstream oxidation catalyst and air injection might be required on
some vehicles. A CO standard somewhere between 6 and 9 grams per mile
could preclude the need for an oxidation catalyst and air injection and
would make the compliance task easier for 3-way catalyst systems in this
time period.
0.41 HC, 3.4 CO. 0.4 NOx
Following the same rationale as discussed above, the timetable for
introduction of the 0.41 HC, 3.4 CO, 0.4 NOx standards could be 1984,*
even though these standards could be met as early as 1982. This would
permit more time for the development of the necessary technology that
* This comment applies to the two smaller U.S. manufacturers and especially
to car lines that may not have been downsized (well under 10% of the national
market). It considers only the issue of optimal engineering phasing for
these particular cars, and not health, costs, and other factors.
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would also incorporate good fuel economy calibrations. One of the more
important pacing items for this standard is the lead time necessary to
develop and adopt the sophisticated fuel metering systems that may be
required. Feedback carburetion may not be good enough, and fuel injection
systems of some type may be needed. Additional time would also permit
further optimization of catalyst performance.
Discussion of Conclusion 3
A vehicle can be designed with emission control technology that will
have poor fuel economy at a given emission standard if the control
technology relies on non-optimal engine calibrations or is short of
emission control capability. To compensate for the shortcoming in
emission control capability, engine calibrations may have to be set so
as to reduce emissions in a manner that compromises fuel economy, and
fuel economy penalties can result.
However, if the emission control system has excess capability to control
emissions, the use of engine calibrations that provide good fuel economy
performance is feasible and emission standards can be met with no fuel
economy penalty. In model year 1975, for example, the use of new
emission control technology (i.e. catalysts) allowed better fuel economy
calibrations to be used on the engine. This permitted fuel economy
gains over model year 1974, even though the emission standards for model
1975 were substantially more stringent than those for model year 1974.
However, the use of even the best emission control technology does not
guarantee good fuel economy, since fuel economy is determined principally
by certain basic engine calibrations. If these basic engine calibra-
tions deviate from the good fuel economy calibrations, fuel economy
losses can result, regardless of the emission control technology used.
The calibrations that result in good fuel economy for a given engine are
a complicated combination of, for example, spark timing, air-fuel ratio,
and EGR rate as a function of engine speed and load. Much experimental
work is now underway to determine these calibrations for the engines
planned for use in future model years. Considering the three calibration
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variables of spark timing, air-fuel ratio, and EGR rate, it appears that
a good fuel economy calibration can be obtained over a range of air-fuel
ratios. However, if EGR is not used, the air-fuel ratio calibration for
good fuel economy is known to be slightly lean of stoichiometry.
This means that if an engine is operated at the stoichiometric air-fuel
ratio, without EGR, as could be the case for a 3-way catalyst emission
control system, a fuel economy loss would result when compared to slightly
lean operation without EGR. Even though the emission control might be
satisfactory without EGR, the desire to obtain good fuel economy cali-
brations might require the use of EGR and concomitant spark timing
recalibration. This could tend to improve the NOx control while making
HC control more difficult.
This sensitivity of fuel economy to engine calibrations and the still-
evolving understanding of the interrelationships among the calibration
variables often lead to a wide divergence of technical opinion about the
fuel economy potential of a new emission control technology. This is
particularly true during the early stages of development when emphasis
is placed on determining the emission performance.
Historically, new emission control systems have improved in fuel economy
over the years as more experience has been gained in system optimization.
The improvement in fuel economy of the 1976 models over the 1975 models
was to some degree due to the continued optimization of engine calibra-
tions. Further, the fuel economy penalties apparent at the more stringent
California emission standards is an illustration of compromises in
engine calibration when an emission control system (e.g. the oxidation
catalyst) approaches its limit of control capability.
In order to meet future, more stringent emission standards while retain-
ing good fuel economy calibrations, emission control systems will have
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to be used that have improved emission control capability over systems
currently in production. These improved systems will need emission
control capability beyond that just required to meet the emission
standards. Such improved systems are now being developed by the auto-
mobile industry.
The status of the development of these systems is, of course, the
subject of this report.
The development of technology to control emissions and permit good fuel
economy calibrations to be maintained is expected to take longer than
just the development of technology solely for the purpose of controlling
emissions. For example, the use of electronic controls which have the
potential to be an important part of future low emission, fuel efficient
systems will require the generation and analysis of significant quan-
tities of new engine data in order to determine more optimal calibrations.
Certain automobile manufacturers have indicated that, given time, future
emission standards as stringent as 0.41 HC, 3.4 CO, 1.0 NOx can be met
with little or no loss in fuel economy. Other manufacturers, however,
maintain that fuel economy penalties will exist at these emission levels.
Although the capability to meet the statutory emission standards (0.41
HC, 3.4 CO, 0.4 NOx) while retaining good fuel economy calibrations is
also possible, little data have been reported with complete, improved
emission control systems targeted toward these standards. The reason
for this lack of data may be that 0.4 NOx may not have been considered
to be a real target.
The impact of future emission standards on fuel economy should also be
considered in relationship to other technological approaches for im-
proving fuel economy. Taken in combination, reduced vehicle weight,
improved rolling resistance, lower friction, drivetrain improvements,.
improved accessory drives, improved aerodynamics, and vehicle power-to-
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weight ratio changes can have a much larger impact on fuel economy than
the fuel economy penalties reported by some as being due to emission
control.
Discussion of Conclusion 4
Several manufacturers called for an ultimate CO standard higher than 3.4
CO in their submissions to EPA, basing their remarks at least in part on
their interpretations of the Air Quality Panel report* from the "Interagency
Motor Vehicle Goals Study". It is not the purpose of this report to
discuss air quality-related issues. However, it is appropriate to
discuss the differences in technological approaches that might be used
to meet the two different CO levels.
For this technical discussion HC standards of 0.41 and NOx standards of
1.0 or 0.4 are considered in conjunction with the CO values. The basic
emission control system type that is considered to be the most representative
of the systems to be utilized at these emission levels is the 3-way
catalyst.
The 3-way catalyst system used to meet 3.4 CO will tend to be more
complicated and costly than the basic 3-way catalyst system to meet 9
CO. It will need to have more cold-start CO control than the 9 CO
system. It may require thermal reactors and/or a start catalyst and/or
a supplementary oxidation catalyst with air injection which is switched
between the exhaust ports and downstream of the main 3-way catalyst.
Much improved chokes and/or special quick warm-up devices such as super
EFE may also be needed. Achievement of good driveability at the 3.4 CO
* Air Quality, Noise and Health, Report of a Panel of the Interagency
Task Force on Motor Vehicle Goals Beyond 1980, March 1976.
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level may be more difficult than at 9 CO unless systems of the types
described above are employed. If, because of cost or other considerations,
driveability is sacrificed at 3.4 CO, in-use vehicles could be maladjusted
in an attempt to improve driveability with possible losses of emission
control capability. Current experience with in-use vehicles shows that
substantial losses of emission control capability results from simple
maladjustments although the actual causes for maladjustment are not well
established. However, there is sufficient reason for concern that poor
driveability may be a significant motivating factor.
Meeting 3.4 CO with a 3-way catalyst system will require improvements
over current practice. Improvements in engine-out emissions and in high
mileage catalyst efficiency are the most important. Improvements in
these areas can be expected, but the magnitude of these improvements
remains to be determined.
Another example of potential cost and/or complexity differences between
3.4 and 9 CO is related to control of sulfuric acid emissions. If large
quantities of excess air are used to control CO to the 3.4 level in the
downstream oxidation catalyst of a 3;-way plus oxidation catalyst system,
sulfuric acid emissions can be expected to increase. Controlling the
sulfuric acid emissions, while retaining adequate CO control, might
require a modulated air injection system which is expected to be more
sophisticated than current air injection systems.
Discussion of Conclusion 5
EPA, the petroleum and additive industry, and the automobile manufac-
turers are actively studying MMT's effects on emission control systems.
The data to date are somewhat scattered and contradictory. The automobile
manufacturers are extremely concerned about MMT's effects on emission
control systems and this concern was magnified when EPA decided to
require the use of MMT in the certification fuel for 1979.
2-14
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At the time this report was being prepared, no definitive conclusions
regarding MMT's effects on emission control systems could be made.
Therefore in order to proceed with this report, assumptions had to be
made. As far as this report is concerned the possible deleterious
effect of MMT on emission control systems has been ignored. The con-
clusions and discussions in this report are based on this assumption: If
MMT has a significant deleterious effect on emission control systems
many of the conclusions of this report will need to be changed.
A conclusion that can be drawn about MMT, however, is that the technical
effort that is required to properly assess the effects of MMT on emission
control systems can only dilute the automobile industry's efforts to
develop and evaluate future emission control systems. Also, any research
and development effort to adapt or redesign emission control systems to
account for MMT will have additional negative impacts on the rate of
progress in the development of emission control technology.
Discussion of Conclusion 6
EPA has been interested in several currently unregulated emissions,
among which are: (1) sulfuric acid, (2) particulates, (3) ruthenium,
(4) hydrogen cyanide, (5) polynuclear aromatic hydrocarbons, and (6)
dimethylnitrosoamines. An update of the status of the investigation of
some of these substances can be found in Section 6.
For systems considered for future use, two additional categories of
unregulated emissions have been identified. Both arise from the poten-
tial use of 3-way catalysts.
The first category deals with ammonia (NH_) emissions. Like most
systems that control NOx catalytically, 3-way catalysts can produce NH .
Ammonia production has long been a concern with dual catalyst systems
since the NH_ can be oxidized back to NO over the oxidation catalyst
2-15
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thus reducing the total system conversion efficiency for NOx. With a 3-
way catalyst system this difference between gross and net efficiency is
important when there is a downstream oxidation catalyst to provide
further control of HC and CO. Limited data suggest that ammonia can
form a large family of ammonium salts (e.g. sulfates, nitrates) and
could also be a precursor of nitrites and nitrates. It is also present
as a common atmospheric component arising from both natural sources
(decay of vegetation, soil bacteria) and man-made sources (fertilizers).
The degree to which ammonia emissions from automobiles is considered to
be a health concern is an open question. No definitive answers have as
yet been generated, thus more work may be required in this area.*
Another potential category of unregulated emissions from 3-way catalysts
has to do with the catalyst composition. Many ingredients are used, or
are being considered for use, in 3-way catalysts beside platinum (Pt)
and rhodium (Rh). Each ingredient is used to improve catalyst efficiency,
widen the window of 3-way operation, and promote special chemical reactions
such as the water-gas shift and steam reforming reactions. Unfortun-
ately, the identity and amounts of these special materials are considered
proprietary by manufacturers and are not generally available to EPA.
These materials may be present in the catalyst in quantities signifi-
cantly in excess of the quantities of noble metals. Some of these
materials could be oxides of transition metals such as nickel, iron,
cobalt, copper, chrome, cerium, and other rare earth metals. Also,
lanthanum, barium, and magnesium might be present in the washcoat. The
attrition byproducts of these materials (if any) and/or any potentially
undesirable by-products of the desired and undesired chemical reactions
catalyzed by these ingredients are not known to EPA at present. Although
this discussion has concentrated on 3-way catalysts, it is possible that
some of these concerns are also applicable to other catalysts.
Discussion of Conclusion 7
The National Ambient Air Quality Standard for hydrocarbons specifically
excludes methane (CH,). Until the advent of catalytic emission controls,
* Ammonia emissions do not seem to be significant. See pages 6-40 through
6-43 for a discussion.
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however , it was not considered important to switch automotive HC measure-
ment to a non-methane basis since it would have been simply a numerical
exercise having minimal impact on either air quality or emission controls.
The introduction of catalytic converters and the development of necessary
instrumentation has changed this consideration significantly. There is
general agreement that vehicles that made up the baseline from which the
statutory 0.41 total HC (THC) standard was determined had about 5 per
cent CH, in the exhaust. Therefore, the equivalent NMHC standard would
be approximately 0.39 grams per mile.
EPA is considering proposed rulemaking that could permit the exclusion
of methane from the determination of HC in automobile exhaust. This
rulemaking would permit the manufacturers the option of certifying at
0.41 THC or 0.39 NMHC, both of which are equivalent to a 90% reduction
of HC as required by the statutory HC standard. The earliest that NMHC
testing could be performed by EPA is for Model Year 1979 certification.
Not all future emission control systems are affected in the same way by
a NMHC standard. Since the engine-out exhaust methane fraction appears
to remain at about a constant 5% even with emission control achieved by
extensive engine modification, the NMHC standard will have little if any
impact on non-catalyst technologies. Manufacturers using non-catalyst
technology can choose to certify to either standard, the decision affecting
only the instrumentation they choose to use on the Federal Test Procedure.
On the other hand, systems that employ catalysts (probably the vast
majority at a 0.39 NMHC standard) would benefit from a NMHC standard.
This is because catalysts tend to preferentially oxidize the more
reactive HC species and generally have a difficult time oxidizing less
reactive HC species such as CH,. Therefore, the methane mass fraction
of the HC in the tailpipe of a catalyst-equipped vehicle is higher than
the engine- out mass fraction. This means that with a total hydrocarbon
standard of 0.41 the catalyst system must control the non-methane HC
emissions considerably more than would be required for the 0.39 NMHC
standard.
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The exact CH, fraction is dependent on the details of the specific
catalyst system. If it is assumed that the 0.39 NMHC standard is
roughly equivalent to a 0.50 THC standard for a catalyst equipped
vehicle, then the possibility exists that some important benefits could
be associated with a NMHC standard. Possibly the most important benefit
is in fuel economy. For a given vehicle, if the capabilities of the
aftertreatment system are not adequate to reduce total HC to the desired
level, calibrations in spark timing that have a deleterious effect on
fuel economy may have to be used. Alternatively a change to a more
costly and complex emission control system that has more control cap-
ability may be required. If a given vehicle/control system/calibration
is close to the required HC level on a THC basis with a good fuel economy
calibration, the change from THC to NMHC could allow the vehicle to meet
the standards with no calibration changes that might affect fuel economy.
For a system which has control capability well below 0.41 THC, a change
to a NMHC basis may allow for spark advance recalibrations or compression
ratio changes which might improve fuel economy (as long as octane problems
do not arise). In addition to fuel economy improvements, reductions in
system cost might be possible, as well as possibly some improvements in
driveability. Although EPA can directionally identify these benefits of
a NMHC standard, EPA cannot guarantee that gains in fuel economy and/or
reductions in system cost and/or improvements in driveability will
actually be made. How to apportion the potential benefits of a NMHC
standard is a decision that will be made by each individual manufacturer.
Discussion of Conclusion 8
Compared to the efforts that would be expected to be seen if the statutory
standards (0.41 HC, 3.4 CO, 0.4 NOx) were being pursued for 1978, the
efforts of industry are low. Compared to the development efforts that
would be required to meet standards of intermediate stringency in the
near term, the efforts are also low. As reported last year, it appears
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that the industry is still pausing with emission control development
pending amendment of the Clean Air Act.
During the last year, efforts on improved fuel metering and 3-way catalysts
have received more emphasis. However, the efforts, especially in the
very important area of testing durability vehicles with complete emission
control systems, is lacking compared to what could be reasonably expected.
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SECTION 3
DEVELOPMENT TRENDS
The development trends discussed below are considered to be the ones of
the most technical interest that have become apparent during the past
year. These trends are highlighted because they appear to be ones that
show the possible directions for future development and effort toward
meeting more stringent emission standards. Other efforts, such as the
detailed system design, and evaluations of specific engine/vehicle
applications and cost/effectiveness engineering studies are continually
underway and may even consume more technical effort. However, the
trends discussed in this section are considered to be more important in
indicating the development directions.
3.1. Emission Control Systems Containing 3-Way Catalysts Are
Receiving the Most Effort
The two most important generic systems now under development are the 3-
way catalyst and the 3-way plus oxidation catalyst systems. These
systems are variously referred to as 3-way, 3-way + ox. cat., or 3W + OC
in this report.
Systems employing 3-way catalysts appear to be the ones that are being
considered most seriously for future application and most manufacturers
are working on such systems, this emphasis on systems employing 3-way
catalysts has resulted in less emphasis on other systems that were under
consideration, especially those targeted for low NOx standards.
The term "3-way catalyst" refers to a catalyst which has been specifically
formulated for control of HC, CO, and NOx simultaneously in one catalyst
bed. In physical appearance, a 3-way catalyst looks like an oxidation
-------
catalyst. The container and the size and the shape of the catalyst are
virtually identical to the catalysts in use today. Three-way catalysts
differ from conventional oxidation catalysts in the type of catalytically
active material and washcoat preparation.
Most oxidation catalysts use platinum (Pt) or platinum/palladium (Pt/Pd)
mixtures as active ingredients. Three-way catalysts typically use
platinum/rhodium (Pt/Rh) mixtures as active noble metal ingredients'.
Some 3-way catalysts also use other active materials like nickel (Ni)
for example.
To operate effectively, a 3-way catalyst must receive a precisely
controlled exhaust gas mixture from the engine. This mixture must be
very close to the chemically correct or stoichiometric mixture. The
need for this precisely controlled exhaust gas mixture is why fuel
metering systems involving feedback control are being developed for use
in conjunction with 3-way catalysts. The feedback control allows
adjustment of the engine's air-fuel ratio on a continuous basis, pro-
viding the correct exhaust gas composition to permit effective control
of HC, CO, and NOx in one catalyst.
The type of development work that is potentially of the most importance
has been the search for catalysts with low rhodium content. Since Rh
plays a crucial role in determining the important properties of a 3-way
catalyst such as efficiency, durability, NH_ formation, etc., its supply
availability is a matter of substantial debate and concern. This area
is considered to be the most important development task remaining before
the 3-way catalyst can be used on a widespread basis. Durability of the
electronic controls and the oxygen sensor required for control of the 3-
way system no longer appear to be areas of a major concern.
3-2
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3.1.1. The Importance of "Mine-Mix" Rhodium Content for 3-Way Catalyst
Some of the better performing 3-way catalyst systems tested to date have
used relatively high loadings of Rh compared to Pt. This ratio is
usually expressed as the Pt/Rh ratio.
This ratio is considered by many to be a very important parameter
because of the supply/production aspects of these precious metals. As
the precious metals are produced, the naturally-occurring (the mine-mix)
Pt/Rh ratio is approximately 19/1. Because the producers of precious
metals will apparently be reluctant to increase Pt production just to
get more Rh, it appears that the long-term ratio for Pt/Rh in automobile
emission control systems will have to stabilize at a value close to 19/1
if additional Rh cannot be procured. There are other competitive uses
for Rh so the prospects of using more Rh than the mine mix might involve
higher costs for the Rh, which are already much higher in cost than Pt.
Increasing the Total Loading
If the catalyst performance is a function of the total Rh content (as
opposed to Pt/Rh ratio), then one approach to attaining the desired
performance is to increase the total noble metal loading. Three-way
catalysts have shown reasonable performance at approximately 0.1 troy
ounce total loading with a 5/1 Pt/Rh ratio. To get the same amount of
Rh on a mine-mix catalyst (19/1), the total loading would have to be
approximately tripled with cost and possible supply difficulties.
Little work has been reported in this area.
Mine-Mix Redistribution on the Vehicle
Another approach is to consider a 3-way plus oxidation catalyst system
with a total noble metal content of the two catalyst components that
will reflect the mine-mix. Conceptually, this is achieved by depleting
3-3
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the Rh associated with the Pt that could be mined for the oxidation
catalyst and using this Rh to enrich the 3-way catalyst. This could
allow the 3-way catalyst to be closer to 10/1 than 19/1, which may be
enough to provide the necessary performance. Other types of redistribution
could also be considered such as taking the palladium (Pd) associated
with the Pt in the 3-way catalyst and adding it to the oxidation catalyst
because Pd is a good catalyst for CO oxidation. Those manufacturers who
are concentrating on the 3-way plus oxidation catalyst approach are
considering this redistribution approach.
Conceptually this redistribution could occur within a single catalyst.
If the noble metals could be distributed along the catalyst in a manner
such that the first part of the catalyst had a low Pt/Rh ratio, that '
part of the catalyst might be an effective 3-way catalyst and the other
part of the catalyst might be more effective as an oxidation catalyst.
This approach could also be done by taking the separate 3-way and
oxidation catalysts referred to above and placing them adjacent to each
other, thus having a segmented catalyst. Some work has been reported in
these areas.
Stockpiling Rh
A Pt/Rh ratio different from the mine-mix could also be used if the Rh
associated with the Pt that will be used in the oxidation catalysts for
the next few years were stockpiled and then used for a 3-way application.
This approach could be used as a temporary measure only. Eventually' the
Pt/Rh ratio would have to approach the mine-mix ratio. For example, if
Rh were stockpiled for 4 years, then one year would be satisfied at 5
/
times the mine-mix, 2 years at 3 times the mine-mix, 4 years at twice
the mine-mix, etc.
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The Mine-Mix Fleet
If a manufacturer does not need systems containing 3-way catalysts for
all of his vehicles, then his entire fleet could be a mine-mix equi-
valent by increasing the Rh in the 3-way vehicles, and using Pt and/or
Pt/Pd in the vehicles that use just oxidation catalysts. As the emission
standards become more stringent, this approach might be less attractive
on an industry-wide basis since the majority of the systems for use at
more stringent emission standards for the near term are systems em-
phasizing 3-way catalysts.
Mine-Mix May be an Unnecessary Restriction
As the previous discussion has indicated, there is much concern with the
issue of the mine mix Pt/Rh ratio for 3-way catalysts. There is, however,
more Pt produced every year than that just for automobile catalyst use.
This Pt, over and above the automobile catalyst requirement, has some Rh
associated with it. The possibility exists that this Rh could be
available for automobile catalysts, if the total non-automobile catalyst
demand for Pt is for Pt alone, rather than for Rh and the other noble
metals. If, for example, the customers for Pt do not need or want the
Rh, then this Rh could be used for the automobile catalyst market.
It is difficult to determine precisely what the future supply of Rh will
be. The worldwide noble metals supply and production appear to be
somewhat of a cartel, dominated by the Union of South Africa and the
Soviet Union*. Based on the inability of accurately determining what
future Rh supplies are likely to be, the option of departing from the
* Policy Implications of Producer Country Supply Restrictions:
The World Platinum and Palladium Markets, Prepared for Experimental
Technology Incentives Program, National Bureau of Standards, U.S.
Department of Commerce, Contract #4-35960, Submitted by Charles River
Associates Incorporated, 1050 Massachusetts Avenue, Cambridge, Mass.,
02138, August 1976.
3-5
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mine-mix Pt/Rh ratio for future 3-way catalysts cannot be ruled out,
although most of the current emphasis is on the use of mine-mix catalysts.
3.1.2. Improving the Catalysts
From a technical standpoint, the most satisfactory solution lies in
improved catalysts. Work in the area of improved 3-way formulations can
occur in two areas: (1) catalysts containing other materials that do
not require the use of high Rh loadings and (2) the preparation of
mine-mix catalysts.
Some work has been done to investigate replacing or augmenting Rh with
other catalytic materials. While active work is underway, no materials'
have been reported to EPA that have superior catalytic performance for
HC, CO, NOx, steam reforming, etc., with more favorable supply implications
than Rh.
Ruthenium (Ru) has been studied extensively for both NOx catalyst and 3-
way catalyst use but it has proved to be a difficult component to use
effectively. Although it is a good NOx catalyst with excellent se-
lectivity (low NH production), the active formulations have not been
stable (Ru is lost) and the stable formulations have not been particu- '
larly active. Periodically, claims for stabilization of Ru in an active
state have been made but vehicle tests have generally been disappointing.
The latest indication of Ru stabilization in an active state has been
made by Ford, but the extensive vehicle tests needed to evaluate the on-
vehicle performance have not been reported to EPA.
The bulk of the work on improved 3-way catalysts apparently has been in
the area of improving the high mileage efficiency of the mine-mix Pt/Rh
catalysts. Active material dispersion, improved washcoats, active
material/washcoat interactions, and various combinations of the other
(usually unspecified) active materials included in 3-way catalyst
formulations are all under intensive study.
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Mine-mix 3-way catalysts at their current state of development are
probably adequate for control of NOx down to 1.0 NOx. To get NOx
control significantly below 1.0 NOx, improvements in catalyst efficiency
and/or improvements in engine-out NOx control are needed.
3.2. Improved Fuel Metering Systems Continue to Receive High Emphasis
The general area of improved fuel metering has been one that has always
received great interest and emphasis. In the last year or so the trend
has been to concentrate more on a given type of fuel metering. In the
past, fuel metering systems were under consideration that spanned the
range of nominal air-fuel ratio from rich systems for rich thermal
reactors and dual catalyst systems through stoichiometric systems for 3-
way catalyst systems to lean systems for lean thermal reactor, non-
catalyst, or stratified charge systems. Now, the bulk of the fuel
metering system development appears to be concentrated on stoichiometric
systems with feedback control of air-fuel metering using an exhaust gas
oxygen sensor. In addition, a trend is apparent, at least as far as the
domestic manufacturers are concerned, which appears to emphasize feedback
carburetion as contrasted to feedback fuel injection. The decision to
concentrate on feedback carburetion may have been one in which cost
considerations were paramount, since it has not yet been reported that
feedback carburetion has any significant emissions, fuel economy,
performance, or driveability advantages over feedback fuel injection.
There are a wide variety of fuel metering systems under consideration
for application to future emission control systems. Some of their
properties and EPA's estimate of the current emphasis being expended on
such systems is shown in Table 3-1.
The choice of fuel metering system may be important as far as meeting
future requirements for emissions. For example, the engine-out CO
levels and the cold start emissions performance are considered two areas
of importance for future systems.
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Table 3-1
Types of Fuel Metering Systems
Descriptive
Name of System
Fuel Introduced
Fuel Introduction
Continuous (C)
or Timed (T)
Typical Introduction (I)
Control (C) Method
Remarks
Direct Cylinder
Directly into
the cylinder
I - Mechanical
C - Mechanical
Under study for
Diesels and some
stratified charge
engines only.
Separate Cylinder
Control
Into each intake
port
I - Electromechanical
C - Electronic
Very little reported
with systems that
control each injector
independently
Multiple
Into each intake port
i Simultaneous
00
I - Electromechanical
C - Electronic
Bosch D-and L-
Jetronic. Some
interest by foreign
manufacturers
Continuous
Mechanical
Into each intake port
I - Mechanical
C - Mechanical
Bosch K-Jetronic
is an example.
High interest by
European manufacturers
Central Point
Injection
Upstream of
Throttle plate
I - Electromechanical
C - Electronic
1 or 2 injectors per
engine. Some interest
by domestic
manufacturers.
Feedback
Carburetion
Upstream of
of throttle plate
I - Pneumatic/Mechanical Many different ways
C - Electronic/ to implement
Mechanical/ air/fuel control
Pneumatic under consideration
High interest by
domestic manufacturers.
-------
3.3. Significant Use of Electronic Controls Appears to be a Relative
Certainty in the Next Few Years
Electronic control of individual engine/system parameters such as spark
timing and EGR is assured. It is clear that in the next few years
electronic control of virtually all variable engine parameters will be
integrated via microprocessors. These electronic systems may also
monitor and/or control other, non-emission related systems.
The current trend appears to be one in which the control logic is
obtained by means of stored computer memory in the form of stored
digital data, or "look-up tables". For a given set of sensed para-
meters, the lookup tables will provide information as to what the
controlled parameters should be. Little work has been reported on
dynamic logic systems that would actually compute the outputs as a
function of the inputs. Therefore, the current emphasis is on obtaining
engine data for the values required in the look-up tables.
The full impacts of the widespread use of electronic control systems on
the manufacturing, supply, service, and regulatory aspects of the
automobile industry have yet to be determined.
Two areas, the impact on the service industry and the emissions impact
of the widespread use of electronic controls should be highlighted.
Electronic control systems could have positive implications for the
service industry. If the control units could be used to generate
information when hooked up to a diagnostic instrument, identification of
problems could be done quickly and accurately, with potential benefits
to the public in terms of maintenance quality and cost. This potential
benefit would of course require one type of diagnostic instrument that
could be used for all vehicles. Unfortunately there appears to be no
trend in the direction of supplying the compatibility needed in order
3-9
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to have one common diagnostic instrument be effective. In practice, a
specialized diagnostic instrument might be required for GM vehicles, a
completely different one for Ford vehicles, etc. While the impact of
this diversity on new-car dealers might be slight, the impact on the
rest of the service industry would be most significant. It is not
realistic to expect all independent service organizations to be able to
afford to buy and store several different types of specialized electronic
diagnostic equipment. If the independent service industry cannot service
most kinds of vehicles, as it does today, their business may be negatively
affected. Not having the capability in the service industry to deal
with a wide range of vehicles could also have a negative impact on
Inspection and Maintenance (I/M) programs. A requirement that service
compatibility be considered in the initial design and development of
electronic control systems has obvious trade secret and anti-trust
problems. Thus, how to service electronic controls in the field raises
unanswered questions.
The emissions impact of electronic controls is also of concern to EPA.
Most systems will have some sort of failure mode logic in them, i.e.,
when an inappropriate signal is received from a sensor, or when part of
the system fails, there will be some sort of operational mode that will
be used until the vehicle can be fixed. Exactly what these modes will
be, how the vehicle driver will know that something is wrong and needs
to be fixed, and the emissions produced during these modes are currently
unknown.
Another emissions-related area of concern to EPA is how the electronic
control systems will be programmed to operate under conditions that are
only slightly different from the very specific conditions of the official
EPA emissions test. The degree to which emission control may be sacrificed
when the vehicle is operating under slightly different conditions could
be a concern, by opening entirely new ways of introducing hard-to-spot
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Defeat Devices. Electronic controls will provide a great amount of
flexibility to the vehicle designer and EPA will have to take steps to
ensure that this flexibility does not result in excessive emissions
during environmental and driving conditions different from the FTP test
specifications.
3.4. Non-Catalytic Engine and Emission Control Technology is Also
Showing Some Interesting Developments
Two examples of progress made in the area of engine technology and non-
catalytic emission control systems are those reported by Nissan and
Ethyl.
Nissan has made modifications to a conventional engine that have shown
low mileage NOx results below 0.4 NOx without catalytic control of NOx.
The Nissan approach is basically a twin spark plug cylinder head. The
use of two spark plugs apparently increases the EGR tolerance of the
engine thus allowing use of increased EGR rates for better NOx control.
HC and CO are controlled via an oxidation catalyst. It remains to be
seen, however, if the HC and CO emissions can be controlled to the
required levels at high mileage. Low mileage emission results below the
statutory levels were reported by Nissan, with fuel economy equivalent
to their 1977 vehicles.
What perhaps is most important about the Nissan results is that they
demonstrate that further advances in the control of the basic engine's
emissions are still possible. Successful implementation of such an
approach might indicate that meeting NOx levels below 1.0 NOx without
catalytic control of NOx may be possible for relatively lightweight
vehicles such as the one tested by Nissan. This may have positive
implications in allowing higher Pt/Rh ratios (i.e. closer to mine-mix)
for vehicles that require a system containing a 3-way catalyst to get
below 1.0 NOx.
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It remains to be seen how transferable the twin plug/high EGR rate
approach is to other engine/vehicle combinations. It should be pointed
out, however, that cylinder head design/development/production is an
area in which the industry has a great deal of knowledge and experience.
The Ethyl results also show progress in the non-catalytic emission
control system area. The Ethyl Corporation, one of the major suppliers
of tetraethyl lead additive for gasoline, has long been interested in
emission control systems that are compatible with leaded fuel operation.
Ethyl's current systems are a refinement of their improved mixture prep-
aration and distribution/thermal reactor system. Ethyl's results show
extremely low HC (values at or below 0.10 HC) and low CO (below 3.4 CO)
at low mileage and are considered to be important advances because they
show that non-catalytic emission control systems can be designed to have
low HC and CO emissions. The greater than 90 per cent reductions in HC
and CO emissions from the baseline were achieved with fuel economy
results approximately 10 per cent lower than the baseline vehicles. The
fuel economy results obtained by Ethyl on one advanced prototype vehicle
was approximately 9 per cent better than the nearest comparable 1977
certification vehicle. The emission results are also important because
they show promise for systems that combine technology like that under
development by Ethyl with catalyst technology. HC control with such a
system could be good enough to eliminate the need for any compromises in
spark timing with a concomitant positive impact on fuel economy.
Taken together, the Nissan and the Ethyl results could be conceptually
combined to infer that control to levels below 0.41 HC, 3.4 CO, 0.4 NOx
might be possible with a non-catalytic, conventional engine based
system. A more important conclusion is that emission control advancements
are being made in areas other than just catalysts. Basic engine controls,
such as Nissan's, and non-catalytic emission controls such as Ethyl's,
are continually being reported. Such developments tend to lower the
emission levels that can be achieved, with or without catalysts, and are
examples of developments, not previously reported, that can change the
conclusions about the capabilities to control emissions with various
types of emission control technology.
3-12
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3.5. Catalyst Developments Other Than the 3-Way Catalyst Are Also
of Interest
Two areas of interest in the catalyst field, other than the 3-way
catalyst efforts, are considered important. They are perovskite catalysts
and metallic substrate monoliths.
Perovskite-based catalysts have received some interest in the past year.
The HC conversion efficiency is apparently still not competitive with
conventional catalysts and these catalysts still must be operated at a
higher temperature than most conventional catalysts. However the potential
of this approach for NOx control may not have been fully evaluated
because little effort is being expended in the NOx catalyst area now.
On balance, the development of perovskite catalysts may have been somewhat
of a blind alley although there is not universal agreement on this
point. Perovskites serve as an example of why the time and effort it
takes to pursue initially promising developments leads to the requirement
for much research and preliminary development work in the emission
control field.
Most of the substrates in use today for monolithic catalysts are non-
metallic, ceramic-based materials employing a typical cell density of
300 cells (or passageways) per square inch. Recently there has been
some interest shown in monoliths with metallic substrates. If the
substrates can be effectively coated then some improvements in catalyst
performance might be expected since metallic substrates can be made with
significantly higher cell densities than with current ceramic substrates.
A potential problem however might be plugging of cells with deposits
such as combustion products of MWT or ash components of lubricating
oils.
The application of metallic substrates could produce two benefits. For
a given catalyst volume, emission control performance could be improved.
3-13
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On the other hand, at a given emission control level, catalyst size
(i.e. weight and cost could be reduced). Metallic substrates may have
other properties that need to be investigated. They may reduce the need
for special mounting techniques now used between the substrate and the
catalyst can. On the other hand, they may conduct heat away from the
front face too quickly - delaying front-end catalyst light-off. Finally,
the potential emission products of such substrates need to be investigated,
especially with fuels containing representative (i.e. higher than past)
levels of fuel sulfur.
3.6. There Are Indications That the Space Required for Emission
Control Systems May Become a Future Problem
The potential problem is this: New generations of automobile designs
are being designed and developed in an attempt to comply with future
fuel economy requirements and EPA is beginning to receive indications
that the space availability required for future emission control systems
may not be adequate in these future vehicles. It is too early to tell
if this is going to be a significant issue, but if it becomes one, the
emission control and/or fuel economy consequences could be serious.
3.7. Turbocharging as a Means to Increase Vehicle Performance
Is an Active Area
Some of the approaches to improved fuel economy can have negative
vehicle performance attributes. Two examples are: (1) reducing the
vehicle power to weight ratio, generally by installation of an engine
with smaller displacement and (2) decreasing the numerical value of the
axle ratio.
In order to attempt to maintain or improve vehicle performance while
fuel economy improvements are made, some manufacturers are exploring the
possibility of using turbochargers to increase engine output. Basically,
3-14
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a turbocharger is a supercharger which uses a turbine in the exhaust
flow to drive a compressor which in turn compresses the intake charge.
The resulting increase in manifold pressure allows the induction and
combustion of more air-fuel charge in a given amount of time, thus
generating more power.
Turbocharged gasoline engines are under investigation by GM and Saab and
one is currently available on a Porsche model. Daimler-Benz and VW are
experimenting with turbocharged Diesel engines.
In theory, a vehicle equipped with a turbocharger could have the same
fuel economy as a vehicle with a naturally aspirated engine, of the same
displacement, while delivering performance equivalent to a larger
displacement engine. In practice, both of these goals may not both be
completely achieved, with the emphasis being more directed toward fuel
economy for some manufacturers and performance for other manufacturers.
The emission impact of turbocharging has not been quantitatively de-
termined at this point in time. Data reported to EPA to date indicate
that emission performance equivalent to naturally aspirated engines can
be achieved.
Little information exists with turbocharged vehicles targeted toward low
emission levels, so conjecture about the thermal inertia of the turbo-
charger delaying catalyst light-off cannot be confirmed. Based on the
information available, it appears that turbocharging has neither a
positive nor a negative impact on vehicle emission control.
3.8. Diesel Engine Development Continues to Receive Emphasis -
But the Development Work on the Diesel's Problem Areas Does Not Seem
to be Receiving the Intensive Effort Which May be Necessary
to Meet Stringent Emission Standards
More and more manufacturers have reported work on investigating the
possible application of Diesel engines to automobiles. Among those who
3-15
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have worked or are working on Diesels are: GM, Ford, Chrysler, Isuzu,
VW, Volvo, Nissan, BMW, Daimler-Benz, Peugeot, Fiat, Toyota, Alfa Romeo,
and British Leyland. It can be seen that the interest is widespread.
Certain engineering society members have even recommended research and
development into specific Diesel subjects.*
While widespread, this interest generally has been in the areas of the
Dieselization of gasoline engines and investigations of some of the
areas in which Diesel powered vehicles have been expected to be somewhat
different from gasoline engine powered vehicles, like noise and performance.
In addition to the development and evaluation work reported to EPA,
several manufacturers took the opportunity to comment on their views of
the low emission capability of the Diesel. The comments generally
reflected opinions that the Diesel would be ruled out at some specific
NOx level. These claims have been made and these positions have been
discussed for at least 3 years. However, the data needed to back up
these claims and assertions were generally not supplied. EPA has
pointed out for several years now that the emission challenge for the
Diesel lies in particulate and NOx control. This control will require
an extensive research and development effort. Based on the development
efforts reported to EPA, the efforts expended in this area appear to be
less than is expected to be necessary. Controlling Diesel particulate
and NOx emissions may require a development effort equal 'to, or greater
than, that expended for the development of the catalytic converter for
gasoline engines.
As an example of the magnitude of the problem, a catalyst-equipped
gasoline engined-vehicle emits about 0.02 to 0.05 grams per mile total
particulate. Current Diesels emit about 0.40 grams per mile total
* Automotive News, 28 February 1976, page 8B.
3-16
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particulate, somewhere from 8 to 40 times greater than a gasoline
engine powered vehicle.
Control of NOx to low levels may tend to increase particulate emissions.
It appears that with the use of EGR, Diesels can achieve low NOx values,
below 1.0 NOx and possibly below 0.4 NOx. More exotic systems such as
those involving Variable Compression Ratio (VCR) pistons* have also been
projected to meet low NOx (below 0.4 NOx) levels. Although interesting
and encouraging, the VCR work presents only computer projections, not
vehicle data, and the smoke, odor, and particulate characteristics are
not well known. If EGR (used for low NOx levels) increases particulate
emissions, the total particulate from Diesels might be 50 or more times
greater than the total particulate from gasoline-fueled vehicles using
unleaded gasoline.
The possible increase in total particulate may indicate that extensive
effort may be needed to control Diesel particulate, since there are
indications that a large number of Diesel vehicles at 0.40 grams per
mile total particulate may exacerbate the Total Suspended Particulate
(TSP) burden in many Air Quality Control Regions.**
It is not clear, however, that the total mass of particulate emissions
from automobiles is the most appropriate way to characterize the parti-
culate emissions. Particulate size, size distribution, and chemical
nature all may be important in terms of air quality and/or health impli-
cations. EPA has Diesel particulate under study, but it is a difficult
and complex subject and the information that could support the setting
* A Low NOx Lightweight Car Diesel, by S. H. Hill and J. L. Dodd
SAE paper 770430, presented at the 1977 SAE Congress, 3 March 1977.
** Air Quality, Noise and Health, Report of a Panel of the Interagency
Task Force on Motor Vehicle Goals Beyond 1980, March 1976.
3-17
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of a particulate emission standard appears to be a long time away.
The lack of specific information as to what levels of Diesel particulate
will be considered acceptable may be one of the reasons why so little
has been reported in the control technology area. Lacking standarized
test procedures and a clear idea of acceptable tailpipe levels, the
developers may find it difficult to choose effective control technology.
Traps and combustion modifications appear to be two of the general
approaches that could be considered, although not much in either area
has been reported to EPA.
3.9. The Efficiency at Which Development Information on Emissions
Related Subjects Is Reported to EPA May Be Decreasing
In order to prepare this Status Report, EPA solicits from U.S. and
foreign manufacturers information on their development programs for
emission-related technology. The responses requested from the manu-
facturers are expected to be full and complete descriptions of their
emission-related development programs. However, EPA technical staff
have reason to believe that not all of the development effort on emissions-
related work may be completely reported to EPA in a timely fashion.
As an indication of the nature of the information which has apparently
not been completely reported to EPA, the following examples are given.
New Engine Development Programs
The development and introduction of a basically new engine is a sub-
stantial undertaking. A new engine is defined here as one that requires
a new or different engine block or is a different method of combustion,
for example Diesel versus homgeneous spark ignition. It is generally
accepted that such a program takes a significant period of time.
3-18
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New engines are expected to be technologically improved over older
engines, and it is not unreasonable for EPA to expect that improved
emission performance would be considered in the design and development
of new engines. Therefore, the reporting of the development of new
engines is considered important by EPA. Recent examples of new engine
developments not previously reported to EPA are projects of Volvo, GM,
and VW.
Volvo started a development program on a Diesel engine with Ricardo &
Company in 1974. To date, 6 vehicles have been equipped with this
Ricardo/Volvo engine. The first time that Volvo reported the infor-
mation concerning this engine development project was in their 1976
Status Report to EPA.
GM has reported development work on V-6 configuration engines, as it
pertains to the Buick 231 cubic inch engine and its derivatives. The
existence of GM's plans to produce an all-new V-6 engine completely
different from the Buick V-6 has been recently reported in a trade
publication.* A Chevrolet V-6 (200 CID) engine was found in the 1978 GM
Application for Certification, but GM did not report the development of
this engine in their status report.
The basic information that VW presented on their Diesel engine concerned
their 4-cylinder engine. However, under their contract with the U.S.
Department of Transportation (DOT/TSC 1193), VW is to provide information
(including emissions data) on 4, 5, and 6 cylinder Diesel engines. The
work on the 5 and 6 cylinder Diesel engines was not reported to EPA.
VW's progress in the development of a vehicular, ceramic, gas turbine
engine has been reported in the press.** Tests have apparently been
run, yielding claims for better fuel economy than vehicles equipped
* Ward's Engine Update, 10 December 1976, Volume 2, Number 25, page 3.
** Automotive News, 28 February 1976.
3-19
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with gasoline engines. The engine is also reported to have been designed
for low emissions. VW did not report any information about this engine
to EPA.
Electronic Controls
In this rapidly expanding area some work is now being reported to EPA.
Apparently, some of the work had been ongoing for some time before the
results were reported to EPA.
Because electronic controls offer flexibility to the emission control
engineer that mechanical systems may lack, electronic controls are
important. They may alter relationships between emission control and
fuel economy that may have existed in the past. As long as EPA is
unaware of the actual status of development of such new technology, EPA
will tend to undervalue the emission control and fuel economy benefits
and overstate the time it would take to implement such new technology.
GM first reported work on what was eventually to become the MISAR
electronic spark control system in 1975 in their Application for Sus-
pension.* However, according to the Application for Suspension and a
publication** the development started in 1970 and took six years before
it was introduced for model year 1977 in limited production.
GM did not report test results on a spark knock sensor in their status
report. The GM status report did report that they are working on a
combination of a knock-actuated spark control system and increased
compression ratio. EPA has recently learned, however, from the 1978 GM
Application for Certification that GM plans to introduce a knock-actuated
spark control system in model year 1978 on a vehicle using a turbocharger,
not on a .vehicle using increased compression ratio.
* "General Motors Application for Suspension of the 1977 Federal
Emission Standards," 10 January 1975, Volume III, Appendix 8, pages 3-4,
**Simanaitis, Dennis J., Automotive Engineering, January 1977,
Volume 85, Number 1, page 29.
3-20
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Turbocharging
GM and Saab indicated in their 1976 status reports that they plan to
introduce turbocharged vehicles for model year 1978. Neither Saab nor
GM reported development of turbocharged engines in their 1975 status
reports. Either it takes less than one year to design, develop, test
and commit to production for a turbocharger, or work was underway
earlier and not reported to EPA.
GM* and Ford** have also been reported as having development work
underway on turbocharged engines that were not reported to EPA. GM did
report "many programs in GM to develop turbocharged engines", though
only a V-6 engine was discussed and a Vega engine was mentioned in
passing.
Mechanical Octane Improvements
The spark timing calibrations and compression ratio of an engine in-
fluence its emission and fuel economy characteristics. Any changes in
the octane requirements of an engine may allow alterations in spark
timing calibrations and/or compression ratio. It has been reported***
that Saab has developed a method to allow for increased compression
ratio. This work was not reported by Saab in their status report to
EPA.
* Ward's Engine Updated, 18 February 1977, Volume 3, Number 4, pages 1 and 8.
** Automotive News, 7 March 1977, page A3
*** Automotive News, 28 February 1977, page 61.
3-21
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Transmissions
The automobile industry is studying the impact of improved transmissions,
Much of the interest has been on multispeed torque converters with
lockup clutches for improved fuel economy. For example a recent tech-
nical paper* projected substantial gains in fuel economy (in excess of
15%) with the use of such a transmission.
The emissions produced by the engine may be altered with use of a lockup
transmission because the torque/speed relationships during the test are
changed. The transmission is an important part of an automobile's
emission control system. Very little in the way of the emissions from
advanced transmissions/advanced emission control systems has been
reported to EPA. It does not seem reasonable that experimental and/or
analytical work has not been done. Rather it appears more likely that
the work has not been reported.
Catalysts
GM reported running a fleet of possibly improved catalysts in their
status report. When asked by EPA for the data on the then incomplete
program, GM indicated that they would not provide the data until they
were done with the program and had time to analyze the information
themselves.
The above examples show that EPA may not be kept abreast of techno-
logical developments as much as is necessary. For the preparation of a
report of this type, there is not enough time to go back to all the
manufacturers and get continual updates of their programs, as areas not
reported fully become known. EPA has to rely to a large extent on the
* Ghana, Howard E., et al., "An Analytical Study of Transmission
Modifications as Related to Vehicle Performance and Economy, SAE
Paper Number 770418.
3-22
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manufacturers to supply full and complete reports so that EPA can make
its own timely judgments as to what the data mean. Not getting important
data on a timely basis can only hamper EPA's estimates of future emission
control capability.
EPA technical staff realize that the preparation of responses to the EPA
requests for information on progress is a difficult undertaking, and
that some degree of judgment is required in deciding what to include in
the response. However, the foregoing items of data that were not completely
reported appear on their face to be so significant as to raise questions
as to why they were not reported; it seems unlikely that they were
screened out as being too unimportant to mention. Thus some thought on
how reports of this type are to be prepared in the future is in order,
to assure that these annual reports can continue to serve the important
purposes for which they are prepared.
3-23
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SECTION 4
FUEL ECONOMY AND COST
4.1. Fuel Economy
The Federally-mandated fuel economy standards for automobiles are:
1978, 18.0 MPG ; 1979, 19.0 MPG ; 1980, 20.0 MPG ; 1981, 1984 to be
determined by the Secretary of Transportation; 1985, 27.5 MPG .
Projecting of the fuel economy of automobiles in future model years is
a difficult and complex task. EPA has recently participated in two such
studies. The first study was entitled "Analysis of Some Effects of
Several Specified Alternative Automobile Emission Control Schedules" and
was published on April 8, 1976. Other participants in the study were
the U.S. Department of Transportation and the Federal Energy Administra-
tion. The second study was entitled "Analysis of Effects of Several
Specified Alternative Automobile Emission Control Schedules Upon Fuel
Economy and Costs" and was published in February of 1977. These studies
will hereafter be referred to as Study 1 and Study 2.
Studies 1 and 2 have indicated that:
1) The impact of emission standards on fuel economy for future model
years for various postulated emission standards cannot be specified
as a single value due to uncertainties in projecting which fuel
economy and emission control technologies will be used in the
future by the automobile manufacturers. The impacts are best
expressed as a range of possible outcomes.
2) If advanced emission control technology, that is now in the pro-
totype stage can be integrated into effective emission control
systems, there need be no negative impact on fuel economy due to
stringent emission standards in the future.
-------
3) The fuel economy standards for future model years can be met at
any future level of emission standards considered. However,
meeting 0.41 HC together with either 1.0 NOx or 0.4 NOx will
require the use of more sophisticated emission control hardware
than would be required at less stringent NOx levels.
The data from Studies 1 and 2 provide input for the EPA estimates of
fuel economy later in this section.
4.1.1. An Historical Look at the Fuel Economy of Various
Manufacturers
Before various fuel economy estimates are discussed, it is worthwhile to
look at historical trends in fuel economy.
Sales weighted fuel economy data for various vehicle manufacturers are
presented in Table FE-1. Of particular interest in this table is the
fact that in terms of sales projections for 1977 only Ford, Chrysler,
Rolls Royce, and Checker were under the 18.0 composite fuel economy
level required for model year 1978; The actual sales weighted fuel
economy levels may of course change when actual 1977 production data are
available. The 1977 values in Table FE-1 are revisions to the values
presented in SAE paper number 760795* which were based on earlier data.
Figure FE-1 depicts the changes in the sales weighted fuel economy of
the complete industry which have occurred as a function of time over the
past and present model years.
* J. D. Murrell, et al., "Light Duty Automotive Fuel Economy - Trends
Through 1977", SAE Paper 760795.
4-2
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Table FE-1
50 State Fuel Economy for Various Manufacturers
Manufacturer
MPG
CM MPG"
MPGh
Ford
Chrysler
AMC
W
Toyota
Nissan
Volvo
Audi
Fiat
Triumph (BLMI)
Saab
Fuji
Daimler-Benz
Honda
Toyo Kogyo
1974
10.54
14.55
12.03
12.67
18.62
14.80
11.89
17.00
13.75
14.46
19.52
16.37
22.61
35.05
26.91
19.19
28.59
22.52
20.69
30.00
24.05
16.55
24.66
19.42
19.14
29.67
22.78
18.89
27.01
21.85
19.3
27.7 .
22.3
18.41
21.91
19.84
22.5
31.0
25.7
13.30
18.76
15.30
26.05
36.99
31.11
11.69
17.07
13.62
1975
13.49
18.67
15.41
11.64
17.11
13.60
13.45
19.20
15.54
16.77
22.57
18.96
23.04
35.62
27.39
18.92
28.17
22.17
21.46
31.09
24.94
16.35
24.42
19.21
20.33
31.58
24.21
19.00
27.12
21.96
20.35
29.22
23.57
21.15
25.23
22.81
23.20
32.11
26.51
15.03
21.25
17.35
27.16
38.36
31.27
14.36
20.97
16.73
1976
14.50
20.28
16.64
15.19
20.96
17.34
14.27
20.03
16.39
16.15
21.83
18.29
22.95
34.38
26.98
21.19
31.87
24.95
22.46
31.87
25.90
16.45
24.75
19.37
21.89
30.83
25.17
19.94
29.78
23.05
20.83
29.44
23.98
20.00
27.59
22.82
26.46
35.02
29.78
16.32
22.52
18.63
28.47
39.69
32.62
18.93
27.19
21.93
1977
15.95
21.87
18.16
14.91
20.72
17.07
14.29
20.58
16.57
16.87
22.27
18.93
25.88
38.49
30.35
24.74
35.65
28.69
23.81
32.72
27.13
17.01
25.25
19.94
22.14
32.77
25.92
19.88
30.16
23.48
22.60
31.82
25.99
20.64
28.95
23.70
26.17
37.08
30.16
17.16
22.48
19.20
31.31
42.59
35.55
24.58
33.90
28.05
Manufacturer 1974
17.5
Porsche 27.3
20.9
8.2
R.R. 10.9
9.2
20.6
Alfa Romeo 26-8
23.0
9.4
Jaguar (BLMI) 13.9
11.0
19.6
Renault 26 . 9
22.3
16.58
Peugeot 23.05
18.98
16.69
BMW 24.79
19.54
21.6
Austin-Morris (BLMI) 30.2
24.8
Checker
17.3
BLMI (all) 24.8
20.1
All companies JJPG
1975
16.56
25.89
19.76
9.03
12.03
10.17
19.44
25.26
21.69
10.95
16.18
12.81
23.52
32.33
26.81
19.98
27.51
22.79
15.45
22.93
18.11
20.37
28.60
23.40
14.90
19.49
16.70
18.48
26.50
21.39
15.58
1976
17.14
26.90
20.48
10.03
13.22
11.25
19.48
26.90
22.24
10.83
15.57
12.55
19.73
26.23
22.21
16.52
22.94
18.90
18.42
31.87
22.74
15.70
20.36
17.50
18.16
27.40
21.41
17.76
1977
16.01
27.74
19.78
9.97
12.93
11.11
20.59
30.42
24.09
11.37
15.93
13.05
23.25
37.75
28.11
24.14
30.12
26.15
17.71
25.15
20.43
17.75
29.67
21.67
15.54
20.94
17.58
18.4
27.7
21.7
18.64
Production sales values used for 1974 whenever possible,
1975, 1976, and 1977 estimate based on estimated sales.
-------
y Figure FE-1
Automotive Fuel Economy As a Function of Time*
50-STATES
55/45 FUEL ECONOMY, MPG
19
18
17
16
15
13
I I I I II
I iillll L
J I
1958-
1967
68 69 70 71 72 73 7« 75
76 1977
MODEL YEAR
* SAE Paper 760795
4-4
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It is important that in 1977 the sales weighted fuel economy of the
California fleet (calculated using the appropriate California sales) was
virtually equivalent to the sales weighted fuel economy of the 49-state
fleet (calculated using the appropriate Federal sales fractions) despite
the large difference in emission standards between the two fleets.
These data are shown in Table FE-2.
Table FE-2
Fuel Economy of the 49-State, California,
and 50-State Fleets
49-State
Fleet
les 17.82
:les 27.70
18.66
__„_ MPP —_-._—____
California
Fleet
15.94
26.05
18.49
50-State
Fleet
17.68
27.29
18.64
Domestic Vehicles
Imported Vehicles
All Vehicles
The values in Table FE-2 for all vehicles were previously reported to be
18.6 for the 49-state fleet and 18.0 for the California fleet by J. D.
Murrell, et al.* These values were based on earlier data than used in
this report. Since some of the foreign manufacturers had not certified
at the time of the Murrell paper, the fuel economies of both fleets
increased as more vehicles were certified.
An explanation for the nearly equivalent fuel economy between the 49-
state fleet meeting 1.5 HC, 15 CO, 2.0 NOx and California fleet meeting
0.41 HC, 9 CO, 1.5 NOx is that the sales weighted inertia weights
between the two fleets are different. The sales weighted inertia weight
of the 49-state fleet is about 3930 pounds and the California fleet is
* J. D. Murrell, et al., "Light Duty Automotive Fuel Economy - Trends
Through 1977", SAE Paper 760795.
4-5
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about 3520 pounds. The main reason for the difference in inertia weight
is that a higher proportion of the vehicles sold in California are
imports as shown in Table FE-3. The inertia weight of the 49-state
fleet is expected to more closely resemble the California fleet in
future model years as weight reduction programs are implemented by the
domestic vehicle manufacturers.
Table FE-3
Fraction of 50-State Fleet Sales
49-State
Fleet
0.7938
0.1145
0.9083
California
Fleet
0.0593
0.0324
0.0917
50-State
Fleet
0.8531
0.1469
1.0000
All Vehicles
Fuel economy estimates which were made for the 1977 model year by
various sources are shown in Table FE-4. The Federal emission standards
changed from 1.5 HC, 15 CO, 3.1 NOx in 1976 to 1.5 HC, 15 CO, 2.0 NOx in
1977.
•Table FE-4
Previous Estimates of Changes in
Fuel Economy of 1977 Federal Vehicles
Source of
Estimate Estimate Actual Change
Chrysler 7% loss for Chrysler,,compared 0% for Chrysler
to 1976
Ford no estimate given 0% for Ford
GM 5% loss for GM, compared to +9% for GM
what could be accomplished
at 3.1 NOx
Study 1 5% to 8% increase compared to 1976 +5% for Fleet
Study 2 no estimate given +5% for Fleet
4-6
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4.1.2. Comparison of Fuel Economy Estimates at Various Emission Levels
Between Three Domestic Vehicle Manufacturers and EPA
The most important consideration in, projecting the fuel economy of
future vehicles are 1) the applicable emission standard, 2) the applicable
model year, 3) the technology which is assumed to be available in a
given model year to the manufacturer, 4) the changes in vehicle weight
which are assumed to be applicable for a given model year. When con-
sidering per cent changes in fuel economy, the base year or reference
point in time is also of importance.
The recent status reports to EPA from Chrysler, Ford, and General Motors
contained the estimates of comparative vehicle fuel economy at various
emission levels compiled by these respective manufacturers. The EPA
estimates will be compared to the industry estimates of the impact of
emission standards on fuel economy in this section.
The submissions of the three manufacturers which are most important to
this discussion are presented as Table FE-5 to FE-7. These tables were
extracted directly from the manufacturers' submissions to EPA.
4-7
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Table FE-5
i
00
Standards
nc or
1977 Federal
1980-81 Dlngell-EPA .9
1982 Dlngell-EPA
NOx
2.0
1.5 15
9.0 2.0
.41 3.4 2.0
1977 California
Conference Report
.41
.41
9.0 1,5
3.4 1.0
1978 Statutory
.41 3.4 0.4
GM Fuel Economy Estimates
(From GM Submission)
Fuel Economy Losses
Percent
Baseline
10-20
Potential System Hardware
Ox1d. Converter, EGR
Oxld. Converter, AIR, EGR
Ox1d. Converter, AIR, EGR
Oxld. Converter, AIR. EGR
Large Engine/Small Car
Oxld. Converter, AIR, EGR
3-way converter C/L, EGR
Dual Converter C/L, AIR, EGR 10-20
Same catalyst system selec-
tions as .41/3.4/1.0 stds.
(18.4 HPG
Base)
(D
18.4
18.4
14.7-16.6
„(«
15-30
0-20
10-20
16.4
12.9-15.6
14.7-16.6*
14.7-16.6
10-30? 12.9-16.6
(1) EPA calculation of 1977 GM fleet average based on Part 1 Certification sales forecasts.
Remarks
Includes a 5X fuel economy loss from 1976 standards
(1.5/15/3.1).
Lead time requirements would prevent AIR and 8PEGR •
usage 1n 1978.
Further Improved catalyst system performance and
durability for 1978 and later years may reduce
penalty to lower end of rantje shown. Current
systems show penalties up to 20S.
Limited product availability.
Larger engines and higher axle ratios reduce
NOx emissions by reducing engine load.
The fuel economy losses may be at the lower end of
the range only If satisfactory catalyst durability
can be developed and an adequate supply of catalyst
material Is available. To date, no system has been
developnd that meets EPA emission test requirements
for 50,000 miles with reasonable maintenance
requirements.
Meaningful assessment of fuel economy penalty cannot
be made since control systems have not been demon-
strated to meet statutory standards through the
complete certification process Including the 50K
mile durability requirements.
(2) Loss would be more than 15t If California's methane allowance, audit requirements, and carry across of Federal durability data were not
permitted.
Note: Diesel engines are not Included but are discussed 1n Section VII. G.
Change communicated to EPA by letter
* Fuel economy value changed to 18.4 MPG by GM.
dated 21 December 1976.
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Table FE-6
Ford Fuel Economy Estimates
(From Ford Submission)
FORD MOTOR COMPANY
PROJECTED PERCENTAGE EFFECT OF VARIOUS EMISSIONS STANDARDS ON
CORPORATE AVlifJiGK U.S. PASSENGER CAR FUEL ECONOMY AMD Pl'.lCE
MODEL
YEAR
77/78 Fed
77/78 Cal
79/80 Fed
79 Cal/
81 Ted
No
Sulfate
Standard
1981
With
Sul fate
Standard
(15 mg/ini)
EMISSION CONTROL SYSTEM
DESCRIPTION
Opt. Conventional, IIC/CO
Catalyst, lean A/F, EGR
As above .
Opt. Coiivcntional , IIC/CO
Catalyst, Air, ESC/EECR
' TWC, IIC/CO, Air, EGR,
Carb feedback
TWC, IIC/CO, Air, Carb. .
feedback, ESC/EEGR
TWC, HC/CO, Air, EEC
(EFM, f'back, EEGR, ESC)
As above, and managed air
u u n « N
n n MM n
u n N n N
AVERAGE M-II FUEL ECONOMY
PERCENT B/(W) THAN BASE
o
•
X.
in
r-4
in
rH
UASEj
1%
o
CM
O\
Ol
O
(2%)
1
'
X
"^
\ "
r-> .
V.
O
in
•
c*
r-4
^
O
.-t
^
x.
rH
1-
O
(11%) (15-175) DNME
| ( 8)
( 3)
0
2
(13)
( 8)
( 5)
( 3)
(ll)b/
(11)
( 4)
( 1)
• 1
(16)
( 9)
( 6)
( 4)
DNME
(Ct)
( 3)]
( l)j
nNME
(11)
( 8)
( 6)
RETAIL
PRICE
EQUIVALENT
(0)/U '
BASE a/
BASE
$(1-10-220)
$(150-220)
$(220-290)
$(280-360)
HA
NA
NA
NA
a/ System and emission level assumed for costing is indicated by I I ;
Costing based on hardware levels currently under development.
b/ California penalty less than if the car was certified for 49 States
~ at same emissions because of unique California certification regula-
tions with respect to 50,000 mile durability car requirements and
standards in terms of non-methane hydrocarbons.
DNME Docs not meet emissions requirements.
NA Not Avail-able
HC/CO IIC/CO is a Hydrocarbon, Carbon Monoxide oxidation catalyst.
TWC Three-way catalyst
ESC Electronic spark control
EEGR Electronic exhaust gas recirculation
EEC Electronic engine control (integrated controls for fuel, with feed-
back, exhaust gas recirculation, and spark).
Data on this page subject to change on a monthly basis as development
progresses.
B/(W) =-Better/(Worse)
4-9
-------
HC
1.5
1.5
0.9
0.4
0.4
0.4
0.4
CO
Table FE-7
Chrysler Fuel Economy Estimates
(From Chrysler Submission)
EPA
Composite Fuel Economy
Percent
Individual Percent
Step Cumulative
NOx
15
15
9
3.4
3.4
3.4
3.4
3.1
2.0
2.0
2.0
1.5
1.0
0.4
Base
-5%
-3%
-3%
-3%
-3%
*
Base
-5%
-8%
-11%
-14%
-17%
*
* No Chrysler data available upon which an estimate can be made.
No catalyst system appears capable of achieving these low levels
with adequate durability.
Table FE-8
Fuel Economy at 0.9 HC, 9 CO, 2.0 NOx
Model Year
1978
1979
1980
1981
Source
Chrysler
Ford
GM
Study 1
Study 2
Chrysler
Ford
GM
Study 1
Study 2
Chrysler
Ford
GM
Study 1
Study 2
Chrysler
Ford
GM
Study 1
Study 2
Estimated % Change
in Fuel Economy
(-3)
-2
NE
+3 to +9
NE
(-3)
+1
NE
+6 to +13
NE
(-3)
+1
0
+8 to +15
+12 to +15
(-3)
NE
0
• +10 to +17
+15 to +17
Technology Assumed
Available
Proven technology
EGR/OC
PL/EEGR/ESA/AIR/OC/SC
Proven technology
ESC/EEGR/AIR/OC
same
Proven technology
ESC/EEGR/AIR/OC
AIR/EGR/OC
same
same as Study 1
Proven technology
AIR/EGR/OC
same
same
NE = no estimate
4-10
-------
To facilitate comparisons of the data, Table FE-8 to FE-11 have been
generated to more clearly illustrate the estimates from the various
sources with respect to emission standards. The Chrysler data has been
adjusted to a 1.5 HC, 15 CO, 2.0 NOx base to make this base common to
all data sources. Since no applicable model years were included in the
Chrysler data, their estimates are considered applicable for all model
years and will be enclosed in parentheses. The Study 1 and 2 estimates
also were modified to remove the effects of reduced vehicle weight in
future model years to make the EPA estimates consistent with the others.
Though not specified by Chrysler, Ford, and GM, it was assumed from
their discussions that constant vehicle weight was an assumption in
Tables FE-5 to FE-7.
Tables FE-8 through FE-11 tend to show differences between the estimates
of the vehicle manufacturers and those of Study 1 and Study 2. The
Study 1 and 2 estimates are generally more optimistic than those of the
vehicle manufacturers. These discrepancies between fuel economy es-
timates have historically been present and may continue to exist.
4-11
-------
Table FE-9
Fuel Economy at 0.41 HC, 9 CO, 1.5 NOx
Model Year
1978
1979
1980
1981
Source
Chrysler
Ford
GM
Study 1
Study 2
Chrysler
Ford
GM
Study 1
Study 2
Chrysler
Ford
GM
Study 1
Study 2
Chrysler
Ford
GM
Study 1
Study 2
Estimated % Change
in Fuel Economy
NE
-15 to -17
-11 to (7-15)
NE
NE
NE
-11
NE
NE
NE
NE
-11
NE
NE
NE
NE
-4 to +1
NE
NE
NE .
Technology Assumed
Available
AIR/ESA/EEGR/OC
AIR/EGR/OC
AIR/ESA/EEGR/OC
AIR/ESA/EEGR/OC
AIR/EEC/3W/OC
Table FE-10
Model Year
1979
1980
1981
1982
Fuel Economy at 0.41 HC. 3.4 CO. 2.0 NOx
Source
Chrysler
Ford
GM
Study 1
Study 2
Chrysler
Ford
GM
Study 1
Study 2
Chrysler
Ford
GM
Study 1
Study 2
Chrysler
Ford
GM
Study 1
Study 2
Estimated % Change
in Fuel Economy
(-6)
-8
NE
+1 to +11
+2 to +12
(-6)
-8
NE
+2 to +13
NE
(-6)
-3 to +2
NE
. +5 to +17
NE
(-6)
NE
-10 to -20
+9 to +21
+12 to +21
Technology Assumed
Available
Proven Technology
ESA/EEGR/AIR/OC
PL/EEGR/ESA/AIR/IFM/OC/SC
Study 1 + EAIR
Proven Technology
ESA/EEGR/AIR/OC
same
Proven Technology
AIR/EEC/3W/OC
same
Proven Technology
AIR/EGR/OC
same
same
4-12
-------
Table FE-11
Fuel Economy at 0.41 HC. 3.4 CO. 1.0 NOX
Estimated % Change Technology Assumed
Model Year Source in Fuel Economy Available
1981 Chrysler (-12) Proven Technology
Ford -6 to -1 AIR/EEC/3W/OC
GM* 0 to -30 FBC/EGR/AIR/3W/ OC
Study 1 +3 to +15 PL/EAIR/EEGR/ESA/IFM/SC/3W
Study 2 +4 to +16 same as Study 1
* Model year not stated by GM but assumed to be 1981 as
indicated by the Conference Committee Report.
The most important interpretation of the results in Tables FE-8 through
FE-11 is the fact that as improved emission control technology is installed
on vehicles, such as for 0.41 HC, 3.4 CO, 1.0 NOx in 1981, the fuel
economy penalty estimates made by the manufacturers become almost insig-
nificant (Ford says -1% with their best technology) or include a range
that has no penalty (GM says 0 to -20%). This illustrates that estimates
of the fuel economy impact of future emission standards are highly
dependent on the technology that is assumed to be in production. The
fuel economy penalties shown by the manufacturers at less stringent
emission levels could be explained by their assumption of the use of
emission control technology that may not be optimal for fuel economy at
those emission levels.
4.1.3. Engine-Related Systems for Near Term Improvements in Fuel Economy
There are several engine-related approaches currently under development
by the industry which appear to be capable of providing substantial
improvements in vehicle fuel economy. These systems include improved
EGR systems, intake and exhaust valve deactivation systems, turbocharged
engines, electronic emission control systems, and fast burn systems.
Improved EGR Systems
Ford previously suggested that the switch to backpressure EGR would
4-13
-------
provide up to 1 MPG (not specified as urban or composite) improvement in
fuel economy. Ford has now nearly completed the conversion, as have
AMC, Oldsmobile, Cadillac, and Buick, but a number of prominent domestic
manufacturers including Chrysler, Chevrolet, and Pontiac are still
primarily using ported or venturi vacuum amplified EGR systems.
All of the big three domestic manufacturers have reported efforts on
electronic EGR systems. Electronic EGR systems are expected to be even
better than backpressure EGR. Only Ford has reported comparative data
between similar vehicles using a new generation EGR system. The results
shown in Table FE-12 were from similar 3500 pound IW vehicles using the
302 engine and an automatic transmission. These results compare the use
of sonic EGR to backpressure EGR on advanced oxidation catalyst systems
calibrated to 0.41 HC, 3.4 CO, 1.0 NOx. Neither EGR system in Table FE-
12 was electronically controlled. Ford is known to be investigating
both electronically controlled and pneumatically controlled sonic EGR
systems. Ford reported these tests as "best effort results".
Table FE-12
A New Generation EGR System*
HC
.55
.21
. CO
3.00
1.58
. 7 *\ T?TP ——_— ——.
NOx
"
.77
.74
MPG
u
10.5
11.5
Backpressure
Sonic
The sonic EGR system achieved better emissions in addition to the 10%
improvements in urban fuel economy. The 10% may understate the fuel
economy advantage of sonic EGR because of the large discrepancy in HC
emissions between the two systems and because the data were reported in
December of 1975. It must be assumed that considerable development has
been conducted since then.
* Ford Status Report, December 1975, page IB3,
4-14
-------
The only possible restrictions on spark advance at these emission levels
for 3-way or oxidation catalyst systems are: 1) the HC emission standard
and 2) octane requirement. If the spark advance is not at the octane
restriction of the engine/drivetrain combination (which it is not in the
case of the Ford vehicles here), then the spark can be advanced to
accomodate higher HC emissions and improved fuel economy. NOx increases
can be handled catalytically or by higher EGR rates which may also yield
higher HC emissions which must be considered in the spark advance
calibration.
Intake/Exhaust Valve Deactivation Systems
The big three domestic auto manufacturers have all reported plans to
evaluate or have already evaluated the Eaton-type valve deactivation
system. The system is reported* to function as shown in Figure FE-2.
Ford efforts have concentrated on the 300 CID truck engine and prototype
PROCO engines. The system deactivates 3 of 6 cylinders (3x6) on the 300
CID engine when power requirements are reduced, and deactivates both 2
and 4 cylinders of the V-8 PROCO (4x6x8). No vehicle testing was reported
by Ford. General Motors reported the only available data in Table FE-13
for a 4x8 system on a 4000 pound IW vehicle with a 350 CID engine.
Emission results were inconclusive, except for NOx reduction.
Figure FE-2
Probable Operation of Valve Deactivators
Normal operation
rfti tflSr
-rl
Cylinder locked out
Teeth
O CD
stem
RocKer arm stud .
* Machine Design, 21 October 1976.
4-15
-------
Table FE-13
The Effect of the Valve Deactivation System
Standard Vehicle 1
Vehicle 1 + Valve
Deactivation
Standard Vehicle 2
Vehicle 2 + Valve
HC
0.67
0.68
0.55
0.76
CO
5.4
2.2
5.0
9.0
NOx
1.98
1.80
1.85
1.05
MPG
u
15.7
16.9
15.3
16.7
MPG,
h
18.8
21.6
18.9
20.8
MPG
c
17.0
18.7
16.7
18.4
Deactivation
Composite fuel economy showed about a 10% improvement.
A 2x4x6x8 configuration was reported* to. be installed on a V-8 PROCO
engine at Ford. This system on the PROCO was said to have "the poten-
tial to be 50% more economical on fuel than conventional engines are".
Turbocharged Engines
Turbochargers can be adapted to both spark ignition and compression
ignition engines for the purpose of improving fuel economy. This is
accomplished by maintaining the peak power output of a particular engine
approximately constant by the addition of a turbocharger and a concomitant
reduction in engine displacement. Alternately the engine displacement
could remain constant and a substantial improvement in power output
would be expected.
Five vehicle manufacturers are now believed to be considering the use of
turbochargers on production vehicles. They are Saab, Daimler-Benz,
* Ward's Engine Update, Vol. 3, Number 6, 18 March 1977.
4-16
-------
Volkswagen, Ford, and General Motors. Very little was reported on the
Ford and Volkswagen programs. The Daimler-Benz program is related to
compression ignition engines and will not be considered further in this
section as the Diesel application is probably designed for a power
output increase and not a fuel economy improvement.
As shown in Figure FE-3 the Saab effort with their 2.0 litre engine and
3-way catalyst system was dedicated to improved power output with even
some losses in brake specific fuel consumption. An illustration of the
Saab turbocharger is shown in Figure FE-4.
Compared to the Saab effort, the General Motors' effort is less oriented
toward improved power output. The data in Table FE-14 show the changes
in economy and performance of a prototype 1978 "A" car and a prototype
1978 "B" car when the turbocharger was adapted to a 231 CID, V-6 engine.
All tests were reported to be at calibrations for 1.5 HC, 15 CO, 2.0
NOx. The "A" car line includes the Buick Century, Oldsmobile Cutlass,
Pontiac LeMans, and Chevrolet Chevelle. The "B" car line includes the
Buick LeSabre, Oldsmobile Delta 88, Pontiac, and Chevrolet.
The naturally aspirated vehicles in Table FE-14 are also of interest as
they are some of the heavier vehicles in the GM line, and are all above
the 1978 fuel economy level of 18.0.
4-17
-------
Figure FE-3
Engine Dynamometer Testing of Turbocharged
Saab Engines
Tof$UE
L&-fT 0HP
7/n
-no
16o -
tfo •
n? -
no •
120 -
110 •
100 -
tfr
n>
i&>
let
So
ft*5l CONS. M
1&/MP
Of6f
0,t»-
0,$r-
0,*-
0,tf-
4>
J&
THR.OT71E FVM/eK
fat
ft*j
4-18
-------
Figure FE-4
-------
Table FE-14*
1978 Prototype GM Vehicles Using Oxidation Catalysts
Naturally Aspirated With Turbo
Vehicle MPG** 0-60 time (sec) MPG** 0-60 time (sec)
"A" 20.4 15.7 22.0 12.4
"B" 18.7 18.0 20.5 14.0
** Not specified by GM as urban or composite
With the addition of the turbocharger, the improvement in fuel economy
ranged from about 8-10% with improved vehicle acceleration. These
performance and fuel economy gains are reported using the naturally
aspirated 231 CID V-6 as the baseline. If the baseline engine were an
engine of larger displacement equal in performance to the turbocharged
V-6, the fuel economy gains would be expected to be even higher.
Electronic Control of Spark Advance (ESA)
The addition of electronic control of the spark advance could result in
improved fuel economy, improved vehicle emissions, improved driveability,
or some combination of modifications to all three. The actual changes
in calibration of spark timing would determine the precise changes in
emissions, economy, and driveability.
The results in Table FE-15 show two applications of electronic spark
control in the 1977 certification program. All four vehicles are
Oldsmobiles with 403 CID engines, automatic transmissions, and 2.73
axles at 5000 pounds inertia weight. In family 730P4UY the spark
recalibration resulting from the use of ESA yielded considerably higher
NOx emissions and about a 9% improvement in composite fuel economy. In
family 730M4AU, CO emissions were increased somewhat and composite fuel
economy was improved about 3%. Thus in both cases, the ESA system was
not designed for improved emissions. The precise goals for the use of
* GM Status Report, December 1976, page VII-133.
4-20
-------
ESA on these two engine families could have been related to either
driveability or fuel economy. The rather substantial improvement in
' fuel economy of the one family suggests that improved fuel economy was a
primary goal in that application.
Table FE-15
The Addition of ESA to 1977 Oldsmobiles
Family
730P4UY
730M4AU
VIN
Without
ESA ESA HC
CO
NOx
(with DF)
7341F3
7341F4
7331C5
7331C6
X 0.83
X 0.85
X 0.35
X 0.36
5.4
5.2
5.8
8.9
1.3
1.9
1.3
1.4
MPG MPG,.
u
11.9
13.1
11.2
11.4
ii
17.3
18.5
17.5
18.5
MPG
c
13.8
15.1
13.4
13.8
Feedback Air-Fuel Metering
Feedback air-fuel metering could enter production as either feedback
carburetion (FBC), single-point fuel metering (SPFM), or multi-point
fuel injection (FI). Though comparative data for these different
systems on similar vehicles are not abundant (see Ford data in Section
7.1.3.), EPA believes that the use of FI + 3-way catalysts is currently
being weighed against the use of FBC or SPFM + 3-way + oxidation catalysts
+ AIR at statutory HC and CO levels with NOx levels of 1.5 gm/mi or lower.
The primary need for both AIR and the oxidation catalyst is for CO
control. SPFM and FBC are suspected of having poorer engine out CO
emissions. This suspicion is based on: 1) the observation that typical
+2
-------
Cylinder to cylinder air distribution problems can be controlled with FI
systems by either injector matching or electronic compensation of the
signal to the injector on electronic FI systems. Also the system response
time of the FI system is better because fuel flow corrections can be
made closer to the cylinder.
CO emissions out of the engine are highly dependent on air-fuel ratio
and increase very rapidly as the air-fuel ratio goes richer than stoi-
chiometry.
EPA technical staff believe that closed loop air-fuel metering may not
be necessary on lighter inertia weight vehicles (less than about 3000
pounds IW) even at NOx levels of 1.0 or less with statutory HC and CO.
The efforts of Nissan with their fast burn engine are the most illus-
trative of this fact. Ford efforts on oxidation catalyst vehicles in
the Low NOx Fleet (3500 IW) further substantiate this. GM efforts show
that these levels can be achieved at low mileage on vehicles up to 4500
pounds inertia weight when thermal reactor, electronic controls, plus
oxidation catalyst systems are used; however, fuel economy objectives
may not be as easy to attain with open loop air-fuel metering systems.
Ford efforts on air-fuel ratio perturbations show that fluctuations in
air-fuel ratio may be valuable in certain applications. This work shows
that the 3-way catalyst window can be widened by the addition of oxygen
storage components to the 3-way catalyst and by introducing air-fuel
ratio fluctuations of controlled amplitude and frequency. Some of the
more successful Ford work has been concentrated around air-fuel fluctu-
ations of - 1 air-fuel ratio at 1 Hz frequency.
Near Stoichiometric Versus Lean.Calibrations
The Ford Low NOx Fleet provides a reasonable comparison of Stoichiometric
air-fuel ratio calibrations versus lean air-fuel ratio calibrations for
4-22
-------
the same emission target. Both the stoichiometric and lean vehicles
were calibrated to 0.41 HC, 3.4 CO, 1.0 NOx and used backpressure EGR
and AIR. The stoichiometric systems used a 3-way plus oxidation catalyst
emission control system, and the lean systems used oxidation catalysts.
No advanced, electronic emission control systems were used. The average
urban fuel economy results for the 3W + OC systems were about 40% higher
than for the OC systems on these nearly identical vehicles. The spark
calibrations of the 3W + OC vehicles appeared to be considerably more
advanced and HC emissions out of the 3W + OC vehicles were considerably
higher, though probably still adequate for a statutory NMHC standard.
While the fuel economy of the OC vehicles could be adjusted upward to
account for lower HC emissions, this adjustment probably would not make
up the 4.5 MPG differential (15.9 MPG versus 11.4 MPG ) between the 3W
u u u
+ OC and OC systems.
Knock Limit Control Systems
Only General Motors and Exxon Research and Engineering (under contract
for EPA) are currently known to be evaluating such a system. The only
known application of the system at GM is on their turbocharged V-6 for
the 1978 model year. GM will apparently investigate an approach similar
to Exxon's. The Exxon work is attempting to increase the compression
ratio of an engine while retaining its ability to operate on 91 RON
fuel.
The purpose of the system is to detect spark knock and if spark knock
occurs, retard the spark timing until conditions permit the spark to be
advanced. These systems have the potential to detect spark knock before
it becomes audible to the driver. Prolonged knock at high air flow
rates is potentially destructive to the engine of the vehicle and must
be avoided.
4-23
-------
This system could have several applications. In addition to the potential
uses mentioned, the system could be used for attaining more spark advance
at a constant compression ratio with 91 RON fuel or attaining the ability
to operate on fuel of less than 91 RON with the same compression ratio.
Since GM has not reported data that would isolate the effect of the
knock control system, the Exxon efforts will be discussed. A schematic
of the GM system is shown in Figure FE-5.
The vehicle being used at Exxon is a 1975 California Nova with a 350 CID
engine and an automatic transmission at 4000 pounds inertia weight. The
knock limit control system has been installed on the vehicle, however,
emissions from the vehicle have not yet been measured with the system
operational. The emissions are not expected to change much from those
without the knock limiter system as the vehicle is wide open throttle
(WOT) knock limited and WOT conditions will not be encountered on the
FTP. Octane requirement testing in the laboratory on an engine dyna-
mometer has suggested that a gain in compression ratio of one full
number (from 8.0:1 actual to 9.0:1 actual compression ratio) can be
attained. This assumes that the octane requirement increase will be the
same at 9.0:1 as at 8.0:1. Fuel economy and emission results of the
vehicle at the two compression ratios without the knock limit control
system are shown in Table FE-16.
Table FE-16
Effect of a Change in Compression Ratio from 8:1 to 9:1
Compression
Ratio
8.0:1
9.0:1
//
Tests
4
4
HC
0.54
0.62
_ 7 C T?TT>
CO
5.98
8.11
NOx
1.67
2.24
MPG
u
11.4
12.3
uel Econom
MPG,
n
16.5
18.1
MPG
c
13.2
14.4
About a 9% increase in composite fuel economy is shown for the increase
in compression ratio. An emission penalty was initially noted, however,
when the EGR system was changed from ported to backpressure EGR (and
recalibrated) and the choke was leaned one notch, the emissions then
4-24
-------
Figure FE-5
NJ
KNOCK LIMIT CONTROL
HEI DISTRIBUTOR •'
CONTROL .
ELECTRONICS
KNOCK
DETECTOR
ACCELEROMETER
•^-NORMAL FIRE
~"L KNOCK DELAYED
j FIRE
SPARK
ej COIL
_L
-------
were 0.51 HC, 3.92 CO, 1.72 NOx (3 test average) and fuel economy was
further improved to 14.8 MPG .
c
GM efforts on a similar vehicle with a compression ratio change from
8.3:1 to 9.2:1 show about an 8% improvement in fuel economy, but suggest*
that a more universal relationship is about 6% increase in fuel economy
for each number of compression ratio increase.
Other Electronic Controls
General Motors reported data on a single vehicle which was calibrated
for 0.41 HC, 3.4 CO, 1.0 NOx using electronic control of 1) spark
timing, 2) EGR, 3) cold enrichment, and 4) idle speed. The 350 CID
Chevrolet was also equipped with thermal reactors and a production
oxidation catalyst. The emission and fuel economy results of this
vehicle and some 1977 Federal certification vehicles of similar IW and
with the same displacement engine are shown Table FE-17.
Table FE-17
Emission and Fuel Economy Gains
Vehicle
Electronic Control
Cert # 7160F5
Cert # 7160F5
Cert # 7168F4
§ 4K values for cert cars, without DF.
While the electronically controlled vehicle shows substantially improved
emission control capability at low mileage, its fuel economy is also
with Electronic
Engine
350
350
350
350
IW
4000
4000
4000
4000
~ fi~
•HC
0.25
0.29
0.28
0.53
Controls
/5 FTP 5
COS
1.20
3.80
2.40
2.80
NOx
0.75
1.32
1.46
1.68
MPG
u
13.2 .
14.9
14.1
12.7
ael Econoi
MPG,
n
18.6
20.1
18.1
15.9
ny
MPG
c
15.2
16.9
15.7
14.0
* James J. Gumbleton, et al., "Effect of Energy and Emission Constraints
on Compression Ratio," SAE Paper 760826.
4-26
-------
less than two of the three 1977 Federal certification vehicles. No
similar oxidation catalyst equipped vehicles without the electronics
which were calibrated to similar emission levels could be found.
It should be noted that this testing was done by GM on an oxidation
catalyst system instead of a 3-way catalyst system. GM indicated that
this system was considered so that they will have systems ready for
production in case their 3-way catalyst systems encounter problems. The
fuel economy of a 3-way catalyst vehicle using similar technology may be
considerably higher than the fuel economy of this vehicle, as the Ford
Low NOx Fleet results indicate.
Fast Burn
The Nissan fast burn system (see Nissan section 7.3.9.) represents an
attractive system at statutory emission levels due to its excellent fuel
economy performance. The key components to the system are one additional
spark plug in each modified combustion chamber, EGR, and an oxidation
catalyst (similar to many current production vehicles). The EGR rates
are extremely high for a gasoline engine, but their use permits attain-
ment of statutory NOx levels at low mileage. The development of the
system has been very rapid, and the testing very limited. The results
shown in Table FE-18 represent some of the best results reported on the
single vehicle using this system.
Table FE-18
Nissan Fast Burn System
2750 IW
HC
0.22
0.24
CO
2.09
2.01
NOx ,
0.38
0.37
MPG
u
22.2
22.6
MPGU
n^
33.1
33.4
MPG
c_
26.1
26.4
The fuel economy results are within the range of the similar Nissan 1977
Federal emission data and durability vehicles.
4-27
-------
4.1.4. Other Engine-Related Systems for Improving Fuel Economy
The engine-related fuel economy/emissions control systems discussed in
Section A. 1.3. do not cover some of the advanced emission control
technology discussed in previous years' reports. These approaches are
still potential candidates for use if, for example, a manufacturer's
fuel economy performance is limited by HC control, rather than octane
considerations.
These technical approaches include: (1) heat conservation (port liners,
insulated combustion chambers, thermal reactors, insulated exhaust
manifolds, insulated exhaust pipes), (2) controlled air injection
systems, (3) improved warm-up emission control (start catalysts, EFE and
Super EFE, charcoal storage, vaporizing chokes, on-board distillers,
catalysts with improved light-off performance, heated fuel injection
nozzles, electrocally modulated chokes), (4) improved warmed-up emission
control (larger catalyst volumes, higher noble metal loadings, improved
resistance to thermal and chemical deactivation), and (5) improved fuel
metering (electronic accelerator pump, fuel shutoff on deceleration,
improved intake air-fuel mixture distribution, etc.).
All of the above approaches can be used to reduce emissions and therefore
have the potential to be part of an emission control system that could
be applied to a vehicle calibrated for best fuel economy. Some vehicles
may not need any of these advanced emission control techniques, but all
of these technical approaches are considered by EPA to be available to
the manufacturers, should they need additional emission control for
improved fuel economy and/or driveability.
4.1.5. Other Engines
Several alternate engine concepts which have the potential for improved
fuel economy and low NOx emissions are being considered by the industry.
4-28
-------
These options include Diesel engines, the Ford PROCO engine, and the
Honda CVCC engine. The current fuel economy and emissions performance
of vehicles using these alternate engines is shown in Table FE-19. The
fuel economy comparison is made between the alternate engine and the
sales weighted fuel economy of all 1977 Federal certification vehicles
at the same inertia weight. This is done to compare the fuel economy of
vehicles of the same weight. Generally, the performance characteristics
of the vehicles equipped with these prototype alternate engines are not
reported, so making a comparison based on equal performance is not
possible. In many cases, the performance of the vehicles with the
alternate engines is expected to be somewhat poorer than the average
performance of the vehicles to which they are compared. Therefore, the
results shown on Table FE-19 may be inflated somewhat.
4.1.6. Other Fuel Economy Improvements
The fuel economy section of this report has concentrated on engine-
related fuel economy effects, since these are most directly involved in
emissions/fuel economy interactions. It should be noted, however, that
fuel economy is influenced by several other factors not treated in
detail in this report. Among these factors are: vehicle weight effects,
drivetrain effects, power-to-weight ratio effects, accessory drive
effects, rolling resistance, aerodynamic effects, etc.
Of the above-mentioned factors that influence fuel economy, some are
expected to have directionally positive impacts on the capability to
control emissions. These factors are those that tend to reduce the
exhaust volume generated by the vehicle during the test. These factors
are reduced vehicle weight, improvements in accessory drives, improve-
ments in rolling resistance (tires, lubricants, engine frictions,
drivetrain friction), and aerodynamic effects. These factors, especially
reduced vehicle weight, can have a much greater impact on fuel economy
than most of the engine-related topics discussed in this report.
4-29
-------
Table FE-19
Alternate Engines with Good Fuel Economy
Sales Weighted
MPG in IW
Class in 1977 % Increas
Manufacturer
Honda
Ford
Daimler-Benz
i Peugeot
o
GM
VW
Engine
CVCC
PROCO
Diesel
. Diesel
Diesel
Diesel
IW
2000
5000
3500
3500
4500
2250
HC
1.4
0.22
0.37
1.04
0.85
0.78
CO
6.2
0.1
1.2
2.1
1.8
1.0
NOx
1.4
0.78
1.43
0.91
1.50
0.61
MPG
u
41
15.5
24.8
27.7
20.8
50.4
MPG,
h
54
22.7
33.5
34.7
29.7
64.6
MPG
c
46
18.1
28.1
30.1
24.0
55.8
Certification
35.
14.
20.
20.
16.
31.
9
4
5
5
7
8
MPG *
c
28
26
37
47
44
75
* Increase over sales weighted fuel economy of all 1977 Federal Certification vehicles at the
same IW as shown for alternate engines. Emission data do not include DF.
-------
The impacts on emissions of drivetrain improvements and power-to-weight
ratio changes are not well known at this time. Improvements in both
areas yield fuel economy gains, because the engine is operating "harder"
(at a higher load factor) during the test. Operation at a higher load
factor could yield higher engine-out emissions for NOx. However, catalyst
light-off performance and EGR tolerance are expected to improve with
higher load factors, so the actual result could be an improvement in
emissions. More information is required in this area before more
specific conclusions can be drawn.
4.2. Cost
The Cost Section in this year's status report represents a preliminary
effort to obtain cost information. Further study is currently in
progress to provide this information with greater accuracy and in much
greater depth and detail than has been reported in the past. These
detailed findings will be the subject of a separate report.
As has been the case in previous years, the majority of manufacturers
submitted little or no cost information in their submissions to EPA. A
few manufacturers, among whom were AMC, Toyo KogyOj and Saab, provided
information in somewhat better detail than did other manufacturers.
As an example of the range of the types of responses concerning emission
control system cost information submitted by the manufacturers Attach-
ment Cost-1 and Attachment Cost-2 (which can be found at the end of this
section) have been prepared. Attachment Cost-1 is AMC's response, and
Attachment Cost-2 is GM's response.
Estimations of the likely increase in vehicle cost or "sticker" price
associated with meeting a particular emission level begin by assuming
what control system or range of control systems are necessary to attain
that emission level. These control systems must then be broken down
4-31
-------
into the various components which comprise each system. Next, the types
of materials, their amount or weight, and their cost per unit weight
must be identified and the costs summed together to get a total cost of
materials for each component. Depending on the level of knowledge
available, there are generally two basic methods which may then be used.
(See Figure Cost-1.) The first (Method //I) simply employs a factor to
get from the cost of materials used to its contribution to "sticker"
price. This method is used where little is known as to the other
elements of cost which make up the final cost to the consumer. The
other method (Method #2) is much more detailed and involves basically
three levels: the plant, the corporation, and the dealer.
Method //2 involves a detailed estimate of several influencing factors:
materials, labor, overhead, investment writeoff, development writeoff,
warranty provisions, shipping charges, profit, etc. These factors are
not the same for each automobile company and may vary with the specific
type of emission control component. The length of time necessary to
investigate each of these elements precluded making a detailed EPA cost
estimate of this type for this report.
The following two tables (Table Cost-1 and Table Cost-2) present the
ranges of costs for specific emission control components and for systems
to be used at various emission levels as reported by the manufacturers.
EPA's estimates are to be included in a separate report as discussed
above. In Table Cost-1, estimates for many of the emission control
components were not provided in this year's submissions to EPA thus last
year's estimates as reported by the manufacturers are presented and are
noted with an asterisk.
Table Cost-2 shows "sticker" estimates, as provided by the manufacturers,
of the cost ranges to meet various emission standards relative to a
specific base year/emission standard.
4-32
-------
Figure Cost-1
Elements of Cost Estimates for Various Methodologies
f •
Dealer
i
Corpo
i
t
Pla
>
ration
r
I
nt
— —
_ . .
-,_ .
. ~_. — .
Markup
r Factor
•s
Variable
1 Costs
j
—
— .
-x
J
Markup
*" Factor
Part Cost
>- to the
Corporation
-
*
Profit
Overhead & Shipping
Labor
Profit
Warranty Provision
Development Writeoff
Investment Writeoff
Overhead
(includes shipping)
Labor
Materials
Profit
Investment Writeoff
Overhead
Labor
Materials
Method #1
Method Used
by
some of the
Manufacturers
Method #2
4-33a
-------
Table Cost-1
Emission Control Component Retail "Sticker" Costs
Range of Manufacturer's
Item/Compenent/Subsystem Estimate, Dollars
PCV Valve 2 to 3*
Anti-Dieseling Solenoid 2 to 6*
Air Injection System 40 to 50
Air Switching System 15 to 30*
Reed Valve Air System 11
EGR System 10 to 40
Pelleted Ox. Cat. (each) 16 to 150
Monolithic Ox. Cat. (each) 66 to 153*
Pelleted Red. Cat. (each) 72 to 150*
Monolithic Red. Cat. (each) 90 to 157*
Monolithic Start Cat. (each) 49 to 66
Monolithic 3-Way Cat. (each) 55 to 137
Metallic Red. Cat. (each) 100*
Oxygen Sensor 14 to 20
Electronic Fuel Metering 100 to 137
Thermal Reactor (each) 4 to 86*
Port Liners (each) 1*
Quick Heat Manifold N.R.
Super EFE N.R.
Electric Choke 4 to 9*
High Energy Ignition 27 to 116*
Improved Exhaust System 30 to 40*
Insulated Exhaust Pipe N.R.
Carb Mods for Altitude Comp. N.R.
Garb Mods for Feedback Control 5 to 10%
over cost of similar,
non feedback carb
Electronic Control Unit 68
Air Modulated System N.R.
Inlet Air Sensor N.R.
Engine Load Sensor N.R.
* These cost figures were not reported in this year's submission thus
the figures shown are last year's values as reported by the manufacturers,
N.R. means not reported this year or last year.
4-33b
-------
Table Cost-2
Emission Control System Retail "Sticker" Cost Increases
to Meet Various Standards
Emission Standards
HC/CO/NOx (year)
1.5/15/2.0
1.5/15/2.0
('78 Fed)
('78 Fed)
Range of Manufacturer Estimates
Dollars Base Year
-20 to 120
45 to 60
'77 Fed
'74 Fed
0.9/9/2.0 ('79 Fed)
not requested
0.41/9/1.5 ('77-'79 CA) 53 to 136
0.41/9/1.5 ('78 CA) -70 to -50
0.41/9/1.5 ('78 Fed) 0 to 237
0.41/9/1.5 ('78 Fed) 339 to 345
'77
'77
'77
'74
Fed
CA
Fed
Fed
0.41/3.4/2.0
C79-'80)
0.41/3.4/2.0
('79-'81 Fed)
0 to 380
339
'77 Fed
'74 Fed
0.41/3.4/1.0 ('81 Fed) 113 to 376
0.41/3.4/1.0 (?) 0 to 470
0.41/3.4/1.0 ('79-'81 Fed) 339
0.41/3.4/1.0 ('79-'80 Fed) 32
'77 Fed
'77 Fed
'74 Fed
'77 Fed
0.41/3.4/0.4
('8x or ? Fed)
0.41/3.4/0.4 ('82 CA)
423 to 538
186
'77 Fed
'77 CA
4-34
-------
Attachment Cost-1
AMC Cost Information
from AMC Status Report
4-35
-------
V- 1
V. COST INFORMATION
A. First Cost
The estimated costs of the systems discussed in this report are
contained in tables 1 through 7. In many of the systems discussed
the accuracy of the estimates may be questionable since designs
have not been finalized and supplier cost data are not available.
Only the 1978 model cost data can be considered reasonably accurate.
B. Operating Cost
On tables 8 and 9 we have listed the estimated operating costs of
the systems discussed. On table 10 we list catalytic converter
maintenance costs. In the case of MPG data for 1978 systems we
have used 1977 model year MPG label information since the systems
are essentially carryover. Projections for systems beyond 1978 are
difficult since compliance with emissions standards have not been
achieved and therefore specific MPG data are not available.
4-36
-------
TABLE 1
AMERICAN r^DTORS CORPORATION
ESTIMATES) FUTURE DEALER/CUSTOMER COST PENALTIES FOR
EMISSIONS HARDWARE DESIGNED TO MEET
1.5 HC, 15 CO, 2 NOx EMISSIONS STANDARDS
1973 MODEL VERSUS 1977 M3DEL
Induction System
(outside air)
Evaporative Control System
1. 4-port canister
2. Carburetor-mechanical
bowl vent
3. Additional hoses, etc.
4. Auxiliary fuel trap in
bowl vent line
4-Cylinder
6-Cylinder
(1)
.46
(2)
(1)
(2)
Man Auto Man Auto Man Auto Man Auto
2.43 2.43 2.85 2.85
.46 .54 .54
.46 .46
.54 .54
1.44 1.69 1.69 1.69
.86 .86 1.01 1.01
8-Cylinder
_ (1) (2)
AutO AutO
3.88 4.56
.46 .54
2.01 2.36
.86 1.01
1.15 1.35
Ignition System Revised
(Ford Distributor)
.46 .46
10.19 10.19 11.99 11.99 10.19 11.99
.54 .54 15.38 15.38 18.08 18.08 18.55 21.81
(1) Est. wholesale (dealer) price
(2) Est. average (sticker) price
-------
TABLE 2
AMERICAN MOTORS CORPORATION
ESTIMATED FUTURE DEAISR/CUSTGMER COST PEXAUTIES FOR
EMISSIONS PU^K-JARE DESIGNED TO MEET
.41 HC, 9 CO, 1.5 NOx EMISSIONS STANDARDS
EPA TEST PROCEDURES
1973 ?40DEL VERSUS 1977 MODEL
r
00
Induction System
(outside air)
Evaporative Control System
1. 4-port canister
2. .Carbjretor-mechanical
bowl vent
3. Additional hoses, etc.
4. Auxiliary fuel trap in
bowl vent line
Air Injection System Revision
Catalyst
Underflcor
Pre-catalyst
Exhaust System Revision
Ignition System. Revision
4-Cylinder
(1)
(2)
Man
Auto
Man
Auto
.46
.46
.54
.54
5.52 5.52
6.49 6.49
6-Cylinder
(1)
(2)
Man Auto Man Auto
2.43 2.43 2.85 2.85
.46 .46
.54 .54
1.44 1.44 -1.69 1.69
.86 .86 1.01 1.01
5.98 5.98
c./o 1977 c/o 1977
41.40 41.40 48.71 48.71
1.15 1.15 1.35 1.35
10.19 10.19 11.99 11.99
7.03 7.03 57.93 57.93 68.14 68.14
(1) Est. wholesale (dealer) price
(2) Est. average (sticker) price
8-Cylinder
(1) W
Auto Auto
3.88 4.56
.46
.54
2.01 2.36
.86 1.01
1.24 1.46
97.75
82.30
2.30
10.19
201.49
115.00
97.41
2.71
11.99
237.04
-------
TABLE '<
AMERICAN MOTOR _OR?'OPATIOX
ESTIMATED FUTURE DEALER/OJSTOMER COST PENALTIES FOR
EMISSIONS HARDWARE DESIGNED TO MEET
.41 HC, 3.4 CO, 2 NDx EMISSIONS STANDARDS
(FIRST CHOICE)
1979/80 MODEL VERSUS 1973 MODEL
4-Cylinder
6-Cylinder
(1)
(2)
(1)
(2)
Man
Auto
Man
Auto
Man
Auto
Man
Auto
Ignition System
Microprocessor (spark control)
Sensors • "\
Misc. electronic cables, etc
J
58.37 58.37 68.67 68.67
34.50 34.50 40.59 40.59
*•
j*> Distributor
lion^
23.67 23.67
(9.65) (9.65)
Electronic Ignition_J 20.12 20.12
Delete EGR System (8.20) (8.20)
Delete Air Guard System
Closed Loop Fuel Control
Oxygen Sensor
Catalyst
Improved Underfloor (delete) (97.75) (97.75) (115.00) (115.00)
3-Way Catalyst 116.31 116.31 136.84 136.84
(8.20) (8.20) (9.65) (9.65)
(33.87) (33.87) (39.85)(39.85) (33.87) (33.87) (39.85)(39.35)
27.46 27.46 32.31 32.31
11.50 11.50 . 13.53 13.53
35.57 35.57 41.85 41.85 50.80 50.80 59.76 59.76
(1) Esc. wholesale fdaa3.er) price
(2) Est. average (sticker1) price
8-Cylinder
Auto Auto
58.37 68.67
34.50 40.59
92.87 109.26
-------
T.C.S. System
Ignition System
AMERICAN MC/TC: JOK-;CRATIG:-;
ESTIMATED FUTURE DEM^R/CUS'POMER COST PENALTIES FOR
EMISSIGr-S HARDWARE DESIG\ED TO MEET
.41 KG, 3.4 CO, 2 NOx EWISSIGKS STANDARDS
D CHOICE)
6-Cylinder
1979/80 MODEL VERSUS 1978 MODEL
(1)
Man
4.43
Auto
4.43
(2)
Auto
5.21 5.21
r
§
Distributor revisions
Feedback fuel controlled carburetor
Oxygen sensor
Exhaust system modifications
New 3-way catalyst
Delete
Oxidizing catalyst
EGR system
Air guard system
(1) Est. wholesale (dealer) price
(2) Est. average (sticker) price
15.53 15.53 18.27 IS.27
11.94 11.94 14.05 14.05
1.15 1.15 1.35 1.35
116.31 116.31 136.84 136.84
(97.75) (97.75) (115.00)(115.00)
( 3.20) ( 8.20) ( 9.65)( 9.65)
(33.87) (33.87) ( 39.85)( 39.85)
9.54 9.54 11.22 11.22
-------
T.C.S. System
Ignition System
TAliL?
AMERICAN y£»TC:
V-o
ESTIMATED FUTURE DEALER/CCSTCi-IER COST PrTiAUTIES FOR
EMISSIONS HARIKARE DEGIGreD TO XEET
.41 HC, 3.4 CO, 2 XCX EMISSIC-MS STANDARDS
{THIRD CHOICE)
1979/80 MDDEL VERSUS 1973 MODEL
6-Cylinder
(1)
Mar. Auto
4.43 4.43
(2)
Man Auto
5.21 5.21
Distributor revisions
Revised air guard
Feedback fuel controlled carburetor
Oxygen sensor
Exhaust system modifications
Catalyst System
New 3-v,-ay catalyst with
added oxidizing catalyst
Oxidizing catalyst (delete)
Delete
EGR system
Air guard system
(1) Est. wholesale (dealer) price
J2) Est^ average (sticker) price
29.62 29.62
15.53 15.53
11.94 11.94
1.15 1.15
34.85 34.35
18.27 18.27
14.05 14.05
1.35 1.35
172.50 172.50 202.94 202.94
(97.75) (97.75) (115.00)(115.00)
( 8.20) ( 3.20) ( 9.65) ( 9.65)
(33.87) (33.87) ( 39.85)( 39.85)
95.35 95.35
112.17 112.17
-------
•"•-7
TABLi^o
AMERICAN MOTORS CORPORATION
ESTIMATED FUTURE DEALEVCUSTQMER COST PENALTIES FOR
EMISSIONS HARDv&RE DESIGNED TO MEET
.41 HC, 3.4 CO, 1 NOx EMISSIONS STANDARDS
1981 MODEL VERSUS 1979/80 MODEL (FIRST CHOICE)
4-CYLINDER
6-CYLINDER
(1)
(2)
(1)
1. Feedback Fuel Control Carburetor
(includes oxygen sensor, etc.)
2. Oxygen Sensor
3. New 3-way Catalyst
(delete present)
Exhaust System Modifications
Other sensors for distributor central
digital microprocessor control
Distributor revisions to provide for
No. 5 above
Inproved air cleaner and carburetor
sealing
Programmed air injection
(new microprocessor and other)
Delete microprocessor
(1) Est. wholesale (dealer) price
(2) Est. average (sticker) price
£ 4.
5.
6.
7.
8.
Man Auto Man Auto
(2)
1.15 1.15 1.35 1.35
57.50 57.50 67.65 67.65
36.80 36.80 43.29 43.29
17.69 17.69 20.81 20.81
Not on 4-cylinder engine
Man Auto Man Auto
115.87 115.87 136.32 136.32
172.50 172.50 202.94 202.94
(97.75) (97.75) (115.00)(115.00)
1.15 1.15 1.35 1.35
6.19 6.19 7.28 7.28
2.30 2.30 2.71 2.71
17.69 17.69 20.81 20.81
29.62 29.62 34.85 34.85
63.25 63.25 74.41 74.41
(57.50) (57.50) (67.65) (67.65)
113.14 113.14 173.10 133.10 253.12 253.12 293.02 298.02
-------
V-8
TABJb;? 7
AMERICAN J-ETORS CCPPORATION
ESTIMATED FUTURE DEALE.VOJSTOMER COST PENALTIES FOR
EMISSIONS HARDWARE DESIGNED TO MEET
.41 HC, 3.4 CO, .4 MOx EMISSIONS STANDARDS
198X MODEL VERSUS 1981 MODEL
*•
U)
Induction System
Carboretor
Fuel Injection
Exhaust System Revisions
Ignition System Revisions
Programed EGR
Air Injection Revisions
Catalyst System Upgrading
Exhaust System Revisions
4-CYLINDER
6-CYLINDER
(1)
(2)
(1)
(2)
Man Auto Man Auto Man Auto Man Auto
(1) Est. wholesale (dealer) price
(2) Est. average (sticker) price
116.75 116.75 13-7.35 137.35
23.44 23.44 27.58 27.58
140.19 140.19 164.93 164.93
-------
V-9
TABLE 8
OPERATING COSTS - DOLLARS/50, 000 MILES
1978 (1977 1981
1973 1978 Calif. Stds.) 1979/80 198X
Fuel Costs
6-cyl. compact
3500 Ib I. W.
$1190 $1711 $1912
$1800 $2167 $2500
$1625
$1912'
$ 223. 02 $ 184. 15 $ 184. 15
$ 182.77
$ 258.69 .$ 209. 90 $ 209.90
$ 209.90
$1807.77
$2121.90
NA
V-8 full size
4500 Ib I. W.
Maintenance Costs
6-cyl. compact
oil, filter, coolant &
emission control system
Total
V-8 full size
oil, filter, coolant &
emission control system
Total
Total of itemized operating
costs --
6-cyl. compact: $1413. 02 $1895. 15 $2096.15
V-8 full size $2058.69 $2376.90 $2709.90
*compact car @ 4000 Ib I. W.
Assumed fuel costs $. 65/gal. ($. 45/gal. in 1973)
Assumed MPG
1973 - from previous 1975 year AM report.
1978 - Use 1977 EPA labeling data (combined MPG) - 6-cyl. compact 19 MPG
V-8 full size 15 MPG
1978 49-state with California standards - same as 1978 California systems
1977 EPA California labeling data (combined MPG) 6-cyl. compact 17 MPG
V-8 full size 13 MPG
NA
NA
1979/80 - based on 1980 legislated fleet requirement of 20 MPG -
1981 ?; 198X - not available
i
All costs based on 1976 dollars.
6 cyl. compact 30 MPG
V-8 compact 17 MPG
4-44
-------
V-10
TABLE 9
MAINTENANCE COSTS (Dollars/50, 000 Miles)
(Not including catalytic converters)
1978 (1)
1978 (1) (California '77 Stds. ) 1979-80 (2)
Parts Labor Total Parts Labor Total Parts Labor Total
6-Cyl. $126. 19 $ 57. 96 $134. 15 $126. 19 $ 57. 96 $184. 15 $126. 19 $ 56. 58 $182. 77
V-8 $140.90 $ 69.00 $209.90 $140.90 $ 69.00 $209-90 $140.90 $ 69.00 $209.90
Maintenance schedules and costs for 1979-80 arc estimates.
Maintenance schedules and costs for 1981 and 198X are not available.
(1) See 50, 000 mile maintenance schedule on page 11
(2) See 50, 000 mile maintenance schedules on pages 12 and 13.
Cost indicated are owner costs.
4-45
-------
V-ll
TABLE 10
CATALYTIC CONVERTER MAINTENANCE
1978 Model Year - no maintenance required for first 50, 000 miles.
1978 Model Year (1977 California standards) - no maintenance planned for
first 50, 000 miles.
1979-80 - No maintenance planned for first 50, 000 miles.
1981 - 198X - No maintenance information available.
CATALYTIC CONVERTER MAINTENANCE (If Required)
1978 Model Year 1.5HC, 15 CO, I NOx
pellet change, single converter 6-cyl. & 8-cyl.
1978 Model Year . 41 HC, 9 CO, 1-1/2 NOx
pellet change 6-cyl. 1 converter, V-8 2 converters
new warm up converter 6-cyl. 1 converter, V-8 2 converters
1979-80 Model Years .41 HC, 3. 4 CO, 2 NOx
pellet change single converter 6-cyl. 8* 8-cyl.
1978 (.41,9,1-1/2)
1978 6-cyl. V-8 1979-1980
pellet cost $72.75 $72.75 $145.50 $72.75
pre-converter cost -- $113.50 $227.00
labor cost $ 8. 28 $ 16. 56 $ 22. 09 $ 8. 28
Total $81.03 $202.81 $394.59 $81.03
Costs indicated are owner costs.
4-46
-------
Attachment Cost-2
GM Cost Information
from GM Status Report
4-47
-------
XI-1
XI. COST
Listed below are costs to the consumer estimates applicable
to the emission control systems described in previous sections
of this report. It should be recognized that most of the
hardware components contained in these systems are still in
the development stage and there are no manufacturing plans
or volumes available upon which to base a formal cost esti-
mate. Therefore, these cost estimates represent our best
estimates as to the effect on vehicle prices, under these
limitations. It must be recognized, however, that since
development work is still in progress, significant variances
between this estimate and the ultimate cost can occur.
First Cost
Advanced GM Exhaust Emission Control System
Estimated Cost to the Consumer
Over Current 1977 Systems
Cost to the Consumer
•' - '-$
Air Injection Reactor 25
Three-Way Converter Closed Loop System 70 - 110
Dual Converter System 190 - 230
It should be noted that the three-way converter and dual
converter systems comprehend the usage of rhodium as a
catalytic agent. Our estimates attempt to allow for various
price and usage requirements of both rhodium and platinum.
This is mainly the reason for the cost ranges associated
with these systems. Due to the many ramifications of the
rhodium situation supply and price (as previously discussed
in this report) even this wide range is tenuous.
4-48
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XI-2
Maintenance Cost
At this time, it has not been determined what additional
maintenance would be required. However, it is likely that
the oxygen sensor will have to be replaced two or three times
within the 50,000 mile limitation at an estimated additional
cost of $15-$20 per replacement. As yet, GM has not demon-
strated the durability of the three-way converter over the
required 50,000 miles. In view of the aforementioned
rhodium complexity, the bead replacement cost of the three-
way catalyst is estimated to be in the area of $60-$100.
4-49
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FE-1078
Environmental Activities Staff
General Motors Corporation
General Motors Technical Center
Warren. Michigan 48090
March 15, 1977
John P. DeKany, Director
Emission Control Technology Division
Environmental Protection Agency
2565 Plymouth Road
Ann Arbor, Michigan 48105
Dear Mr. DeKany:
This letter is in reply to your request for additional comments on
emission control system component costs. Our comments are in the form
of a review of pp. 4-17 to 4-21 from your report to the Administrator,
"Automobile Emission Control—The Current Status and Development Trends
As of March 1976." These comments are provided 1n addition to our
previous submissions FE-1047 (February 10, 1977) and FE-1055 (February 18,
1977), responding to questions you and your staff-raised regarding our
1976 emission control progress report.
If I can be of further assistance, please call me at 575-1259.
Gerald J. Barnes
Automotive Emission Control
GJB/rmn/th/158
Attachment
4^50
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General Motors Comments on EPA Cost Analysis
Statement on Page 4-17 - "Unfortunately, as has been the
case in the past, the responses on cost from most manufacturers
were not wholly responsive to the request from EPA on cost
information. Some manufacturers submitted nothing, most
submitted inadequately substantiated information ..."
Comment
The EPA cost request involved a level of detail that was not
available. For instance, the Corporation is developing a
Closed Loop control 3-way catalyst system. This is still in
the development state and the cost estimates available are
"best guess" only and are not based on formal cost estimating
procedures. At this point, it would be meaningless to try
to estimate what emission control devices would go on our
various product lines and to report the fraction of each
product line that require specific devices at various emission
control levels.
Any GM speculation as to the equipment and cost tailored to
our product lines would indicate a level of sophistication
that does not exist for this technology at this time.
Table 4-12
This table depicts a methodology for estimating emission
control hardware costs based on ratios of various elements
of consumer cost. That this methodology should be developed
is understandable in light of the EPA's need for cost
estimates to perform economic impact studies. However, the
data generated by this methodology can differ significantly
from manufacturer's estimates, 'and when studies are published,
4-51
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-2-
based on these estimates, they should be highly qualified.
For instance, the methodology used to estimate cost of a
catalytic converter would not necessarily be valid for
air/fuel ratio control systems.
Table 4-13
This is a listing of emission control hardware cost to the
consumer estimates. This listing reflects a range of manu-
facturers estimates and EPA estimates.
General Motors estimated consumer costs, where available,
are generally at the lower bound of the manufacturer's cost
ranges.
It is difficult to understand why some of the EPA estimates
reflect an upper range estimate lower than the bottom of the
manufacturer's range. Perhaps one reason might be the fact
that the manufacturer's estimates reflect associated com-
ponent costs. For example, GM estimates the Air Injection
Reactor System at $25 cost to the consumer. EPA's estimate
is $10-$20. It is conceivable that the difference is the
$6-$8 estimated mounting provision and plumbing included by
GM. If we were estimating an air pump only, we would be in
agreement with EPA.
Statement on Page 4-21 - "It is probably most appropriate to
allocate to emission control a dollar figure near to the
lower bound cost estimates, and to allocate to fuel economy
improvements the difference between the higher and lower
cost elements."
4-52
-------
-3-
Comment
The purpose of this segregation is not clear. None of the
emission control devices on our vehicles are installed to
improve fuel economy. They are there to control exhaust
emissions. Any device that improves fuel economy over a
less costly device is merely attempting to restore the
economy and driveability that is lost due to emission regula-
tions. For example, the catalytic converter treats the
exhaust gases outside of the engine and allows for engine
adjustments to maximize fuel economy at a given regulatory
level, but to call a catalytic converter a fuel economy
device is misleading. If it were not for the need to control
pollutants, a catalytic converter would not be installed on
a vehicle.
GJB/rmn/th/025
3/15/77
4-53
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SECTION 5
DRIVEABILITY
EPA has become more interested in the subject of vehicle driveability
because the poor in-use emission performance of vehicles may be due, in
large part, to maladjustments that were made in order to attempt to
improve inadequate driveability performance.
The relationship between emission control, driveability, and fuel
economy is expected to become an even more important concern as emission
standards and fuel economy standards become more stringent.
It is expected that it will be a difficult technical job to provide
vehicles with acceptable emissions, fuel economy, and driveability
performance. Obtaining a satisfactory rating in more than one vehicle
characteristic, for example emissions and driveability, as opposed to
just emissions, is expected to require more effort and possibly require
more sophisticated, complex, and costly technology.
Obtaining acceptable emissions, fuel economy, and driveability is
expected to require a significant amount of effort beyond just that for
obtaining acceptable emissions and fuel economy. Besides emissions/
fuel economy considerations, emissions/driveability, and fuel economy/
driveability relationships must be developed and considered. The level
of effort required cannot be precisely determined, but it could be as
large as that expended on emissions or fuel economy. Because standards
exist for emissions and fuel economy, and not for driveability, it is
possible that efforts concentrated on attaining acceptable driveability
might be sacrificed in order to meet the requirements for emissions and
fuel economy.
If the driveability of future vehicles is a problem, in-use driveability-
induced maladjustments could negate the improvements in emissions and
-------
fuel economy that might be indicated by compliance testing. For that
reason, this report includes a basic discussion of issues related to
vehicle driveability.
Driveability is one of the performance characteristics of a vehicle. As
used here, driveability is a subject separate from the quantification of
vehicle performance that deals with acceleration performance and handling.
In general, the evaluation of vehicle driveability involves an assessment
of how well the vehicle responds to inputs from the driver. More speci-
fically it concerns the degree to which the powertrain responds to the
operator's instructions to deliver prompt, reliable, engine starts;
smooth, responsive acceleration and cruise performance; and freedom from
misfire, backfire, and other harsh operation. Figures Driveability-1*
and -2* describe the common driveability problems.
The automotive industry has long been concerned with driveablity and has
historically devoted considerable attention to optimizing the driveability
of their products for all operating situations and ambient conditions.
The industry evaluates driveability by subjecting a vehicle to a series
of tests that are designed to bring out any faults or problems. These
tests include both cold start and hot start tests along with a wide
assortment of acceleration and cruise conditions. These test procedures
are designed by persons who are familiar with the common 'driveability
weaknesses and who understand the underlying technical mechanisms behind
them. As a result, the testing effectively surfaces any latent problems.
Driveability problems can range in importance from items that are only
mildly annoying such as a trace hesitation to such potentially hazardous
conditions such as an engine stall when the vehicle is moving. To
account for the varying significance of these conditions the manufacturers
have devised complicated rating formulas that take into account both the
nature and severity of the problems. The resultant rating is believed
* Advanced Emission Control Program Status Report to the U.S. Environ-
mental Protection Agency, Nissan Motor Co., Ltd., December 1976, pages
A-2 and A-3.
5-2
-------
Figure Driveability-1
No.
1
2
3
'
Item
Surge
Hesitation
«•
Stumble
Definition
A continued condition of short, sharp
fluctuations
•o
0)
0)
0.
0)
1-1
o
•s
>
in power;
o) Surge^^ >£,
Surge p, 7^^^
./
V"
•3 s\
*' - " _. ..X \
Normal > Normal
Time — Time — —
A temporary lack of initial response in
acceleration
•o
opened //"
Hesitation
Time — —
A short, sharp reduction in acceleration rate.
•
.
1'
-------
Figure Driyealjility-2
No.
4
5
6
7
8
9
10
11
Item
Stretchness
Backfire
Afterf ire
Idle Quality
Startability
Deceleration
Performance
Run on
Stall
Definition
A lack of
movement.
-a
4)
anticipated response to throttle
Normal ^^.
Stretchness
Time — —
•
An audible explosion in the intake system.
An audible explosion in the exhaust system.
A driver evaluation of : the- smoothness-: of -"the
engine idle.
Start easiness.
. An ability of the engine
torque .
to produce negative
A condition where the engine continued to run
after the ignition key off.
Any occation during the test on which the
engine stops with. the ignition'switched onl;
Repeated stalls while starting the engine
are not considered as stall.
5-4
-------
to be an accurate measure of the average driver's overall impression of
the vehicle driveability quality. Manufacturers generally have a
minimum acceptable score for driveability which must be demonstrated by
prototype vehicles before the manufacturers consider them to be marketed.
Ford, for example, reduces their rating to a score that lies between
zero and ten.
As indicated earlier, EPA's interest in driveability stems from the
suspected role it plays in in-use vehicle emission performance. The
Restorative Maintenance (RM) and Emission Factors (EF) test programs
have shown that vehicle maladjustment is a major underlying cause of
excessive in-use vehicle emissions. The nature and frequency of the
maladjustments found in the RM and EF programs tend to fit a pattern
which suggests that, rather than the random result of sloppy mainten-
ance, these maladjustments were performed with an objective in mind.
Two conceivable objectives are the improvement of fuel economy and the
improvement of driveability. The net effect of these types of malad-
justments has been a negative influence upon fuel economy. However,
many of these changes can tend to have a positive effect upon driveability.
Some recent testing performed at the Sun Company Laboratories in Marcus
Hook, Pennsylvania illustrates the magnitude of the effect that these
maladjustments can have on a vehicle's driveability. The Coordinating
Research Council (CRC) Cold Start Driveability Test was performed on a
1975 automobile in two states of tune. The first state corresponded to
the factory correct condition with all engine adjustments conforming to
the manufacturers specifications and with all emission control components
operative. The second state was a maladjusted state, considered to be
one that is within the capability of the service industry to perform.
The CRC Cold Start Driveability Test uses a demerit rating system which
penalizes the car for objectionable performance. The higher the demerit
rating, the worse the driveability. In the factory correct condition
the vehicle scored 259 demerits. In the maladjusted state the vehicle
5-5
-------
scored only 72 demerits. Ratings are subjective but normally 200 demerits
or more is considered very poor and 100 demerits or less is considered
good. No emission testing was performed on this car but based on the
types of maladjustments and their effect on emissions, it is reasonable
to conclude that the vehicle would have exceeded the required emission
levels in the maladjusted state.
The Coordinating Research Council performs periodic driveability testing
on current model year vehicles. Figure Driveability-3* compares the
driveability of representative samples of 1968, 1969, and 1973 cars.
Because of the influence of fuel volatility, this figure compares the
driveability for fuels with equivalent volatility ratings. It can be
seen from this study that vehicle driveability experienced a significant
decline between 1969 and 1973. Figure Driveability-4** compares the
driveability of five matched pairs of 1973 and 1975 cars and shows that
the average driveability tended to remain at about the same level
between these years. No driveability test results have been released by
CRC for the 1976 or 1977 model year vehicles but there have been indica-
tions that driveability has improved to some degree. If this is true,
it may be due to the fact that the manufacturers have had several years
at virtually constant emission levels and this may have allowed them to
better optimize driveability. However, the future outlook is for
significantly reduced emission'levels. If these reductions are not
accomplished in a skillfull manner that emphasizes good driveability,
further deteriorations in vehicle driveability may occur. These in turn
may result in increased incidences of maladjustment in in-use vehicles.
* "1972 CRC Intermediate Temperature Driveability Program - Pasco
Robles", Prepared by the Coordinating Research Council, December 1975,
page 37, (CRC Report No. 483).
** "Driveability Performance of 1975 Passenger Cars at Intermediate
Ambient Temperatures - Pasco Robes", Prepared by the Coordinating
Research Council, December 1975, page 37, (CRC Report No. 486).
5-6
-------
Figure Driveability-3
AVERAGE PERFORMANCE of 1973 and 1968-69 MODEL
CARS at 40-50° F on SAME DRIVING
SCHEDULE and DEMERIT SCALE
250
200
H
5
UJ
UJ
°150
UJ
UJ
S
P. 100
0 TEN 1973 PRODUCTION MODELS
+ TEN 1968-69 MODELS, ALL FUELS
X FIVE 1969 MODELS, BASE FUELS
•• -1973
1968-69
SO
80 90 100 110 120 130 140 150 160 170 180 190 200 210 210
VOLATILITY PARAMETER
5-7
-------
Figure Driveability-4
COMPARI SON OF 1975 AND 1973 MATCHED CARS (60-70° F)
300
co
£ 25°
-------
Fuel metering plays the largest single role in determining vehicle
driveability and an analysis of its influence upon emission control can
shed light on the typical conflicts and compromises that frequently
occur. To perform smoothly and responsively, each engine cylinder must
continuously receive a fuel-air mixture that is both readily combustible
and correctly constituted for the power demands placed upon the engine
at that moment. This requires that the fuel metering system adapt to
rapidly changing power demands, mass flow rates and engine temperatures.
Unfortunately, the conventional carburetion and manifold systems currently
used on most engines have a difficult time metering and distributing the
fuel with sufficient control accuracy. This results in wide swings in
the air-fuel ratios being received by the individual cylinders. These
swings can result in poor driveability. Spark ignition engines are
particularly sensitive to lean excursions which can produce misfire,
hesitation, stumble, and stalling. To counteract this, it was formerly
a common practice for manufacturers to richen up the air-fuel ratio
adjustments enough so that even during the leanest excursion encountered,
the leanest cylinder in the engine would still be rich enough to avoid
misfire, hesitation, etc. This practice of operating in a relatively
rich regime, however, resulted in emission and fuel economy drawbacks.
Most manufacturers responded to emission control requirements by leaning
out the carburetor air-fuel ratios. For the most part this enleanment
was not accompanied by any significant measures to improve the metering
and distribution characteristics, which might have served to offset the
negative impact on driveability.
Another important fuel metering characteristic that has had a negative
influence on driveability is cold start enrichment. Conventional
carburetion and induction systems do not vaporize fuel very effectively
under cold start conditions. To make up for this, conventional carburetors
employ chokes to add extra fuel. Because of the adverse effect of this
extra fuel on emissions, the manufacturers have both leaned out the
choke calibrations and reduced the time duration of the choke assisted
5-9
-------
period following cold start. This has been offset to some degree by
quick heat intake manifolds and other aids to improve fuel vaporization
but the impact upon driveability has until very recently been generally
negative in spite of these measures.
Another item that has contributed significantly to degraded driveability
is poorly tailored EGR. EGR works as an effective NOx suppressant by
reducing peak combustion temperatures. NOx is produced by the engine at
a rate that is dependent upon engine load. This means that to be most
efficient in reducing NOx, the EGR flow rate should also be somewhat
proportional to engine load. Fortunately, the engine's tolerance of EGR
also tends to increase with load so that driveability is not necessarily
affected by EGR when it is added at an efficient rate for NOx suppression.
Many EGR systems, however, do not accurately tailor the EGR to be propor-
tional to engine load. These systems often provide too much EGR at low
engine loads and too little at high loads. This can cause excessive
charge dilution and driveability problems. Some manufacturers are
making progress in this area with, for example, the use of back-pressure
modulated EGR systems which are more closely proportional.
Some other important contributors to poor driveability are retarded
spark, positive crankcase ventilation, lowered compression ratio, and
lower volatility fuel. The first three of these have been evidenced
for several years and are fairly obvious in their cause and effect. The
last, lower volatility fuel, is a recently reported condition which
merits some discussion. As the demand for unleaded fuel rises, the
petroleum industry is increasingly strained to meet the required volume
while maintaining satisfactory octane ratings and volatility specifica-
tions. The octane problem is well known. The volatility problem has
more recently come to EPA's attention. As was shown in Figure Drive-
ability-3, volatility has a strong effect upon driveability. Spark
ignition engines require a fuel which is well tailored to their starting
and operating needs. This means that the fuel distillation curve should
provide for sufficient vaporization of fuel at temperatures corresponding
5-10
-------
to cold start and normal operation without providing too much vapori-
zation, which could lead to vapor lock and/or excessive evaporative
emissions. This is accomplished by blending techniques which bring
together many different hydrocarbon species. The distillation curve of
the final blend satisfies the engine's varying needs reasonably well.
The correct blend differs according to the ambient temperature, e.g., a
winter blend needs a larger fraction of the high volatility components.
There have been recent indications that the petroleum industry is having
difficulty in supplying sufficient amounts of the high volatility consti-
tuents for unleaded fuels. This has reportedly caused some degradation
in the cold starting performance of these fuels. This problem can be
attacked either through blending or refining changes by the oil industry,
or through engine/fuel metering modifications by the auto manufacturers.
An interesting related matter is the comparative volatility character-
istics of the average gasolines in the field versus those of the official
Certification fuel, Indolene Clear. Recent studies* have shown that
typical field gasolines are less volatile than Indolene Clear and,
hence, could be expected to result in generally poorer driveability
performance. This is a matter of concern because the manufacturers
develop and calibrate their vehicles for emissions to a large extent
with the use of Indolene Clear in mind. Driveability problems, such as
stalls, can increase emissions during the official EPA emission test.
If vehicles are performing acceptably on the emission test, partially
because of the superior fuel, they may have more driveability problems
in the field with pump fuel.
The quantitative relationships between driveability and emission control
were discussed in a Ford submission** to EPA. In this submission Ford
* Bartlesville Energy Research Center (BERC) Survey,"BERC/PPS-76/1 Motor
Gasoline, Summer 1975"by Ella Shelton published January 1976. Motor
Vehicle Manufacturers Association (MVMA) National Fuel Survey, Fall
Season, January 15, 1976.
**'"Application for Suspension of 1977 Motor Vehicle Exhaust Emission
Standards," Submitted to EPA by Ford Motor Company, January 1975, Vol. 2,
Appendix 3B.
5-11
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reported that it employs "driveability trade-off factors" in determining
their emission control capability. These factors were developed from
vehicle test data for 1975 vehicle systems. The factors are as follows:
+0.5 drive number = +0.1 HC, +2 CO, + 0.1 NOx
-0.5 drive number = -0.1 HC, -2 CO, -0.1 NOx
Ford's driveability rating is scored on a scale of 0 to 10. The above
relationships between driveability and emissions are based upon a specific
emission control technology, i.e., oxidation catalyst, AIR, EGR, etc.
Different technologies will have different emissions/driveability
relationships.
5-12
-------
SECTION 6
UNREGULATED EMISSIONS
Introduction
As hydrocarbon, carbon monoxide, and nitrogen oxide emissions are
controlled, various unregulated emissions may be altered. Introduction
of a new emission control system can increase or decrease the level of a
particular unregulated pollutant or, in extreme cases, result in formation
of entirely new pollutants. It is important that these pollutants be
characterized to be certain that control of regulated emissions creates
no problems in other areas.
The unregulated pollutants discussed in this section are sulfuric acid,
hydrogen cyanide, ammonia, ruthenium, polynuclear aromatic hydrocarbons,
and Diesel particulate.
6.1. Sulfuric Acid
6.1.1. Introduction
The use of oxidation catalysts results in oxidation of both hydrocarbons
and carbon monoxide. In addition, oxidation catalysts oxidize a portion
of the sulfur dioxide in the exhaust to sulfuric acid. The sulfur
dioxide in the exhaust is formed by combustion of trace quantities of
organic sulfur compounds in gasoline to sulfur dioxide. Gasoline
contains an average sulfur level of 0.03% which is very low compared to
other fuels. As a result, sulfur dioxide emissions from gasoline-fueled
vehicles are less than 1% of the total sulfur dioxide emissions. Most
sulfur dioxide emissions come from stationary sources.
-------
The sulfur dioxide in the atmosphere is photochemically oxidized to
sulfuric acid. Even if the oxidation catalyst converted all of the
sulfur dioxide to sulfuric acid, the resultant sulfuric acid contribution
from these vehicles would be less than 1% of the total sulfuric acid in
the atmosphere.
However, it is possible to have high localized levels of sulfuric acid
along heavily traveled roads. EPA has determined that the condition of
most concern is a heavily traveled freeway with maximum traffic flow.
EPA developed a driving cycle called the Congested Freeway Driving
Schedule (the CFDS) with an average speed of 35 mph to represent this
condition. During the past year, various companies have obtained exten-
sive emission data using this cycle. Laboratory studies have also been
done to determine how different parameters (e.g. catalyst composition)
affect sulfuric acid formation. Work has also been done to measure
sulfuric acid levels along roadways and to determine vehicle sulfuric
acid emissions at higher mileages.
6.1.2. Mechanisms and Laboratory Studies
Experiments were conducted by GM, Ford, and Chrysler using laboratory
apparatus or, in some cases, engine dynamometers or vehicles, to determine
the effect of various parameters on sulfuric acid formation. The laboratory
work performed was less extensive than that conducted in previous years
when little was known about the formation of sulfuric acid over automotive
catalysts.
GM studies showed that rhodium containing catalysts produce less sulfuric
acid than those containing only platinum or palladium. This confirms
vehicle work done under an EPA contract with Exxon which showed that a
rhodium containing catalyst had unusually low sulfuric acid emissions.
6-2
-------
Ford studies on the effect of noble metal composition on sulfuric acid
formation show that it is possible to produce a. palladium catalyst that
forms less sulfuric acid than either a platinum-palladium catalyst or a
platinum-rhodium catalyst. Additional Ford work shows that a rhodium
containing catalyst also has very low sulfuric acid emissions.
Ford conducted extensive engine dynamometer tests on 24 catalysts
divided into four series (6 catalysts per series) to evaluate their
sulfuric acid emissions. The catalysts were aged 100 hours for pre-
conditioning prior to sulfuric acid testing. Catalyst light-off tem-
perature and HC/CO conversion efficiency was measured at 800°F. Sulfuric
acid measurements were made under conditions approximating 55 mph steady
state operation of vehicle. Catalysts tested included Pt/Pd, Pt/Rh
(with varying ratios of Pt/Rh), and platinum. The major finding of
these tests is that rhodium containing catalysts emit less sulfuric acid
than catalysts without rhodium. There is a marked change with catalysts
containing more than 10% rhodium, which emit far less sulfuric acid
(about 10% conversion) than catalysts with less than 10% rhodium (about
40% conversion). Ford indicated that €here is a loss in HC control with
the increased rhodium content. However, it appears that the change in
HC emissions is less than that for sulfuric acid.
Ford also conducted some laboratory studies on catalysts that had been
installed on vehicles and operated for 50,000 miles. Formation of
sulfuric acid was compared between the 50,000 mile Engelhard II B
catalysts and fresh catalysts. It was found that the aged catalysts had
much lower sulfuric acid formation depending upon factors such as
presence of reducing gases (certain HC compounds and CO), and space
velocity. Even though the aged catalysts had high activity for propane
and CO conversion, they had a two to six-fold decrease in sulfuric acid
formation versus the fresh catalysts. These results are in accord with
vehicle test data discussed later which show very low sulfuric acid
emissions from catalyst vehicles with extended mileage.
6-3
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GM conducted further experiments on the effect of temperature, space
velocity, 0_ levels, and CO levels on sulfuric acid formation. It was
found that low oxygen levels, higher CO levels, high catalyst tempera-
ture, and possibly low space velocity all lead to low sulfuric acid
formation. These results are in complete agreement with previous tests
run by GM, as well as past studies by Ford, Chrysler, other automobile
manufacturers, and EPA contractors.
GM and Ford both reported results of laboratory studies on sulfuric acid
storage. Storage of sulfuric acid occurs on fresh catalysts under most
operating conditions, resulting in low sulfuric acid emission rates.
This effect is overcome on a vehicle, generally within the first 1000
miles. After that, high temperatures result in release of sulfuric acid
(frequently as SO-) with subsequent low temperature operation permitting
storage once again. Since much of the stored sulfuric acid can be
released as SO. at the higher temperatures, sulfuric acid emissions can
be lower for systems which store significant quantities of sulfuric acid
(e.g., pelleted catalyst systems). Again, this recent work agrees well
with earlier work done by the automotive companies and EPA.
Ford reported some laboratory test results on both fresh and aged 3-way
catalysts. The results on fresh catalysts show that all three 3-way
catalysts tested (M-152C2-3, M-253, and M-257) have comparatively low
sulfuric acid formation (e.g., 40% formation) compared with a fresh
Engelhard II B oxidation catalyst under the same conditions (e.g., 80%
formation of sulfuric acid). These data indicate that some 3-way catalyst
formulations have inherently lower sulfuric acid formation than conventional
oxidation catalysts independent of other conditions (i.e., 0_ level).
Dynamometer-aged 3-way catalysts were also evaluated in the laboratory
reactor apparatus. Three-way catalyst samples aged for 470 hours showed
about 10% sulfuric acid formation in a laboratory reactor compared with
about 50% sulfuric acid formation for fresh catalyst samples.
6-4
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Chrysler did some limited studies using a vehicle (Car 685) to investi-
gate the effect of CO and 0- levels on sulfuric acid formation. Chrysler
modified the exhaust system of this car to allow injection of known
quantities of CO and CL. Sulfuric acid emissions were measured at 40
mph steady state conditions. The results of this work agree with earlier
work showing that oxygen levels of 1% or less result in low sulfuric
acid emissions (e.g., 1 mg/mi) while higher oxygen levels of 2% or more
result in increased sulfuric acid emissions (e.g., 40 mg/mi or more).
Ford also did further work on how exhaust oxygen levels affect sulfuric
acid emissions. A Pinto was equipped with a 3-way plus oxidation catalyst
system. A managed air injection system (with a flow control valve in
the secondary air flow upstream of the oxidation catalyst) was used to
give variable amounts of oxygen (0.5%, 1%, 2%, and 5%). Complete test
results are not available yet. Preliminary results suggest that lower
oxygen levels result in lower sulfuric acid levels, but perhaps at the
expense of some CO control.
Nissan has also done some engine dynamometer work on sulfuric acid using
a 4 cylinder Datsun engine with either a pelleted or monolithic catalyst.
This work shows a sharp increase in sulfuric acid emissions when the
air-fuel ratio increases from 14.5 to 15.5 but only a moderate increase
in sulfuric acid when the air-fuel ratio is increased further. This work
also shows that monoliths and pellets emit the same quantity of sulfuric
acid at temperatures over 600°C. Below this temperature, the monoliths
tested by Nissan emitted more sulfuric acid presumably due to lower
storage capacity. The Nissan work also shows lower sulfuric acid
emissions from rhodium or barium (a stabilizer used in the substrate)
containing catalysts. Additional work by Nissan shows sulfuric acid
emissions to be greater for catalysts with more noble metal dispersed
near the surface.
6-5
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6.1.3. Sulfuric Acid Emission Data - Current Vehicles
GM tested seven of the 1975-76 vehicles used in their Sulfuric Acid
Dispersion Experiment. These vehicles were tested on a driving schedule
similar to the driving experienced around the GM Proving Ground track
during the Sulfuric Acid Dispersion Experiment. This test cycle took
two hours to complete with sulfuric acid measurements being taken every
half hour (i.e., four measurements over two hours). The fuels used
contained 0.032 wt % sulfur. The vehicles were tested at both the GM
Proving Ground and Research Labs. The last sulfuric acid measurement
for each vehicle is listed in the table below:
Table 6-1
Sulfuric Acid Emissions from
Dispersion Experiment Cars
Car Lab* Sulfuric Acid (mg/mi)
'75 302 Ford (Federal) GM PG 31.8
GM RL 41.1
'76 302 Ford (Federal) GM PG 73.8
GM RL 61.0
'75 Chevrolet (Federal) GM PG 14.4
GM RL 14.0
'75 Chevrolet (California) GM PG 69.6
GM RL 94.0
'75 Chevrolet (California) GM PG 73.9
GM RL ,98.8
'75 318 Chrysler (California)GM PG 84.6
GM RL 78.2
'76 Pontiac GM PG 32.7
GM RL 55.1
* Proving Ground = PG
Research Labs = RL
These tests showed an overall sulfuric acid emission rate of 51 mg/mi
which compares with the 37 mg/mi emission rate calculated for the entire
352 car fleet used for the Sulfuric Acid Dispersion Experiment. There is
reasonably good agreement between the two laboratories.
6-6
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GM also measured sulfuric acid emissions from 12 other 1975-76 production
vehicles, using the Congested Freeway Driving Schedule (CFDS). It is
assumed that 0.032 wt % sulfur fuel was used. These test results are
shown in the table that follows.
Table 6-2
Sulfuric Acid Emissions from
GM Production Cars
Car Emission Control System Sulfuric Acid (mg/mi)
'75 Cadillac California AIR 79
'75 Oldsmobile California no AIR 17
'75 Nova California AIR 136
'75 Vega California AIR 18
175 Vega Federal pulsed AIR 1
'76 302 Ford Federal AIR 58
'76 Cutlass California no AIR* 17
'76 Cutlass Federal no AIR 2
'76 Cutlass California no AIR 2
.'76 Cutlass California AIR 44
'76 Nova Federal no AIR 0.3
'76 Nova Federal no AIR 0.3
*3.6% exhaust 0~ for this car; 0- not measured for other cars
These test results show that cars with air injection and presumably high
exhaust oxygen levels have high sulfuric acid emissions while cars
without air pumps and presumably low exhaust oxygen levels have much
lower sulfuric acid emissions. Unfortunately, GM did not measure oxygen
levels from these cars which would be useful in interpreting these
results. Also, GM did not report the mileage of these vehicles.
Ford has measured sulfuric acid emissions from two 1976 Ford LTDs, a
California version and a Federal version, both with the 400 CID engine.
Ford not only obtained emission data on these cars but also investigated
the effects of spark timing, EGR, oxygen concentration, and catalyst
composition on sulfuric acid formation.
6-7
-------
With the Federal car, Ford found high sulfuric acid emissions (about 50-
60 rag/mi) with oxygen levels from 1% to 5%. Under 1% oxygen, the sulfuric
acid emission levels decreased dramatically to under 20 mg/mi (as low as
about 5 mg/mi in one test with about 0.3% oxygen). However, sulfuric
acid emissions were under 10 mg/mi on this car over the CFDS with oxygen
levels anywhere from 1.5% to 6.5%. It is unusual to see significantly
higher sulfuric acid emissions at a steady state speed than over the
CFDS. Other work conducted by EPA, GM, Exxon, Southwest Research Institute,
and Chrysler did not indicate this phenomenon. Perhaps the higher
sulfuric acid emissions are due to lower "spikes" of reducing gases such
as HC and CO over a steady state mode versus a transient driving cycle.
It could be that the particular Ford tested was more sensitive to such a
phenomenon than other vehicles. It could also be that the immediate
preconditioning before the CFDS resulted in purging of stored sulfuric
acid with subsequent storage over the CFDS. It was found that changing
the spark timing (from 6° to 16° BTDC) and plugging the EGR did not
affect sulfuric acid over the CFDS.
Ford investigated the effect of using Pt/Pd, Pt/Rh, or Pd catalysts all
with the same substrate on both the California and Federal cars. Tests
of these catalysts on the Federal and California vehicle showed the
following results.
Table 6-3
Sulfuric Acid Emissions of Different Catalysts
Vehicle Catalyst Driving Cycle Sulfuric Acid (mg/mi)
Ford - Federal Pt/Pd 45 mph 70
28
10
10
10
8
28-40
25
42
6-8
Catalyst
:ral Pt/Pd
Pt/Rh
Pd
Pt/Pd
Pt/Rh
Pd
.fornia Pt/Pd
Pt/Rh
Pd
Driving Cycle Su!
45 mph
45 mph
45 mph
CFDS
CFDS
CFDS
CFDS
CFDS
CFDS
-------
These results show that Pt/Rh catalysts do no always give lower sulfuric
acid emissions than other catalysts.
Ford also ran tests comparing different versions of the CFDS denoted as
SET 7 and SET 7D. The SET 7 had more small speed fluctuations (called
"noise") than the SET 7D. The SET 7 is extremely difficult if not
impossible for the driver to follow all the time while the SET 7D has
the "noise" modified by removing those parts difficult for the driver to
follow. Furthermore, the present requirements outlining allowable
driver tolerances for the FTP (- 2 mph within 1 sec) resulted in the
earlier SET (the one with high "noise") having different drivers following
the CFDS in different ways. That is, a driver could either follow or
not follow the "noise" and still have a valid CFDS. Since the "noise"
was difficult to follow, many drivers would not follow it. The modified
CFDS (SET 7D) is easy enough for the average driver to follow the "noise"
so that most cycles would be driven the same. Ford ran a total of about
6 SET 7 and SET 70s on a 1976 Calfornia Ford. Both cycles gave about 50
rag/mi sulfuric acid emissions with the SET 7D being about 18% lower than
the SET 7. These results are in general agreement with those obtained by
EPA even though the Ford results show greater differences. Extensive
EPA tests (both in-house and at Southwest Research) on about 20 repetitions
of the CFDS (both without any noise whatsoever, a precursor of SET 7,
and SET 7D) show the SET 7D to have about 15% lower sulfuric acid emissions,
Chrysler ran sulfuric acid tests on two 1976 production vehicles. The
first car (Car 176, a Dodge Coronet equipped with a 318 CID engine, a
90 cu in. catalyst, and an air pump) showed very high sulfuric acid
emission (82 mg/mi) over the CFDS. The second vehicle (Car 155, a Dodge
Dart equipped with a 225 CID engine, a 90 cu in. catalyst, and an air
pump) showed much lower sulfuric acid emissions (9.4 mg/mi) over the
CFDS.
Most of the test results on prototype cars are somewhat higher than
those found in the EPA baseline study. This study involved sulfuric
6-9
-------
acid testing of 78 current and future prototype cars. These tests
showed catalyst cars without air injection to emit about 10 rag/mi
sulfuric acid while catalyst cars with air injection emitted about 20
rag/mi sulfuric acid.
6.1.4. Decrease in Sulfuric Acid Emissions with Extended Mileage
Very extensive sulfuric acid emission data have been taken on oxidation
catalyst vehicles at low mileages. The bulk of these data were taken in
1975 and summarized in the EPA Status Report on Sulfate Emission Control
Technology as well as the EPA Report on the Baseline Study. In the
Baseline Study, about 60 vehicles were tested for sulfuric acid emissions.
However, almost no sulfuric acid data have been taken on vehicles at
extended mileage. EPA funded a major contract with Southwest Research
Institute to measure sulfuric acid emissions on four catalyst vehicles
as they accumulated 50,000 miles. Exxon Research and Engineering funded
an in-house study to accumulate 50,000 miles on 20 cars and measure
sulfuric acid emissions at various intervals. Both studies showed a
significant decrease in sulfuric acid emissions occurring at roughly
20,000 miles. While sulfuric acid emissions can be high initially, most
of the vehicles had emissions below 10 mg/mi after the drop occurred.
As a result of this work, EPA has asked the following companies to
measure sulfuric acid emissions about every 5,000 miles on certain
vehicles as they accumulate AMA type mileage.
Manufacturer Number of Vehicles to be Tested
GM 12 cars
Ford 8
Chrysler 6
AMC 2
Toyota 2
Datsun ' 2
VW 2
6-10
-------
These cars would probably come from existing fleets accumulating mileage
(e.g., precertification fleet) to keep the cost of such a program at a
lower level. The manufacturers have indicated their willingness to
participate in this program and to have these tests completed by the end of
1977.
Aside from this program, both GM and Ford have reported current data on
sulfuric acid emissions of cars at higher mileages.
GM is testing six vehicles (1975 Impalas) in a GM transportation pool as
they accumulate mileage. Four of these cars were designed to meet the
1976 California standards while the other two cars are Federal cars.
The cars currently have from 5,000 to 15,000 miles. The results to date
are given in the table that follows for the CFDS and 60 mph cruise.
6-11
-------
Table 6-4
GM Sulfuric Acid Tests of
Car
R5947
(Federal)
R5949
(California)
R5951
(California)
R5948
(Federal)
R5950
(California)
R5952
(California)
Transportation Pool Cars
Mileage Fuel Sulfur
700 0.004%
5000
600 0.004%
10000
15000
1800 0.004%
5000
1700 0.036%
5000
11000
15000
600 0.036%
5000
10000
800 0.036%
10000
15000
Sulfuric Acid
CFDS
0.3
0.4
6
1
0.8
2
0.8
4
3
2
1
108
55
15
64
36
14
Emissions (mg/mi)
60 mph
7
9
16
14
12
14
15
45
73
76
58
134
111
132
112
121
106
6-12
-------
These results show a marked degradation in sulfuric acid emissions over
the CFDS but very little degradation during 60 mph test conditions.
Additional emission testing will be done as these cars accumulate
mileage. GM did not report gaseous emissions (HC, CO, NOx) from these
cars.
Ford ran a series of sulfuric acid emission tests on some of their
50,000 mile 1977 certification cars. The following test sequence was
used with 0.03% sulfur fuel:
222 miles AMA preconditioning
LA-4 prep followed by cold soak
FTP
505 sec of LA-4
2 minutes idle
CFDS
10 minutes idle
CFDS
10 minutes idle
CFDS
10 minutes idle
CFDS
10 minutes idle
HFET
Each test was repeated on two additional days. Ford also tested three
1976 California Capri vehicles at 4,000 miles. The test results are
given as follows. All of the vehicles had Pt/Pd catalysts and are
50,000 mile vehicles unless noted otherwise.
These vehicles frequently, but not always, show low sulfuric acid
emissions at 50,000 miles. However, three of the cars had significantly
higher sulfuric acid emissions (18-108 mg/mi) than the others. Ford
points out that two of these cars also had low CO emissions, showing an
inverse relationship between CO and sulfuric acid for this system.
Ford is also measuring sulfuric acid on some of the 1978 certification
cars.
6-13
-------
Table 6-5
Ford Sulfuric Acid Test Results
on 1976-77 Cars
Vehicle
4A
5A
11A
10A
10A
10A
2 IB
8A
14A
16A
17B
14B
14B
21A
5C13*
5C15*
5C16*
Engine
Disp.
2.3 litre
2.3 litre
2.3 litre
2.3 litre
2.3 litre
2.3 litre
2.3 litre
2.8 litre
250 CID
302 CID
302 CID
400 CID
400 CID
400 CID
2.3 litre
2.3 litre
2.3 litre
Catalyst
El
MB
UOP
MB
MB
MB
El
El
UOP
UOP
UOP
El
El
El
MB
MB
MB
Sulfuric Acid
Emissions-
CFDS (mgpm)
HC
FTP Emissions
(gin/mi)
CO NOx
0.51
0.61
6.07
0.61
0.72
0.47
0.64
1.67
1.98
45.65
107.80
1.34
1.79
17.60
21.57
31.62
9.39
0.20
0.15
0.10
0.11
0.05
0.05
0.10
0.12
0.16
0.10
0.07
0.23
0.15
0.15
0.08
0.07
0.07
3.86
5.20
2.62
4.47
1.53
1.72
2.92
2.16
5.25
0.66
0.12
9.57
7.88
3.13
0.12
0.76
0.44
1.29
1.03
1.65
1.75
1.54
1.5P
1.31
0.96
0.93
1.13
0.94
1.06
1.02
2.33
1.00
1.10
0.84
* 1976 California 4K Vehicle
6-14
-------
6.1.5. Sulfuric Acid Emissions from Future Prototypes
GM tested 12 future prototype vehicles for sulfuric acid emissions.
These vehicles included lean burn and 3-way catalyst vehicles. The lean
burn vehicles had higher sulfuric acid emission while the 3-way catalyst
vehicles had low sulfuric acid emissions. The results of these tests
for the CFDS are given below. GM did not supply gaseous emission
results or any other details on the control systems other than what is
listed in the table.
Ford measured sulfuric acid emissions from a variety of oxidation
catalyst, 3-way and oxidation catalyst, and dual catalyst cars designed
to meet low NOx standards. Even though two of the oxidation catalysts
had 50,000 miles on them, the sulfuric acid emissions were still sig-
nificantly high. The sulfuric acid emissions from the 3-way catalyst-
oxidation catalyst prototypes were also high, because of S0~ oxidation
occurring over the oxidation catalyst with air injection before the
oxidation catalyst. The conventional 3-way catalyst would, of course,
be expected to have very low sulfuric acid emissions. Finally, Ford
found high sulfuric acid emissions (69 mg/mi) from the Gould dual
catalyst system. Independent EPA tests confirm that the Gould dual
catalyst system does have high sulfuric acid emissions.
The results of the Ford tests are given in Table 6-7 for the CFDS.
6-15
-------
Table 6-6
Sulfuric Acid Tests on
Car
'74 Chevelle
'74 Chevelle
'74 Chevrolet
'74 Chevrolet
'74 Chevrolet
'74 Oldsmobile
'74 Oldsmobile
'75 Chevelle
'75 Chevelle
'75 non GM
'76 Chevelle
Control System
lean burn engine,
production catalyst
lean burn engine,
production catalyst
closed loop fu
3-way catalyst
closed loop fu
3-way catalyst
closed loop ca
3—way catalyst
production catalyst,
no AIR
production catalyst,
no AIR
production cat
production catalyst,
warm-up catalyst, AIR
stratified charge
engine, fuel inje
monolith catalyst
production catalyst,
AIR swit hing
Prototype Vehicles
Fuel Sulfur
Level
st 0.06%
st 0.031%
injection,
0.06%
injection,
0.06%
retor,
0.031%
'St
0.031%
•st,
0.031%
•st, AIR 0.031%
'St
AIR 0.031%
iction,
: 0.012%
'St,
0.031%
Exhaust Oxygen
Level
2.1%
2.1%
0.7%
0.3%
0.7%
1.5%
1.6%
1.5%
1.5%
0.5%
1.6%
Sulfuric Acid (mg/mi)
99
42
0.2
0.1
0.2
44
76
41
15
6
4
-------
Table 6-7
Ford Sulfuric Acid Tests
Vehicle
8D1-302-5P
(50K oxidation
catalyst)
8D1-302-5P
(oxidation catalyst
from 8D1-302-6P,
5 OK)
8D1-302-6P
(5OK oxidation
catalyst)
8D1-302-1P
(3-way and
oxidation catalysts) 0.16
on Low NOx Prototypes
HC
gm/mi
0.06
-
0.06
0.07
0.07
-
0.01
0.05
0.06
-
0.06
0.06
0.05
-
0.05
0.05
0.03
0.03
-
0.04
0.09
-
0.07
0.12 ;
0.09
_
0.08
0.08
0.15
-
0.16
0.15
0.16
-
0.18
0.18
CO
0.01
-
0.03
0.00
0.05
-
0.00
0.01
0.02
-
0.05
0.03
0.02
-
0.04
0.00
0.02
0.02
-
0.01
0.68
-
0.66
0.68
1.06
_
0.97
0.83
0.16
-
0.14
0.13
0.17
-
0.14
0.18
NOx
gm/mi
0.57
-
0.58
0.61
0.64
-
0.62
0.62
0.57
-
0.56
0.56
0.65
-
0.62
0.62
0.65
0.60
-
0.65
0.46
-
0.47
0.47
0.42
-
0.42
0.43
0.60
-
0.70
0.67
0.55
-
0.55
0.56
H SO
mg/mi
139.4
103.2
107.1
110.9
162.1
106.9
114.5
115.4
88.5
86.8
95.0
87.8
103.6
95.6
92.3
104.6
102.5
117.9
119.7
106.8
12.6
19.9
17.4
19.4
13.7
12.8
14.4
15.3
56.2
51.2
61.4
62.3
69.8
53.6
71.4
61.2
6-17
-------
Table 6-7 (cont.)
HC CO NOx
Vehicle gm/mi gm/mi gm/mi mg7mi'
* FTP data
8D1-302-7P
(3 -way and
oxidation catlyst)
Gould catalyst
(1975 400 CID LTD)
0.14
-
0.13
0.14
0.13
-
0.13
0.14
0.33*
0.28
0.40
-
0.43
0.29
0.28
-
0.20
0.26
0.46*
0.39
0.49
-
0.50
0.49
0.61
—
0.67
0.64
0.25*
0.17
27.9
33.3
25.8
34.5
37.4
43.0
45.7
40.1
69.0
6-18
-------
Chrysler has run sulfuric acid emission tests on advanced prototype
vehicles including the lean burn (with and without oxidation catalyst),
start catalyst, and dual catalyst (Gould reduction catalyst followed by
an oxidation catalyst) vehicles. The lean burn vehicles .(cars 209 and
271) without catalyst showed very low sulfuric acid emissions while the
lean burn vehicle (Car 4028) with oxidation catalyst showed higher
sulfuric acid emission (41 mg/mi). Chrysler tested three start catalyst
systems (Cars 454, 332, and 270) which were 1977 California prototypes.
All three cars had 22 cu in. start catalysts and 90 cu in. main oxidation
catalysts with air pumps. ' These three cars produced 53, 25, and 62
mg/mi sulfuric acid emissions over the CFDS which is in the same range
as that expected from conventional oxidation catalysts without start
catalysts.
Chrysler tested three dual catalyst type vehicles. The first of these,
Car 178, had a Gould reduction catalyst followed by a 152 cu in. monolithic
catalyst with an air pump. This car emitted a very low 5.4 mg/mi sulfuric
acid over the CFDS which is similar to values Chrysler reported in 1975.
The second car, Vehicle 232, has a monolithic Chrysler reduction catalyst
followed by a 90 cu in. oxidation catalyst and air pump. This vehicle
also produced very little sulfuric acid (13-25 mg/mi over the CFDS).
The third vehicle (car 623) also has a monolithic Chrysler reduction
catalyst followed by a 90 cu in. oxidation catalyst. This car has an
air modulation system which injects about 7% oxygen upstream of the
reduction catalyst for the first 90 seconds after a cold start. After
this, sufficient air is injected into the oxidation catalyst to result
in a 2% oxygen level (a diverter valve is used to achieve this). With
the 2-3% oxygen level, 11.1 ing/mi of sulfuric acid is emitted over the
CFDS. However, if the diverter valve is inoperative and all of the air
is injected into the oxidation catalyst (7% oxygen), sulfuric acid
emission levels of 46.3 mg/mi are observed over the CFDS.
The sulfuric acid emission results for the start catalyst and dual
catalyst systems over the CFDS are given in the table that follows.
6-19
-------
Table 6-8
Chrysler Sulfuric Acid Test Results
Sulfuric Acid Oxygen CO
Vehicle (mg/mi) % %_
454 (start 51.4 6.4 0.099
catalyst) 59.4 4.9 0.466
49.7 4.8 0.649
13.6 3.2 0.850
17.1 3.2 0.822
332 (start 14.5 3.0 0.220
catalyst) 18.5 4.0 0.270
Right Exhaust 12.9 4.0 0.304
14.2 4.0 0.308
Left Exhaust 7.6 3.0 0.060
14.8 4.0 0.043
10.0 3.7 0.078
13.2 4.0 0.068
Left Exhaust
Dummy Main 2.9 4.0 0.090
Left Exhaust 6.8 3.3 0.358
Dummy Start 16.9 3.7 0.268
270 (start 61.8 4.8 0.134
catalyst)
178 (dual catalyst) 5.4 2.2 3.257
232 (dual catalyst) 13.1 5.3 2.949
15.6 6.1 2.267
25.1 6.1 1.732
623 (dual catalyst) 11.1 3.3 2.66
46.3 7.3 1.29
6-20
-------
6.1.6. Sulfuric Acid Traps
GM is the only company reporting information on sulfuric acid traps.
EPA has also done extensive work on sulfuric acid traps through a contract
at Exxon Research and Engineering. The sulfuric acid trap is simply a
chemical placed in a container (a muffler or catalyst-like container is
satisfactory) on the vehicle after the oxidation catalyst. All of the
exhaust passes through this container allowing the sulfuric acid to
react with the sorbent.
The EPA work at Exxon showed several promising sorbents, the most
promising of which was 85% CaO, 10% A^O-, and 5% Na20. This sorbent
can be fashioned into either pellets or rings. Tests on the sorbent
show extremely high efficiency (about 90%) in trapping sulfuric acid
even after extended mileage (25,000 miles). However, the sorbent swells
causing an unacceptably high pressure drop causing the vehicle to lose
power and increase its fuel consumption. EPA and Exxon spent a second
year in a contract extension to try to remedy these problems and were
unsuccessful. The second year Exxon program did identify a number of
sorbents that could be considered promising. The overall conclusion of
the EPA-Exxon work is that, if vehicle sulfuric acid reductions are
needed, the sulfuric acid trap is a potentially promising candidate but
will need a very large development effort. Even with a large development
effort, it is not certain that a viable sulfuric acid trap would result.
In their work, GM screened many different sulfuric acid sorbents and
found two promising candidates, CaO and a Na_0-Al?0_ sorbent. The
latter sorbent is especially attractive in that it is sufficiently
selective that sulfuric acid alone with no S0_ is trapped. A vehicle
test on the CaO material showed 95% efficiency when fresh but only 70%
efficiency (over the CFDS) or 40% efficiency (at 40 mph) after 32,000
km.
6-21
-------
The Na90-Al~0~ trap has been tested only 1600 km and shows no loss in
efficiency. Even though the GM program is less extensive than the EPA-
Exxon program, the GM results seem to be in agreement with those of EPA-
Exxon.
6.1.7. Sulfate Measurement Methods
Both GM and Ford reported work on measurement methods for sulfuric acid.
This work involves both the collection methods used for automotive
sampling and the analytical methods used on the collected samples.
GM has investigated CVS flow rate and concludes that either a 300 or 600
CFM flow rate is adequate for a large (18 inch diameter - 20 foot length)
dilution tunnel. However, GM feels that a lower flow rate of 335 CFM
will not work with a smaller dilution tunnel (8.4 inch diameter - 10
foot length) due to high sulfuric acid losses. The 335 CFM flow rate is
used on almost all current CVS units. GM also stated that sample zone
temperatures of over 200°F will result in lower sulfuric acid values
(possibly by loss of sulfuric acid from the filter or incomplete con-
densation of sulfuric acid). GM also found that tunnel inlet temperatures
of less than 200°F (caused by long connecting tubing between the vehicle
and tunnel) cause low sulfuric acid readings. GM stated that smaller
variations in paired samples were noted with critical flow venturi
sampling versus CVS sampling. All of these items are being investigated
by an EPA contract currently in progress at Southwest Research.
GM also stated that neither 5300 nor 25,000 CFM cooling fans result in
vehicle temperatures during dynamometer operation that are typical of
on-road operation. EPA generally uses a combination of several
6-22
-------
5300 CFM fans to assure adequate cooling; EPA has also purchased a
25,000 CFM fan. EPA has just started a contract with Olson Laboratories
to investigate the configuration of cooling fans that will result in
vehicle cooling approximating that occurring during road operation.
Finally, GM notes that their work shows the perchlorate titration
system to be equivalent to the barium chloranilate system for analysis
of filter samples containing sulfuric acid. Ford has done similar work.
EPA work also shows both systems are equivalent.
Ford has extensive work (both in-house and some EPA contract work) in
progress investigating analytical methods for sulfuric acid and S0~.
Ford is currently working on an instrument for continuous S0_ measure-
ment of automotive exhaust. Furthermore, Ford is doing some work on
analysis of sulfuric acid by mass spectrometry. In particular, electron
impact mass spectral analysis offers the potential of distinguishing
between sulfuric acid itself and salts of sulfuric acid (ammonium sulfate),
Such instrumentation would be very useful in ambient air monitoring,
where sulfuric acid particles could be distinguished from its salts.
Such distinction is valuable since the two compounds probably have
different health effects.
6.1.8. Correlation of Sulfuric Acid Tests among Different Laboratories
During the past year, several vehicles tested by GM and Ford have also
been tested by EPA. Vehicles tested by the GM Proving Ground were also
tested by EPA in the Sulfuric Acid Baseline Program. These tests showed
generally good agreement between the laboratories.
Ford recently completed construction of dilution tunnels at their
Scientific Research Laboratory and another Dearborn Laboratory.
Ford tested a 1976 vehicle equipped with a 400 CID engine at both of
their facilities and sent the car to EPA for correlation testing. The
test results show reasonably good
6-23
-------
(but not complete) agreement among the three laboratories in the sul-
furic acid emission values obtained.
As part of the sulfuric acid deterioration factor program to be conducted
by the manufacturers and EPA during the coming year, sulfuric acid
correlation testing will be needed among the different laboratories. A
round robin car will be used for this purpose.
6.1.9. Roadside Sulfuric Acid Levels
Both the GM and Ford submissions discussed work on measuring roadside
levels of sulfuric acid. In particular, GM completed a major experiment
this past year titled the Sulfate Dispersion Experiment. This work
involved running 352 cars, equipped with catalysts and air pumps (designed
for the 1976 California standards), around a loop at the GM Proving
Grounds. The cars were preconditioned with 0.032% sulfur fuel and
operated at about 55 mph. The average sulfuric acid vehicle emission
rate during these tests was about 0.037 mg/mi. Ambient air levels of
sulfuric acid were monitored. Also, a tracer gas (SF ) was emitted from
o
eight pickup trucks participating in the experiment. Measuring the
level of SF- and sulfuric acid under various meterological conditions
o
allowed verification of an EPA predictive air quality model and also
gave an independent measurement of roadside sulfuric acid levels.
It was found the normal levels of sulfuric acid in the air samples due
to the vehicles were 3-5 yg/m . Under adverse meterology increments of
3
15 ug/m were found. The increased level of sulfuric acid inside the
vehicles was also measured and found to be about 4 yg/m . There was
very good agreement between results obtained with the SF, tracer and the
sulfuric acid measurements.
6-24
-------
These results showed that the EPA Highway Model overpredicts sulfuric
acid emissions at the pedestrian level downwind from the roadway. The
overprediction occurs for stable meterological conditions and gets worse
as the wind speed decreases (when roadside sulfuric acid levels would be
highest). The EPA Highway Model is more or less satisfactory under
unstable meterological conditions (when sulfuric acid levels along
roadsides would be much lower). Apparently, "mechanical mixing" due to
traffic flow is an important parameter and not accounted for in the EPA
Highway Model. Various government agencies (EPA, DOT, and DHEW) as well
as other automobiles companies helped participate in this work.
In addition to the massive GM experiment, Ford has been conducting
monitoring experiments in the Allegheny Tunnel on the Pennsylvania
Turnpike. Initially, Ford monitored rubber tire particulate there and
then diesel and sulfuric acid particulate. The cars driving through the
tunnel would be those designed for the Federal standards and therefore
have lower sulfuric acid emission rates than the California cars used in
the GM experiment. However, to date, no sulfuric acid increment has
been noted from the introduction of catalyst cars.
6.1.10. Conclusions
Work during the past year confirmed earlier studies showing that exhaust
oxygen levels are the most important single parameter affecting sulfuric
acid emissions. Low exhaust oxygen levels (such as those found with 3-
way catalyst cars) can result in sulfuric acid emission levels from
catalyst cars of under 5 mg/mi which is equivalent to levels found with
non-catalyst cars.
Sulfuric acid tests on current catalyst cars run this past year agree
well with previous tests. Oxidation catalyst cars without air injection
usually emit under 10 mg/mi of sulfuric acid. Current oxidation catalyst
cars with air injection emit greater quantities of sulfuric acid,
6-25
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generally 20 mg/mi or higher. Tests of advanced oxidation catalyst
vehicle prototypes (which generally have air injection) show similar
sulfuric acid emission levels. Prototype 3-way catalyst cars show very
low sulfuric acid emissions. However, 3-way catalyst cars with a down-
stream oxidation catalyst and air injection show sulfuric acid emission
levels similar to conventional oxidation catalyst cars equipped with
air injection.
One major area needing additional investigation is the effect of mileage
on sulfuric acid emissions. Limited test results so far show high
mileage oxidation catalyst vehicles have lower sulfuric acid emissions.
Sulfuric acid emissions are reduced by a factor of two and, in some
cases, even more. Some results have even approached the level of non-
catalyst cars (1 mg/mi). Significant data are still needed to determine
whether this reduction with extended mileage is such that sulfuric acid
emissions are not a problem. The car companies are running tests on
catalyst vehicles as they accumulate mileage to determine the extent of
this reduction.
Finally, during the past year, GM completed a major test track exper-
iment measuring roadside sulfuric acid levels. This work showed road-
side sulfuric acid levels far below levels predicted by EPA air quality
models. These lower levels, combined with a possible reduction in
sulfuric acid emissions at higher mileages, may result sulfuric acid
emissions being considered much less of an air quality problem than
was previously the case.
6-26
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6.2. Hydrogen Cyanide
6.2.1. Introduction and EPA Work
In 1974, it was reported by Bell Laboratories that automotive catalysts
could, under very unusual conditions in a laboratory reactor, form
hydrogen cyanide (HCN) from laboratory gases. EPA found in early 1976
that vehicles using a 3-way catalyst could produce HCN under rich mal-
function modes. Since Volvo and Saab were certifying 3-way catalyst
systems for use in California in 1977, EPA had to make a rapid determina-
tion on the levels of HCN that would be acceptable from a health stand-
point. EPA was concerned primarily about the worst case situation, i.e.
localized levels of HCN that could occur in indoor parking garages and
along heavily traveled roadways. The highest HCN emissions were observed
under rich malfunction modes when CO emissions were also highest (approaching
levels found in some uncontrolled pre-1968 vehicles).
EPA considered two types of worst case situations in determining accept-
able levels for HCN exposure in localized areas. The first was a closed
environment situation (i.e. garage-type exposure) while the second was
a highway-type exposure situation. In the closed environment situation,
an upper bound of 5 ppm HCN could result from a maximum raw exhaust
level of 10 ppm. The corresponding CO level under these conditions
would be 6500 ppm. The adverse health effects of CO would overshadow
possible adverse effects of HCN by more than two orders of magnitude.
For the highway type exposure, a 150 mg/mi HCN emission rate would
result in a 1.1 ppm HCN level with 17000 vehicles/hr. along a heavily
traveled freeway, under the worst meteorlogical situation, with each car
emitting the maximum amount of HCN. EPA-ORD states that 1 ppm HCN exposure
would not have unacceptable health effects.
6-27
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It was also thought that a primary factor affecting HCN formation was
the rhodium content of the catalyst. The Engelhard catalysts planned
for use by Volvo contained about 16% rhodium. Most 3-way catalysts
contain rhodium, sometimes at lower levels (e.g. 7%). Many oxidation
catalysts also contain small amounts of rhodium (i.e., 7% or less).
Some 1975 Ford oxidation catalysts (those made by Matthey Bishop) and
oxidation catalysts used by many of the foreign manufacturers contain
rhodium.
EPA therefore required that all 1977 certification cars equipped with
rhodium catalysts be tested by EPA-ORD for HCN emissions. All such cars
tested to date have been below the HCN levels that had been established
as safe with a large margin of safety on a preliminary basis by EPA.
Typical data found for a Volvo equipped with a 3-way catalyst by EPA-ORD
are given below.
Table 6-9
EPA-ORD Test Results on Volvo
(Rich Malfunction)
HC
Test gm/mi
Idle* 0.32
FTP 1.66
CFDS 1.13
HFET 0.88
30 mph 0.84
40 mph 0.80
CO
gm/mi
4.42
40.5
28.2
22.4
24.5
20.3
NOx
gm/mi
0.062
0.503
0.314
0.383
0.032
0.07
HCN
mg/mi
1.70
66.3
110.6
78.8
16.4
47.1
NH3
mg/mi
7.9
493
627
735
110
176
H S
mg/mi
0.47
6.88
10.1
7.59
NA
NA
COS
mg/mi
0.03
1.89
2.11
1.72
1.32
0.71
50 mph 0.94 23.9 0.21 113.8 270 NA 1.16
* g/minute
Another Volvo 3-way catalyst system (Car 7712) was tested by Exxon
Research and Engineering under both normal and malfunction conditions.
The rich malfunction mode was induced by disconnecting the oxygen
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sensor. Instead of the pyridine-pyrazolone wet chemistry method used
for EPA for HCN analysis, Exxon used a selective ion electrode method,
The results of the Exxon tests are given in the table that follows.
Table 6-10
Exxon Test Results on Volvo
Test
Idle*
FTP
CFDS
FET
30
40
50
Idle*
FTP
CFDS
FET
30
40
50
HC
gm/mi
0
0.21
0.08
0.05
0.06
0.03
0.06
2.97
1.08
0.77
0.68
0.76
0.90
0.85
NOx
gm/mi
HCN
mg/mi
NORMAL OPERATING CONDITIONS
0
2.70
0.55
0.31
0.88
0.08
0.45
0.45
0.32
0.11
0.08
<0.02
0.16
0.08
<0.4
<2.3
<1.9
<2.6
<1.0
<0.6
<0.6
5.8
36.
29.
28.
RICH MALFUNCTION MODE
29.12
24.97
17.19
14.36
19.27
15.97
24.55
0.43
0.74
0.63
1.14
0.14
0.50
0.68
<0
22
21
19
29.0
62.0
146.5
10.6
10.6
43.8
9.4
327.8
493.9
425.4
187.1
481.4
749.0
* g/minute
It can be seen from these data that HCN emissions are negligible under
normal operating conditions. However, HCN emissions definitely increase
under rich malfunction conditions to levels as high as 110 mg/mi.
Rhodium containing oxidation catalyst also has the potential of producing
HCN under rich malfunction conditions. Since oxidation catalysts generally
contain less rhodium than some 3-way catalysts, they would be expected
to produce far less HCN. EPA-ORD tests on three VW 1977 certification
cars show this to be true. The test results for one of these cars (an
Audi 100) are given in the following table.
6-29
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Table 6-11
EPA-ORD Test Results on VW Certification Cars
HC CO NOx
Vehicle Test gm/mi gin/mi gm/mi
Audi 100
(Car 5202,
certification
tune) FTP 0.18 1.94 1.24 3.03
CFDS 0.13 0.72 1.40 1.40
FET 0.11 0.62 1.40 0.97
IDLE
(925 rpm)* 0.01 0.12 0.02 0
IDLE
(2000 rpm)* 0.12 0.03 0.05 0
Audi 100
(Car 5202, Rich
malfunction,
1.6% CO) FTP 0.36 9.92 1.15 5.65
CFDS 0.22 3.83 1.05 3.37
FET 0.12 1.44 1.16 1.09
IDLE
(925 rpm)* 0.11 4.28 0.02 1.08
IDLE
(2000 rpm)* 0.02 0.11 0.05 0.08
* g/minute
Test results for two other VW certification cars (an Audi 80, Car 8389
and a VW Rabbit, Car 6846) were similar. The highest HCN emissions
observed for these three cars was 7 mg/mi for the VW Rabbit over the FTP
under the rich malfunction mode.
6.2.2. GM Work
In the 1975 Status Report, GM discussed tests they ran on non-catalyst
cars and 1975 vehicles for HCN emissions. The non-catalyst cars emitted
11-14 mg/mi which should be considered the baseline with which all of
the catalyst cars should be compared. The 1975 oxidation catalyst
production cars emitted about 2 mg/mi.
6-30
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In the 1975-76 work discussed in the most recent report, GM tested
several additional cars for HCN emissions using a modified colorimetric
method. The first cars tested were two 1975 GM production cars (Cars
R5454 and R5452) designed to meet California standards with the standard
Pt-Pd pelleted catalyst. The first car was tested with the air pump
disconnected to enrichen the exhaust. CO emissions were lower (5.1
gm/mi) with the air pump disconnected than when it was connected (8.9
gm/mi). Under either condition, HCN emissions were very low at 2 mg/mi.
The second car was run with both the standard and a specially designed
rich operating carburetor. HCN emissions were very low under both
conditions being 2 and 0 mg/mi respectively while CO was 3.1 and 96.1
gm/mi. While GM does not specify test conditions, it is assumed these
cars Were tested on the FTP.
GM also tested two experimental cars for HCN emissions (Cars CH42216 and
ES66344). The first vehicle contained an experimental 3-way catalyst
(HN-2217) and a closed-loop carburetor with an oxygen sensor. This car
had FTP emissions of 3.1 HC, 85.5 CO, 0.7 NOx. However, HCN emissions
were only 4 mg/mi. Presumably, this vehicle was operating under a mal-
function condition giving the high CO emissions.
The second car was a Vega with electronic fuel injection, an oxygen
sensor, and Degussa experimental 3-way catalyst (HN-3032). This vehicle
was tested under both normal operating conditions and rich malfunction
conditions. The rich malfunction was induced by enriching the car
electronically in the open loop mode. The highest HCN value found in
these tests was 18 mg/mi which is only slightly higher than HCN values
found with non-catalyst cars during previous tests. The car was then
retested in the closed-loop mode using an HN-3032 catalyst that had been
aged 50,000 miles. HCN emissions were 9 mg/mi which is slightly higher
than the fresh catalyst. The car was not tested in a malfunction mode
with the aged catalyst.
6-31
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The test results for this car are given below for the FTP.
Table 6-12
HCN Test Results of 3-Way Catalyst Vega
HC CO NOx HCN
Test Condition gra/mi gm/mi gin/mi mg/mi
Fresh catalyst
closed loop 0.29 2.8 0.23 2 2
open loop -
6% rich 0.30 3.4 0.86 2 3
12% rich 0.83 19.7 0.13 16 211
18% rich , 1.75 60.0 0.11 11 259
50,000 mile catalyst
closed loop 0.63 5.36 0.60 9 8
GM did not specify the rhodium content of the 3-way catalysts tested.
However, HCN emissions from these catalysts are much lower than those
found for the Volvo 3-way catalyst systems.
6.2.3. Ford Work
Ford has done more extensive work on HCN emissions than any other
automobile company to date.
The initial Ford work involved lengthy validation of both the pyridine-
pyrazolone and the ion selective electrode method for HCN. Both of
these methods can be used to analyze HCN trapped in a potassium hydroxide
solution contained in a bubbler. Ford bubbles a small sample from their
dilution tunnel into the bubbler. The first test done by Ford showed the
injection of 6.74 ppm HCN, approximately 90 mg/mi, resulted in 93.8% HCN
recovery. The tests were repeated with lower levels of HCN injected.
Quantities of HCN corresponding to 3.14 ppm or approximately 45 mg/mi
resulted in poor recovery, the reasons for which are unknown at the
present time. Ford then added known quantities of HCN to the dilution
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tunnel stream when a vehicle was being tested at a 45 mph cruise condi-
tion. These tests showed an HCN recovery rate of only 50% indicating an
interference problem with both methods. Ford work identified the problem
to probably be a low concentration of potassium hydroxide in the bubblers
(caused by reaction of acidic exhaust components) which allowed HCN to
escape. Modifying the method by using more hydroxide resulted in a
recovery of 94% of the HCN. Ford work shows the limit of detection of
both methods is about 0.06 mg/mi of HCN. While more work is needed to
refine the method, the method as it stands now can be used for reasonable
approximation of automotive HCN emissions.
Ford vehicle tests were conducted on a Granada equipped with a 302 CID
engine amd a 3-way catalyst followed by an oxidation catalyst (Vehicle
9P), a Pinto equipped with a 2.3 litre engine with a similar system, and
a 1978 prototype Pinto with a 3-way catalyst.
Tests on the Granada were conducted with the air injection functioning
normally and with the air injection after the 3-way catalyst disconnected
simulating a rich malfunction condition. This car was tested over the
CFDS, idle, and 45 mph steady state conditions. With the air pump
disconnected, HCN emissions were 12.3 mg/mi compared to about 0.15 mg/mi
with the air pump functioning. CO emissions over the CFDS were about 16
gm/mi with the air pump disconnected and only 2 gin/mi with the air pump
functioning.
The Pinto (Vehicle T791) with the 3-way plus oxidation catalyst system
was tested under the same conditions as Vehicle 9P. The HCN emissions
were under 5 mg/mi for all tests. CO emissions were extremely low both
with the air pump disconnected (under 0.1 gm/mi) and with it functioning
correctly (also under 0.1 gm/mi). It is possible that the low CO on
Vehicles 9P and T791 are partly responsible for the low HCN formation.
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The 1978 3-way catalyst prototype (Vehicle 61E28) was tested with a line
to the carburetor being plugged to deactivate the oxygen sensor. This
resulted in a 12:1 air-fuel ratio. The vehicle was also tested in a
13:1 air-fuel ratio configuration. The car was tested under idle (slow
and fast), 50 mph, the CFDS, a hot start FTP, and the FET. HCN emissions
were in all cases under 2 mg/mi. However, CO emissions were considerably
higher than usual (96, 113, and 88 gm/mi over the CFDS, hot start FTP,
and FET) giving ample opportunity for HCN formation.
Finally, Ford has done some laboratory studies with catalyst samples in
their pulse flame reactor and also with simulated exhaust gas samples
blended from gas cylinders.
The simulated exhaust gas experiments showed that higher NO and CO
concentrations caused higher HCN formation as expected. Maximum HCN from
a Pt-Pd PTX catalyst and a pure platinum catalyst is formed at 550°C. The
temperature for maximum HCN formation is slightly lower for a rhodium
containing catalyst. Space velocity (from 20,000 to 200,000 hr~ ) did
not influence HCN formation at 550°C. It should be noted that the
simulated exhaust contained NO, CO, and hydrogen but no water vapor (a
component normally found in vehicle exhaust).
However, the pulse flame reactor tests show that roughly the same
amount of HCN is formed from 550° to 800°C for all of the catalysts
tested (except one containing iridium). Additional tests showed that
lower space velocities decrease HCN formation. The pulse flame apparatus
results may be different from the laboratory test apparatus results
because the gas used in the former experiments contained water vapor.
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6.2.4. Chrysler Work
The initial Chrysler work on HCN consisted of running engine dynamometer
tests with a variety of catalysts. Catalysts tested included an Engelhard
Pt/Rh and three Chrysler catalysts (Pt, ruthenium-perovskite, and Pt/
Rh). These tests were run with 1.5% to 5% CO (mostly 5%). Even though
the CO levels were high, less than 1 ppm of HCN was formed. Chrysler
even ran an engine dynamometer test with the catalyst at 1300°F where
they thought HCN formation would be a maximum. Again, almost no HCN was
formed.
Chrysler then decided to run some basic laboratory tests with simulated
exhaust gases. Using a gas containing 3% CO, 1% hydrogen, and 0.2% NO
in nitrogen, the following results were obtained with different catalysts.
Table 6-13
Chrysler HCN Laboratory Studies
Catalyst HCN (ppm)
platinum-rhodium 72
platinum 0.9
ruthenium-perovskite <0.5
rhodium 160
Further tests with the platinum-rhodium catalyst shows that doubling the
CO input also doubles the HCN emissions. Doubling the NO input also
increases the HCN emissions but by less than a factor of two.
Chrysler did some further tube furnace laboratory studies involving the
platinum-rhodium catalyst in one furnace and a platinum catalyst in a
second furnace (in series). Such an arrangement approximates a dual
catalyst system (a reduction catalyst followed by an oxidation catalyst).
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On a dual catalyst system, an air pump provides air injection after the
reduction catalyst but before the oxidation catalyst. A vehicle air
pump failure can be easily simulated in the tube furnace by not adding
air between the two furnaces. Chrysler did this and varied the temper-
ature of the oxidizing catalyst. The following results were obtained
using two different feedgases.
Feedgas A
Temperature
600°F
800
1000
1300
(oxidizing catalyst
removed)
Table 6-14
Chrysler HCN Laboratory Studies
1
HCN (ppm)
67
65
67
114
65
Feedgas B
Temperature
750°F
900
1050
1200
1350
1500
HCN (ppm)
1
3
9
49
92
88
Feedgas A:
1.9% CO
0.8% hydrogen
0.19% NO
rest nitrogen
Feedgas B:
0.7% ammonia
1.9% CO
0.8% hydrogen
rest nitrogen
These results show the greatest HCN emissions at about 1300° F.
Finally, Chrysler reports some work done on analytical methods. Chrysler
uses the Liebig titration, the pyridine-pyrazolone method, and the
selective ion electrode method. Chrysler states that heavy metals
(nickel, copper, iron, and zinc) and the sulfide anion interfere with the
selective ion electrode. However, Chrysler finds no evidence of any of
these interfering species in the liquid impinger sample they collected.
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6.2.5. Conclusions
Early studies by EPA showed HCN emissions from vehicles with 3-way
catalysts operated under malfunction conditions. These emissions were
always under 150 mg/mi for any driving mode and under 5 ppm for idle.
Almost no HCN emissions were found from vehicles with 3-way catalysts
under normal operating conditions. EPA has concluded that these levels
of HCN do not represent a health concern.
The manufacturers have done extensive work developing analytical methods
to measure HCN emissions. Also, considerable work was done measuring
HCN on a number of non-catalyst and catalyst cars. Non-catalyst cars
have been found to emit from 11-14 mg/mi of HCN. Oxidation catalyst
cars emit far less HCN than non-catalyst cars even under malfunction
conditions.
Therefore, currently available data indicate HCN emissions from catalyst
cars is not a problem. However, HCN measurements should, of course, be
done on future emission control systems as they are developed.
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6.3 Ruthenium Emissions
6.3.1. Introduction
Ruthenium is being considered by several companies for use in catalysts.
Chrysler has considered it for reduction catalysts, 3-way catalysts, and
start catalysts. Ford has conducted extensive work with ruthenium for
use in reduction catalysts. In addition, both Exxon and Gulf had done
work in the past on ruthenium containing reduction catalysts but are not
now conducting any further work. The basic reason ruthenium is being
considered is its low cost and attractiveness for nitrogen oxide control.
Ford has considered use of ruthenium in the past for NOx reduction
catalysts and is currently considering ruthenium as a possible component
of 3-way catalysts.
The higher oxides of ruthenium (RuO ) are volatile and easily formed
under oxidizing conditions. Various companies in previous years (Ford
and Exxon) have tried to stabilize ruthenium so that it is not lost from
NOx reduction catalysts. These attempts were unsuccessful due to high
loss of catalytic activity in the process or the loss of ruthenium.
Recently, DuPont has worked on stabilizing ruthenium in a rare earth
oxide perovskite structure. This work is still in progress. Since
ruthenium oxides are very toxic, it seems that use of ruthenium catalysts
depends on no significant emission of their oxides. EPA is not currently
in a position to quantify what, if any, levels of ruthenium emissions
would be considered significant. EPA health effects studies are in-
vestigating the toxicity of ruthenium and ruthenium oxides.
6.3.2. Chrysler
Chrysler is the only company to have reported studies on ruthenium
emissions. Chrysler ran dynamometer and vehicle tests. Chrysler also
sent the vehicle they tested to Exxon for independent tests.
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The dynamometer tests showed from 14 to 36 mg/km of ruthenium being
emitted. At this rate, all of the ruthenium would be lost in 32,000
miles.
Chrysler has also conducted ruthenium tests on Research Car 232. Car 232
contains a small (58 cu in.) ruthenium perovskite monolith catalyst
close to the exhaust manifold. This catalyst can function as a reduction
catalyst. A conventional Pt oxidation catalyst follows the reduction
catalyst. Particulate samples were collected from the dilution tunnel
using a Fluoropore filter which was analyzed for ruthenium by neutron
activation. This car was run on AMA durability for 25,000 miles. The
Chrysler tests indicated significant ruthenium loss. After 25,000
miles, the car was sent to Exxon for particulate tests. These tests
showed again that ruthenium was being emitted at a substantial rate
(about 150 mg/mi). The Exxon results were about three times higher than
the Chrysler results. The Chrysler results indicated that all of the
ruthenium on the catalyst would be lost in about 30,000 miles (if the
emission rate were constant).
6.3.3. Conclusions
Tests by Chrysler show that ruthenium is in fact lost from ruthenium-
containing catalysts. While ruthenium is not being used in any pro-
duction catalysts currently, it is being considered for future catalysts.
It is important that ruthenium losses be measured from prototype catalysts
so that the health impact of these emissions can be determined.
6-39
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6.4. Ammonia
6.4.1. Introduction and EPA Work
Ammonia emissions have been known to occur for some time now with dual
catalyst systems under rich operating conditions. With a dual catalyst
system, ammonia formed over the reduction catalyst is frequently
reoxidized to NO over the oxidation catalyst. Ammonia formation in a
dual catalyst system thus generally results in loss of NO control. It
is possible to have incomplete oxidation of the ammonia over the oxida-
tion catalyst which could result in significant ammonia emissions.
Also, an oxidation catalyst system malfunction (e.g., air pump failure)
can result in significant ammonia emissions.
In addition to possible ammonia formation with dual catalysts, ammonia
can be formed with 3-way catalyst systems. Early EPA data show that the
Volvo 3-way catalyst can have significant ammonia emissions under rich
malfunction conditions. Data obtained by EPA-ORD and Exxon on ammonia
emissions was given in detail in some of the tables in the HCN section.
Essentially, these data showed 20-30 mg/mi ammonia under cyclic operation
conditions with the vehicle correctly tuned and as high as 300-500 mg/mi
under rich operating conditions.
Ford points out in their status report that ammonia will be emitted from
their 3-way catalyst systems. Ford has also asked EPA from time to time
on what level of ammonia emissions would be acceptable from a health
standpoint. EPA is currently investigating possible health effects from
automotive ammonia emissions including both entire air quality regions
and localized situations (e.g., indoor parking garages and heavily
traveled freeways). Currently, there is inadequate information to
permit determination of the level of automotive ammonia emissions that
would be acceptable.
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6.4.2. Ford Work
Ford routinely measures ammonia emissions in all of their 3-way catalyst
screening work. A parametric study performed by Ford on catalysts
identical in all aspects but Pt/Rh ratio shows a linear decrease of net
NOx conversion (which is inversely related to ammonia formation) with
increasing Pt/Rh ratio.
Laboratory studies of various catalysts show increasing ammonia formation
as the A/F ratio becomes "richer" in the laboratory pulsator apparatus.
For example, catalyst M268A shows an increase in ammonia formation from
0% of total NOx to 20% as the A/F ratio changes from 14.38 to 14.08.
Catalyst M268B shows a change in ammonia formation of only 0% to 2%
under these conditions. Catalyst M275D2 produces from about 0% to 40%
ammonia as the A/F ratio is changed from 14.48 to 14.08. These tests
were generally run at 550°C.
Ford has also done some ammonia measurements of 3-way catalysts being
durability tested. Testing was done with isooctane containing 0.007
gm/gal lead, 0.0008 gm/gal phosphorus, and 0.02% sulfur. As the catalyst
ages, the A/F ratio units for optimum NO, CO, and HC conversion generally
shifts about 0.1 A/F units to the rich side. Ammonia formation was
noted to decrease significantly in some of the catalysts (M-270 and M-
273), thereby aiding net NOx conversion.
Ford also reported some engine dynamometer work on ammonia formation
with catalysts containing differing amounts of rhodium. The results
were those obtained in the laboratory apparatus mentioned earlier. These
tests showed the ammonia formation was found to be inversely proportional
to the rhodium content of the catalyst. Perhaps sulfur poisoning of the
aged catalyst results in different ammonia formation characteristics
than a fresh catalyst.
6-41
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Finally, Ford reported ammonia formation characteristics of an exper-
imental 3-way catalyst containing 3% TiO (titanium oxide). The TiO
apparently affects oxygen storage capacity and the rates of oxygen
transfer. The ammonia formation from this catalyst was very high, 26% at
a point 2% rich of stoichiometric.
6.A.3. GM Work
Last year GM reported that ammonia emissions from four catalyst prototype
vehicles are 1-3 mg/mi over the FTP.
Table 6-15
GM Ammonia Data
Ammonia
Car Catalyst mg/mi
0-39680 HN 2236 3
0-38608 HN 2236, AIR 2
E564346 HN 2221 and 2364
(dual catalyst,
reduction and oxidation) 1
C4361 HN 2217 and 3059
3-way + oxid. catalyst,
closed loop fuel injection 2
GM work on 1975 production cars without air injection under rich mal-
function conditions show ammonia emissions of 43-165 mg/mi. In this
year's status report, GM reports ammonia emissions on a 1975 Vega with a
3-way catalyst. Since this car was also tested for HCN emissions, the
ammonia test results were given previously in the HCN section. This car
showed 2-8 mg/mi of ammonia under normal operating conditions, 3 mg/mi
when operating 6% rich, and 211-259 mg/mi when operating 12-18% rich.
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GM also tested four 1975 catalyst cars and one 1974 non-catalyst car for
organic amines over the FTP. Amine compounds are very similar to
ammonia. No amine emissions were found using the wet chemistry iodio-
metric analysis method which has a limit of detection of 2 mg/mi.
6.4.4. Conclusions
Ammonia emissions may be significant from vehicles with 3-way catalysts
but only under malfunction conditions. Ammonia emissions should be
measured from vehicles with 3-way catalysts as they are being developed.
Ammonia emissions from vehicles equipped with oxidation catalysts do not
appear to be significant.
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6.5. Polynuclear Aromatic Compounds (PNA)
6.5.1. Introduction
Polynuclear aromatic compounds (PNAs) are of interest due to their
carcinogenicity. The PNAs are a group of multi-ring aromatic hydro-
carbon compounds with very low volatility and high molecular weight.
About 90% of total PNAs in the atmosphere come from stationary sources
(in particular from coal burning). Only about 10% of the total PNAs
come from mobile sources. Even though little PNA work has been done on
Diesels, it is estimated that about half of this 10% comes from Diesels.
The other half of the 10% comes from other motor vehicles.
Sometimes benzo(a)pyrene (BaP) is measured by itself instead of measuring
total PNAs (which consist of about 20 compounds). The amount of BaP
found can generally be correlated to total PNAs. BaP is relatively easy
to measure and is more carcinogenic than most other PNAs.
PNA compounds in automotive exhaust have been studied for some time.
Early contract work through CRC-APRAC from 1968-72 thoroughly character-
ized PNAs. This work was done at Exxon and involved testing several
cars. It was found that post-1968 cars had about half the PNA emissions
of pre-1968 cars. The control of HC and CO also resulted in decreases
of PNA. Exxon did some work on prototypes equipped with "advanced catalysts
and thermal reactors. Both systems were found to greatly reduce PNAs
(generally by 95% or more compared to uncontrolled vehicles. Subsequent
work by UOP showed that catalysts preferentially oxidize PNA compounds
resulting in very low PNA emissions from vehicles with catalysts.
Very little work has been done on measuring PNAs from light duty Diesels.
However, work at Southwest shows heavy duty Diesels emit much greater
quantities of PNAs than do gasoline engines. It is important that PNA
work be done on light duty Diesels.
6-44
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6.5.2. VW Work
The only PNA data reported in the submissions came from VW.
Volkswagen (VW) presented an interesting summary and discussion of their
testing concerning the levels of PNA from different types of emission
control technologies, alternative engines, and alternative fuels. VW
did not provide complete details concerning the test procedures utilized
in VW's testing for PNAs. Also missing from the VW discussion was any
mention of PNA emissions from Diesel engines.
VW reported that their studies showed extremely low levels of PNA
concentrations in automobile exhaust emissions. These levels are
reported to be approximately 0.001 gin/km (0.0016 gm/mi) on the European
Emission Test Procedure. This level is higher than found by other
investigations.
In addition to utilizing the European Test Procedure, the data were
collected under the following conditions:
(1) Europe Fuel ERF-G1 was used in all procedures. This type of
fuel has a composition of 55% paraffins, 8% olefins, and 37%
aromatics. Its lead content is 0.71 gm/litre (2.68 gin/gal).
Lead free fuel (VK 91) was used with noble metal catalyst
equipped engines. The lead free fuel contains 1% more aromatics.
(2) The motor oil was a standard brand heavy duty oil. The oil
was changed before every PNA test to avoid PNA enrichment of
engine oil.
(3) The test vehicles had accumulated between 2,000 and 15,000
miles of city driving at the start of the test.
6-45
-------
Volkswagen presented the data in Figure UE-1 which illustrate the
distribution by percent of PNAs in automobile exhaust emissions produced
by a variety of engine design concepts. The column labeled "Carcinogenic
properties" is VW's estimate of the relative severity or danger of
producing cancerous effects in humans. This opinion does not reflect
EPA's position indicating which PNA are more carcinogenic than others.
It should also be noted that the PNA listed in Figure UE-1 are less
stable as they preceded down the list and hence easier to break down
with exhaust aftertreatment.
Volkswagen drew the following conclusions concerning PNA from vehicles
equipped with gasoline fueled engines:
(1) There is a certain and insignificantly varying pattern of
distribution of the measured ten individual PNA components
from fluoranthene through coronene. The lower four-ring PNAs
represent approximately 80% of this pattern. VW mentioned
that among the ten measured PNA components there are three
each which combine two or three individual PNA components.
There is one triplet each in the chrysene and in the benzo-
fluoranthenes, and one twin in the indenopyrene.
(2) The present production vehicles produce the following scatter
on European Test Procedure - PNA total emissions of between
2000 pgm/test and 10,000 ygm/test, and between 50 vgm/test and
215 ygm/test in the benzo(a)pyrene emissions.
(3) The following percent reduction of PNA emissions are obtained
with other concepts when compared to gasoline powered vehicles.
production vehicles = 100%
catalytic design concepts = 5%
thermal reactor concepts = 15%
methanol vehicles = 10%
6-46
-------
Figure UE-1
PNA
FLUORANTHENE
PYRENE
CHRYSENE+M 226 +
BENZO(A)ANTHRACENE
BENZOFLUORANTHENE
BENZO(E)PYRENE
BENZOAIPYRENE
PERYLENE
INDENOPYREME+
DIBENZ(AH)ANTHRACENE
BENZO(G,HI)PERYLENE
. CORONENE
Cancero
genie
properties
4- slight
f4medium
»--f4strong
0
0
+
•n-
+
•f++
0
+
++ +
0
0
Vehicle Concepts
Produc-
tion
Vehicles
Catalytic
Concepts
Thermal
Reactor
Concepts
Methanol
Vehicles
% of TOTAL PNA
24
36
20
3
25
2,5
0,5
2
7
4,5
22
26
15
5
4
2.5
0,5
4
11
9
25
32
13
5
4
2,5
0,5
2
9
7
37
42
8
3
2
1,5
0.3
1.5
3
2
% DISTRIBUTION OF TOTAL PNA
TOTALS IN VARIOUS PRODUCTION
VEHICLES IN |jg/Test
100%
2000
to
10 000
PERCENT SHARE' OF CANCERO-
GENIC PNA'S
, ,
/TN
(_•'}
\^r
5%
15%
10 %
approx. 20 to 30%
PNA PERCENT DISTRIBUTION
IN EXHAUST EMISSIONS 647
(BASIS:EUROPETEST)
-------
(A) The distribution pattern of vehicle concepts other than
production vehicles show limited but characteristically
shifted PNA patterns. The four-ring PNAs are lower in cat-
alytic concepts than in the thermal reactor concepts while the
six and seven-ring benzo(ghi)perylene and coronene components
show a distinct increase in the catalytic concepts. This
indicates that these after-burner concepts reduce the latter
components less when compared with the lower PNAs.
On the other hand, engines operated on methanol show an extremely
strong presence of 80% of the lower four-ring fluoranthene and
pyrene components. This means that the absence of the PNAs
and of the other aromatics components in methanol fuel not
only produces a PNA emission that has been reduced by one
order of magnitude but that higher PNA synthesizing is impeded.
(5) The investigation shows the total of the more or less car-
cinogenic individual components (as far as such carcinogenic
effects are known from various sources) to amount to approx-
imately 20% or 30% per volume of total PNA emission.
VW .produced another graph (Figure UE-2) which shows the results obtained
with an engine using propane and gasoline. VW notes that propane
operation reduces the PNA content to 10% (similar to methanol operation)
when compared with gasoline operation.
VW feels this fact permits an interesting conclusion in regard to the
influence of engine oil, i.e. that engine oil influence on PNA emissions
in gasoline operation is bound to be lower than 10%. VW stated, it is
of additional interest that identical hydrocarbon emissions were measured
in the European Test Procedure under both modes of operation. They feel
this confirms the experience found elsewhere in a great many areas that
6-48
-------
Figure UE-2
ON
I
70
55
gasoline operation
propane operation
air-cooled 1-6 liter engine
2AQ
57
FLT PYR CHY BFLT BEP
+M226
PER IND BqhiP COR BAP
+DahATC
TOTAL PNA EMISSION -GASOLINE VERSUS
PROPANE OPERATION
-------
the level of hydrocarbon emissions can not be used to draw conclusions
about PNA emissions.
Another interesting graph (Figure UE-3) from VW presents the PNA emis-
sions compared to CO emissions. This graph shows the results obtained
from different gasoline engine equipped vehicles. Each point represents
one test vehicle. The graph allows for the following VW findings:
All measuring points are located in a band that spreads with
the increase in CO emissions, and the upper limit of which is
set by the ascending slope of approximately 5000 ygm PNA/100
gm CO and the bottom limit by 1000 ygm PNA/ 100 gm CO.
Water-cooled engine equipped production vehicles produce a
much higher PNA emission than do air-cooled engine equipped
production vehicles.
The distinguishing characteristics between water-cooled and
air-cooled system are futher affected by additional engine
characteristics. Nevertheless, it does not appear to be
unrealistic to expect the markedly cooler combustion chamber
walls in water-cooled engines to tend to produce higher PNA
emissions because the'se close-to-the-wall zones with their
inherent incomplete combustion due to wall-quenching, must be
considered highly responsible for the production of PNA emissions.
These quench zones also tend to be greater in water-cooled
engines.
6.5.3. Conclusions
The VW work confirms earlier work done by Exxon and UOP which shows
about 5% of the amount of PNA from non-catalyst cars is found in catalyst
cars. VW also showed that use of methanol as an alternate fuel reduces
PNA emissions and causes different types of PNAs to be emitted.
6-50
-------
Figure UE-3
10000 •
pg/Test
8000 -
6000 -
£000 -
2000-
GASOLINE PROCESS,HYDRO CARBON OPERATION
<
CL
O
B3 WANKEL WITH THERMAL REACTOR
n THERMAL REACTOR CONCEPTS
A CATALYST CONCEPTS
o WATER-COOLED
* AIR-COOLED
0 20 40 60 80 100 |i2Q UO 160 130 200 220
-~^ATALYSTJ-»-THERMAL REACTOR^—«^l PRODUCTION VEHICLE RANGE
RANGE • RANGE ^- WITHOUT EMISSION CONTROL
260 260 CO *.
g/Test ij
PNA EMISSIONS AS FUNCTION OF CO-
EMISSION.IN EUROPE-TEST
1
-------
An important area not addressed by any of the manufacturers is PNA
emissions from light duty Diesels. With the planned introduction of the
VW and Oldsmobile Diesels, this area is important.
6-52
-------
6.6. Diesel Particulate Emissions
6.6.1. Introduction and Background
Mobile sources contribute a small but still significant part of the
total suspended particulates in ambient air. For example, prior to the
introduction of unleaded fuel, automobiles using leaded fuels contributed
between 2 and 13% of the total suspended particulates in urban areas.
With about half of the air quality control regions around the country
3
over the total suspended particulate air quality standard of 75 u g/m
automotive particulate emissions are important to the attainment of the
total suspended particulate standard.
With vehicles burning fuel with maximum lead concentrations (containing
about 2.5 gm lead/gal), the resultant particulate emissions are 0.25
gm/mi. On the other hand, a non-catalyst vehicle burning unleaded fuel
emits only 0.01 gm/mi of particulate. Catalyst equipped vehicles emit
much less particulate than vehicles burning leaded fuel but more particulate
than non-catalyst vehicles burning unleaded fuel. An approximate particulate
emission rate for these catalyst cars is 0.02 gm/mi and is based on
testing of over 100 cars. Particulates from non-catalyst vehicles
burning unleaded fuel consist mostly of high molecular weight organic
compounds. Particulates from catalyst cars burning unleaded fuel consist
primarily of sulfuric acid and its water of hydration.
As the use of unleaded fuels in catalyst equipped vehicles displaces the
use of leaded fuels (which emit 0.25 gm/mi particulates), the automotive
contribution to urban air total suspended particulates will decrease
from 2-13% to about 0.2-1.3%.
The introduction of large numbers of light duty Diesels may reverse this
trend and increase the automotive contribution to total suspended particulates.
Therefore, it is important to investigate the quantity of Diesel particulates
emitted.
6-53
-------
6.6.2. Composition of Diesel Particulates
The composition of light duty Diesel particulates has not been com-
pletely determined. It is known that a major constituent of these
particulates is elemental carbon with the ability to adsorb other
compounds on it much like activated charcoal. The types of compounds
that have been found adsorbed are S02, sulfate, high molecular weight
organic compounds, and polynuclear aromatic hydrocarbons.
The quantity of hydrocarbons including polynuclear aromatics (PNA)
present in Diesel particulates is currently being investigated by EPA in
contracts with Southwest Research Institute (SwRI). A problem impeding
progress in this area is that the sampling and collection procedures are
in a rudimentary stage of development, particularly for PNA. Some
measurements are currently being conducted for one PNA species, benzo(a)pyrene,
in light duty Diesels under the EPA contract work with SwRI. Also, PNA
emissions were investigated to some extent by a previous CRC contract
with Gulf Research.
The amount of sulfate in Diesel particulate has been determined accurately
by EPA work (both in-house and contract work) and found to represent
only a small fraction (about 1-2%) of the sulfur in Diesel fuel. While
this conversion to sulfate is about the same for the Diesel as for non-
catalyst gasoline cars, Diesel sulfate emissions are greater than those
from non-catalyst gasoline cars (0.1 vs. 0.01 gm/mi) due to the higher
sulfur content of Diesel fuel compared to gasoline (about 0.23% vs.
0.03%). Still, sulfate emissions account for a very small part of the
total particulates from Diesels.
6-54
-------
There is some overlap between Diesel particulate and hydrocarbon measure-
ments. Some of the compounds measured as gaseous hydrocarbons by the
heated FID (at 375°) used in the Federal Test Procedure are also collected
as particulates since the dilution tunnel filter is about 120°F. The
amount of overlap has not been quantified accurately, but some fraction
of the particulate is being measured and subject to the HC emissions
standards.
Diesel particulates are very small in size with most of the Diesel
particulates below 1 micron in size. Attempts to determine the size
distribution by impactors have not been successful since impactors
separate particulates from 1 to 10 microns in size. This information on
particulate sizes is important to the determination of how far they
penetrate into the respiratory system.
The health effects associated with Diesel particulates have not been
determined. EPA has a contract with SwRI to do some bioassay tests on
Diesel particulates and is also doing some in-house animal tests in
Cincinnati.
6.6.3. Quantity of Diesel Particulates
Almost all of the work done to obtain emission factors on light duty
Diesels has been done by EPA either through contract or in-house testing.
Little data have been provided by the manufacturers.
These programs have employed the standard dilution tunnel approach to
measurement. Tests completed to date have included the vehicles shown
in Table 6-16. The results are also shown in the table.
The Oldsmobile prototype tested by EPA is similar to but not identical
to the version being considered by GM for production in 1978. EPA
contract work at SwRI involved testing a number of Diesel vehicles.
6-55
-------
Particulate emissions rates are given for several cycles including the
FTP, CFDS, and FET. Of special interest are the FTP results, since this
driving schedule represents driving patterns in an air quality control
region as a whole. Since gaseous emissions over the FTP are used in air
quality models and for emission factors in the EPA booklet AP-42, particulate
emission factors over the FTP can be used likewise. The CFDS represents
congested freeway driving while the FET represents rural highway-type
driving.
The Mercedes 300D was tested by both SwRI and EPA. The particulate
results obtained by EPA (0.43, 0.27, 0.25 gm/mi over the FTP, CFDS, and
FET) agree well with those obtained by SwRI, (0.49, 0.37, and 0.39 gm/mi
over the FTP, CFDS and FET). The gaseous emission numbers also agree
well. The same Oldsmobile Diesel was also tested at both labs but EPA
did not obtain particulate mass measurements during the tests. The
particulate numbers on the VW Diesel from SwRI (0.29, 0.26, and 0.25
gm/mi over the FTP, CFDS, and FET) agree well with those obtained by EPA
(0.32, 0.23, and 0.26 gm/mi over the FTP, CFDS, and FET). The gaseous
emission results between the two laboratories on the VW agree reasonably
well, but the HC at EPA (0.11 gm/mi) is lower than that found at SwRI
(0.37 gm/mi).
6-56
-------
Table 6-16
. Particulate Emission Rates of Light-Duty Diesel Vehicles
1.
2.
3.
4.
5.
6.
6a.
7.
7a.
8.
9.
10.
11.
12.
13.
14.
15.
16.
•-
Vehicle/Model
Mercedes 220D
Mercedes 240D
Mercedes 300D
Peugeot 204D
Perkins 6-247
VW Diesel*
VW Gasoline
Oldsmobile Diesel
Oldsmobile Gasoline*
Pinto Diesel
Postal Van Diesel
VW Rabbit Diesel
Chrysler Diesel
VW Rabbit Diesel
Mercedes 300D
Oldsmobile Diesel
Nissan Diesel
Peugeot 504
Engine
Disp.
(CID)
134
146
183
83
247
90
350
260
165
90
200
90
183
350
122
129
Inertia
wt
(Ibs)
3500
3500
4000
2500
4500
2250
4500
4500
2750
3000
2250
4500
2250
4500
3500
3000
FTP Gaseous Emissions
Test
Lab
SwRI
SwRI
SwRI
SwRI
SwRI
SwRI
SwRI
SwRI
SwRI
AA
AA
AA
AA
AA
AA
AA
RTP
RTP
HC
g/mile
0.18
0.29
0.16
1.11
0.72
0.37
0.23
0.76
0.39
0.24
0.14
0.11
0.26
0.23
0.16
- 0.52
0.25
0.49
CO
g/mile
1.30
0.97
0.85
1.71
2.87
0.79
3.70
2.00
2.16
1.21
1.47
0.98
1.22
1.11
0.92
1.92
1.10
1.45
NOx
g/mile
1.05
1.27
1.72
0.68
1.50
0.87
1.01
1.13
1.37
0.76
2.54
1.22
1.82
0.93
2.17
1.47
1.37
2.30
Sulfates
rag/mile
SET
9.2l|
14.12|
16.53,
8.217
18.26
7.02
1.65
16.62
20.90
8.53
10.14
9.34
12.24
5.47
7.85
8.52
7.0
Particulates g/mile Fuel Eco. (MPG)
FTP
0.60
0.48
0.49
0.38
0.81
0.29
0.007
0.92
0.009
0.35
0.47
0.32
0.19
0.31
0.43
0.3
0.51
SET
0.43
0.36
0.37
0.24
0.49
0.26
0.002
0.58
0.016
0.38
0.27
0.23
0.17
0.20
0.27
0.42
.31
HFET
0.38
0.31
0.39
0.30
0.54
0.25
0.003
0.48
0.021
0.28
0.24
0.26
0..17
0.20
0.25
0.39
0;33
0.40
FET
33.5
33.7
30.0
43.8
28.3
53.7
36.1
2
23.0
54.5
37.8
51.0
25.7
5.17
29.5
2
33.8
35.9
FTP
25.9
25.7
23.8
35.9
25.7
42.7
24.6
2
15.5
44.8
29.9
31.6
22.4
40.6
23.8
2
26.2
26.4
*Gasoline car included for comparison to diesel counterpart
Sulfate values for these tests are over the FTP.
GM requested the diesel fuel economy for the Oldsmobile be kept confidential at this time.
-------
The four tests on the three Mercedes vehicles tested gave an average
particulate mass of 0.50 gm/mi over the FTP. The two Peugeot vehicles
tested gave 0.45 gm/mi of particulate over the FTP. The Nissan had
particulate emissions of 0.30 gm/mi. The VW Rabbit Diesel also had
particulate emissions of 0.30 gm/mi. This level of particulate emissions
is still over 40 times the level found from the VW gasoline prototype.
The Oldsmobile Diesel emitted a relatively high level of particulates
(0.92 gm/mi over the FTP). This level is 100 times the level found from
the gasoline counterpart (an Oldsmobile 350 gasoline vehicle). However,
GM states that this Oldsmobile Diesel is a prototype and may be changed
before final production.
The two gasoline counterparts (Oldsmobile and VW) had somewhat lower
particulate emissions than found for vehicles equipped with catalysts
general (0.02 gm/mi). The 0.02 gm/mi number is based on extensive tests
of over a hundred cars and should be considered a number for general
comparison of gasoline and Diesel cars. For individual models, it is
more appropriate to use numbers from Diesel-gasoline counterparts if
available.
The average particulate emissions from the four tests on the three
Mercedes, the two tests on the VW, the test on the Oldsmobile, the two
Peugeots, and the Nissan are about 0.5 gm/mi over the FTP. The number
can be used as an approximate Diesel particulate emission factor for air
quality models. It can be updated as more data are available. The
numbers from the experimental vehicles (Pinto, Postal Van, and Chrysler
Diesels) were not included in this average but would not significantly
change it.
6.6.4. Conclusions
Tests conducted to date show very high particulate emissions from light
6-58
-------
duty Diesels (0.5 gm/mi) which is about 25 times comparable values for
gasoline vehicles equipped with catalysts (about 0.02 gm/mi).
These particulates consist of elemental carbon as well as various hydro-
carbon compounds and small quantities of sulfate. EPA does not know yet
what the health effects of these particulates are.
6-59
-------
SECTION 7
INDIVIDUAL MANUFACTURER REVIEWS
7.1. Domestic Manufacturers
7.1.1. American Motors
7.1.1.1. Systems Under Development
American Motors is currently planning to continue using powerplants
built basically from current engine tooling for the 1978 through 1982
model years, thus their present emission control system development
efforts are directed toward internal combustion, reciprocating, four
stroke, gasoline fueled engines.
Oxidation Catalysts
Pelleted type oxidation catalysts are currently being considered by AMC
for use on all 4, 6, and 8 cylinder engines in meeting the near term
Federal emissions standards. To meet near term California emissions
standards, AMC uses monolithic, start catalysts on the 6 and 8 cylinder
engines with the 8 cylinder engine having two monolithic start catalysts
and two pelleted catalysts. These catalysts are described in Table AMC-
1.
AMC has recently started testing on three improved underfloor oxidation
catalysts. These catalysts are supplied by AC Spark Plug. They are all
160 cu in. pelleted catalysts. One of these has a 0.05 troy ounce
loading with a 71% Pt/29% Pd compositon but, AMC apparently does not
know the loading or composition ratio of the others. They are testing
these catalysts with and without the above described monolithic start
catalysts. These systems are described in Table AMC-2.
-------
Table AMC-1
AMERICAN MOTORS OXIDATION CATALYSTS
Type
Substrate -
Volume -
Composition -
Loading -
Location -
Cat. Supplier
Canner -
Main Catalyst
Oxidation
Pellet
160 cu in.
71% Pt/29% Pd
0.05 troy ounces
Underfloor
Engelhard
AC Spark Plug
Start Catalyst
Oxidation
Monolith
21.5 cu in.
67% Pt/33% Pd
0.02 troy ounces
At Exhaust Manifold
Engelhard
Maremont
7-2
-------
Table AMC-2
AMERICAN MOTORS IMPROVED OXIDATION CATALYST VEHICLES
Vehicle Model:
Vehicle Number:
Inertia Weight:
Engine/Garb:
Ignition System:
Transmission:
Axle Ratio:
Catalyst System:
Pacer
D76-46C
and
D76-47C
Pacer
D76-76C
and
D76-78C
Pacer
D76-50C
and
D76-51C
Air Injection:
EGR:
3500 Ibs 3500 Ibs
258 CID 6 cylinder/2V
3500 Ibs
Electronic
Breakerless
Auto
3.08:1
Monolith Start Cat
Electronic
Breakerless
Auto
3.08:1
Monolith Start Cat
Electronic
Breakerless
Auto
3.08:1
No
Start
Cat
23 cu in.
67% Pt/33% Pd
0.02 t.o.
23 cu in.
67% Pt/33% Pd
0.02 t.o.
Underfloor Pellet Underfloor Pellet Underfloor Pellet
160 cu in.
71% Pt/29% Pd
0.05 t.o.
160 cu in.
Loading and
Ratio Unknown
belt driven vane belt driven vane
type air pump, type air pump,
exh port injection exh port injection
carb port vac carb port vac
exh B/P mod valve exh B/P mod valve
160 cu in.
Loading and
Ratio Unknown
belt driven vane
type air pump,
exh port injection
carb port vac
exh B/P mod valve
0 mi Veh //I
Veh #2
5000 mi Veh #1
Veh #2
10,000 mi Veh //I
HC
CO NOx MPG
0.41, 1.2, 1.48, 11.5
0.38, 2.1, 1.28, 11.4
0.46, 3.5, 1.24, 12.8
HC
CO NOx MPG
HC
CO NOx MPG
0.39, 4.7, 0.84, 11.2 0.47, 6.3, 1.24, 12.4
0.46, 4.2, 1.51, 12.65 0.51, 4.8, 1.19, 11.6
0.43, 3.1, 1.11, 12.0
0.41, 4.3, 1.36, 12.9
0.55, 4.9, 1.08, 13.3
0.52, 4.9, 1.32, 12.7
7-3
-------
3-Way Catalysts
AMC is investigating a 3-way catalyst system using closed loop air-fuel
ratio control on a Pacer equipped with a 6 cylinder engine. They are
evaluating two different oxygen sensors (Bosch and AC) plus pelleted and
two-biscuit monolithic catalysts with air injection between the two
monolithic catalysts. The vehicle is described in Table AMC-3. Best
results to date have come from the AC 0- sensor and Maremont two-biscuit
monolithic catalyst.
Table AMC-3
CLOSED LOOP 3-WAY CATALYST VEHICLE
Vehicle Model:
Vehicle Number:
Inertia Weight:
Engine:
Fuel System:
Intake:
Exhaust:
Ignition system:
Transmission:
Axle Ratio:
Catalyst System:
Air Injection:
EGR:
Oxygen Sensor:
Pacer
D66 - 63K
3500 Ibs.
6-cyl. 258 CID
Carter IV Garb with exh 0- feedback control
Cast iron EFE
6-port cast iron with bi-metal control
exh heat valve
Electronic breakerless
Auto
3.08:1
160 cu in. pellet or dual biscuit monolith
Belt driven vane type (two biscuit cat. only)
None
Bosch or AC
7-4
-------
Best emission levels have been 0.28 HC, 1.0 CO, 0.70 NOx, 14.1 MPG with
u
levels typically being about 0.3 HC, 1.8 CO, 0.74 NOx, 16 MPG with this
vehicle. AMC judges these results as encouraging against a 2.0 NOx
standard but concludes that it falls short of the targets required to
achieve 0.41 HC and 3.4 CO standards.
3-Way Plus Oxidation Catalysts
AMC currently projects that a 3-way plus oxidation catalyst system will
be used on their 6 and 8 cylinder engines to meet emission levels of
0.41 HC, 3.4 CO, and 1.0 NOx and on their 4 and 6 cylinder engines to
meet 0.41 HC, 3.4 CO, and 0.4 NOx.
Durability testing (SOHIO Courtesy Fleet Program) was conducted on four
vehicles - two equipped with Walker and two with Maremont 3-way plus
oxidation catalyst systems. These vehicles are described in Table AMC-
4. Both systems used carburetors calibrated to flow roughly constant
air-fuel ratios rather than a closed loop control system. Though the
Maremont systems performed slightly better, the four vehicles were
unable to achieve AMC's target emission level of 0.41 HC, 9 CO, 1.0 NOx.
One of the Maremont equipped vehicles finished the 50,000 mile durability
test at 0.42 HC, 7.4 CO, 0.72 NOx, 13.0 MPG . Vehicle system problems
unrelated to the catalyst systems such as sticking fresh air opening
ducts in air cleaner snorkels and burned out choke gaskets caused some
of the excessive CO levels on two vehicles. Throttle cable sticking was
noted on all four vehicles early in the testing due to dust shield
deterioration but no effect on emissions was indicated by AMC. Other
problems included two vehicles with cracked exhaust manifolds at 31,711
and 39,025 miles but no problems occurred in the exhaust system or
catalyst components. Table AMC-5 shows the catalyst conversion effi-
ciencies at the beginning and end of durability testing. Most of the
catalyst systems retained good HC and CO conversion efficiency. NOx
conversion efficiencies were less predictable and the variability could
not be explained by AMC. -
7-5
-------
Table AMC-4
SOHIO Fleet 3-Way Plus Oxidation Catalyst Vehicle Descriptions
Vehicle
Test Inertia
Trans/Axle Ratio
Ignition System
EGR System
Air Injection
Carburetor
Matador w/258 CID w/Quench Combustion Chamber
4000 Ibs
Auto/3.08:1
Distributor - #106 Motorcraft
Spark plugs - N12Y (.035" gap)
Idle RPM - 700 in drive
Timing - 8° BTDC (160°F CTO* spark override)
Back pressure modulated (115°F CTO EGR override)
Air to exhaust manifold until 115°F CTO
switches air to catalyst
Carter BBD 2V with 92 MMJ and special
metering rod. Typical A/F ratio as follows:
Speed (MPH)
A/F
Man Vac (in He)
Idle
10
20
30
40
50
60
60
60
60
14.0
14.6
14.5
14.7
14.8
14.8
14.4
14.2
14.0
13.5
14.2
16.2
14.6
14.0
11.0
10.8
5.0
4.0
3.0
2.0
* CTO = coolant temperature override
7-6
-------
Table AMC-5
SOHIO Fleet - 50 MPH 3-Way Plus Oxidation Catalyst Conversion Efficiencies
50 MPH S.S.
BEFORE CONVERTER
Veh. #
#37
#38
#42
#43
Catalyst
Canner MILES
Walker 52
41825
47449
Walker 41
32352
39092
48397
Maremont 44
40245
49625
Maremont 45
16888
23417
31712
40584
HC
ppm
600
1410
1300
300
1300
1300
1043
700
910
1200
400
1400
1200
1020
1350
CO
%
2.42
4.18
5.36
2.58
4.38
5.36
0.80
2.58.
2.84
1.0
0.81
5.82
1.85
2.27
2.40
NOx
Ppm
1400
505
158
133.7
225
177
252
138.7
192
223
250
84
82
98
94
AFTER CONVERTER
HC
PPm
13.5
1075
180
10
200
160
135
15.5
50
68
33.0
270
200
190
200
CO
ppm/%
362. 6p*
3.62%
2.76%
1115p
2.14%
2.20%
0.04%
884. Ip
2.28%
0.04%
163. Ip
2.36%
0.16%
0.10%
0.06%""~
NOx
PPm
40.5
458
126
68.5
145
141
48
75.5
97
140
32.0
60
53
63
69
EFFICIENCY
HC
%
97.5
23.7
86.2
96.7
84.6
87.7
87.0
97.8
94.5
94.3
91.8
80.7
83.3
81.4
85.2
CO
%
98.6
13.4
48.5
96.0
51.1
58.9
95.0
96.6
19.7
96.0
98.0
59.5
91.4
95.6
97.5
NOx
%
71.1
9.3
20.3
49
35.6
20.3
80.9
46
49.4
37.2
87.2
28.6
35.4
35.7
26.6
* p = ppm
-------
Dual Catalysts
The Gould dual catalyst program has been terminated by AMC. Two vehicles,
originally equipped as 1977 California cars with carburetor modifications
to maintain a 14.0 A/F ratio, were involved in the program with the only
difference being the use of a pelleted oxidation catalyst on one vehicle
with a monolith on the other. Overall HC and CO results were somewhat
better with the monolith but AMC seems unconvinced that this may be due
to faster warmup characteristics as compared to the pelleted catalyst.
After witnessing high nickel particulate emissions using 0.03% versus
0.01% sulfur fuel, AMC concluded that the presence of sulfur in the fuel
attacks the nickel in the reducing catalyst and would eventually destroy
its reducing efficiency. These systems are described in Tables AMC-6
and AMC-7 and results from the concluding tests are presented in Table
AMC-8.
Other Systems
Some development work has been done on a Bendix programmed electronic
breakerless ignition system installed in a 6 cylinder, 232 CID Pacer.
Test data seem to indicate potential fuel economy benefits, however,
more optimization work appears necessary.
AMC is expected to expand their engine mapping efforts in conducting
multi-parameter engine optimization studies. They apparently are not
now utilizing a computer in their data analysis but anticipate the need
for one along with associated test equipment and additional manpower.
In view of their projected future use of programmed spark, EGR, air
injection, and carburetor operation through a central digital micro-
processor, the lack of adequate computing facilities could be a problem.
7-8
-------
VEHICLE
TARGET STANDARDS
TEST INERTIA
N/V
TRANSMISSION
ENGINE TYPE
DISPLACEMENT
CARBURETOR
CHOKE
INTAKE MANIFOLD
EGR SYSTEM
EXHAUST MANIFOLD
IGNITION SYSTEM
VACUUM ADVANCE CONTROL
CATALYST TYPE
a. Active Material
b. Loading
Table AMC-6
GOULD DUAL CATALYST
D50-2L (K)
0.41 HC, 3.4 CO, and 0.40 NOx - 1978 statutory
3500 Ibs.
42.5 with a 3.08:1 axle ratio
Automatic, 3 speed
6 cylinder, inline, reciprocating
258 C.I.D. with revised 1977 combustion chamber
1976 IV with modified metering to achieve 14.0 A/F
+ 0.5 at part throttle
Bimetal, hot air control with electric assist
1976 Hot Spot Manifold
Backpressure regulated with 115°F coolant over-ride
10 in H_0 sensor and .410 EGR orifice plate
1976 production
1976 breakerless, modified curve with 8° BTDC initial
1976 California TCS-above 35 mph only. Dist. vacuum
advance controlled by a 160°F coolant switch.
GEM 68 REDUCING
Nickel alloy
non-noble metals
OXIDATION-UNDERFLOOR
1975-76 production
A. C. Spark Plug
Model 160
c. Substrate Structure Wire Mesh
d. Manufacturer
e. Canner
f. Volume
AIR INJECTION
a. Supplier
b. Modulation
Gould, Inc.
Gould, Inc.
110 cu in.
Getter = 40 cu in.; Red. = 70 cu in.
19 CID Vane Pump at 1:1 ratio
Saginaw Steering Gear
Production diverter valve removed
c. Injection Location Exhaust manifold cold; oxidizing converter inlet hot
d. Switching Control 160°F engine coolant switch to RPD air switching valve
7-9
-------
VEHICLE
TARGET STANDARDS
TEST INERTIA
N/V
TRANSMISSION
ENGINE TYPE
DISPLACEMENT
CARBURETOR
CHOKE
INTAKE MANIFOLD
EGR SYSTEM
EXHAUST MANIFOLD
IGNITION SYSTEM
VACUUM ADVANCE CONTROL
CATALYST TYPE
a. Active Material
b. Loading
c. Substrate Structure
d. Manufacturer
e. Canner
f. Volume
AIR INJECTION
a. Supplier
b. Modulation
c. Injection Location
d. Switching Control
Table AMC-7
GOULD DUAL CATALYST
D50-4L (K)
0.41 HC, 3.4 CO, 0.40 NOx 1978 Statutory
3500 Ibs.
41.0
Automatic, 3-speed
Inline, reciprocating, 6-cyUnder
258 CID revised 1977 combustion chamber
1976 IV with modified metering to achieve 14.0 A/F
+ 0.5 at part throttle
Bimetal, hot air control with electric assist
1976 Hot Spot Manifold
Backpressure regulated with 115°F coolant over-ride
10 in H20 sensor and .310 EGR orifice plate
1976 production
Breakerless, 1976 modified with 8° BTDC initial
1976 California TCS-above 35 mph only. Vacuum advance
controlled by a 160°F coolant switch
GEM 68 REDUCING CONVERTER OXIDIZING CONVERTER
Nickel alloy
Non-noble metals
Wire mesh
Gould, Inc.
Gould, Inc.
Platinum/Palladium
0.095 Troy ounces
Monolith
Engelhard Inc.
Maremont Corp.
110 cu in. 102 cu in. total
GETTER = 40 cu in., RED. = 70 cu in.
19 CID vane pump at 1:1 ratio
Saginaw Steering Gear
Production diverter valve removed
Exhaust ports cold; oxidizing converter inlet hot
160°F engine coolant switch
7-10
-------
Table AMC-8
GOULD DUAL CATALYST - CONCLUDING TESTS
Baseline (AMC lab)*
Baseline (Gould lab)*
NOx catalyst
installed (150 miles)
Run //2
(Gould lab)
Recheck (AMC lab)
Recalibrate for
driveability and MPG
choke 1 lean (was 4 lean)
New air switching valve
New air cleaner
2.73 axle
New heat tube
6072 Test Miles
11,000 Test Miles
HC
.329
.69
D50-2L (K) (AC-Gem 68)
CO NOx
(grams/mile)
1.59
D50-4L (K) (Maremont - Gem 68)
.35
.37
.36
.452
16,000 Test Miles
.47
.81
.49
.65
4.42
5.93
2.00
1.12
.55
.53
.54
.542
.501
.52
.48
.50
.52
.53
.52
13.5
13.3
13.4
13.8
14.7
14.6
14.6
14.4
14.6
14.5
14.7
15.6
15.1
14.6
14.9
14.7
HC CO NOx MPG
Baseline* .381
Run #2 .338
Average - .359
(grams/mile)
1.97 1.38
1.50 1.62
1.73 1.50
NOx catalyst .204 1.71
installed .285 0.90
Average - .244 1.30
80 Miles .328 3.11
.751
.684
.718
.511
14.5
14.7
14.7
14.5
3014 Miles
Run #2
Average -
8221 Miles
Run #2
Run #3
Average -
New air
switching valve
(8400 miles) Avg. .407 3.67 1.01 14.9
Baseline* .220 4.0 1.97 15.2
Recheck .220 2.6 2.07 15.2
Average - .220 3.3 2.02 15.2
.375
.367
.371
.296
.351
.334
.327
.423
.392
3.41
3.28
3.34
1.64
3.27
3.02
2.64
4.56
2.78
.482
.433
.458
.794
.853
.727
.791
.962
1.05
13.6
14.5
14.1
15.9
15.7
15.1
15.5
15.0
14.7
* 1977 California specification with carburetor modification to 14.0:1 A/F ratio.
-------
Other Development Efforts
Three vehicles equipped with lean burn systems are currently being
studied by AMC. These are described in Table AMC-9. The test data from
these vehicles indicate a potential for achieving a 0.41 HC, 3.4 CO, 2.0
NOx standard. Substantial improvement in NOx control is needed for this
system to meet a 1.0 or lower NOx level, and increases in catalyst
volume may be needed to maintain HC and CO control at high mileage.
7.1.1.2. Systems to be Used at Various Emission Levels
AMC's choices of systems to be used at various emission levels are
presented in Tables AMC-10 through AMC-15. At the 0.41 HC, 3.4 CO, 2
NOx level AMC is considering three alternatives which will be dependent
upon the availability of vendor prototype hardware, vendor engineering
assistance, and production units. For statutory emission levels, AMC
has not yet projected what systems will be used on their 8 cylinder
engines.
The estimated future retail costs for the systems to be used by AMC to
meet various emission levels occurring in various years compared to
previous years are presented in Tables AMC-16 through AMC-18. The
cumulative costs for these systems compared with AMC's 1977 emission
control systems are shown in Table AMC-18. To meet statutory emission
levels sometime after 1981 with their 6-cylinder engines, AMC estimates
that it will cost the consumer approximately $538 over the price of
their 1977 6 cylinder models. All the costs shown in these tables
represent approximately a 17% markup over dealer costs.
7.1.1.3. Durability Testing
Normally, AMC does not conduct any durability testing until the systems
chosen are reasonably near final design. Some data are available,
however, for three out of four of AMC's 1977 California durability fleet
and for four 3-way plus oxidation catalyst vehicles in the SOHIO fleet
described in Table AMC-4. These data are presented in Tables AMC-19 and
AMC-20.
7-12
-------
Table AMC-9
LEAN BURN VEHICLES
Vehicle Model:
Vehicle Number:
Inertia Weight:
Engine:
Fuel System:
Intake:
Exhaust:
Ignition System:
Transmission:
Axle Ratio:
Catalyst System:
Air Injection:
ECU:
Selected Test
Data
(Low Mileage)
Hornet
D60-23L
3500 Ibs
6-cy Under, OHV, 258 CID
2 V carburetor
Cast iron, EFE, exhaust heat
6-port, cast iron, bi-metal control heat valve
Chrysler electronic programmed spark control
3-speed automatic
2.53:1
45 cu. In. oxidizing monolith
None
None
HC . . CO NOx MPG MPG.
— — — — • — u n
0.27 0.9 1.24 17.0 24.9
0.34 1.1 1.31 16.9 25.9
0.33 1.1 1.49 15.0 22.1
0.31 1.0 1.6 16.4 24.7
0.31 1.0 1.63 16.5 22.4
0.34 0.8 1.22 16.1
Hornet
D70-40C
3500 Ibs
6-cy Under, OHV, 258 CID
2 V carburetor
Cast iron, EFE, exhaust heat
6-port, cast iron, bi-metal control hei
Chrysler electronic programmed spark cc
3-speed automatic
2.73:1
45 cu. In. oxidizing monolith
None
None
HC CO SOx MPGu MPG^
0.37 1.3 1.66 15.8 22.0
0.36 1.3 1.19 14.9 20.7
Hornet
D70-50C
3500 Ibs
6-cylinder, OHV, 258 CH>
2V carburetor
Cast iron, EFE, exhaust heat
6-port, cast iron, bl-netal control
Chrysler electronic programmed spark
4-speed manual
2.73:1
45 cu. in. oxidizing monolith
None
Rone
-------
Table AMC-10
EMISSION CONTROL SYSTEMS FOR 1978 - 1.5 HC. 15 CO. 2.0 NOx. 6 EVAP
Engine
Engine Modifications
Inertia Weight
Transmissions
Fuel Supply and
Induction
Exh. Man. and
Ports
Ignition System
ECR System
Air Injection
Oit:tlvsts
Kv.ip. Svstt-ra
staged 2V carb, alum H-0
heated intake, TAG
4-port cast iron
breaker point with
mech and vac adv
spark port vac control
belt driven vane type
pump, port injection
oxidation, pellet, underfloor
closed fuel system, tank and
carb vented to induction system
purged activated charcoal canister
Sub Compact
232, 258 CID
c/o '77
3000, 3500 Ibs
3 & 4 spd man,
3 spd auto
6-cyl
Compact
232, 258 CID
c/o '77
3500 Ibs
3 & 4 spd man,
3 spd auto
Mid/Large
258 CID
c/o '77
4000 Ibs
3 spd auto
Compact
304 CID
c/o '77
4000 Ibs
3 spd auto
8 cyl
Mtd/Largf
304, 160 CID
c/o '77
4500 Ibs
3 spd ;iuto
IV 2V carb, cast iron EFE exh heated
int man, TAG
6-port cas t iron
electronic breakerless with mech and vac adv
spark port vac and exh B/F control
belt driven vane type pump, port injection
with and without
underfloor oxidation
with and without
underfloor oxidation
oxidation
pellet,
underfloor
closed fuel system, tank and carb vented to
induction system purged activated charcoal canister
2V carb with cast Iron 2-lcvel
intake with crossover oxh heat, TAC
two 4-port cast iron exh man
with bi-metal control heat valve
elect, breakerless with mech and vac adv
spk port vac and exh B/P control
belt driven vane pump, port injection
oxidation, pellet, underfloor
closed fuel sys, tank and c.irb vented
to ind sys purged activ charcoal can
-------
i
H»
u>
Table AMC-11
EMISSION CONTROL SYSTEMS FOR 1978-0.41 HC. 9 CO. 1.5 NOx. 6 EVAP
4-cyl
Sub Compact
Engine 121 CID
Engine Modifications c/o '77
Inertia Weight
Transmissions
Fuel Supply and
Induction
Exh Man and
Ports
Ignition System
EGR System
Air Injection
Catalysts
Evap System
3000 Ibs
4 spd man, 3 spd auto
6-cyl
Sub Compact
258
c/o
3500
.0 • 4 spd man,
CID
'77
Ibs
3 spd auto
Mid /Large
258
c/o
3500
4 spd man,
CID
'77
Ibs
3 spd auto
8-cyl
Compact
304
c/o
4000
3 spd
CID
'77
Ibs
auto
Mid/Large
360
c/o
4500
3 spd
CID
'77
Ibs
auto
staged 2V carb, alum
H.O heated intake, TAC
4-port cast iron
breaker point with
mech and vac adv-
spark port vac control
belt driven vane type
underfloor oxidizing pellet
closed fuel system, tank and carb
vented to induction system purged
activated charcoal canister
IV , 2V carb, cast iron EFE exh
heated int man, TAC
6-port cast iron, bi-metal heat valve
electronic breakerless distributor
with mech and vac adv
spk port vac and exh B/P control
belt driven vane pump, port injection
underfloor oxidizing pellet with
monolith start cat
closed fuel system, tank and carb
vented to induction system purged
activated charcoal canister
2V carb, cast iron 2-level exh
crossover heated int man, TAC
two 4-port cast iron exh man
with bi-metal conduct heat valve
electronic breakerless distributor
with mech and vac adv
spk port vac and exh B/P control
belt driven vane pump, port injection
2 underfloor oxidizing 2 underfloor oxidizing
pellet with monolith pellet with 2 monolith
start cat start cat
closed fuel system, tank and carb
vented to induction system purged
activated charcoal canister
-------
- Table AMC-12
EMISSION CONTROL SYSTEMS FOR 1979/80- 0.41 HC. 3.A CO. 2.0 NOx. 6 EVAP
Engine
Engine Modifications
Inertia Weight
Transmissions
Fuel Supply and
Induction
4-cyl
Sub Compact
121 CID
Compact
121 CID
6-cyl (first choice)*
Sub Compact Compact
232, 258 CID 232, 258 CID
c/o '78 with c/o '78 with
hydraulic tappets hydraulic tappets
2750, 3000 Ibs 3000 Ibs
4 spd man, 3 spd auto 4 spd man, 3 spd auto
staged 2 V carb with closed loop fuel
control, alum H.O heated int man, TAG
Exh Man and
Ports
4-port cast iron 4-port cast iron
Ignition System electronic breakerless electronic breakerless
EGR System
Air Injection
Catalysts
Evap System
none
3-way
none
none
3-way
closed fuel system, fuel tank and
carb vented to induction system
purged activated charcoal canister
basic '78 c/o, possible new
combustion chamber for 258
3000 Ibs 3500 Ibs
3 & 4 spd man, 3 spd auto
IV , 2V carb with cast iron
EFE exh heated int man, TAC
6-port cast iron with bi-metal
controlled exh heat to int
elect breakerless with programmed spk
none
improved oxidizing cat
closed fuel system, fuel tank and
carb vented to induction system
purged activated charcoal canister
8-cyl
Compact
304 CID
basic '78 c/o
4000 Ibs
3 spd auto
2v carb, cast iron
2-level exh crossover
heated int, TAC
two 4-port cast iron
with bi-metal heat
elect breakerless with
programmed spk
spk port vac and
exh B/P control
belt driven pump
port injection
improved oxidizing cat
closed fuel system, fuel tank
and carb vented to induction
system purged activated
charcoal canister
* See Table AMC-13 for second and third choice systems for 6-cyl
-------
Table AMC-13
EMISSION CONTROL SYSTEMS FOR 1979/80 -0.41 HC, 3.4 CO. 2.0 NOx. 6 EVAP
I
I-1
-»J
Engine
Engine Modifications
Inertia Weight
Transmissions
Fuel Supply and
Induction
Exh Man'and
Ports
Ignition System
EGR System
Air Injection
Catalysts
Evap System
6-cyl (second choice)*
Sub Compact Compact
232, 258 CID
basic "78 c/o, possible new
combustion chamber for 258
3000 Ibs 3500 Ibs
3 & 4 spd man, 3 spd auto
2V carb with closed loop fuel
control, cast iron EFE exh
heated int, TAC
6-port cast iron with bi-metal
heat control
electronic breakerless with
TCS if required
none
none
new 3-way
closed fuel system, fuel tank and
carb vented to induction system
purged activated charcoal canister
6-cyl (third choice)*
Sub Compact Compact
232, 258 CID
basic '78 c/o, possible new
combustion chamber for 258
3000 Ibs 3500 Ibs
3 & 4 spd man, 3 spd auto
2 V carb with closed loop fuel
control, cast iron EFE exh
heated int, TAC
6-port cast iron with bi-metal
heat control
electronic breakerless with
TCS if required
none
belt driven pump to
downstream ox cat
new 3-way with
downstream ox cat
closed fuel system, fuel tank and
carb vented to induction system
purged activated charcoal canister
* See Table AMC-12 for first choice system for 6-cyl
-------
I
M
00
Table AMC-14
Emission Control Systems for 1981-0.41 HC. 3.4 CO, 1.0 NOx, 2 Evap
4-cyl
Engine
Sub Compact Compact
121 CID
Engine Modifications basic '80 c/o, modifications
not determined
Inertia Weight 2500 Ibs 3000 Ibs
Transmissions 4 spd man, 3 spd auto
Fuel Supply and
Induction
Exh Man and
Ports.
Ignition System
EGR System
Air Injection
Catalysts
Evap System
staged 2 V oarb with closed
loop fuel control, alum H.O heated
int, TAC
4-port cast iron
elect breakerless with programmed spk
possible spk port vac control
none
3-way
closed loop fuel system, tank and
carb bowl vented to ind sys purged
charcoal canister, improved carb and
air cleaner sealing
6-cyl
Sub Compact
232, 258 CID
basic '80 c/o, possible
displacement and other mods
3000 Ibs
3500 Ibs
4 spd man with possible O.D.,
3 spd auto
staged 2 V carb with closed loop
and fully programmed fuel control thru
central digital processor
6-port cast iron with bi-metal
ext heat
elect breakerless with central digital
microprocessor programmed control thru
multi-inputs including eng spd, load,
inlet air temp, baro, H_0 temp,
and others
spk port vac and exh B/P control or
microprocessor programmed
programmed air injection
3-way with downstream ox cat
closed loop fuel system, tank and
carb bowl vented to ind sys purged
charcoal canister, improved carb and
air cleaner sealing
8-cyl
304 CID
basic '80, modifications
not determined
3500 Ibs
improved efficiency
3 spd auto
2V carb with closed loop
fully programmed fuel control
thru central digital microprocessor
two 4-port cast iron with
bi-metal heat control
elect breakerless with central digital
microprocessor programmed control thru
multi-inputs including eng spd, load,
inlet air temp, baro, H?0 temp,
and others
programmed EGR
programmed air injection
3-way with downstream ox cat
closed loop fuel system, tank and
carb bowl vented to ind sys purged
charcoal canister, improved carb and
air cleaner sealing
-------
I
I—1
vO
Engine
Engine Modifications
Inertia Weight
.Transmissions
Fuel Supply and
Induction
Exh Man and
Ignition System
EGR System
Air Injection
Catalysts
Evap System
Table AMC-15
EMISSION CONTROL SYSTEMS FOR 198X -Q.41 HC. 3.4 CO. Q.4NOxt 2 EVAP
4-cyl 6-cyl
Sub Compact
121 CID
not determined
2500 Ibs 3000 Ibs
4 & 5 spd man, improved
efficiency lock-up auto
staged 2V with closed loop and
fully programmed fuel control thru
central microprocessor, alum H_0 heated
int, TAC, possible fuel injection
4-port cast iron with
thermal management
elect breakerless with central
microprocessor spk programming
programmed EGR
programmed air injection
3-way with downstream oxidation catalyst
closed fuel system, tank and carb
bowl vented to ind sys purged
charcoal canister, improved carb
and air cleaner sealing
Sub Compact
Mid/Large
same basic engines as in '81 with possible
displacement changes and weight reduction
probable 2500 Ibs
not determined
probable 3000 Ibs
probable 3500 Ibs
possible multi-speed man with OD and improved
lock-up auto
staged 2V carb with closed loop and
fully programmed fuel control thru
central digital microprocessor, possible fuel injection
6-port cast iron with controlled
exh heat to int with thermal management
elect breakerless with central digital microprocessor
control thru multi-inputs including engine spd, load,
inlet air temp, baro, H.O temp, and others
programmed EGR
programmed air injection
3-way with downstream oxidation catalyst
closed fuel system, tank and carb
bowl vented to ind sys purged
charcoal canister, improved carb
and air cleaner sealing
8-cyl
No
Projections
Available
at this
Time
-------
I
NJ
O
Induction System
(outside air)
Ignition System
Revised (Ford Distr)
Air Injection System
Revision
Catalyst
-Underfloor
-Pre-cat.
-Exh. System
Revision
Evap. System
-4 port canister
-Carb. mech
bowl vent
-Add'l hoses, etc.
-Aux. Fuel trap in
bow 1 vent line
Table AMC-16
AMC ESTIMATED FUTURE RETAIL EMISSIONS HARDWARE COSTS*
1978 VS 1977
1.5 HC. 15 CO. 2.0 NOx
4-Cyl 6-Cyl 8-Cyl
(Man & Auto) (Man & Auto) (Auto)
0.54
2.85
11.99
0.54
0.54
1.69
1.01
18.08
4.56
11.99
0.54
2.36
1.01
1.35
21.81
0.41 HC. 9 CO. 1.5 NOx
4-Cyl 6-Cyl
(Man & Auto) (Man & Auto)
2.85 4.56
11.99 11.99
6.49
c/o '77 c/o '77
48.71
1.35
0.54 0.54
1.69
1.01
-
—
115 . 00
97.41
2.71
0.54
2.36
1.01
1.46
7.03
68.14
237.04
* Cost represent approx. 17% over dealer costs.
Dollar basis 1977.
-------
Table AMC-17
Ignition System
-Microprocessor (Spk Control)
-Sensors, misc. elect, cables
-Distr., elect, ignition
4-Cyl
(Man & Auto)
AMC ESTIMATED FUTURE RETAIL EMISSIONS HARDWARE COSTS*
1979/80 VS 1978
0.41 HC. 3.4 CO. 2.0 NOx
First Choice
6-Cyl
(Man & Auto)
68.67
40.59
8-Cyl
(Man & Auto)
68.67
40.59
Second Choice
6-Cyl
(Man & Auto)
Third Choice
6-Cyl
(Man & Auto)
23.67
136.84
3-Way Catalyst
3-Way plus Ox. Cat.
Exh. S.ys. Modifications
Feedback Carburetor
Oxygen Sensor
T.C.S. System
Revised air guard
Delete
-EGR System
-Air Guard System
-Underfloor Ox. Cat.
* Costs represent approximately 17% over dealer costs.
Dollar basis 1977.
136.84
- -
-
32.31
13.53
- . -
-
(9.65) (9.65)
(39.85) (39.85)
(115.00)
41.85 59.76
- • -
1.35
18.27
14.05
5.21
"
(9.65)
(39.85)
(115.00)
109.26 11.22
202.94
1.35
18.27
14.05
5.21
34.85
(9.65)
(39.85)
(115.00)
112.17
-------
Table AMC-18
AMC ESTIMATED FUTURE RETAIL EMISSIONS HARDWARE COSTS*
i
NJ
ro
1981 vs
0.41
:.)
icessor
other)
1979/80 (First Choice)
HC, 3.4 CO, 1.0 NOx
4-Cyl
(Man & Auto)
_
_
1.35
67.65
43.29
20.81
N/A
-
_
133.10
6-Cyl
(Man & Auto)
136.32
202.94
1.35
7.28
2.71
20.81
34.85
74.41
(115.00)
(67.65)
298.02
198X vs 1981
0.41 HC, 3.4 CO, 0.4NOx
6-Cyl
(Man & Auto)
Fuel Injection 137.35
Programmed EGR 27.58
164.93
Cumulative vs. 1977 Costa*
4-Cyl 6-Cyl 8-Cyl
1978 0.54 18.08 21.81
'79/'80 42.39 77.84 131.07
1981 175.49 375.86 N/R
198X N/R 540.79 N/R
N/R - Not reported
Feedback Carb.
(includes 0_ sensor, etc.)
New 3-Way Cat.
Exh. System Modifications
Other Sensors for Distr.
Central Digital Microprocessor
Control
Distributor Revisions
for above
Improved Air Cleaner and
Carb Sealing
Programed Air Injection
(new microprocessor and other)
Delete
-3-Way Cat.
-Microprocessor
* Costs represent approximately 17% over dealer costs.
Dollar basis 1977.
* Includes evaporative systems costs.
-------
Table AMC-19
AMC Durability Vehicles
Family
I-2C
Actual
System Miles
4,838
9,855
14,838
19,838
24,934
29,913
29,932
34,938
39,918
44,940
49,767
Calc. Df
Cert. DF
Family
I-C
Actual
System Miles
4,854
9,835
14,835
19,834
24,853
29,837
29,854
34,827
39,835
44,832
49,901
Calc. DF
Cert. DF
Family
II-C
Actual
System Miles
4,838
9,833
14,831
19,816
24,839
29,833
29,851
34,831
39,833
44,836
49,832
Calc. DF
Cert. DF
HC
0.40
0.50
0.41
0.43
0.41
0.44
0.42
0.48
0.39
0.44
0.45
1.012
1.012
HC
0.39
0.37
0.45
0.44
0.39
0.43
0.37
0.40
0.37
0.35
0.28
0.791
1.000
HC
0.32
0.35
0.43
0.67
0.46
0.37
0.41
0. 32
0.31
0.39
0.45
0.961
1.000
CID
258
CO
2.0
4.2
3.3
3.2
3.4
3.5
3.2
3.1
3.3
2.2
4.1
1.083
1.083
CID
232
CO
0.7
1.4
4.8
3.8
0.9
1.4
1.1
1.7
1.0
0.9
0.7
0.356
1.000
CID
304
CO
3.5
4.8
5.6
8.7
4.2
3.8
3.7
3.3
4.5
6.0
7.3
1.237
1.237
System
EGR+AIR+Start Catalysts-
Oxidation Catalyst
NOx
1.23
1.17
1.34
1.08
1.10 .
1.04
1.00
1.20
1.22
1.58
1.41
1.200
1.200
System
EGR+AIR+Start Catalyst+
Oxidation Catalyst
NOx
1.24
1.11
1.27
1.17
1.15
1.02
1.04
1.15
1.04
1.14
1.01
0.850
1.000
System
MPG
14.0
14.1
13.7
15.1
14.6
14.7
14.6
14.3
14.7
12.2
13.9
0.958
-
MPGo
14.7
14.0
12.7
12.6
13.6
14.1
14.6
14.2
13.4
13.1
14.5
1.003
-
EGR+AIR+2 Start Catalyst+
2 Oxidation Catalyst
NOx
1.15
1.32
1.48
1.30
1.16
1.21
1.18
1.46
1.57
1.24
1.33
1.085
1.085
MPG
11.7
11.4
10.6
11.5
11.9
11.8
11.5
11.4
11.4
11.2
11.1
0.989
-
7-23
-------
Table AMC-20
SOHIO FLEET* - 3-WAY PLUS OXIDATION CATALYST DURABILITY -DATA
Veh
37
38
42
43
Catalyst Supplier/Canner
Englehard/Walker
Calc. DF
Engelhard/Walker
Calc. DF
Engelhard /Maremont
,
Calc. DF
Engelhard/Maremont
Calc. DF
Mileage
41
52
366
8754
16618
23902
32155
39025
47449
23
41
353
8112
16615
26067
32353
39092
48146
16
28
44
245
7711
16422
24423
31961
40245
49625
17
34
45
238
432
8009
16888
23417
31711
40584
HC
0.36
0.36
0-30
0.44
0.43
0.37
0.45
0.49
0.62
1.5522
0.48
0.42
0.31
0.40
0.41
0.49
0.53
0.42
0.52
1.3007
0.53
0.45
0.44
0.31
0.36
0.52
0.42
0.49
0.68
0.42
1.3159
0.46
0.33
0.40
0.33
0.30
0.42
0.46
0.55
1.52
0.39
2.2373
CO
5.2
5.1
4.8
4.5
8.1
3.0
7.8
9.1
11.9
3.2961
5.0
5.5
4.3
6.2
21.2
18.7
12.4
7.0
10.0
0.7175
6.8
4.2
5.4
4.0
8.2
12.5
4.6
10.9
11.0
7.4
0.9529
3.4
1.2
3.6
12.5
4.1
6.9
7.4
12.2
26.4
5.0
1.9632
NOx
0.61
0.62
0.84
1.05
0.84
1.06
1.04
1.14
1.24
1.3461
0.75
0.72
0.92
0.78
0.60
0.76
0.93
1.15
0.92
1.6319
0.65
0.70
0.64
0.88
1.04
0.76
0.88
0.74
1.02
0-72
0.8319
0.63
0.59
0.78
0.82
0.95
1.06
0.74
1.00
0.90
1.10
1.1431
MPG
11.9
12.1
12.6
13.7
12.5
13.5
13.6
13.2
1.0054
11.3
11.8
12.1
11.5
12.9
13.4
12.9
1.2520
11.4
11.9
11.7
12.4
12.6
11.8
12.6
13.9
13.0
1.0928
11.1
11.5
11.6
11.9
11.8
13.3
13.7
* See Table AMC-4 for more vehicle information.
7-24
-------
7.1.1.4. Problems and Progress
Many of AMC's problems appear to hinge on economic considerations. AMC
is vendor dependent for components which comprise emission control
systems such as catalysts, air pumps, ignition systems, carburetors, and
EGR Systems. According to AMC they are limited as to the range of
control techniques that can be explored because of the requisite financial
commitments that must be made between AMC and vendors.
AMC is also reluctant to investigate the Diesel for its potential in
achieving good fuel economy. They claim the uncertainty that exists in
regard to future NOx standards and the lack of demonstrated ability of
existing Diesel designs to meet stringent future NOx standards precludes
their investment of the capital required to design, develop, and tool a
Diesel engine for production. AMC did not indicate whether or not the
4-cylinder engine they are currently using (which is adapted from a
VW/Audi design) would be capable of being Dieselized in the same manner
as the VW engine.
Related to engine and system development, AMC does not have the instru-
mentation to measure such dynamic aspects as engine exhaust flow rate,
air flow rate, EGR flow, and air injection flow as a function of time
during the Federal Test Procedure. They also do not have computer
controlled test equipment for conducting engine dynamometer and chassis
dynamometer multi-parameter optimizing programs. They do, however,
anticipate expanding their work in such optimization programs. This
work must be accomplished soon if AMC is to provide programmed control
of fuel metering, ignition timing, EGR, and air injection to meet emission
levels of 0.41 HC, 3.4 CO, 1.0 NOx and lower.
AMC is concerned with proposed and anticipated changes to EPA test
procedures for 1979, presumably the 2 gram evaporative standard, in-
creasing the light duty truck coverage to include up to 8500 Ibs GVW,
and fuel economy regulation changes in road load determination, inertia
7-25
-------
weight increments, fuel specifications, and using actual distance
traveled. They claim some of the test procedure changes will result in
an increase in stringency of both the emission standards and fuel
economy requirements while creating confusion and doubt in their currently
scheduled programs and plans. AMC also estimates these procedural
changes will mean an 8% loss in fuel economy with an equal emissions
penalty for their 1979 model year vehicles.
If the Federal protocols (i.e. no line crossing) were used in analyzing
their 1977 California durability vehicle data, all of AMC's durability
vehicles would not have met the 0.41 HC, 9 CO, 1.5 NOx standards. AMC
contends that there is insufficient lead time to redesign or recalibrate
their California systems and run the required 50,000 mile durability
distance to release these systems for 1978 49-state production.
If 1977 emission standards are carried over to 1978, AMC expects to
maintain an approximate fleet fuel economy of 19.2 MPG compared to the
legislated requirement of 18 MPG . AMC's development efforts targeted
for 1979+ are directed toward vehicles with 4 and 6-cylinder engines.
AMC estimates that these engines will represent the largest part of
their sales volume for this period and thus will have a major impact on
their ability to meet future fuel economy requirements.
7-26 -
-------
7.1.2. Chrysler
7.1.2.1. Systems Under Development
Oxidation Catalyst Systems
Chrysler's oxidation catalyst system work over the past year has been
fairly limited. The following areas have received some attention:
1. Improved oxidation catalysts.
2. Air switching during closed throttle.
3. Modulated air injection.
Chrysler reported a limited amount of work aimed at upgrading conven-
tional oxidation catalysts. This was confined for the most part to
evaluating vendor samples with new arrangements of noble metal and
substrate. Chrysler reported that none of these evidenced improved
activity as compared to 1977 production models. Of interest was a
British catalyst which featured a metallic honeycomb substrate. This
catalyst showed high activity at very low inlet oxygen levels but its
activity dropped off sharply at higher oxygen levels.
Chrysler has evaluated samples of precious metal, perovskite oxidation
catalysts supplied to them by DuPont. Perovskite catalysts bind up the
catalytically active metal in a perovskite crystal lattice. Test evidence
has indicated that this provides some degree of protection against lead
poisoning. Chrysler's evaluation procedure involved a dynamometer
procedure which simulated 100 hours of operation on fuel containing 1.5
gm/gal lead. Chrysler reported that although HC activity for the complete
catalyst was not diminished, a more detailed investigation showed that
the front edge of the catalyst had lost much of its activity. This
implies that as with conventional catalysts, the lead poisoning proceeds
from the front edge on toward the rear of the catalyst, but how long
this takes and how much of the activity is lost in the interim is unclear.
Chrysler performed single cylinder studies to determine the effect of
7-27
-------
single cylinder-studies to^ determine the effect of temperature on the HC
and CO conversion efficiency of perovskite catalysts using leaded fuel.
This study indicated that at high temperature (1200°F) a 2 1/2 hour
exposure to leaded fuel showed little effect upon CO conversion effi-
ciency but caused a 50% drop in HC conversion efficiency. The HC
conversion efficiency remained constant, but the CO conversion effi-
ciency dropped for low temperature (800°F) exposure. The HC conversion
efficiencies for these perovskite catalysts were substantially lower
than the HC conversion efficiencies of conventional oxidation catalysts.
Chrysler reported on their evaluation of an air switching system that
provides air to the exhaust manifolds during closed throttle modes.
These modes produce relatively cool, HC rich, exhaust; thus manifold air
injection should improve conversion efficiency. However, to prolong the
life of the start catalyst in this system, it is necessary to switch air
downstream during normal warmed-up operation. Chrysler evaluated this
system by comparing emission results to emission results with the coolant
controlled air switching system. The closed throttle switching system
also contained the coolant controlled switching feature. The coolant
controlled system is standard equipment on 1977 California models. It
diverts air from the exhaust manifold to a position downstream of the
start catalyst after the coolant temperature reaches 98° F. Table
Chrysler-1 shows the test results of the two systems. Chrysler indicated
that the closed throttle air injection system would not be pursued
further because the HC benefit did not warrant the increased cost and
complexity.
Table Chrysler-1
Closed Throttle Air Switching
4000 IW, 225 cu in. , Start Catalyst Plus Main Catalyst
System
Air switched upstream on
closed throttles (4 run avg.)
Air switched upstream for
HC
0.683
0.745
CO
4.53
4.39
NOx
0.618
0.559
Fuel Economy-MFC
14.66
14.68
coolant below 98°F (3 run avg.)
7-28
-------
Following up on earlier dynamometer work which showed that a significant
improvement in HC conversion efficiency resulted from a decrease in
excess secondary air injection, Chrysler outfitted a vehicle with an air
modulation system. The modulating valve was a Dodge Colt air switching
valve which Chrysler had modified to provide about 2.5% excess air.
Test results for this system are shown in Table Chrysler-2. These
results show degraded HC and CO emission control for the modulated
system. These results did not confirm the trend indicated by the
dynamometer results. It is not known how well the air control system
performed in providing the desired amount of injected air as a function
of speed and load. Considering the sulfuric acid emission benefits (and
potential gaseous emission benefits) of truly optimized air injection
systems it appears that optimized air injection systems, possibly more
sophisticated than the one investigated by Chrysler, may require furthur
development work.
Table Chrysler-2
Modulated Air Testing
1975 Dart, 225 cu in., Oxidation and Reduction Catalysts
System
Full Air (2 test avg.)
Modulated Air (2 test avg.)
HC
0.10
0.13
CO
0.36
1.65
NOx
0.98
1.00
3-Way Catalyst Systems
Chrysler has assembled and tested both single and dual bed 3-way catalyst
systems. These systems are called a 3-way catalyst system, and a 3-way
plus oxidation catalyst (3-way + OC) system.
Chrysler believes that the most promising formulations for 3-way cat-
alysts are platinum/rhodium and perovskite stabilized ruthenium plus
platinum. Their evaluation procedure consists of laboratory testing,
dynamometer testing, vehicle screening testing, and durability testing.
7-29
-------
These different phases tend to be sequential, i.e., a catalyst formu-
lation will progress from one test phase to the next if results continue
to indicate good potential. Unfortunately, Chrysler's vehicle test
work, both durability and screening, may have been hampered by the use
of open loop air-fuel metering. They have identified Electronic Fuel
Metering (EFM) as an essential constituent of their future 3-way catalyst
systems. The need for EFM or an alternative advanced fuel metering
system is related to the conversion characteristics of 3-way catalysts.
These dictate that the air-fuel ratio must be held fairly precisely at
stoichiometric in order to maintain good conversion efficiency for all
three pollutants. Chrysler's catalyst development efforts have for the
most part been done with conventional carburetors operating open loop,
i.e., no feedback. This may have made it difficult for Chrysler to
accurately assess the capabilities of the catalyst formulations under
consideration.
The majority of the platinum/rhodium catalysts evaluated have had Pt/Rh
ratios in the area of 5/1. Catalyst volumes have been small (20 to 30
cu in. is typical) which is possibly the result of space limitations.
Most of Chrysler's screening tests for conventional 3-way catalyst
systems were conducted on five cars. These cars represented a fairly
broad range of engines and inertia weights. All employed conventional
carburetors. Table Chrysler-3 shows the best emission results achieved
along with brief vehicle and catalyst descriptions.
7-30
-------
Table Chrysler-3
3-Way Catalyst Screening
Conventionally Carbureted Systems
1977**
Model CID Catalyst HC CO NOx MPG MPG
J— — — u u_
Valiant 225 Chrysler 5/1* 0.32 2.A 0.71 16.6 16.7
Duster 225 Engelhard 5/1 0.31 2.6 0.77 19.1 16.7
VW Rabbit 97 Unspecified 0.37 8.8 0.52 25.4 24.9
Volare 225 Unspecified 0.59 7.9 3.41 16.5 16.7
Fury 318 Chrysler 5/1 1.09 10.3 0.95 13.6 13.6
* Ratio of platinum to rhodium
** Fuel economy of 1977 Certification durability car.
Chrysler reported one vehicle evaluation of a Pt/Rh catalyst on a system
that included closed loop carburetion. This involved two 30 cu in.
catalysts installed on a Plymouth Fury equipped with a 360 CID engine
and a Holley closed loop feedback carburetor. One 1975 FTP test was
reported with the following emission results: 0.367 HC, 8.96 CO and
1.64 NOx.
Chrysler has done a limited amount of 3-way catalyst screening using a
360 CID Plymouth equipped with Bendix Electronic Fuel Injection (EFI).
This system included EGR, closed loop oxygen sensor control with adjust-
able features, and secondary air during warmup. The system was used to
evaluate two types of perovskite 3-way catalysts. The first type was
composed of two biscuits. One biscuit was a perovskite material supplied
by DuPont and the other was of unspecified content supplied by UOP.
Chrysler tried several air-fuel ratio and EGR settings and also reversed
the order of the biscuits. The best emissions from this system were
0.32 HC, 4.81 CO and 0.65 NOx.
7-31
-------
3-Way Plus Oxidation Catalyst Systems
Chrysler has identified 3-way plus oxidation catalyst (3-way + OC)
systems as their first choice approach to meet the 0.41 HC, 3.4 CO, 1.0
NOx and 0.41 HC, 3.4 CO, 0.4 NOx levels. The appeal of the 3-way + OC
system is due in a large part to the improved control of HC and CO
derived from the extra "clean up" oxidation catalyst. This can also
give NOx control benefits by allowing the system to be biased slightly
rich of stoichiometric, thereby increasing the NOx control. The HC and
CO control suffer when this is done but the increased HC and CO may be
able to be handled in the oxidation catalyst. An important drawback to
3-way + OC is that the sulfuric acid emissions are likely to be higher
than with a 3-way catalyst system alone. Another disadvantage is that
any ammonia generated in the 3-way catalyst is converted to NOx in the
oxidation catalyst, thus decreasing the net system NOx conversion.
As with their single bed 3-way catalyst development work, Chrysler may
have been handicapped in their evaluation of 3-way + OC catalyst per-
formance by a lack of suitable advanced fuel metering systems. Further
constraining their performance were the packaging limitations present in
current body structures. Thus catalyst sizes were fairly small with 22
cu in. being the most common size. Chrysler's evaluation efforts have
been directed primarily toward platinum/rhodium and perovskite stabilized
ruthenium plus platinum formulations. The use of the term "stabilized"
to describe Chrysler's ruthenium-containing catalyst is Chrysler's.
Tests run to measure ruthenium loss (see Section 6) have shown that the
stabilization may not be effective. Chrysler reported low mileage
catalyst screening testing on twelve vehicles. Table Chrysler-4 shows
some of the better emission results for this testing along with brief
system descriptions.
7-32
-------
Table Chrysler-4
3-Way + Oxidation Catalyst Screening
Conventional Carburetor Systems
Model CID Catalyst
Valiant 318 Chrysler Pt/Rh
Fury 318 Chrysler Pt/Rh
Dart 360 Chrysler Pt/Rh
Duster 225 Chrysler Pt/Rh
HC
0.20
0.26
0.35
0.49
CO
3.35
3.6
3.5
2.2
NOx
0.63
0.56
0.73
0.34
MPG
u
11.7
11.9
11.1
17.9
1977*
MPG
u
13.6
-
16.7
* Fuel economy of 1977 Certification durability car.
Chrysler reported test results for a 3-way + OC system on the Holley
closed loop carburetor equipped Fury described earlier. Table Chrysler-
5 shows emission results for a Chrysler perovskite 3-way + OC system on
this car. Also shown are results of this same 3-way + OC system but
with an open loop four barrel carburetor.
System
3-way cat.*
closed loop
3-way** + OC
closed loop, EGR
3-way** + OC
Table Chrysler-5
3-Way Catalyst System Results
500 IW Fury 360 CID V-8
3-way** + OC
open loop, EGR
H£
0.367
0.24
0.17
closed loop, no EGR 0.19
0.22
0.21
0.33
CO
8.96
1.65
2.44
NOx
1.64
0.81
0.83
MPG
11.6
3.51
1.67
1.85
1.75
0.96
0.78
0.73
0.87
10.4
10.6
11.6
11.6
11.5
* Pt/Rh
** Perovskite
7-33
-------
Dual Catalyst Systems
In last year's submission Chrysler reported some promising results from
their base metal NOx catalyst development program. Chrysler's latest
system at that time included their M 23AC' base metal catalyst along
with air switching and heat conservation techniques, i.e., exhaust port
liners and an insulated exhaust system. At the time of the last report,
a car with this system had accumulated 20,000 miles of durability while
remaining well below statutory emission levels. Chrysler provided an
update on this car in this year's report.
Some degradation of emission control occurred between 20,000 and 28,000
miles. At 20,000 miles the emissions were 0.32 HC, 2.50 CO, 0.36 NOx.
At 28,000 miles the emissions were 0.40 HC, 5.73 CO, 0.49 NOx (5 test
average). At 28,000 miles an involved series of carburetor adjustments
were made. Chrysler then discovered changes in the pressure drop across
the catalysts. Investigating this, they found that all of the catalyst
material was missing from one container and part of the material was
missing from the other. There is some uncertainty about the role played
in this failure by the extensive carburetor calibration work.
Chrysler has been working on alternative base metal formulations and
substrate types. These include higher chromium alloy formulations and
ceramic substrates. Chrysler installed one of the higher chromium alloy
catalysts on one side of the vehicle used for the previously described
test. The other side contained the original formulation. After 30,000
miles Chrysler reported that both catalysts showed significant material
loss but the high chromium alloy had fared better. The ceramic substrate
catalyst and an International Nickel Company catalyst (INCO 1013) have
shown favorable dynamometer test performance and Chrysler intends to
start vehicle testing soon. Some interesting data were presented
showing the effects of heat conservation techniques on dual catalyst
systems using base metal NOx catalysts. Table Chrysler- 6 shows this
data for a system identical to the original test vehicle for the MR
23AC* catalyst.
7-34
-------
Table Chrysler-6
Effect of Heat Conservation Techniques
1976 Plymouth Fury, 360
System
Production manifolds,
Insulated
Indicated
manifolds ,
improvement
CID
, Dual
HC
no
port
port
liners
liners
0.
0.
45
34
24%
Catalyst
CO
4.04
2.93
27%
NOx
0
0
.64
.34
47%
MPG
u_
11.37
11.
-2%
18
In their previous status report Chrysler reported the accumulation of
15,000 miles of durability on a Gould GEM 68 dual catalyst system. At
this point,- Chrysler noted a substantial increase in pressure drop
across the NOx catalysts and suspended testing. Subsequent study by
Gould of the durability characteristics of GEM 68 has revealed an
intolerance to fuel containing fuel sulfur levels representative of
typical pump fuel. This intolerance results in depletion of the catalyst
and an increase in pressure drop across the catalyst. The Chrysler
experience appears to fit this pattern.
Other Development Efforts
Chrysler is evaluating several advanced fuel metering systems for
possible future useage in oxidation catalyst, 3-way catalyst, and dual
catalyst systems. These systems are Bendix Electronic Fuel Injection
(EFI), the Holley Closed Loop Carburetor, the Carter TQ carburetor, and
two Chrysler-developed,closed loop carburetors.
Chrysler's testing of the Bendix EFI system has shown that when operating
open loop the system produces less than half the air-fuel ratio fluctua-
tions normally experienced with carburetion. This system is currently
being evaluated on a 3-way catalyst equipped 1975 Plymouth with a 360
CID engine. The most recent emission testing of this system showed 0.32
HC, 4.81 CO, 0.65 NOx and 11.08 MPG . The urban fuel economy of this
same model in 1977 durability testing was 11.94 MPG.
7-35
-------
The Holley closed loop carburetor has undergone preliminary evaluation
testing by Chrysler with initially favorable results. Chrysler reports
that this closed loop fuel metering control system shows only about one
fourth of the variation normally seen with carburetors. Emission results
for this carburetor on a 3-way catalyst system were shown in Table
Chrysler-5.
Both the Carter TQ carburetor and Chrysler's in-house developed car-
buretors are closed loop feedback systems which employ linear solenoids
to move control needles in the air bleeds of the main and idle circuits.
The details provided were quite sketchy but the TQ carburetor is assumed
to be a two barrel or four barrel unit since it has been installed on a
V-8 engine. One of the Chrysler carburetors is a modified Holley model
1945. This model is a one barrel unit used on the 225 CID six cylinder
engine. Both the Chrysler and Carter systems have recently been installed
in vehicles equipped with 3-way catalysts. No emission data were reported.
Chrysler is working on a second closed loop carburetor of their own
which is a four barrel unit and reportedly includes several interesting
features. These include electronic compensation for sensor aging, open
loop operation during warm-up, and monitoring features to detect incipient
and actual failures. The compensation feature for sensor aging was
originally intended to make use of the small alternating current "ripple"
component produced by the sensor when the air-fuel mixture is at the
stoichiometric point. The circuitry would evidently have keyed upon
this and automatically adjusted for drift due to aging. Chrysler
reported that problems were experienced with the circuitry which resulted
in inadequate response. They are now pursuing an alternate approach to
achieve sensor aging compensation. The system for detecting sensor
deterioration and failure monitors the electrical resistance of the
sensor. This resistance increases significantly as it deteriorates.
This increase is detected and the circuitry is programmed to revert to
open loop operation. This feature could be used to alert the operator
to the need for sensor replacement. No dynamometer or vehicle emission
data were provided for this carburetor.
7-36
-------
Chrysler is also developing their own Electronic Fuel Metering (EFM)
system. This system features a proprietary air flow measurement tech-
nique and a single point fuel injection system. It will sense important
operating parameters such as coolant temperature, atmospheric pressure
and ambient temperature and tailor the fuel metering to accurately
compensate for changing conditions. Air-fuel ratio fluctuations and
cylinder-to-cylinder variation will reportedly be reduced by improved
transient response characteristics and better air-fuel mixing. One
version of the system will include closed loop oxygen sensor feedback
control. The electronic control unit is currently an analog unit but
eventually will become digital for improved control capability and
compatibility with Electronic Spark Advance (ESA) which is also being
converted to a digital system. Chrysler appears to be putting a sig-.
nificant portion of its research and development resources into EFM and
is relying on it to play a central role in future systems. Chrysler has
three potential modes of operation in mind. These are:
1. very lean (target is vicinity of 20:1)
2. stoichiometric, open loop
3. stoichiometric, oxygen sensor feedback
Some of the better low mileage test results from vehicles equipped with
EFM, ESA, and oxidation catalysts can be found in the following Table.
No air injection or EGR were used on the test vehicles.
7-37
-------
Table Chrysler-7
Low Mileage EFM Results*
Car HC CO NOx MPG.. MPG,
#293
#294
#529
#639
0.364
0.329
0.324
0.231
0.194
0.335
0.268
0.276
0.350
0.345
0.409
0.403
0.286
0.322
1.77
2.38
2.76
1.35
1.34
2.53
2.26
3.31
2.87
2.06
1.30
2.02
1.77
1.60
1.53
1.42
1.82
2.07
2.00
1.56
1.44
1.55
1.53
1.17
1.22
1.34
1.60
1.43
9.4
11.0
9.7
9.7
9.2
8.0
10.1
10.5
11.8
11.9
11.9
12.9
9.9
11.2
n
12.8
19.9
19.0
18.9
18.9
-
17.8
19.1
19.7
19.8
19.4
19.9
18.8
19.3
* All vehicles were equipped with 360 CID engines and
automatic transmissions.
Chrysler reported that comparative durability testing is in progress on
oxygen sensors from three manufacturers. These are Bosch, UOP and |
Nippondenso. To date, the durability performance of the three is \
approximately equivalent and ranges from about 10,000 to 38,000 miles.
The main cause of failure is reportedly water splash which occurs when
the cars are driven through a water splash trough. Chrysler is working
on a splash protection system which should be a straightforward type of
problem to solve.
Chrysler reported evaluation work on an electrically heated vaporizer
tube which is situated in the carburetor above the throttle blade.
This device is intended to permit leaner mixtures for cold start and
7-38
-------
warm-up than a conventional choke. Chrysler reported that they were
unable to achieve the degree of precision in vaporization control that
they deemed necessary. As a result, Chrysler has suspended work on this
item.
Some of the better reported results from two vehicles equipped with the
vaporizer are shown in Table Chrysler-8. Car 216 had a lean calibration,
and did not use a catalyst, air injection, or EGR. Car 633 was equipped
with a base metal NOx catalyst, an oxidation catalyst, air injection and
EGR. Both vehicles used 318 CID engines and were tested at 4500 IW.
Table Chrysler-8
Low Mileage Vaporizer Testing
MPG,
Car
#216
#216
#216
#633*
#633*
#633*
#633
#633
#633
HC
1.19
1.21
1.25
0.42
0.47
0.40
0.49
0.45
0.39
CO
6.07
6.14
5.68
2.84
3.18
3.50
1.26
2.57
2.46
NOx
1.96
2.28
2.02
0.33
0.43
0.38
0.40
0.44
0.52
MPG
11.4
11.7
12.0
13.3
11.1
12.2
11.4
11.6
11.5
15.8
18.5
17.7
18.3
* without vaporizer
Chrysler reported development work on turbulent flow (TF) intake manifold
systems for the 225 CID six cylinder engine and a V-8 (displacement
unspecified). Chrysler's units are variations of the Ethyl system and
include a provision for admitting EGR through an annular plate at the
base of the carburetor. No emission results were presented but Table
Chrysler-9 presents data showing substantial improvements in cylinder-
to-cylinder distribution of EGR and fuel-air mixture.
7-39
-------
Table Chrysler-9
Turbulent Flow Manifold System
Manifold EGR Variation Fuel-Air Variation
Production 1-bbl. 5.7 to 16.7% 2.1 to 7.2%
TF 1-bbl 2.2 to 7.3% 1.7 to 3.0%
Production 2-bbl 11.2 to 24.4% 3.4 to 7.7%
TF 2-bbl 2.3 to 8.1% 1.4 to 3.6%
Chrysler is performing engine studies to determine the optimum scheduling
of their electronic fuel metering (EFM), electronic spark advance (ESA),
and electronic EGR (EEGR). Ultimately, these systems will be controlled
through a central microprocessor which will be programmed to provide
optimum scheduling of fuel-air ratio, spark advance and EGR. Chrysler
is currently working on a computer model to select the optimum schedules.
Although Chrysler's current ESA and EFM systems are analog units, they
intend to switch over to digital units as soon as practicable. This
should provide improved control and programming capability.
Chrysler reports progress on their electronically controlled EGR (EEGR)
system. Problems were experienced in the following areas: debugging
the electronics, achieving sufficient flow rates, and getting adequate
flow during acceleration modes without getting excessive rates during
cruise modes. As a result of these difficulities Chrysler has decided
to wait until their central electronic control unit is available before
introducing EEGR. Theoretically this central unit will have a greatly
improved ability to specify the optimum amount of EGR.
Chrysler reported development studies on cooled EGR. The principal
benefits here would be a decrease in maximum combustion temperature,
decreased octane requirement, and increased EGR flow rate through a
given orifice (minor benefit). Chrysler is using two schemes to accomplish
7-40
-------
the cooling; water and air. The air cooling arrangement appears to be
the most effective in terms of temperature drop of the EGR. However,
vehicle test data were inconclusive. Two vehicles were equipped with
the air cooled systems and one car with the water cooled. One of the air
cooled vehicles showed a reduction in NOx but the other two vehicles
showed increases.
Chrysler has evaluated the effectiveness of slowing the warm-up of
engine coolant and reducing the coolant temperature as a means of reduc-
ing NOx. This is accomplished by bypassing the thermostat and routing
the coolant directly to the radiator. A temperature actuated switching
mechanism does this at warm ambient temperatures only, due to the
driveability problems that would occur at cold temperatures. It is
presumed that the bypass flow would be operative primarily during the
emission test conditions. As shown in Table Chrysler-10 the test data
showed some reduction in NOx emissions but at a concurrent penalty in HC
emissions and fuel economy. Chrysler has specified this system for
future systems meeting stricter emission levels. They also refer to
this system as the dual range thermostat.
Table Chrysler-10
Thermostat Bypass System
Baseline
Bypass
HC
0.16
0.19
1975 Dodge, 360
CO
3.1
2.4
CID, 5000 IW
NOx
1.41
1.23
MPG
10.5
10.3
MPG.
19.0
18.8
Chrysler reported continued work on ceramic coated combustion chambers.
The objective is to insulate the chamber, thereby creating higher
surface temperatures which should decrease HC emissions. To date
Chrysler's work has been limited to single cylinder engine testing, but
7-41
-------
results have been promising (lower HC and decreased deposits). The big
question marks are octane requirements and durability. Chrysler will
reportedly equip a six cylinder engine with the ceramic coated com-
bustion chamber to evaluate these factors. It has taken a long time for
this project to move from the single-cylinder phase of testing to the
multi-cylinder engine dynamometer phase.
Having established the emission control and fuel economy benefits of
exhaust port liners, Chrysler is studying the feasibility of making them
an integral part of the head casting. This new configuration has been
designed and will soon be tried out in production core boxes.
Chrysler is evaluating two systems intended to improve highway fuel
economy by selectively switching out engine cylinders. No technical
details or data were provided but the systems were identified as the
"Dolza" and "Eaton Valve Selector" systems. The systems will be eval-
uated for their effect upon emissions, fuel economy and driveability.
Chrysler is undertaking two Diesel engine development and evaluation
programs. The first is aimed at adapting an open chamber Diesel to
automotive use. Open chamber Diesels are generally harsher, noisier,
harder starting, and produce more NOx emissions than pre-chamber engines.
However, open chamber engines have the advantage of lower heat transfer
and reduced flow losses and, thus have potentially better fuel economy.
To overcome the cited drawbacks, Chrysler is working with Eaton on a
concept called staged injection. Chrysler did not provide any technical
details or test data but they did express confidence that this concept
will result in peak pressures that are low enough to permit the use of
gasoline engine structures and materials. Chrysler also indicates that
NOx levels below 1 gm/mi are attainable while still maintaining a
significant fuel economy advantage over conventional gasoline engines.
Chrysler reported that these promising expectations are based upon
initial single cylinder test results. A multi-cylinder version is now
7-42
-------
undergoing testing, and procurement is reportedly underway for a 225 CID
production engine equipped with this approach.
Chrysler is also pursuing the more conventional approach to Dieselizing
a gasoline engine, i.e., pre-chamber heads and a more conventional
injection pump. Ricardo and Company Engineers Ltd. of England is under
contract to Chrysler to convert a six cylinder gasoline engine. The
Ricardo Comet Mark V indirect injection combustion chamber will be used
along with a Roosa Master injection system. Dynamometer testing is now
underway and a vehicle installation is slated for early 1977.
Chrysler presented some interesting test data showing the effect of EGR
and injection retard on the NOx and fuel economy of a Nissan Diesel.
Table Chrysler-11 is extracted directly from their submission.
Table Chrysler-11
Effect of EGR and Injection Retard
on a Nissan Diesel
EGR Timing NOx Fuel Economy
No Standard Baseline
No 5° Retard Down 21% Down .8%
No 10° Retard Down 37% Down 8.1%
8% Standard Down 32% 0
8% 5° Retard Down 53% Down 5.7%
16% 5° Advance Down 32% Down .4%
16% Standard Down 63% Down 3.6%
16% 5° Retard Down 63% Down 1.6%
.Table Chrysler-12 shows the fuel economy and emissions of the vehicle
with different timing/EGR calibrations. HC and CO tended to increase as
NOx was reduced. The hydrocarbon performance for this vehicle was worse
at all conditions than many other Diesel vehicles tested by EPA. At the
lowest NOx level, (0.7 NOx) the fuel economy was less than 2% lower than
the baseline (1.9 NOx) case, although CO was 5.0 gm/mi and HC was not
reported.
7-43
-------
Table Chrysler-12
Effect of EGR and Injection Timing
Car 439 -
• Nissan Diesel
CCVS Emissions
EGR
No
No
No
Q"/ •
0/0
8%
16%
16%
16%
1977
1977
Injection Timing
Standard (Base)
5° Retard
10° Retard
Standard
5° Retard
5° Advance
Standard (3)
5° Retard
Plymouth Volare (3500 IW)
Dodge Aspen* (4000 IW)
HC
1.0
1.3
3.4
1.7
1.9
1.8
2.2
-
1.0
1.0
CO
1.7
1.7
3.0
2.7
3.1
4.1
4.4
5.0
10
15
, gm/mi
NOx
1.9
1.5
1.2
1.3
0.9
1.3
0.7
0.7
2.0
2.0
Fuel Economy,
Urban
22.0
22.0
20.4
21.8
21.1
21.9
21.2
22.2
20
17
Hwy
29.0
28.4
26.2
29.4
26.7
27.3
26.4
26.4
29
24
MPG
Comp
24.7
24.5
22.7
24.7
23.3
24.6
23.8
24.3
23
20
* 1977 Certification results; best fuel economy of comparable vehicles.
(IW not specified for Diesel Dart)
-------
While Chrysler's ERDA-supported efforts on the automotive gas turbine
program are continuing, they estimate that the anticipated performance
of the engine under development will fall substantially short of the
1985 fuel economy requirements. Chrysler believes that ceramic materials
are a must for the hot rotating components if a gas turbine is to be
competitive with current engines on a fuel economy and initial cost
basis. Chrysler feels that the necessary materials technology will not
be available until the post-1985 time-frame.
Chrysler reported some interest in the Mitsubishi MCA-JET system (see
the section on Mitsubishi). Chrysler is now designing an experimental
version of their 225 CID six cylinder engine with this system incor-
porated. The MCA-JET system reportedly allows the attainment of the
theoretical emissions and fuel economy advantages of super lean mixtures
without the combustion and driveability problems normally experienced.
Chrysler's fuel economy improvement programs emphasize engine and body
weight reduction along with smaller displacement engines. Chrysler
projects a 700 to 900 Ib drop in its fleet average inertia weight by
1985. The details of how this will be done were not provided, but
Chrysler appears to be stressing the use of lighter weight materials
such as plastics and aluminum. Engine weight reduction will be accom-
plished by trimming weight from the cylinder block, heads, and many
internal parts. Downsizing will also be employed, but it appears that
this may not be used to as great an extent as early as forecast by some
other domestic manufacturers. Chrysler is also studying the benefits
and drawbacks of more efficient transmissions. This work has shown a 3%
improvement in urban fuel economy and a 6% improvement in highway fuel
economy with a low stall speed, lockup torque converter. The major
drawbacks to this type transmission are increased complexity, abrupt
shifts and the possibility of degraded durability, according to Chrysler.
7-45
-------
7.1.2.2. Systems to Meet Various Emission Levels
Table Chrysler-13 shows Chrysler's first choice systems to meet various
emission levels. The fuel economy and system cost estimates are from
Chrysler.
7.1.2.3. Durability Testing
Chrysler's durability testing over the past year has been aimed largely
at evaluating the durability of various 3-way catalyst formulations.
Table Chrysler-14 summarizes the reported testing. As previously
discussed, Chrysler intends to use an advanced fuel metering system,
such as their EFM, on 3-way catalyst systems. This is in agreement with
the latest technical knowledge which indicates that relatively precise
air-fuel ratio control is essential. Unfortunately, it appears that
Chrysler has not run many vehicles equipped with this fuel metering
system and advanced 3-way catalyst systems in combination. Consequently,
they have been forced to conduct catalyst durability evaluations with
fuel metering systems that may not effectively simulate the catalyst
performance that would result from their planned future systems. How
Chrysler interprets the results of the testing with these incomplete
systems, and how Chrysler uses the results to predict what the emission
performance of full systems would be, was not reported by Chrysler.
If one considers the results shown on Table Chrysler-14 in light of the
improvements shown on Table Chrysler-5 that would correspond to the
application of feedback carburetion, then an estimate of performance of
the vehicles, if equipped with a feedback carburetor, can be made.
The results appear to indicate that these vehicles could be expected to
meet 0.41 HC, (especially if a methane credit is assumed), to be close
to, but not far enough below 3.4 CO to have much confidence in predicting
compliance, and to be able to meet 1.5 NOx. It should be noted that
many of the vehicles did not use EGR.
7-46
-------
Table Chrysler-13
First Choice Systems To Meet
Various Emission Standards
- Typical V-8 Engine (318) -
Hardware
Electronic Spark Advance
Orifice Spark Advance
Altitude Compensation
Electronic Fuel Metering
Fresh Air System
Heated Air System
Air Pump
Air Switching
Aspirator
Coolant Controlled EGR
EGR Timer
Main Catalyst
Single Start Catalyst
Dual Start Catalyst
Dual Three-Way Catalyst
Oxygen Sensor
Power Heat Valve
Dual Range Thermostat
Idle Enrichment
Constant Idle Speed (AIS)
Solenoid Idle Stop
Vapor Separator
1977 (A)
1.5, 15, 2.0
(Basel
-
X
-
-
X
X
-
-
X
X
-
90 cu in. (50-0)
-
-
-
-
-
-
X
-
-
-
-------
Table Chrysler-13 (continued)
1977 (A) (B) (C) (B) (C)
Hardware 1.5. 15. 2.0 0.41, 3.4 2.0 0.41. 3.4, 2.0 0.41. 3.4. 1.0 0.41, 3.4. 1.0
Increased Thermal - X X X X
Protection (Heat Shields, etc.)
Radiator Fan Speed & - X X X X
Blade Revisions
Increased Radiator - X X X X
Fluid Capacity
Oxygen Sensor Maintenance ' . - • • ' - - - X
Warning Light
Fuel Economy * Base -6% Not Provided -12% Not Provided
System Cost . Base +$255 +$315 +$315 +$350
(A) Main Catalyst- Only (1977 Federal)
(B) Start + Main Catalyst
(C) 3-Way + Main Oxidation Catalyst
* Relative to 1977 49 state standards; Chrysler estimate
-------
I
«-
Table Chrysler-14
Durability Test Results
Model
A-Body
A-Body
A-Body
A-Body
F-Body
B-Body
C-Body
C-Body
IW
4000
4000
4000
4000
4500
5000
5000
5000
System
Engine Catalyst
225 six 3-way + OC*
Pt/Rh + Pt
225 six 3-way + OC
perovskite/Pt + Pt
225 six 3-way + OC
perovskite/Pt + Pt
225 six 3-way + OC
Pt/Rh + Pt
318 V-8 3-way + OC
Pt/Rh + Pt
360 V-8 3-way + OC
Pt/Ru + Pt
360 V-8 3-way + OC
Pt/Ru + Pt
360 V-8 3-way + OC
Pt/Ru + Pt
Fuel
Metering
Carburetor
open loop
carburetor
open loop
carburetor
open loop
carburetor
open loop
carburetor
open loop
carburetor
open loop
carburetor
open loop
carburetor
open loop
Accumulated Emissions
Mileage Start/Finish
HC CO NOx
0
50K
0
25K
0
50K
0
50K
0
50K
0
50K
0
50K
0
50K
0.36
0.52
0.58
0.52
0.48
0.67
0.34
0.52
0.27
0.66
0.47
0.34
0.28
0.39
0.54
0.52
1.78
3.16
4.08
4.72
7.26
11.5
3.6
3.7
3.1
7.9
3.8
2.2
3.6
4.7
2.5
4.4
1.06
1.31
0.77
1.04
0.77
1.12
0.99
1.05
0.74
1.17
0.61
1.54
0.52
1.39
0.77
1.02
MPG
u
13.55
14.51
16.2
17.2
12.79
14.26
17.0
16.6
11.9
12.9
10.3
11.7
11.9
11.8
11.4
11.6
'77
Model**
MPG
u
16.7
16.6
16.7
16.6
16.7
16.6
16.7
16.6
12.9
12.7
11.9
12.5
10.5
9.6
11.9
12.5
* 3-way + Oxidation Catalyst
** Fuel economy of 1977 Certification durability car; 0 mile figure is actually 5K value
-------
7.1.2.4. Progress and Problems
The discovery of the attrition problem with the base metal NOx catalyst
casts serious doubts on this once promising approach.
On the positive side, Chrysler is enthusiastically pursuing their EFM
system. This system, if successful, could open up several attractive
options, such as extremely lean or 3-way catalyst system operation.
Little progress has been made in their ceramic combustion chamber work.
This concept had shown significant potential for reductions in HC
emissions. Progress over the past year has been limited to the coating
of a six cylinder engine for which no test data have yet been reported.
It is difficult to assess Chrysler's ability to comply with 1.0 or 0.4
NOx requirements because they have not tested any systems that bring
together all of their planned hardware. An example of this is their 3-
way catalyst screening and durability testing. The results shown here
were higher than the target standards in many instances, but it is
difficult to determine how much of this is attributable to the catalyst
and how much is attributable to the fuel metering.
Current emission control systems have been compromised in some instances
by packaging limitations of existing chassis/body designs. This is
especially true for catalysts that should be located as close to the
exhaust manifold as possible. Current body structures frequently
prevent the installation of a properly sized unit due to insufficient
space. For example, this may force the designer to get along with a 30
cu in. catalyst instead of the 60 cu in. unit he really needs. The
difference in size between the two, in some cases, is only an inch or
two at the critical clearance dimension. When new, redesigned, body
structures are contemplated for resized vehicles, it has been assumed
that provisions would be made for future emission control items.
7-50
-------
However, in discussions with Chrysler, EPA learned that some future
vehicle bodies may not fully take these emission control system needs
into account. Apparently, it is a matter of priorities, and emission
control may not be high enough on the list.
7-51
-------
7.1.3. Ford
7.1.3.1. Systems Under Development
3-Way Catalysts
Ford has conducted a considerable amount of laboratory testing of 3-way
catalysts. Primary efforts have been in the areas of: 1) effects of
noble metal loading, 2) effects of rodium (Rh) content, 3) the addition
of active materials to enhance the steam reforming for HC control, 4)
the addition of active materials to enhance the water gas shift reaction
for CO control, 5) the addition of active materials to enhance oxygen
storage in the catalyst, and 6) catalyst durability. Ford has also
continued their laboratory investigation of cycling the A/F ratio about
stoichiometry.
For catalysts which had undergone 100 hours of accelerated engine
dynamometer aging, gross NOx conversion was shown to be substantially
higher with noble metal loadings of 50 gm/cu ft. than with loadings of
20 gm/cu ft. for a range of Pt/Rh ratios as shown in Figure Ford-1. Ford
suggested that HC and CO control were not substantially affected by
noble metal loading. No HC or CO data were provided to support this
conclusion. The maximum loading of 50 gm/cu ft. is not considered to be
excessively high. For example, this loading was used by Ford in 1975
production vehicles. At a constant noble metal loading, gross NOx
conversion apparently was not affected by varying the Pt/Rh ratio from
5/1 to 19/1; however, the net NOx conversion efficiency appeared to
increase greatly for the high Rh compositions as shown in Figures Ford-2
and Ford-3. The difference between the gross and net efficiencies is
ammonia emissions. EPA cannot be certain that Pt/Rh ratio is responsible
for these differences between gross and net NOx conversion efficiency as
the catalysts were not thoroughly described by Ford. HC and CO efficiency
were not affected by the Pt/Rh ratio, according to Ford.
7-52
-------
Figure Ford-1*
I
Ui
. I
t
100
I 80
CO
M
0)
I
CJ
60
40
20
10
i Gross NOx Conversion Vs. Precious Metal Loading at Constant
Pt/Rh Ratios at 14.5 - 1.0 A/F at 1.0 Hz
* from Ford Status Report, December 1976, section IIB,
page 10.
100 Hours Accumulated Aeing
20
30 40 50
Noble Metal Loading - gm/cu ft.
Pt/Rh Ratio
O 7/1
A 11/1
0 13/1
A 15/1
Q 3/1.
\) 1.5/1-
60
70
-------
100
Figure Ford-2*
% Gross NOx Conversion vs. Pt/Rh at Constant PM Loadings
at 14.5 +1.0 A/F at 1.0 Hz
i
Ln
.0
80 —
C
o
•H
CO
c
o
X
o
53
CO
en
o
>-i
O
6Q_
100 Hours Accelerated
Aging 50 gm PM/cu ft.
40 gm PM/ cu ft.
30 gm PM/cu ft.
40 —
S.V. 8600 hr
Temp. 1000°F
in
-1
20
20/1
1571
10/1
5/1
Pt/Rh Ratio
* from Ford Status Report, December 1976, Section IIB, page 11.
-------
100^- -v
'••'•_- : '•'•'•"• ,, ". •' .-••'.' .'; Figure, "j'ord-3* . • -..
.-;* % Net NOx Conversion Vs. Rh Loading (gm/ft^)
at Constant PM Loading (Pt+Rh = 40. gm/ft )
Pt/Rh 19/1 : -- 13/1 11/1
5 u
So 60'
QJ 4J
•O <4-l
O O
40—
20-
I
1
I
100 Hour Accelerated Aging
5/1
I
i
Net NOx conversion efficiencies were
calculated from measurments of is'
selectivity of dynamometer aged .
catalysts. Data was obtained in a
laboratory experiment; it does not
represent dynamometer screening data
or vehicle-CVS-data .
I
.M.728 . . 2.592. : '-3.456 4.320 , 5\184 . 6.048 6.912
-il-:."--'. •'-'-:-. .;^,'- ' •-.''. ':'-'•':"- '•" -.:•• Rh gm/ft -::'- - -•_..;• . : ; ' . .- -'.:: •;
* from Ford Status Report, December 1976, secti-On 11%, -page;~t2-r —i-•—•••-:—
-------
The steam reforming and water-gas shift components help expand the 3-way
catalyst window on the rich side of stoichiometry. The four components
tested for their activities were rhodium (Rh), rhenium (Re), nickel
(Ni), and ruthenium (Ru). Rh and Ru were found to have good steam-
reforming activity. Ni and Ru were found to have significant water-gas
shift activity. The results are shown in Tables Ford-1 through Ford-4.
The use of oxygen storage components and air-fuel ratio cycling also
seems to widen the 3-way catalyst window on the rich side of stoichiometry
at 80% conversion efficiency as shown in Figure Ford-A. Though the peak
3-way conversion efficiency is reduced by 2-3%, the air-fuel operational
window is increased by a factor of three. Ford says that the cyclic
air-fuel ratio work is not being conducted for the purpose of developing
air-fuel metering systems, but only to quantify the effects of air-fuel
ratio cycling in current developmental systems. Only one material was
discussed by Ford as an oxygen storage component and that was rhenium
(Re).
The major result of catalyst deactivation generally seemed to be the
collapse of the HC efficiency curve on the rich side of stoichiometry as
shown by results of fresh and aged catalysts of comparable type in
Figure Ford-5. The reason for this loss in HC conversion efficiency is
shown in Table Ford-5. Lead, sulfur, and phosphorus contents were all
higher in the 1974/1975 durability fuels than in the simulated 1977
fuel. Apparently one or more of these contaminants poison the 3-way
catalyst for HC oxidation. The CO and gross NOx efficiency curves were
not greatly affected by aging.
7-56
-------
Table Ford-1*
Effect of Temperature on Steam-Reforming Reaction
Fresh Catalyst
Experimental Conditions:
S.V.
H6
Catalyst
Ruthenium
Rhodium
Rhenium
Nickel
M257
M268A
M196
60,000 hr
0.5%
8.0
7.0
1000 ppm
500
balance
-1
Percent Conversion of Hydrocarbon (°C)
350
22
69
11
12
84
66
66
400
33
77
13
13
88
69
76
450
43
84
17
14
91
73
81
500
54
88
17
20
93
75
84
600
65
90
17
45
95
80
88
Table Ford-2*
Effect of Hydrocarbon Concentration on Steam-Reforming Reactions
Fresh Catalyst
Experimental Conditions:
S.V.
Temp
»7
c6
"
Catalyst
Ruthenium
Rhodium
Rhenium
Nickel
M257
M268A
M196
60,000 hr"1
450°C
0.5%
8.0
7.0
330-1000 ppm C
170-500 ppm C
balance
Percent Conversion of Hydrocarbons at
Inlet Hydrocarbon Concentration (ppm)
500
38
82
18
31
84
71
78
1000
48
84
17
19
88
73
81
1500
43
86
17
14
91
73
80
* From Ford Status Report, December 1976, Section IIB, page 69
7-57
-------
Table Ford-3**
Effect of Temperature on Water-Gas Shift Reaction
Fresh Catalysts
Experimental Conditions: ..
S.V. 60,000 hr
CO 1.5%
H, 0.5
CO. 8.0
H26 7.0
N« balance
Catalyst
Ruthenium 0.18% on Corning monolith
Rhodium, 0.13% " " "
Rhenium, 0.2% " " "
Nickel, ^5% " " "
M257*
M268A
M196
Percent Conversion of CO (°C)
350
62
400
64
450
500 600
65 76 48
no water-gas shift activity
no water-gas shift activity
20 56 71 71 52
43 58 62 64 50
12 46 64 63 44
36 66 85 84 82
*Extreme spread in results. Figures given are a conservative average.
Table Ford-4**
Effect of CO and Hn Concentration on Water-Gas Shift Activity
Fresh Catalysts
Experimental Conditions: ,
S.V.
Temp
CO
\
H76
N2
Catalyst
Ruthenium
Rhodium
Rhenium
Nickel
M257
M268A
M196
60,000 hr
450°C
0.5-2.
1/3 of
8.0%
7.0
balance
CO
Percent CO Conversion at
Inlet CO Concentration (%)
0.5
74
1.0
74
1.5
65
2.0 2.5
60
No water-gas shift activity
No water-gas shift activity
82
76
64
50
76
69
62
67
71
62
61
85
68
56
60
52
50
65
50
55
33
**From Ford Status Report, December 1976, Section II B, page 68
7-58
-------
Figure Ford - 4
C.O 14.0 14.2 14.4 (4.6 14.8 15.0 15.2 15.4 15.6
A/F
Figure Ford-4* Effect of Air-Fuel Modulation on a Catalyst
with Oxygen Storage Capability (a) without modulation
(b) sawtooth modulation 1.0 Hz. Modulation amplitude - 1.0
A/F unit;..catalyst inlet temperature 1000°F (538°C) ; S.V.
50,000 h~ ; catalyst after 50 h of testing.
* from Ford Status Report, December 1976, section IIB, page 16.
7-59
-------
^J
o
Ftgure Ford-5**
Effect of Catalyst Aging
M-268A FRESH CATALYST
100
80
2 60
O
w
cc
l)J
2 40
o
o
_L
LEGEND
CATALYOT: M-2GOA
O CO
AHC
a NO
O NH3 Ac % NO Convorlcd
I
-I
S.V. » 00,000 HR
Tc 550°C
GROSS NO
0.0 1.0 1.2 1.4 1.6 1.8
REDOX POTENTIAL, R
. J'..., .._| _., I . I . I
"».4fl 14.30 14.28 14.10 I4.0C
A/F
AGED M-268A CATALYST
^^'ofT^ 25>00°* Slmul«^d Miles Pulsaxor Aging
with Simulated 1977 Certification Fuel
100
-. 80
3 GO
Ul
S 40
20
LEGEND
CATALYST: M- 2 60 A
O CO
A HC
8.V. = GO,000 HR"
, T = 550 °C
0.0 1.0
, I
1.2 1.4 1.6
REDOX POTENTIAL,R
I
I . I.I
14.1
14.30
I4.2&
A/F.
14.18
14.03
•••• ")7b. section IIB, pages 20 and 31.
-------
- Table Ford-5**
Selectivity and Activity of Fresh and Aged 3-Way Catalysts
A. Width of Window for 3-Way Selectivity
Catalyst
Width of Window for 80% Conversion of Net NO, CO
and EC at 550°C and 60,000 Hour" space-velocity.
___ (A/F Unit)
Fresh 25,000 Simulated
Miles with Lead-
Sterile Isooctane
25,000 Simulated Miles 25,000 Simulated
with Simulated 74/75 Miles with "Simulated"
Certification Fuel 76/77 Certification Fuel
M-152C2-3
M-253
0.16
0.05
0.13
0.05
0
0
0.06
0.04
B. Activity
Temperature (°C) for Simultaneous 50% and 80% Conversion Net NO, CO.
HC at Mean A/F Ratio
Catalyst
50% 80%
50% 80%
50% 80%
50% 80%
M-152C2-3
M-253
200
225
285
245
200
N.M.
300
455
240
430
could not
be reached
could not
be reached
200
225
350
550
* simulated Pulsator Miles
** From Ford Status Report, section IIB, page 47
-------
Ford completed 300 hours of accelerated engine dynamometer aging on 23
different 3-way catalysts. Five of the catalysts had peak NOx conversion
efficiencies greater than or equal to 90% at 300 hours. An additional 5
catalysts had peak NOx efficiencies between 80 and 89% at 300 hours.
Six more catalysts had efficiencies between 70 and 79%. The 80% effi-
ciency windows of operation were not reported. The aging was conducted
at stoichiometry, except for 20 minutes per cycle of thermal degradation
conditions. The remaining 220 minutes per cycle were divided between
idle (15 minutes) and catalyst poisoning condition (205 minutes). The
fuel contained 0.027 gm/gal Pb, 0.003 gm/gal P, and 0.045 weight % S.
%
Oxidation Catalysts
Ford apparently believes that their oxidation catalyst systems are good
enough for any anticipated HC and CO emission levels. The only reported
efforts on oxidation catalysts were to reduce the noble metal loading
from an already low 25 gm/cu ft. to 15 gm/cu ft. Ford suggested that
this reduction in loading probably could be made without deterioration
in catalyst performance. For a 160 cubic inch catalyst, this would
represent about a $4.00 cost savings in noble metal.
Other data concerning noble metal loading were submitted in Ford's
previous status report. That testing used noble metal loadings up to 50
gm/cu ft. and showed distinct improvements in catalyst light off tempera-
ture with higher loadings. These data are shown in Table Ford-6.
Losses in hot HC conversion efficiency at 300 hours are also shown to be
minimized with higher loadings.
7-62
-------
Metal
Loading
(CM/
FTJ)
10a7
15
20a/
25
30 £/
40
50
50*a/
Table Ford-6**
Effect of Noble Metal Loading
Conversion Efficiency
(800°F 40K HR )
HC CO
25 HR 300 HR 25 HR 300 HR
Lightoff Temperature
°F
HC CO
25 HR 300 HR 25 HR 300 H
87.1
87.8
89.1
89.5
88.8
88.8
90.4
91.3
69.8
74.1
78.6
79.1
82.0
79.1
81.8
83.3
99.0
98.0
98.8
97.9
97.3
97.9
95.6
99.5
90.0
93.9
91.
93.
,9
,5
93.8
89.
90.
98.3
604
581
569
517
546
534
523
508
685
684
685
612
595
579
589
565
585
559
546
498
528
513
507
491
670
669
617
591
579
561
568
548
^J 1975 Production type catalyst included as a reference catalyst
in all tests.
a_/ 2 test average
** From Ford Status Report, December 1975, Section II 6, page 2.
7-63
-------
Dual Catalyst
Ford efforts on dual catalyst systems have essentially stopped. The
only testing which was reported was some sulfate testing on a Gould GEM-
68 catalyst-equipped vehicle. The reported sulfate emissions of vehicle
112T531 were 58, 72, and 76 mg/mi over the SET-7 with 0.03 wt. % sulfur
fuel. The hot FTP results of the 400 CID, 5000 Ib. IW vehicle were
reported to be 0.33 HC, 0.46 CO, 0.25 NOx, 10.2 MPG .
Ford has dropped the Gould program until Gould can demonstrate improved
sulfur tolerance and improved efficiency.
Questor System
Since the most recent tests of the Questor equipped Pinto (shown in
Table Ford-7) were not particularly successful, Ford has decided to
"postpone" this program.
Table Ford-7
VIN
38P35
CID # Tests
2.3 litre 3
6
4
6
4
Miles
0
1000
5000
10000
10000
HC
0.10
0.10
0.08
0.31
0.17
CO
2.70
3.77
3.36
11.03
6.92
NOx
0.30
0.23
0.61
1.43
1.30
MPG
u
16.9
15.8
16.5
17.3
17.6*
* Enriched idle CO
7-64
-------
Electronic Control Systems
A system combining electronic control of sonic EGR and spark will be
introduced in 1978. Another electronic control system under development
will also add electronic control of the air-fuel metering system. This
combination of electronic control systems has been anticipated for some
time. Ford maintains that the verification of component durability is
perhaps the biggest problem for this type of system.
In addition to the electronic EGR system, a pneumatically-operated,
sonic EGR system is under development. Possibly this system is being
considered as an improved EGR system for vehicles which will not be
converted to electronic controls. Both systems are actuated by air
pressure from the air pump, and according to Ford, the sonic valve
provides a constant EGR flow at a given valve position with varying
manifold vacuum. Previously submitted data showed large HC reductions
with sonic EGR. Ford representatives indicate that this is due to
better EGR control at light load operating conditions. Current systems
were said to meter excessive amounts of EGR at light load. Since calibra-
tions are based on higher load conditions (high NOx emitting conditions)
and current systems cannot reduce the EGR rate fast enough with decreasing
load, unnecessarily high HC emissions are emitted.
Ford reported that a number of actuation devices for feedback carburetion
were evaluated, and that based on packageability, control, response,
hysteresis, and cost, a stepper motor design has been selected for
durability testing. Very few of these evaluations were presented to
EPA.
In Table Ford-8, an electronic fuel injection (EFI) system is compared
to a sonic, electronic fuel metering system (EFM). Both were feedback
7-65
-------
systems and used similar Bendix electronics. The major difference was
that the EFI system used eight injectors, one at each intake valve, and
the EFM had only two injectors mounted in a sonic throttle body.
Table Ford-8*
EFI Versus Sonic EFM
Engine out emissions (75 FTP)
Tailpipe emissions (75 FTP)
MPG
u
MPG,
n
MPG
c
- 2 0"air-fuel ratio band
over hot 505
part throttle octane
requirement
wide open throttle octane
requirement
EFI
4.35 HC, 31.46 CO, 1.6 NOx
0.36 HC, 1.78 CO, 0.62 NOx
12.1
16.2
13.6
- 0.40
86
95
Sonic EFM
4.47 HC, 44.88 CO, 2.97 NOx
0.45 HC, 2.91 CO, 0.90 NOx
11.2
17.0
13.2
- 0.34
92
97
* From Ford Status Report, December 1976, Section III B, page 5.
Both systems were tested on 400 CID Elites with 3.00:1 rear axles at
4500 pounds IW. The EFI system was superior in all respects except in
highway fuel economy and the operational air-fuel ratio band. Engine out
emissions were not particularly good for either system. The EFM might
improve with further development and the speed-density EFI is not the
most technologically advanced fuel injection system.
Another comparison was presented between the sonic EFM and a 4350
feedback carburetor (FBC). The results are shown in Table Ford-9. Both
were 400 CID vehicles with automatic transmissions and 2.50 rear
7-66
-------
axles at 5000 pounds IW. Both vehicles had cooled backpressure EGR and
3-way plus oxidation catalyst systems. The sonic EFM used a single
plane intake manifold and the FBC used a dual plane intake.
Table Ford-9
Sonic EFM Versus the 4350 FBC*
EFM FBC
Tailpipe ('75 FTP) 0.27 HC, 1.2 CO, 0.71 NOx 0.27 HC, 1.6 CO, 0.68 NOx
- 2 air-fuel ratio band -0.5-0.6 -0.5-0.6
MPG 12.0 12.7
MPG" 18.4 19.2
MPG 14.2 15.0
0-66 time (sec) 12.4 12.2
25-60 time (sec) 8.5 8.4
1/4 mile test (sec) 18.4 18.4
driveability (avg/min) 6.9/5 6.1/6.0
part throttle octane requirement 94 86
wide open throttle octane
requirement 95 89
*From Ford Status Report, December 1976, Section III B, page 7.
The FBC performed very well, and demonstrated the potential for utilizing
feedback carburetion at 0.41 HC, 3.4 CO, 1.0 NOx on vehicles of high
inertia weight and with large engines. It provided better fuel economy,
performance, and octane requirement than the EFM at nearly constant
emissions. The fuel economy and emissions of the EFM vehicle are much
improved over the EFM vehicle in Table Ford-8. The vehicle in Table
Ford-9 is at a higher inertia weight, but does have a lower axle ratio.
The changes in EFM performance are the result of additional development
efforts on the system. The fuel economy of the comparable 1977 Federal
certification vehicles are shown in Table Ford-10. It should be noted
that the fuel economy of the FBC vehicle was 0.3 MPG better than the
best comparable 1977 Federal vehicle from Ford with same displacement,
inertia weight, axle ratio, and transmission. The emissions of the FBC
vehicle were much lower than the 1977 Federal vehicle.
7-67
-------
Based on the previously mentioned testing, sonic EFM has been dropped
from further consideration in programs directed toward 1.0-2.0 NOx.
Table Ford-10
4,000 or 5,000 Mile Fuel Economy of 1977 Federal Certification Vehicles
Vehicle IW MPG MPG. MPG VIN
—^—— — u n c ~—~
Fuel economy/data 4500 12.2-13.0 16.0-18.5 13.7-15.0 701-400-F-65*
Durability 4500 Not Available
Fuel economy/data 5000 11.8-12.7** 14.9-18.2** 13.0-14.7** 7A1-400-G-
69**/701-400F-47
Durability 5000 11.3-12.0***
* 2.50 axle, not 3.00 axle
** running change
*** 2.75 axle ratios
The average driveability of the FBC was somewhat poorer than the EFM,
though still good.
The minimum driveability objective of a rating of six for this development
testing is higher than Ford has considered as acceptable in the past and
may suggest that Ford is trying to improve the driveability of their
vehicles.
Other Development Efforts
Plans for a dual displacement, 300 CID, six cylinder engine were revealed.
No test results or operational details were submitted, though Ford has
reportedly* accumulated about a half million miles of durability on the
7-68
-------
system. The device was developed to improve vehicle fuel economy by
reducing the number of operational cylinders (and thus operational
displacement) when high power output is not required of the engine. The
system is automatically controlled by an electronic system which reportedly**
has eliminated problems with engagement and disengagement of the cylinders.
The system is to be introduced within a few years on light truck, and
fuel economy is said to be increased by 10 to 20% according to the
above-referenced articles.
Sonic Carburetion
Ford tested a IV, open loop, sonic carburetor which was calibrated to
stoichiometry on a 250 CID Comet at 3500 IW. Other emission control
equipment included EGR and a 3-way catalyst. While the system did hold
a close air-fuel ratio band around stoichiometry (- 2tr= - 0.25), the
reported emissions were not impressive. Best results using the 3-way
catalyst were reported to be 0.71 HC, 7.4 CO, 0.61 NOx, 14.0 MPG and
u
1.23 HC, 14.0 CO, 0.39 NOx, 14.0 MPG .
Modulated Secondary Air Injection
Ford has evaluated the use of modulated secondary AIR using simulated,
hot CVS results which were generated from engine maps using full AIR and
no AIR. A simulation for a 3000 Ib IW Pinto with an automatic transmission
showed fuel economy improvements of about 3 to 10% for modulated AIR
over full AIR at constant HC and NOx emissions for a range of NOx
emissions from 1.0 to 2.0 gm/mi. The biggest fuel economy advantage was
* Machine Design,. 21 October 1976.
** Time, 4 October 1976.
7-69
-------
at the lowest NOx level. About 9-10% improvement in fuel economy was
shown for modulated AIR as compared to no AIR over the same NOx range.
Another set of simulated data for the 3000 Ib IW Pinto is shown in Table
Ford-11. Improvements in HC, NOx, and MPG are predicted with modulated
AIR compared to both the no AIR and full AIR configurations.
Since CO emissions were not mentioned by Ford, it is assumed that
adequate CO control was either assumed or maintained by Ford in all
configurations. Also, Ford did not discuss the details of the hardware
that they would use to implement the modulated AIR system on a vehicle.
Fast Burn
Little success has been achieved in increasing the charge burn rate by
modifications to the combustion chamber geometry, but fast burn work for
Ford will be continued at Ricardo. The further efforts are to study the
number and location of spark plugs. If successful, these efforts could
yield improved fuel economy and higher EGR tolerance which could provide
reduced NOx emissions.
Exhaust Heat Conservation
Port liners were installed on a Pinto with a 2.3 litre engine. Exhaust
gas temperatures at the port outlet were increased by 75 to 1008F; but
the expected HC reductions were not obtained. In some cases HC was even
increased by the port liners. Ford attributed the poor HC performance
to insufficient residence time in the exhaust manifold. The reported
data were steady state, engine dynamometer results. No vehicle testing
was reported.
7-70
-------
Pinto
Table Ford-11*
Unconstrained Vehicle Capabilities
From Engine Mapping
Min.
HC
(gm/mi)
30000 IW A/T
3.4 AR
Sec. Air Only 0.73
No Sec. Air 0.70
Modulated Sec Air 0.57
Min.
NOx
(gm/mi)
0.73
0.74
0.69
Projected
Max Fuel
Economy
(MPG)**
24.25
24.55
24.77
Pinto
3000# IW M/T
2.79 AR
Sec Air Only
No Sec Air
Modulated Sec Air
1.46
0.97
0.87
0.44
0.41
0.36
28.68
28.71
29.00
* from Ford Status Report, December 1976, Section III G, page 10.
** MPG is for CVS-Hot.
7-71
-------
Table Ford-12*
400 CID Baseline Engine
Afterburner Spark Retard
20° BTC (From 30° ETC)
Speed/Load
(rpm/lb. ft.) Fuel increase/ Fuel increase/
HC reduction HC reduction
650/40
650/40
650/40
1000/40
1000/40
1000/40
40%/53%
50%/65%
80%/83%
26%/54%
31%/66%
50%/90%
10% 710%
20% 745%
5%/42%
15% 77 8%
* from Ford Status Report, December 1976, Section III H, page 26
Table Ford-13**
Conventional Lean Burn Versus the CVCC
75 FTP - gm/mi Fuel Economy
HC CO NOx MPG MPG, MPG IW
— — u h_ c_ —
2.3 litre M/T Pinto
L.R. Vehicle 1.32 7.4 0.72 21.2 30.5 24.6 3000//
(T511)
Reference
E&RS CVCC Vehicle 1.30 7.7 0.82 21.1 29.2 24.1 3000//
2.3 litre M/T Pinto
** from Ford Status Report, December 1976, Section III J, page 2
7-72
-------
Exhaust Afterburner
Engine dynamometer testing was reported on a 400 CID engine with an
exhaust afterburner as shown in Figure Ford-6. Sufficient fuel was
injected into the afterburner to yield exhaust gas temperatures of about
1200°F. The test results shown in Table Ford-12 were not favorable when
compared to the results obtained with spark retard. The reported data
are, however, very limited and may not represent the optimum operation
of the afterburner. For example, NOx emissions were not considered in
the Ford analysis.
CVCC Versus Conventional Lean Burn at 1.0 NOx
This testing was conducted to see if a conventional lean burn vehicle
could achieve 0.41 HC, 3.4 CO, 1.0 NOx with fuel economy equivalent to a
similar CVCC prototype at the same emission level. The CVCC vehicle was
not described. The lean burn vehicle had a considerable number of
advanced emission control components. These included electronic EGR,
port liners, a 140 cu in. thermal reactor, and an oxidation catalyst.
The input emissions to the catalyst are presented in Table Ford-13
(which is found on the previous page). The emission results are com-
parable and the fuel economy results are also about equivalent. Tail-
pipe emissions were not reported for either vehicle. The biggest
question in this testing concerns the optimization of the CVCC vehicle.
In light of the substantial improvements in fuel economy which have
recently been reported by Honda, it is likely that the fuel economy of
the Ford 2.3 litre CVCC engine could also be improved. Another question
is the cost of the control system. It would seem possible that the cost
of the emission control system on the CVCC would not be as expensive* as
the control system on the conventional engine.
7-73
-------
£X/JAUS7~.. At
£ 'P.
Figure Ford-6*
* from Ford Status Report, December 19)6, section III.H, page 21.
7-74
-------
Lean Reactor Size Comparison
The conventional lean burn engine from the CVCC comparison testing was
then modified to include a 280 cu in. reactor, twice the volume of the
original reactor. No calibration changes were made. As seen in Table
Ford-14, the reactor out emissions of HC were reduced 33% and CO were
reduced 27%. These reductions could be converted to further fuel
economy gains for the conventional lean burn system if catalyst out
emissions are not degraded by slower catalyst light off or reduced
feedgas temperatures.
Table Ford-14
Reactor Size Comparison*
HC CO NOx MPG MPG, MPG
— — u_ h_ c
2.3 litre, L.R. 0.88 5.4 0.70 21.8 30.6 25.0
Vehicle 200% Volume
Reactor
Reference
2.3 L.R. Vehicle 1.32 7.4 0.72 21.2 30.5 24.6
100% Volume Reactor
* from Ford Status Report, December 1976, Section III J, page 3.
Alternate Engines
PROCO
Recent engine mapping efforts on the PROCO engine have been in the area
of reducing HC emissions at NOx levels of 1.0 and 0.4 with the Ford high
injection rate fuel injection system. The only vehicle testing which
was reported at 1.0 NOx is shown in Table Ford-15. These results are
for a 400 CID PROCO in a 5000 IW vehicle with an automatic transmission
and a 2.75 rear axle. The tests were conducted with a 324 cubic inch
oxidation catalyst which had been aged 4000 miles. The fuel economy
7-75
-------
results of the best comparable 1977 Federal certification vehicle* of
similar displacement, inertia weight, and transmission type are 13.0
MPGu, 18.4 MPGh> 15.0 MPG . Thus a 21% increase in composite fuel
economy is shown when compared to the 1977 vehicle. This comparison
should, however consider that the peak power output of the 400 CID PROCO
might be less than that of the conventional 400 CID engine, because the
PROCO may not run as rich as a conventional engine at peak power and may
have more friction to overcome. The tailpipe emissions of the PROCO are
very good; however, the engine out HC emissions may still be quite high.
Over a hot start test, engine-out HC was reported to be 2.1 - 2.4 gm/mi.
Apparently the large catalyst is capable of doing the required oxidation.
Of the 0.22 HC on the cold start test, 32% was reported to be methane.
Table Ford-15*
PROCO Test Results
Tailpipe Emissions (75 FTP)
MPG
MPG"
Performance
0-10 seconds
0-60 mph
50-80 mph
Driveability
Average
Minimum
0.22 HC, 0.1 CO, 0.78 NOx
15.5
22.7
18.1
429 ft
12.8 sec
14.1 sec
6
5+
* from Ford Status Report, December 1976, Section IV A, pages 15 and 16.
These test results are an example of the use by manufacturers of improved
emission controls (in this case a larger catalyst) on engines which may
have some emissions problems, but are considered to have other attractive
properties.
No. engine or vehicle testing was reported on either the injectors
developed for the PROCO by AMBAC, Robert Bosch, and Nippondenso or the
* VIN 7A1-400-G-81, 2.47 axle ratio instead of 2.75 axle ratio.
7-76
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three injection pumps developed by Robert Bosch. Single cylinder engine
testing was done on the injection pump developed by Holec, but secondary
fuel injection problems were encountered.
Electronic control systems are new being developed for air-fuel metering,
spark, and EGR control. Ford stated that the necessary mapping of the
400 PROCO has been completed. The Eaton valve deactivation device has
been applied to the 400 PROCO to make the V-8 capable of operating on
either 4, 6 or 8 cylinders. Ford states that the Eaton device alone
will reduce the HC emissions about 15 to 30% over the FTP and will
increase fuel economy by 10%.
Based on engine mapping, the 0.4 NOx calibrations were projected to
yield the hot start test results shown in Table Ford-16. Based on
similar projections and later vehicle testing at 1.0 NOx, the HC pro-
jections may be optimistic.
CVCC
Ford stated that "if an ultimate 1.0 NOx level is adopted by Congress,
then the application of prechamber engines might be considered for sub-
compact models". Development efforts were continued on both the 2.3
litre and 1.6 litre CVCC engines.
A configuration of the 2.3 litre CVCC targeted for statutory emission
levels was tested. The emission control system utilized electronic EGR
to the main and prechamber; exhaust port liners; a 140 cu in. thermal
reactor; a 135 cu in., Engelhard TWC-16, 3-way catalyst; a 135< cu in. Engel-
hard II C, oxidizing catalyst; and switched secondary AIR. This 3000
pound IW Pinto had a four speed transmission and a 2.79 axle ratio. The
test results were reported to be 0.36 HC, 1.7 CO, 0.15 NOx, 22.7 MPG , 31.5
MPG, , 26.0 MPG . This represents a 2% loss in economy when compared to
the most nearly comparable '77 Federal certification vehicle* which had
* VIN 7Z2-2.3-F-22.
7-77
-------
Injection
Rate
Std.
20:1 A/F
Calib.
18:1 A/F
Calib.
Fast
20:1 A/F
Calib.
NOTES:
Table Ford-16*
PROCO CVS-H Projections
Fast Rate vs. Std. Rate at 0.4 gm/mi NOx
400 CID
5000 Ib. IW
A/T, 2.75 Axle Ratio
(75 grains H20/lb. dry air)
HC
2.5
2.1
CO
;m/mi
8.6
9.6
NOx
gm/mi
0.32
0.33
CVS-H
MPG
16.0
15.9
2.1
12.5
0.33
16.1
1) The fast rate injection resulted in poor combustion at A/Fs richer
than 18:1 at part load, thus no part load tests were carried out at 14.7
A/F.
2) All projections include an A/F of 14.7 at the highest torque conditions
of the CVS cycle.
* from Ford Status Report, December 1976, Section IV A, page 9.
7-78
-------
a 3.18 axle ratio, and achieved 22.9 MPG and 32.5-32.8 MPG, . The air-
u h
fuel calibration and feedgas emission levels of the vehicle were not
mentioned and thus the dependence on the 3-way catalyst for NOx control
could not be determined.
This vehicle demonstrates substantial development activity for the CVCC
concept. This vehicle, without the electronic EGR or reactor and at
2750 pounds IW, was previously reported to achieve 0.27 HC, 1.5 CO, 0.33
NOx, 24.0 MPG . If Ford's efforts continue on this calibration, it may
represent a possible application for their modulated AIR concept as
well. The Honda calibrations of CVCC vehicles at these emission levels
have been very lean and have not utilized 3-way catalytic emission
control systems.
A vehicle with a 2.3 litre engine calibrated to 1.0 NOx and used a lean
calibration, EGR, and an oxidizing catalyst. The 2750 pound IW vehicle
was reported to achieve 0.40 HC, 2.2 CO, 1.01 NOx, 24.4 MPG . The
vehicle with a 1.6 litre CVCC engine which was previously reported to
have achieved 31.3 MPG , 48.0 MPG, and 37.0 MPG , at 2000 pounds IW was
reported at 0.43 HC, 2.6 CO, 0.86 NOx, 31.0 MPG . This vehicle also
used a lean calibration, port liners, a thermal reactor, and an oxidizing
catalyst.
Diesel
A feasibility study has been conducted on the Dieselization of the 351
CID gasoline engine. To maintain maximum interchangeability of parts,
the Diesel version would be a 294 CID engine. The displacement reduction
is required to maintain similar stresses and bearing loads in the engine,
according to Ford. The 294 CID Diesel engine was projected to have a
prechamber, operate at 22:1 compression ratio, and develop 130 net BHP
at 4000 RPM.
7-79
-------
Based on engine mapping of an Opel 21QOD, Ford projected that the V-8
Diesel in a 4500 to 5000 pound IW vehicle could achieve 0.41 HC, 3.4 CO,
2.0 NOx with minor changes to injection timing and small amounts of EGR.
Smoke was projected to be somewhat higher. Based on engine mapping and
computer simulations, the V-8 was projected to be able to achieve 1.0
NOx also, but with higher than statutory HC and CO. The use of ox-
idation catalysts was not considered in the Ford analysis. Smoke was
estimated to be three times higher than on the uncontrolled Diesel V-8.
Odor and said to be three times higher than on the uncontrolled V-8.
Odor and sulfate emissions were said to be additional problems.
Also based on the engine mapping of the Opel engine, a four cylinder
vehicle at 3000 IW was projected to have hot start FTP emissions below
0.41 HC, 3.4 CO, 1.0 NOx with smoke emissions increased by about a
factor of three. The vehicle was also projected to be able to achieve
0.41 HC, 3.4 CO, 0.4 NOx on the hot start FTP with smoke emissions about
seven times higher than for the standard vehicle.
Fuel economy comparisons of both V-8 and 1-4 Diesel engines to their
gasoline counterparts were generated by Ford. The results of the
computer analysis are shown in Table Ford-17. The baseline V-8 and 1-4
were assumed to have 0-60 MPH times of 13 and 15 seconds respectively.
Ford did not reveal a decision on the continuation of Diesel studies.
But since little progress has been reported from last year, it could be
assumed that Ford will not build a Diesel prototype in the near future.
Stirling
Development of the Stirling engine has progressed to the point where an
engine has been installed in a vehicle, but emissions testing has not
been conducted at this point in time, according to Ford.
7-80
-------
Table Ford-17*
Comparison of Fuel Economy Improvements of the
Swirl Chamber Diesel Engine
Relative to the Gasoline Engine
% Fuel
Emission Economy
Standard Improvement on
HC/CO/NOx Actual Tank Fuel (1)
V-8 Gasoline 1.5/15/3.1
Engine Base
Equal displacement 0.41/3.4/2.0 26
V-8 Diesel 0.41/3.4/1.0 16
Equal performance 0.41/3.4/2.0 19
V-8 Diesel 0.41/3.4/1.0 10
1-4 Gasoline 1.5/15/3.1
Engine base
Equal displacement 0.41/3.4/2.0 18
1-4 Diesel 0.41/3.4/1.0 17
Equal performance 0.41/3.4/2.0 6
1-4 Diesel 0.41/3.4/1.0 5
(1) Includes the 11% higher volumetric energy content for Diesel fuels.
* from Ford Status Report, December 1976, Section IV C, page 6.
7-81
-------
7.1.3.2. Systems to be Used at Various Emission Levels
1.5 HC. 15 CO. 2.0 NQx
Future Ford systems for 1.5 HC, 15 CO, 2.0 NOx are much like those used
in 1977 Federal certification efforts. The basic systems use EGR and an
oxidation catalyst with and without AIR. If these standards are retained
for 1978, Ford plans to introduce a new electronic EGR and spark control
system on one model that is equipped with the 302 CID engine. Ford also
plans to introduce some models with pulse AIR, apparently as a cost
saving measure. Minor evaporative emission control system modifications
are planned to meet the 6 gm SHED standard.
Ford stated that they should be able to comply with the 18 MPG standard
in 1978, again assuming 1.5 HC, 15 CO, 2.0 NOx is retained. The cost
increase of 7-11 dollars was said to be for revised evaporative systems.
The cost increase seems to neglect the possible conversion to pulse AIR,
the potential deletion of AIR on some models, and potential reductions
in catalyst loading, all of which would tend to reduce emission control
system costs.
0.41 HC, 9 CO. 1.5 NOx
Ford systems for this emission level in 1978 on a Federal basis may be
very limited, according to Ford. They indicate that the 302 engine
family with AIR, EGR, and oxidation catalysts is the only engine which
achieves these levels in certification for the 1977 model year. Thus
with no additional certification efforts, Ford could sell only about 20%
of their planned 1978 production.
Ford indicated that a 12% fuel economy loss would result even if line-
crossing and a credit for non-methane hydrocarbons were assumed.
7-82
-------
For this standard in California, Ford plans to introduce a 3-way plus
oxidation catalyst system in 1978. The system will also include a
Holley feedback carburetor, an oxygen sensor, EGR, and AIR on the 2.3
litre engine family. A start catalyst will also be added to the 200
CID, six cylinder engine family to attempt to certify this AIR, EGR,
oxidation catalyst family for California.
Though not stated by Ford, this emission level could possibly permit the
deletion of both the AIR injection system and the oxidation catalyst of
3-way catalyst systems like the one used on the 2.3 litre engine family
for California.
0.41 HC. 3.4 CO, 2.0 NOx
At these emission levels in 1979 and 1980, Ford stated that they will
expand the use of 3-way plus oxidation catalyst systems. Feedback
carburetion would be used in combination with the use of electronic EGR
and spark control on those vehicles. Other models would retain oxida-
tion catalyst systems similar to those of 1977.
The cost of these systems would be $180-$380 more than systems to meet
1.5 HC, 15 CO, 2.0 NOx, according to Ford. This will allow for the use
of 3-way plus oxidation catalysts and electronic spark, EGR, and air-
fuel control on large cars and feedback carburetion, 3-way plus oxida-
tion catalyst systems on small cars.
0.41 HC, 3.4 CO. 1.0 NOx
The achievement of these standards in 1981 would be accomplished by
using all 3-way plus oxidation catalyst systems in combination with
electronic EGR and spark control. Vehicles at low inertia weights, such
as the Pinto with a 2.3 litre engine for California in 1978, may not
require electronic spark or EGR.
7-83
-------
Ford stated that the initial cost increase would be $210-$310 over the
1.5 HC, 15 CO, 2.0 NOx systems. This is a smaller cost increase than
stated for 0.41 HC, 3.4 CO, 2.0 NOx, but reflects cost reductions due to
newer electronic control components and higher volume production rates
of the electronic components. According to Ford, the effect on fuel
economy would range from minus 6% to minus 1% compared to 1977-1978
Federal systems. The vehicles with poorest fuel economy have the least
number of electronic emission control systems.
0.41 HC. 3.4 CO. 0.4 NOx
Ford stated that they have not identified emission control systems with
the capability of achieving this emission level. Developmental efforts
were reported at this target emission level for two engine families
which are currently sold by Ford - the 2.3 litre and 351-W. The vehicle
with the 2.3 litre engine (VIN 112T511) did not even come close to low
mileage statutory emission goals. The fuel metering system used on this
3-way plus oxidation catalyst system was a recalibrated, open loop
carburetor. No testing of the vehicle with the 351-W engine was reported,
but the vehicle is to use a more sophisticated air-fuel metering system.
The Ford 8-channel EFI system is to be used in conjunction with the 3-
way plus oxidation catalyst system.
The vehicle with the 351-W engine, which is being developed under the
IIEC-II program and is called a "Concept Car", appears to have incor-
porated some of Ford's better developmental hardware. This hardware
includes EFI, electronic spark control, and electronic EGR control.
Since the catalyst selections were not fully described, it is difficult
to evaluate the selections except to note that the total catalyst volume
may be inadequate for 50,000 miles of durability operation.
7-84
-------
7.1.3.3. Durability Testing
Precertification durability testing is currently in progress on both the
Pinto with the 2.3 litre with the 3-way plus oxidation catalyst system
and the 302 CID, oxidation catalyst vehicle with electronic spark and
EGR control for 1978 model year. The reported test results are shown in
Tables Ford-18 and Ford-19. The 2.3 litre Pintos show the potential to
get as low as 0.41 HC, 3.4 CO, and 1.0 NOx. The design objective for
fuel economy was to get 1 MPG better than the 1977 model Pinto for
California. Ford indicated that the fuel economy objective is being
met. The fuel economy of the comparable 1977 Federal fuel economy
vehicle* was 22.9 MPG , 32.5-32.8 MPG, . In comparison, the vehicles
u n
with the 3-way catalyst systems show a 2-3% urban fuel economy penalty
over the 1977 Federal vehicles. The vehicle with the electronically
controlled 302 CID engine shows good capability for 0.9 HC, 9 CO, 2.0
NOx. The last two tests on Table Ford-19 may indicate capability for
0.39 NMHC, 9 CO, 1.5 NOx. Insufficient information was provided on this
vehicle to permit a fuel economy comparison to be made.
About 20 vehicles equipped with various electronic emission control
systems are either just starting or being prepared for durability
testing. Details of the vehicles and emission targets were not given,
except that a number of feedback carburetors will be tested and that the
NOx objectives are low (probably 1.0 NOx).
The Low NOx Fleet which was reported a year ago has completed durability
testing. The fleet consisted of nine vehicles. All vehicles had 302
CID engines and were tested at 3500 pounds IW. Three vehicles used 192
*'
cu in. oxidation catalyst (OC) systems, and six vehicles used 3-way plus
oxidation catalyst (3W+OC) systems. The vehicles with the 3W + OC
system had 3-way catalysts of 96 cubic inches and an oxidation catalyst
7-85
-------
Table Ford-18
2.3 litre Pinto with FBC
Package : Pinto, 3 door, 3,
Transmission
Catalyst: 80
Mileage
Vehicle # 1
Sign-Off
0
5K
10K
15K
18K
2 OK
25K
3 OK
30K
35K
40K
Vehicle // 2
Sign-Off
0
5K
10K
11K
15K
2 OK
: M-4
CID 3-way plus
HC
0.28
0.31
0.24
0.47
0.43
0.39
0.39
0.35
0.43
0.44
0.51
0.49
0.24
0.31
0.26
0.43
0.24
0.29
0.41
000 Ibs IW,
80 CID OC
f 7C TJTT)
CO
1.92
1.90
1.57
3.67
3.36
2.96
3.20
3.04
3.50
3.26
3.12
2.91
1.75
2.04
2.03
4.46
1.58
1.29
1.83
3.18 Axle
NOx
1.18
0.78
0.77
0.76
0.88
0.58
0.69
0.98
0.71
0.58
0.63
0.69
1.20
1.09
0.62
0.64
0.70
0.77
0.81
MPG
u
19.3
21.3
21.6
21.1
23.6
21.8
23.7
22.4
24.3
23.0
-
22.5 Avg.
20.4
23.3
20.5
21.7
23.1
23.5
Remarks
Replaced faulty solenoid
on FBC
Replaced failed EGR
transducer
Veh. stalls at idle
Before maintenance
After maintenance
5K-40K
Replaced regulator and
adjusted ECU
22.1 Avg. 5K-20K
7-86
-------
Table Ford-19
1978 302 CID Vehicle with
Electronic EGR and Spark Control
Mileage
Develop.
Objective
56
4745
9171
9872
15060
19802
20485
24800
24824
29400
29452
29527
HC
0.40
0.37
0.37
0.36
0.54
0.53
0.44
0.43
0.45
0.48
0.47
0.45
0.75
0.63
0.50
0.53
.__ f 7^ FTP
CO
6.22
4.03
4.95
2.80
3.91
6.32
4.79
3.49
4.12
4.57 .
3.19
4.32
6.38
4.92
4.08
4.04
NOx
1.32
1.74
1.89
2.20
1.97
1.89
2.00
2.00
2.10
1.97
2.13
2.37
4.15
3.82
1.43
1.36
MPG
u
12.4
14.1
14.5
14.2
14.7
14.6
14.4
14.9
14.6
14.3
14.4
14.7
14.8
14.4
14.0
Remarks
"0" Mile Test
5K Test
Bef . and Aft . Carburetor
Replacement
10K Tests
15K Test
20K Test
Repaired broken vac. tee
25K Tests
30K Test
EGR Valve replaced
Tests after repair of
faulty wiring harness
7-87
-------
of 96 cubic inches. The Pt/Rh ratio of 1.5/1 in the 3-way catalysts is
very high and may raise questions concerning production feasibility for
a large number of vehicles.. All nine vehicles used backpressure EGR.
All vehicles used open loop carburetion, though the six carburetors for
3W + OC vehicles were carefully flowed before durability mileage accumulation
started to provide approximately stoichiometric operation. Additionally,
idle CO was periodically adjusted on three of the 3W + OC vehicles to
ensure stoichiometric operation over mileage accumulation. The projected
4000 mile and 50,000 mile emissions and deterioration factors of the
nine vehicles are shown in Table Ford-20.
Table Ford-20
Low NOx Fleet Vehicles
VIN
IP*
2P*
3P*
4P
5P
6P
7P
8P**
9P
System
3W + OC
3W + OC
3W + OC
OC
OC
OC
3W -1- OC
3W -f OC
3W + OC
0.
0.
0.
0.
0.
0.
0.
0.
0.
HC
29
35
29
21
18
20
22
29
34
Projected 4K
CO . NOx .
1.74
1.16
1.11
0.85
0.72
0.74
1.20
1.26
1.43
0.52
0.74
0.89
0.92
0.86
0.84
0.67
0.68
0.82
Projected
HC CO
0.38
0.45
0.40
0.27
0.24
0.35
0.32
0.43
0.34
0.96
1.52
1.72
2.29
0.96
1.71
1.63
1.69
1.58
50K
NOx
0.87
0.62
0.84
0.74
0.87
0.61
1.09
0.58
1.13
HC
1.33
1.25
1.41
1.33
1.33
1.79
1.43
1.51
1.00
DF
CO
0.55
1.31
1.56
2.69
1.33
2.31
1.36
1.34
1.10
NOx
1.70
' 0.83
0.95
0.81
1.01
0.73
1.63
0.86
1.38
* idle CO adjusted throughout durability to maintain stoichiometry
** idle CO adjusted only at 25R
7-E
-------
Ford also reported the catalyst efficiency results from the vehicles
listed in Table Ford-20. These Low NOx Fleet vehicles had their catalyst
efficiency determined at the end of the 50,000 mile durability run. The
results are shown below in Table Ford-21. The HC and CO conversion effi-
ciencies for all systems show improvements compared to current practice.
Table Ford-21
50,000 Mile FTP Catalyst CO Version Efficiency
VIN
IP
2P
3P
4P
5P
6P
7P
8P
9P
These results suggest that Ford could certify the 302 CID engine at 0.41
HC, 3.4 CO, 1.0 NOx with either a 3W + OC system or an OC system. A
fuel economy differential at low mileage (about 4 MPG ) between the two
c
systems on deveopmental vehicles (not low NOx fleet vehicles) suggests
that the 3W + OC system is the logical choice for production as shown in
Table Ford-22.
Table Ford-22
4,000 or 5,000 Mile Fuel Economy
Vehicle MPG MPG, MPG
u h c
Developmental 3W + OC 15.0 22.4 17.5
Developmental OC 11.5 17.0 13.5
177 Federal fuel
economy/data cars* 15.4-17.0 18.6-22.1 16.7-19.0
HC
86
87
85
77
85
83
92
85
90
CO
92
94
92
91
95
95
87
91
91
NOx
66
69
66
5
-2
3
57
62
65
Remarks
Avg.
Avg.
Avg.
Avg.
Avg.
Avg.
Avg.
Avg.
Avg.
4 tests
4 tests
4 tests
3 tests
3 tests
4 tests
4 tests
3 tests
3 tests
* 7K1-302-F-35 and 7Z1-302-F-33
7-89
-------
The urban fuel economy data in Table Ford-23 show that the fuel economy
differential between 3W + OC and OC systems at 1.0 NOx was also found in
the Low NOx Fleet. The fuel economy of the 3W + OC vehicles in Table
Ford-23 are within the fuel economy range of the similar 1977 Federal
vehicles in Table Ford-22.
7.1.3.4. Progress and Problem Areas
Ford has made significant progress on individual emission control
components in the past year. Their program for development of feedback
carburetors has been relatively successful, at least at low mileage.
The development of a first generation of individual and combined electronic
emission control components is now complete, and the development of a
second generation of electronic emission control components is progressing.
Their durability testing has shown the 3-way plus oxidation catalyst
system to be capable of control to 0.41 HC, 3.4 CO, 1.0 NOx with little
Impact on fuel economy. The fuel economy performance could have possibly
been even better had the vehicles used the electronic subsystems that
Ford has under development. Screening of 3-way catalysts has yielded a
number of catalysts which appear to merit durability testing on vehicles.
The M-257 catalyst, shown in Figure Ford-7, appears especially promising.
The major problems for Ford seem to be: 1) to apply advanced emission
control components, such as combined, electronic control of spark, EGR,
and air-fuel metering and 3-way plus oxidation catalysts, to all engine
families and 2) to establish the durability of these combined systems.
While component development programs have been successful, durability
testing of combined systems is just beginning.
Ford stated their major problems to be: 1) experience with component
durability, 2) sufficient lead time to gain field experience with new
components and to permit an orderly introduction of new components on
7-90
-------
Table Ford-23
Low NOx Fleet Fuel Economy
Low and High Mileage Results
VIN
System
IP
2P
3P
4P
5P
6P
7P
8P
9P
3W -1- OC
3W + OC
3W + OC
OC
OC
OC
3W + OC
3W + OC
3W + OC
5K MPG Range
5K-50K MPG Range
13.9 -
16.2 -
15.9 -
10.9 -
11.1 -
11.8 -
14.8 -
15.
. 15.6 -
14.7
16.3
16.3
11.1
12.0
12.0
15.8
5
16.1
13.9 -
14.9 -
15.2 -
10.5 -
11.1 -
10.5 -
14.8 -
14.8 -
14.8 -
17.1
16.6
16.9
12.3
12.3
12.1
17.1
17.0
16.6
Mean MPG * (5K-50K)
15.8
15.8
15.9
11.3
11.7
11.3
15.9
16.1
15.7
* Number of tests at individual mileage points are not equal, mean
includes all test points.
-------
Figure Ford-7
TEMP. EFFECT ON CONVERSION OF NO,
CO, HC OVER M-257 CATALYST
PRETREATMENT: 100 HOURS AT 1500 °F WITH
MODULATIONS OF[l%02/2% CO] AT 6Hz FREQUENCY
100
2 8°
o
o
ID
SU3ANOO
40
20
0
lOi
1 1 1 1
LEGEND
CATALYST S:V. = 60,000 HR~'
O CO R=|.05
A HC
D NO
Q NH3
0=
'tf
MW
•••t
1
0
n n n ~n D -
—
NO NH3 FORMATION ~
••' '"'.' —
2IO°C j j
200 300 400 500 600
T(°C)
7-92
-------
the various engine families, 3) the potential deletion of manual trans-
missions for 200 CID and larger engine families if 0.41 HC, 3.4 CO, 2.0
NOx is required in 1979, 4) the achievement of 1981 and subsequent model
year fuel economy standards along with 0.41 HC, 3.4 CO, 1.0 NOx emission
standards, and 5) the lack of demonstrated capability to control emissions
to 0.41 HC, 3.4 CO, 0.4 NOx for 50,000 miles.
The component durability issue is now being resolved with testing on the
two vehicles with the 2.3 litre engine, the vehicle with the 302 CID
engine, and the twenty vehicle fleet. It is not known why the twenty
vehicles are just now being prepared for durability since all key
components seem to have been ready for some time, with the possible
exception of feedback carburetion. It appears that Ford may have been
waiting for the further development of feedback carburetion before
starting durability testing. Other, possibly more costly, fuel metering
systems may have been the only ones available earlier.
Since Ford has expended considerable effort on systems with potential
for low NOx emissions and high fuel economy, such as 3-way catalyst
systems, the PROCO, and the CVCC, Ford may have highly efficient engines
available for the 1981 and subsequent model years. Ford's plans for
vehicle weight reduction and engine availability have not been released
so 'their ability to comply with 'future fuel economy regulations (which
are as yet undetermined for the 1981-84 time frame) cannot be accurately
determined.
The "Concept Car" is now being built by Ford as a participant of the
Inter-Industry Emission Control Program. The goal for the "Concept Car"
is to demonstrate the 0.41 HC, 3.4 CO, 0.4 NOx emission levels. If the
program is successful, another problem for Ford will be alleviated.
7-93
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7.1.4. General Motors
7.1.4.1. Systems Under Development
The General Motors (GM) systems under development for model year 1978
and post-78 years range from those systems presently used on the 1977
model year vehicles to basic research on potential emission control
hardware. The descriptions of the potential GM systems are described
below. Since GM "...anticipated that 1978 emission standards would be
carry over 1977 standards..."* the bulk of GM's work has concentrated on
improving the system life and fuel economy of the 1977 model year system
consisting of an oxidation catalyst, exhaust gas recirculation (EGR),
ignition timing, and carburetor calibrations. The evaporative emission
control system will be modified by routing fuel vapors from the
carburetor bowl to the evaporative emissions canister during vehicle
shut down. For California, GM plans to meet carryover standards of 0.41
HC, 9 CO, 1.5 NOx. Emission control systems to meet these standards
would be similar to 1977 California systems, consisting of an oxidation
catalyst, back pressure EGR, air injection by AIR or PULSAIR, and im-
proved carburetion. GM may introduce in California a limited production
of vehicles using closed-loop 3-way catalyst systems targeted to meet
standards of 0.41 HC, 9 CO, 1.5 NOx. GM is also planning to introduce a
turbocharged Buick V-6 engine and a 350 CID light duty Diesel engine.
* GM Advanced Emission Control System Development Progress,
December 15, 1976, p. VII-2.
7-94
-------
GM's estimates of potential system hardware and fuel economy at various
emission standards are given in Table GM-1.
Oxidation Catalysts
GM continues to evaluate catalyst samples submitted from approximately
25 catalyst suppliers. This testing includes both engine dynamometer
and vehicle tests in addition to catalyst activity and physical property
testing. GM also has been conducting evaluations for. improving oxidation
catalyst system performance and durability. A five car test fleet was
assembled using four catalysts that appeared promising based on bench
test results. These catalysts are to be compared to the present pro-
duction GM catalysts. Catalysts were rotated between vehicles and after
25,000 miles none of the test catalysts appear superior to the present
production catalyst, according to GM, but they are continuing the testing.
GM has continued to place emphasis on improving catalyst light-off. One
method tried was reduction of converter metal cross-sections which did
not prove successful. Use of small monolithic catalysts installed in
the engine exhausts ports proved to be of no advantage for emission
reduction, according to GM.
Work on reducing the effects of fuel and oil constituents on catalyst
durability was unsuccessful in reducing emission levels as was a study
using an experimental 367 cu in. catalyst in place of the production
260 cu in. pelleted catalyst.
Some interesting work is being conducted by GM on monolithic catalysts,
and lower density pelleted catalyst (approximately 30 Ibs/cu ft.). This
work is investigating potential replacements for the conventional
underfloor, pelleted catalyst. Table GM-2 gives the zero mile tests
results for two types of pelleted catalysts versus a monolithic catalyst.
7-95
-------
Year HC
1977 1.5
1980-81 0.9
1982 0.41
1977 0.41
1978
0.41
Standards
CO
15
3.4
0.41 3.4
3.4
NOx
2.0
2.0
2.0
1.5
1.0
Table GM-1
Emission Standards and Fuel Economy
Potential
System Hardware Percent
Fuel Economy Losses
MFC
(18.4 MPG
Base)
(1)
Oxid. Converter, Baseline 18.4
EGR
Oxid. Converter, 0 18.4
AIR, EGR
Oxid. Converter, 10-20 14.7-16.6
AIR, EGR
(2)
Oxid. Converter, 11v ' 16.4
AIR, EGR
Large Engine/Small 15-30 12.9-15.6
Car, Oxid. Converter
AIR, EGR
3-way converter C/L, 0-20 14.7-18.4
EGR
Dual Converter C/L, 10-20 14.7-16.6
AIR, EGR
0.4 Same catalyst sys- 10-30? 12.9-16.6
tern selections as
0.41, 3.4, 1.0 stds.
Remarks
Includes a 5% fuel economy loss froci
1976 standards (1.5, 15, 3.1).
Lead time requirements would prevent
AIR and BPEGR usage in 1978.
Further improved catalyst system
performance and durability for
1978 and later years may reduce
penalty to lower end of range shown.
Current systems show penalties up
to 20%.
Limited product availability.
Larger engines and higher axle ratios
reduce NOx emissions by reducing
engine load.
The fuel economy losses may be at the
lower end of the range only if
satisfactory catalyst durability can
be developed and an adequate supply
of catalyst material is available.
To date, no system has been developed
that meets EPA emission test require-
ments for 50,000 miles with reasonable
maintenance requirements.
Meaningful assessment of fuel economy
penalty cannot be made since control
systems have not been demonstrated to
meet statutory standards through the
complete certification process inclu-
ding the 50K mile durability require-
ments.
(1) EPA calculation of 1977 GM fleet average based on Part 1 Certification sales forecases.
(2) Loss would be more than 15% if California's methane allowance, audit requirements, and carry across of Federal
durability data were not permitted.
Note: Diesel engines are not included.
7-96
-------
Table GM-2
Zero Mile Testing of the
Effects of Converter Type on Emissions and
Time for Exhaust Exiting Converter to Reach 600"F
Converter Type
260 cu in. Pelleted
(GM Prod.)
160 cu in. Pelleted
(GM Prod.)
150 cu in. Monolithic
FTP
HC
0.35
0.37
0.24
Emissions — gm/mi
CO
3.11
2.82
2.11
NOx
1.40
1.44
1.45
Time to Reach
600°F--seconds
338
224
165
(Competitive Product)
As can be seen from Table GM-2, the monolith, even though it is 42%
smaller than GM's 260 cu in. pelleted catalyst, had improved light-off
and emission performance, at zero miles. If one considers the 160 cu
in. pellet to be roughly the same volume as the 150 cu in. monolith,
emission improvement factors of 0.65 for HC, 0.75 for CO, and 1.01 for
NOx are indicated. Applying these factors to the 260 cu in. pelleted
catalyst results indicates that 0.23 HC, 2.33 CO, 1.41 NOx might be
predicted for a monolithic catalyst of approximately the same volume as
GM's 260 cu in. pelleted catalyst, based on Table GM-2.
Three durability vehicles using the monolithic converters can be found
in Table GM-24. A 43 vehicle customer service fleet is being assembled
to evaluate monolithic catalysts under field use conditions.
Hybrid monolith-pelleted converters (40 cu in. monolith plus 180 cu in.
pelleted), and a system using a catalytically-action cloth made by
Mitsubishi over the pellets in a 260 cu in. container were also evaluated,
No further work is planned for these concepts.
GM continues to investigate the expanded use of the start catalyst
introduced in 1977 on the L-6 engines in California. Reference was also
made to a 48 vehicle test fleet for a close coupled catalyst on the "X"
car which may be a monolith and radial flow pellet design.
7-97
-------
GM has continued research into identifying ways in which the loss of
catalyst activity can occur. Catalyst poisoning by lead and phosphorus
and noble metal sintering are recognized as the two principal modes of
catalyst deactivation. The studies of noble metal sintering has led GM
to conclude that:
-FTP HC emissions were nearly doubled as a result of sintering of
the platinum catalysts. CO emissions increase by 50% to 300%
depending upon the converter volume tested. The palladium catalyst
was much more resistant to sintering, resulting in HC and CO
emission increases of about 25%.
-Nearly all of the increase in CO emissions was caused by decreased
noble metal surface area. Once warmed-up, the sintered catalysts
showed remarkably high CO conversion efficiencies (> 90%) .
-Sintering reduced the HC activity of both the platinum and palladium
catalysts throughout the FTP, with increased HC emissions occurring
in both cold and hot cycles.
-The HC and CO emissions suggest that noble metal surface area
influences oxidation only during those periods of catalyst
operation when reaction kinetics control the overall rate of
oxidation. After the catalyst is fully warmed-up, the CO oxidation
rate becomes mass transfer limited and is no longer controlled by
catalyst metal surface area. HC oxidation, on the hand, is not
completely limited by mass transfer even when the catalyst is fully
warmed-up. Considering the great variety of HC species present in
engine exhaust gases, it is reasonable to suppose that oxidation of
some species is mass transfer limited, while the more oxidation
resistant HC species remain kinetically limited. Thus, overall HC
oxidation continues to be influenced by noble metal surface area in
the hot FTP cycles.
GM investigated methods of rejuvenating alumina supported platinum-
palladium catalysts with dilute solutions of ammonium oxalate. The
7-98'
-------
results indicated a partial removal of lead compounds from poisoned
catalysts, with less effectiveness in regenerating catalysts poisoned, by
a combination of lead and phosphorus, and no effectiveness in regenerating
catalysts deactivated by noble metal sintering.
GM also presented data which indicated that the phosphorus in engine
oils has a potentially detrimental effect on catalyst HC conversion
efficiency.
3-Way Catalysts
At the statutory emission levels, GM maintains that some emission
control systems incorporating a catalytic control of NOx will be nec-
essary. GM is presently running development vehicles using systems
containing: (1) platinum/rhodium 3-way catalysts (0.01-0.02 troy ounces
of rhodium), (2) three-way closed loop catalysts, (3) 3-way plus an
oxidation catalyst, (4) reactor plus a 3-way catalysts, and (4) a
reactor-reduction catalyst-reactor system. The latter concepts will be
discussed later.
GM has maintained that because of limited rhodium availability, the use
of catalysts with high rhodium loadings will not be production feasible.
GM utilizes a closed loop fuel metering system, both carbureted and fuel
injected, to maintain stoichiometric or slightly rich air-fuel mixtures
in the 3-way catalyst systems. Details of the fuel metering systems
were generally not provided by GM.
However, it was revealed in the automotive industry press* that GM is
planning to revamp two carburetion systems for 1978, the Varajet and
Dualjet. The relationship to the needed fuel metering control for 3-way
catalyst and these carburetors is unclear.
* Ward's Engine Update, 4 February 1977, page 1.
7-99
-------
GM is apparently planning significant changes in fuel metering within
the next few years. GM's targets are to make it possible to introduce a
closed loop system on all GM light duty vehicles for start of production,
1980, with a limited sample for California for start of production 1978.
Timing charts for these two programs are shown in Figures GM-1 and GM-2.
Closed loop carburetors (Quadrajet, Varajet, Dualjet, Holley Staged
2bbl) as well as single and dual point fuel injection are being considered,
The results of the development vehicles can be found in Table GM-3 while
the durability vehicle results can be found in Table GM-24. The two 3-
way catalyst durability vehicles, 65375 and 64384, are described in the
durability vehicle sections.
The development of vehicle 66312A was an attempt to use a 3-way catalyst
without EGR. Vehicle testing has been terminated.
These data comprise the total 3-way catalyst development vehicle work
reported by GM. Work continues on evaluating potential 3-way catalysts
using bench and engine dynamometers.
3-Way Catalyst Plus Oxidation Catalyst Systems
GM reported only one vehicle which had a three-way plus oxidation
catalyst system. This vehicle (No. 66313, Nova, 305 CID) was equipped
with a closed loop 4-barrel carburetor, a production underfloor oxidizing
catalyst with programmed air injection, an 0~ sensor, and two 3-way
monolithic catalysts mounted in the exhaust down pipes. No details were
provided concerning the programmed air injection. The 3-way catalyst is
a high platinum-low to medium rhodium Englehard catalyst. The vehicle
is presently on mileage accumulation and the low mileage results can be
found in Table GM-4. A system schematic can be found in Figure GM-3.
7-1QO
-------
GM-1
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Figure GM-2
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Table GM-3
GM DEVELOPMENT 3-WAY CATALYST VEHICLES
VIN
66312
66344
66334
66312A
66365
66315
66352
Model CID Control Sys. Mileage
Vega 2.3 litre BPEGR, 3-way 0
EFI, 0- sensor
EFC*, **
Vega 2.3 litre Same as 66312, 0
***
Vega 2.3 litre Same as 66312 & 0
66344, Will use
100 cu in. Engelhard
monolith for
durability accumulation
Vega 2.3 litre EFI, 0 sensor , 0
EFC, 3-way
No EGR
Rich bias 0
(Terminated vehicle)
Vega 2.3 litre BPEGR, 3-way 0
Single pt. EFI,
Closed loop A/F
Electronic Controller,
Insulated Exhaust,
0- sensor
Chev'elle 350 BPEGR, 3-way, 0
Closed loop 4 bbl, 5
CL sensor 12
Nova H/B 350 Same as 66315 0
except with low
load pelleted
Grace catalyst
FTP Results (gm/mi) Fuel Econc
(10 ) HC CO NOx MPG
0.24 2.70. 0.22 18.2
0.28 1.69 0.23 18.9
0.35 2.89 0.29 18.9
0.25 2.57 0.70 19.6
0.23 4.10 0.36 19.6
0.44 10.0 0.26 19.3
0.29 2.81 0.30 12.9
0.30 4.66 0.27 14.5
0.30 5.18 0.26 14.0
0.29 3.41 0.44 13.0
* Electronic Feedback Control (EFC)
** To evaluate the effect of MMT on catalyst and 0? sensor durability
*** Ashless oil and '77 CO fuel to be used
7-103
-------
Table GM-3 (cont.)
, FTP Results (gm/ml) Fuel Economy
VIN Model CID Control Sys. Mileage (10 ) HC CO NOx MPG
66201 Seville 350 EFI, BPEGR, 0 0 0.25 1.9 1.0 13.2
Sensor, Closed
loop A/F and Idle
Speed control, programable
EGR (targeted
at higher NOx standards)
60291 Chevette 1.6 litre PEGR, Pulsair 0 0.17 2.67 0.30 24.0
3-way, air bleed
closed loop plus
cold spark advance
retard
60358 Chevette 1.6 litre Same as 60291 0 0.23 3.05 O.A1 26.4
except with manual
transmission
7-104
-------
Figure GM-3
THREE-WAY PLUS OXIDATION
CATALYST SYSTEM
AIR
PUMP
CLOSED LOOP CARBURETOR
OXIDIZING
CATALYTIC CONVERTER
EXHAUST GAS
RECIRCULATION
VALVE (R.H.
AIR LINE
EXHAUST OXYGEN
SENSOR
CARBON CANISTER
3-WAY MONOLITH
CATALYTIC CONVERTER
(EACH SIDE)
SCHEMATIC
AIR FLOW >
OXIDIZING
CONVERTER
CLOSED
THROTTLE
SIGNAL
SENSOR SIGMAL
-------
Table GM-4
3-Way Plus Oxidation Catalyst
Car 66313
Mileage (103)
0
5
10
15
15
20
HC
0.19
0.23
0.30
0.27
0.20
0.24
CO
1.33
2.47
3.68
2.67
1.89
3.02
NOx
0.43
0.47
0.53
0.74
0.63
0.59
MPG
13.0
13.3
13.3
13.1
12.4
13.0
Remarks
New Design Carb.
and Controller
Dual Catalyst Systems
GM presented data from three dual catalyst vehicles. One vehicle is a
Vega (Car No. 66333) equipped with a 140 cubic inch (2.3 litre) fuel
injected engine. An exhaust gas oxygen sensor and closed loop fuel
controls are used to maintain the air-fuel ratio close to stoichimetric.
As shown in the schematic of Figure GM-4, the catalyst system consists
of a GM low rhodium loading monolithic reducing catalyst in series with
a production pelleted oxidizing catalyst. Air injection is also used on
this vehicle. The results achieved with low mileage catalysts on this
system are 0.27 HC, 2.02 CO, 0.66 NOx and 16.8 MPG . Development is
continuing to improve the NOx emissions.
The second vehicle is a Chevelle (Car No. 66346) equipped with a 350
cubic inch engine and a closed loop 4-barrel carburetor. International
Nickel Co. base metal reducing catalysts are used in the exhaust down-
pipes along with a production underfloor oxidizing catalyst and air
injection. Insulated exhaust manifolds and port liners are used to
maintain higher exhaust gas temperatures into the reducing converters.
The emission results out to 10,000 miles are shown in Table GM-5.
The base metal reducing catalysts were melted and have been returned to
the vendor for analysis.
7-106
-------
3>T"i!IT[C5 O^/'$CiT"S[!!! F\ n
i 3 tK bYb 8 LlVs
(Rhodium - ASr - Platinum / PaSIadaum)
LOOP-ERVEQA ' '
EXHA6ST GAS
RECIRCULATION
INJECTORS
AIR PUMP
I
t—'
o
PRODUCTION OXIDIZING
CONVERTER
RHODIUM MONOLITH
CONVERTER
COLD START
AIR
AIR
AIR FLOW
FUEL INJECTION
JQ
l-l
INJECTION
SIGNAL
RPM
SIGNAL
COOLANT
TEMPERATURE
SIGNAL
RHODIUM
CONVERTER
,
OXIDIZING
CONVERTER
OXYGEN SENSOR
-------
Table GM-5
Dual Catalyst Results
Mileage (103)
0
5
10
HC
0.29
0.39
0.52
Car No.
CO
1.38
2.73
5.26
66346
NOx
0.36
0.54
0.98
MPG Remarks
12.0
12.4
12.0 Recal. Reg.
The third vehicle (Car No. 66346A) is a Chevelle equipped with a 350
cubic inch engine and closed loop 4-barrel carburetor. Reducing catalysts
are installed in the exhaust downpipes with an underfloor production
oxidizing catalyst and air injection. Insulated exhaust manifolds and
port liners are currently used to maintain high exhaust gas temperatures
into the reducing catalysts.
Zero mile emission results with a high platinum-high ruthenium loading
Dupont perovskite catalyst were 0.48 HC, 1.77 CO, 0.32 NOx, 12.0 MPG .
Additional tailoring will be performed to optimize conditions for this
catalyst. Plans are to screen various other catalysts in this car, to
investigate precious metal loadings and catalyst activity. This screen-
ing will include a low platinum-medium ruthenium Gulf submission. All
previous catalyst submissions from Gulf have contained extremely high
amounts of ruthenium, according to GM. The best candidate will start
durability testing.
Reactor Plus Converter Plus Reactor System
The reactor/converter/reactor system is another approach that employs a
NOx catalyst. This system has three reaction zones. The first zone is
a high temperature manifold reactor in which partial oxidation of HC and
CO is accomplished. The overall air-fuel ratio out of the first zone
remains net reducing so oxides of nitrogen can be reduced in the second
zone which utilizes a metallic NOx catalyst. Additional air is injected
7-108
-------
into the third zone which is another high temperature reactor used to
continue the oxidation of HC and CO. In the past year, a reactor/
converter/reactor system incorporating closed loop electronically
controlled fuel injection, proportional AIR, and BPEGR has been designed
and fabricated. Initial calibration testing is commencing. This type
of system is similar to the system developed by Questor. GM has pro-
posed a new joint limited development test program which Questor is
presently reviewing.
Other Development Efforts
Reactor Plus 3-Way Catalyst Systems
GM gave details concerning their work on systems utilizing reactors and
various 3-way catalysts. Table GM-6 gives the results of one vehicle
(66324) which was used to evaluate not only the reactor plus 3-way
catalyst system, but also to evaluate various 3-way catalysts. Figure
GM-5 presents a schematic of this system. The other vehicle (66404)
used smaller volume manifold reactors plus an Engelhard pelleted catalyst.
This vehicle also will eventually be used to evaluate different 3-way
catalysts. The only details given on the Oldsmobile Twin Point EFI are
shown in Figure GM-6.
Table GM-6
Reactor Plus 3-Way Catalyst Development Vehicles
VIN
Model CID Mileage HC
66324 Chevelle 350
66404 Cutlass 350
0.13
CO
2.50
NOx
0.26
MPG
12.2
Remarks
0.22
0.23
0.21
0.21
3.00
3.56
3.59
4.97
0.29
0.31
0.37
0.21
12.4
13.3
13.0
12.8
HN 2217
HN 3032
HN 3095
HN 3096
Twin Point
EFI,
Doubled
walled
cross-over
pipe.
7-109
-------
Figure GM-5
EXHAUST GAS
RECIRCULATION
ELECTRONICALLY
CONTROLLED
CARBURETOR
MANIFOLD REACTOR PLUS 3-WAY CATALYST
. EMISSION CONTROL SYSTEM
I,-, /-'to*
HIGH ENERGY
IGNITION
ELECTRONIC
'CONTROLLER
ty^ CliMsr
'-^ vv/^'Sr**! ^fTTjr
rV'J&'&H '£lM *
£fejT' C< \ ^
^S^
CARBON CANISTER
3-WAY CATALYTIC
CONVERTER
EFE VALVE
(R.H. SIDE)
EXHAUST OXYGEN
SENSOR
MANIFOLD REACTOR
(Each Side)
FUNCTIONAL SCHEMATIC
AIR FLOW
OXYGEN
SENSOR
ELECTRONIC
CQUTgQLLE
SENSOR SIGMAL
-------
OLDSMOBILE CLOSED LOOP
STOICMiOElflETRIC TWIN POINT FUEL INJECTION
3-V/AY CATALYTIC
CONVERTER
MANIFOLD REACTOR
(Each Side]
THROTTLE
VALVE
TWIN
INJECTORS
4-
R
INJECTOR ; SIG
SIGNAL .
ENGINE
PM |
NAL MAP
SIGNAL
T T
ELECTRONIC
CONTROL
EXHAUST \~ C
COOLANT
TEMP.
SIGNAL
\
OX
SEI
3-WAY
CATALYTIC
CONVERTER
fGEN
4SOR
Figure GM-6
-------
All the catalytic systems described above relied on precise air-fuel
ratio management. GM uses both closed loop electronic fuel injection
and carburetion. The carburetor systems have closed loop A/F control of
both the idle and part throttle circuits. GM prefers to use a carbureted
system because of lower costs and, in GM's opinion, a perceived ability
to provide emissions control and fuel economy as well as EFI.
To gain production experience, GM plans to introduce on some 1978
California vehicles a closed loop 3-way system targeted at 0.41 HC, 9
CO, 1.5 NOx. These vehicles will use carburetion rather than EFI. Low
mileage results of three practice durability vehicles are shown in Table
GM-7.
Table GM-7
Low Mileage Results of 3-Way System Targeted at 0.41 HC, 9 CO, 1.5 NOx
VIN Model
1669 Buick
Skyhawk
ES//2 Pontiac
CID System Mileage (103) HC
231 BPEGR, 3-way,
0- Sensor, ECU
Closed loop 2bbl
151 Ported Slot EGR,
3-way, 0? sensor
ECU, Closed loop
2bbl
0
5
5
0
5
5
0.18
0.33
0.20
0.30
0.27
0.29
CO
2.1
11.6
4.8
3.17
5.20
5.80
NOx
0.32
0.14
0.20
0.91
0.78
0.96
MPG
u
15.9
17.0
17.0
18.9
21.4
21.9
ES#3 Pontiac 151 Same as ES #2 0 0.34 4.14 0.52 19.2
Astre 5 0.32 4.80 0.70 21.8
GM closed their discussion of catalytic treatment of NOx by providing
their estimates of lead time, production difficulties, and technological
advancements at standards of 0.41 HC, 9 CO, 1.0 NOx; 0.41 HC, 9 CO, 0.4
NOx; 0.41 HC, 3.4 CO, 1.0 NOx; or 0.41 HC, 3.4 CO, 0.4 NOx. Since, only
some of the GM vehicles described previously are running below the levels
of 0.41 HC, 9 CO, 1.0 NOx, GM feels that meeting their target of 1980
for all vehicles for closed loop control is going to be difficult and
7-112
-------
that the chance for all closed loop control for 1981 California vehicle
is greater. This statement is made in light of limited 1978 (151 and
231 CID) introduction of vehicles in California. GM's timetable for
faster introduction or total nationwide production by 1980 depends on
the construction of an CL sensor production facility, closed loop car-
buretor tooling release, more "practical" catalyst rhodium loadings,
solution of the development problems surfaced to date, and the results
of the limited 1978 California production. GM indicated that meeting
levels below 0.41 HC, 9 CO, 1.0 NOx will require improvements in catalysts
and in fuel metering.*
Other Conventional Engine Studies
GM reported extensive results obtained with systems which do not use
catalytic control of NOx. The systems are detailed below.
Lean Reactor/Converter Systems
GM has continued to try to develop a lean reactor/oxidation catalyst
(LR/OC) system to meet a standard of 0.41 HC, 3.4 CO, 2.0 NOx with a
lower limit system potential of 1.5 NOx. A fleet of three 350 CID
Chevrolet Monte Carlo vehicles were durability tested to assess the
potential of meeting these emissions goals. The results are shown in
Table GM-8. One additional vehicle (65357) had an A/F calibration
designed to improve fuel economy. Low mileage results of this vehicle
were 0.22 HC, 1.8 CO, 1.7 NOx with no loss in fuel economy as compared
to a similar 1977 data vehicle.
A LR/OC system is also installed on two 151 CID L-4 Pontiac engines.
Low mileage emission results are 0.23 HC, 1.03 CO, 1.3 NOx with 19.1
MPG . Durability testing continues with these vehicles.
* GM Advanced Emission Control System Development Progress, Submitted to
EPA, 15 December 1976, page VII-68.
7-113
-------
Table GM-8
Lean Reactor/Converter Durability Vehicles*
FTP Results Fuel Economy
VIN Mileage
65383 0
5
10
15
20
25
30
35
40
45
50
65382 0
5
10
15
20
25
30
35
40
45
50
(103) HC
0.21
0.19
0.24
0.25
0.30
0.22
0.31
0.35
0.33
0.39
0.41
0.20
0.18
0.22
0.29
0.35
0.34
0.30
0.29
0.25
0.31
0.42
CO
1.4
1.6
3.2
2.1
4.5
1.2
2.0
2.7
2.5
3.5
2.0
1.2
1.0
1.7
1.7
2.2
2.7
2.3
2.3
2.3
3.5
5.2
NOx
1.5
1.4
1.5
1.6
1.4
1.2
1.3
1.4
1.1
1.1
1.2
1.5
1.3
1.2
1.6
1.3
1.3
1.3
1.4
1.3
1.2
1.3
MPG
u
12.0
12.6
12.4
12.6
12.1
12.9
12.9
12.7
12.6
12.3
12.4
12.2
12.1
12.3
12.5
12.7
12.7
12.5
12.0
11.7
11.7
11.7
MPG, MPG
n c
18.8 14.8
19.2 15.1
18.3 14.5
17.1 13.9
18.3 14.6
17.3 13.7
* All vehicles Chevrolet Monte Carlo, 350 CID, A3, 4bbl,
BPEGR, EFE, 135 cu in./side lean reactors
cold spark adv/retard, 260 cu in. OC.
7-114
-------
Table GM-8 (continued)
VIN
65328
Mileage (10 ) HC
CO
NOx
MPG MPG, MPG
c
13.6
0
5
10
15
20
25
30
35
40
45
50
0.14
0.10
0.15
0.15
0.17
0.20
0.24
0.26
0.26
0.18
0.20
1.0.
1.3
2.1
2.0
2.2
2.3
3.0
3.4
2.8
1.2
1.4
1.7
1.4
1.3
1.5
1.4
1.3
1.2
1.3
1.2
1.1
1.2
u
11.0
11.5
11.7
12.0
12.1
12.1
12.4
12.6
12.7
12.3
12.0
n
17.5
17.9
17.5
14.2
14.0
7-115
-------
GM stated that the LR/OC system offers no advantage over an OC/AIR
system at standards of 0.41 HC, 9 CO, 1.5 NOx.
At standards of 0.41 HC, 3.4 CO, 1.0 NOx, GM has attempted to develop
two vehicles with a reactor calibration richer than stoichiometric,
manifold air injection, and an underfloor oxidation catalyst. Zero mile
results on a Vega with a 2.3 litre engine with proportional AIR control
showed 0.10 HC, 2.0 CO, 0.7 NOx with 18 MPG . A 305 CID Chevelle had
zero mile average results of 0.29 HC, 1.38 CO, 0.65 NOx with 12.0 MPG .
GM attempted to meet 0.41 HC, 3.4 CO, 1.0 NOx without resorting to a
reduction catalysts by using high EGR rates, AIR, and OC. GM reported
low emission levels with poor driveability and high losses in fuel
economy (10-30%) when compared to 1977 Federal certification vehicles,
according to GM. Average results are listed below.
Table GM-9
GM 1.0 NOx Target Oxidation Catalyst Systems
FTP
Vehicle
Weight HC
4500
4000
2250
0.
0.
0.
0.
0.
18
21
26
22
22
Emissions
CO
1.
1.
1.
2.
2.
35
68
35
39
56
(gm/mi)
NOx
0.
0.
1.
0.
0.
70
74
16
70
67
MPG
u
10.4
11.0
13.9
22.8
23.5
Fuel Economy
1977 Durability
VIN Vehicle MPG (Range)
(7168)
(7148)
(7110)
12
13
21
.3-13.
.9-15.
.6-24.
u
7
0
3
Engine
350 V-8
250 L-6
1.6 litre L-4 2250
Another experimental system consists of lean manifold reactors, oxidizing
catalysts, lean carburetor (approximately 18:1), back pressure EGR (10-
7-116
-------
15%), modified intake manifold for improved air-fuel mixture and EGR
distribution, and a cold spark advance/retard mechanism for improved
warm-up emission control. In addition, the effect of increasing engine
displacement for a given vehicle weight was studied to determine the
effects of lowering BMEP. Results of this study indicates that while
the emission goals of 0.18 HC, 1.5 CO, 0.6 NOx were met on an experi-
mental basis, driveability and fuel economy were adversly affected.
Other Development Efforts
GM has continued to work on alternative engines, emission control com-
ponents, and other components to achieve various levels of emission
standards or fuel economy improvements.
Diesel Engine
350 Cubic Inch Engine for MY 1978
GM is planning to introduce a Diesel engine for MY 1978 in some light
duty vehicles and light duty trucks. The engine is based on the 350 CID
Oldsmobile V-8 gasoline engine. The bore, stroke, and deck height are
common with the gasoline engine. It uses a divided combustion chamber,
a glow plug for starting assist, a rotary distributor injection pump,
and pencil nozzles. The vehicle will have a larger starter motor and
possibly two batteries. A longitudinal section of the engine is shown
on figure GM-7, and details of the combustion chamber are shown on
figure GM-8.
GM feels that the Diesel will be 25% better in fuel economy, compared to
gasoline power on an equal performance basis. Performance and fuel
economy data are shown on Table GM-10.
7-117
-------
Figure GM-7
350 CID V-8 Diesel
7-118
-------
Figure GM-8
GM Diesel Combustion Chamber
7-119
-------
Table GM-10
Road Test Performance and Fuel Economy
260 V-8 Gasoline
350 V-8 Diesel
Improvement (MPG)
Improvement (%)
292 L-6 Gasoline
350 V-8 Diesel
Improvement (MPG)
Improvement (%)
4500
0-60 MPH
ie 18 Sec.
18 Sec.
'G)
5500
ie 18 Sec.
19 Sec.
'G)
# Cars
City
Traffic
15.9
19.2
3.3
21%
// Trucks
11.9
15.8
3.9
33%
Interstate
55 MPH
19.3
25.0
5.7
30%
12.6
18.0
5.4
43%
50 MPH
Constant
21.4
27.0
5.6
26%
13.8
19.9
6.1
44%
It can be seen from Table GM-10 that GM's fuel economy improvement esti-
mate may be conservative for the light duty truck. Table GM-11 shows
the emissions and fuel economy comparisons for the automobile comparison.
No data were presented for the light duty trucks shown on Table GM-10.
HC
260 Gasoline 0.50
350 Diesel 0.58
Improvement (MPG)
Improvement (%)
Table GM-11
Emissions - EPA Fuel Economy
4500// Inertia Weight
Emissions
CO NOx
6.2 1.99
1.9 1.63
Cars
EPA
MPG
15.4
19.4
4.0
26%
Fuel
MPG
21.1
27.
6.
31%
Economy
MPG
17.5
7 22.4
6 4.9
28%
7-120
-------
GM has produced 18 engines on a pilot production line. The engines were
targeted for a 1.5 HC, 15 CO, 2.0 NOx emission standard. The average,
highest, and lowest emissions with the corresponding fuel economy results
from vehicle tests are shown on Table GM-12.
Table GM-12
Emissions and EPA Fuel Economy Range
350 V-8 Diesel
Eighteen New Engines on Experimental Pilot Production Line.
1.5 HC, 15 CO, 2.0 NOx Design Target
Emissions EPA Fuel Economy
Average
Highest
Lowest
HC
0.93
1.23
0.71
CO
2.78
3.29
2.43
NOx
1.72
2.02
1.45
MPG
16.5
17.7
15.6
MPG
24.7
26.6
22.7
MPG
19.4
20.8
18.2
Other Diesel Studies
GM is apparently conducting an extensive Diesel development program.
Some of their work has been on the Opel Diesel, currently produced in
Germany, but not imported into the U. S.
Figures GM-9 and GM-10 show the effects of EGR on BSFC, smoke, HC, CO,
and NOx for the Opel engine at two different load/speed conditions.
At the lighter load condition (Figure GM-9) there is little effect on
BSFC and BSHC for EGR rates in excess of 25%. NOx is improved and smoke
and CO performance are degraded with EGR. At the heavier load point
(Figure GM-10) EGR rates beyond 15% appear to degrade everything except
NOx. These two figures indicate the possible need for an EGR system
that can control EGR rate based on load and speed.
7-121
-------
LU
>*^d*
o
u
O
a:
«.r> »
D.J »
O
<
Figure GM-9
OPEL DIESEL 126 1-4
1100 R.RAA. 50% LOAD
[•— &"* I ? C** H *^ r*r
s! i u-. v,7« ii
7-122
-------
o
re v
no O
IJ4
m
O
cu
0
Figure GM-10
OPEL DIESEL 126 1-4
2000 R.RM. 75% LOAD
0 5 10 15 20 2
7-U3 PERCENT E.G.R.'
30
-------
Figure GM-11 shows hot start emission test results from an Opel as a
function of road load per cent EGR. HC and CO are seen to increase
substantially above 10% road load EGR. Fuel economy was improved by EGR
up to about 15% EGR and then declined somewhat at higher EGR rates.
GM reported data in their status report on the effects of EGR and retard
on vehicles using EGR and timing retard. The results are shown in Table
GM-13.
The HC and CO results shown in Table GM-13 at the lowest NOx level are
much lower than the results indicated in Figure GM-11. Table GM-14
shows other GM data on an Opel showing similar results but in greater
detail. Note that the use of Electronic EGR allows values of 0.27 HC,
1.30 CO, 0.71 NOx to be achieved, with a negligible (-0.4%) effect on
fuel economy. The information does not indicate if the Electronic EGR
was used to achieve 0.37 NOx.
Table GM-13
EGR/Timing Results on Diesel Vehicles
Baseline (2500 IW)
4° Basic retard
Baseline (2500 IW, AT)
With EGR
Baseline (3000 IW, AT)
EGR for lowest NOx
HC
0.17
0.57
0.27
0.30
0.31
0.78
1975 FTP (gm/mi)
CO NOx
0.75 1.20
1.10 0.97
0.90 1.30
1.20 0.80
0.80 1.30
10.80 0.37
Fuel Economy
MPG
u
29.0
25.5
28.3
28.0
26.2
25.8
An attempt to achieve lowest NOx is shown in the last set of data in the
above table for a 3000 Ib IW vehicle with an automatic transmission.
7-124
-------
o n A +
HC COAAPG
Figure GM-11
I.U
UJ
ca-
ul
O
1.6
1.5
1.4
1.2
1.6
26
OPEL DIESEL 126 I.-4
3000* INERTIA WT.
(Hoi- Sfort Data - Not FTP)
0
1
5
r
10
15~~20 25
ROAD LOAD % E.G.R.
NOTE: CAR-TO-CAR VARIABILITY AND CAR DURABILITY COULD BE SERIOUS
PROBLEMS UTILIZING EGR.
7-125
-------
Table GM-14
Diesel Emissions with Exhaust Gas Recirculation
CO
0.81
1.30
10.8
NOx
1.27
0.71
0.37
Opel Diesel 126 L-4
3000 Ib. Inertia Weight
MPG
26.2 Baseline (10.
26.1 Electronic EG
25.8 EGR for Lowes
HC
0.31
0.27
0.78
GM has also conducted evaluations of the effect of timing and EGR on
emissions and fuel consumption on the 350 CID engine. Figures GM-12 and
GM-13 show the effect on the engine of injection timing at two load/speed
points.
GM's results with EGR on the 350 CID engine are shown on Table GM-15.
Note that the use of EGR and the redesigned combustion chamber resulted
in a 69% reduction in HC, a 24% reduction in CO, a 7% reduction in NOx,
and a 7% increase in fuel economy.
Table GM-15
Diesel Emissions with Exhaust Gas Recirculation
Oldsmobile Diesel 350 V-8
4500 Ib. Inertia Weight
HC CO NOx MPG
0.58 1.9 1.63 19.4 Baseline (17.7 Ib Air/Mile)
0.19 1.2 2.65 20.6 Chamber Configuration redesigned
for minimum HC
0.18 1.4 1.51 20.7 With EGR
7-126
-------
Figure GM-12
IJJ
D:
03
O
«H
X
u
ca
LU
O
LU
u ;D
O
o s o-:
LU ^ -"•
a, ti
L1J
0
OLDSMOB1LE DIESEL
T> r* -f*. \' o
* f, _ . i, - ^ i .I i _>*—
1100 RPA/1 25% LOAD
, AS INSTALLS;
" T l./Vi IN G
INJECTION TIMING DEG. B.T.C.
7-427
-------
Figure GM-13
O
u
LLS
u
o
CO
u.
0
m
UJ
o
LDSMOBILE DIESEL 3SOV-
2000 R.RM. 30% LOAD
O
'O
AS INSTALLED
TI.MING
INJECTION TIMING DEG..B.T.C.
7-123
-------
GM has an extensive program to study Diesel particulate. An outline of
the program is shown in Table GM-16.
Table GM-16
General Motors Diesel Exhaust Particulate
Investigation Programs
I. Particulate Measurements - Evaluating and in some cases developing
measuring equipment for particle volume, size, weight and surface
area. Engineering Staff and Research.
II. Particulate Formation Study - Understanding the process by which
particulates are formed in the combustion process. Research.
III. Engine Modification - Investigation of the effect of engine
mechanical changes on particulate formation. Oldsmobile and
Engineering Staff.
IV. Fuel Additives - Effect of "Smoke Reducing" and other fuel
additives on particulate formation. Engineering Staff.
V. Particulate Traps and Incineration - Design and development
of particulate traps and incinerators, including catalytic
converters. Engineering Staff.
VI. Particulate Health Effects - Health effects of Diesel exhaust
particulates. Research Bio-Medical Sciences Department and
Wayne State University.
As can be inferred from Table GM-16, the program seems to be a wide-
ranging one.
In addition to the aforementioned Diesel particulate studies, GM appar-
ently has conducted or will conduct studies for the measurement of
particulate mass from engines on engine dynamometers and on vehicle
dynamometers. Particulate samples will be analyzed by a variety of
techniques including scanning electron microscopy, thermogravimetric
analysis, gas chromatography, and x-ray diffraction to determine com-
position, topography, structure, volatility, and combustibility.
7-129
-------
Several types of smoke meters will be used to establish correlation
between the indicated opacity and the mass of particulate emissions.
Two experimental Diesel-powered cars were tested at several driving
conditions. The total particulate emissions, given in the following
data, ranged from about 200 to 800 milligrams per mile. The sulfate
emissions were also, determined and were generally between 10 and 15
milligrams per mile. This is equivalent to about 1-1/2% of the fuel
sulfur (0.24%) burned.
Particulate Emissions; Experimental Diesel Cars
Total Particulate - milligrams/mile
Driving Cycle
1975 FTP
S-7
HFE
Idle
30 mph
40 mph
50 mph
60 mph
Car 0-64609
830
540
370
-
440
280
260
300
Car 0-64535
750
440
390
120*
240
250
290
240
* milligrams per minute
GM provided very sketchy details of the modifications to combustion
chambers and fuel injection equipment to reduce particulate formations
that are being evaluated in engine dynamometer tests. For example, no
details were given concerning a special electromagnetic fuel injection
system with flexible features including independent pilot injection
control which is now operational. Nor were there any details given
regarding the several approaches to improve fuel delivery into the
combustion chamber and reduce mixing time that will be evaluated and
include: (1) high injection pressure, (2) vortex generators, (3)
prechamber insulation, (4) pilot injection, (5) outward opening in-
jectors, and (6) moving injection pattern.
7-130
-------
Of equal concern to EPA is GM's brief description of their fuel additive
work to reduce Diesel particulate emissions. No details were given
other than work was underway with these additives. Not only is EPA
concerned with Diesel particulate emission, but other unregulated
emissions which may be produced with the use of fuel additives.
GM reported work on particulate trapping techniques but revealed no
testing results. One method under consideration is the incineration of
trapped particulates. The concern for Diesel particulate may require
closer monitoring of these types of results.
New Diesel Engines
GM is working on other Diesel engines. The engines are shown on Table
GM-17.
Table GM-17
Additional Diesel Engines
Under Consideration by GM
Engine Type Displacement
V8 260 CID
V6 200 CID
L-4 150 CID
GM's position on the Diesel's capabilities at various emission standards
is shown in Table GM-18.
7-131
-------
Table GM-18
GM Position on the Diesel at Various Emission Standards
Emission Standard
(gm/mi) Diesel Development Status
HC_ C0_ NOx
0.9 3.4 2.0 Currently developed engine can meet this
standard.
0.41 3.4 2.0 Achievable with additional development
time. May require a new combustion
chamber and nozzle with some increase in
noise level.
0.41 3.4 1.5 Will probably require exhaust gas recir-
culation (EGR)* to control NOx with
increased particulate emissions.
0.41 3.4 1.0 EGR* is required. NOx level has not been
achieved on an engineering basis.
0.41 3.4 0.4 Currently not attainable with Diesel
engines.
* The adverse effect of EGR on engine durability may preclude its use.
Further development is required to eliminate particulate damage to
engine parts.
GM appears to have a large Diesel program. Not much detail was reported
to EPA in GM's status report. In fact, the information contained in
six of the previous nine tables was not reported to EPA in GM's status
report.
Lean Burn Engine
GM stated that this engine concept had potential to eliminate the use of
of EGR and secondary air injection while retaining good emissions levels,
driveability, and fuel economy with less emission control hardware than
present systems. However, GM feels the system has a NOx limit of 2.0
7-132
-------
gm/mi and offers no potential unless technological advances in air-fuel
metering occur that reduce air-fuel ratio variation. No mention was
made of the current status of this program.
Stratified Charge Engine (SCE)
GM has an extensive ongoing stratified charged engine program. Some of
the subjects under consideration are shown in Table GM-19.
Table GM-19
GM Stratified Charge Engine Activities
Fundamental Studies
1. Combustion Process Modeling - Emissions
2. Combustion Bomb Studies
3. Combustion Photography
4. Schlieren Photography - A/F Distribution
5. Holographic Visualization - A/F Distribution
Dynamometer Evaluation
1. 3 Valve Prechamber Engine
2. 2 Valve Split Port Engine
3. Fuel Injected Prechamber Engine
4. Fuel Injected Direct Injection Engine
5. Staged Combustion Engine
6. Diesel Engine
In-Car Evaluation
1. 3 Valve Prechamber Engine
2. Fuel Injected Prechamber Engine
3. Diesel
4. TCCS
5. Porsche SKS
6. Honda CVCC
7-133
-------
Test results with the 3 Valve Prechamber Engine are shown in Table GM-
20.
Table GM-20
3 Valve Prechamber Engine Program
Engines: L4 140 C1D, V8 350 CID
Vehicles: 3000 IW Vegas, 4000 IW Novas, 4500 IW Chevelles,
5000 IW Impalas
Emission Systems: Reactors, Converters, EGR
4500 IW Comparison
HC CO NOx MPG
— — u
3 Valve - Reactor 0.4 3.4 1.4 10.0
3 Valve - Converter 0.3 0.6 1.5 12,2
Conventional lean - Converter 0.3 0.9 1.6 12.8
3000 IW Comparison
HC CO NOx MPG
~~~ u_
Phase I 0.3 3.0 1.2 17.5
Phase II 0.3 3.5 1.4 17.5
Phase III 0.6 6.0 1.9 17.0
Conventional Lean 0.3 5.0 1.6 17.5
In their Status Report, GM reported the data shown in Table GM-21.
Table GM-21
Emission - Fuel Economy Relationship
for Carbureted Stratified Charge Engine Car
FTP Emissions - gpm FTP Fuel Economy - MPG
HC CO NOx
0.3 0.9 1.6 12.8
0.3 0.6 1.5 12.2
0.2 0.5 0.7 11.6
7-134
-------
Two of the results in Table GM-21 look like two of the results under the
4500 IW comparison on Table GM-20. However, the vehicle at 0.3 HC, 0.9
CO, 1.6 NOx, 12.8 MPG on both tables is labeled a conventional engine
on Table GM-20 and is shown as a carbureted stratified charge engine on
Table GM-21.
As was the case for the Diesel, some information (Table GM-19, Table GM-
20) was not reported to EPA in GM's status report.
Staged-Combustion Engine
The staged-combustion engine embodies two engine concepts in one engine:
charge stratification and hydrogen supplementation. GM did considerable
two-cylinder work on this concept. A 4500 Ib IW vehicle with this
concept had emission results of 0.45 HC, 2.8 CO, 0.37 NOx. GM indicated
that the system complexity, poorer fuel economy, and durability problems
preclude engine development and the work on this concept has been suspended.
Variable-Stroke Engine
GM is monitoring the progress being made by Sandia Livermore Laboratories
on their multi-cylinder, variable-stroke engine.
Gas Turbine Engine
Work continues at GM on gas turbine components directed toward the
development of a practical passenger-car system. Work on a prechamber
combustor continued last year. Preliminary testing indicates the
potential for meeting 0.41 HC, 3.4 CO, 0.4 NOx emission standards with
this combustor plus programmable electronic control. No vehicle emission
results were reported. Work using alternative fuels, various rear axle
ratios, and tires was conducted to assess potential fuel economy improve-
ments for the present generation GM gas turbine.
7-135
-------
Stirling and Rotary Engines
GM continues to monitor ERDA funded Stirling engine programs, plus
continues to postpone introduction of the rotary while conducting
fundamental research on the rotary.
Other Emission Control Components and Concepts
Electronic Controls
GM is working on electronic control of carburetion in conjunction with
their 3-way catalyst system development. Very limited details or dis-
cussion were provided by GM on their accomplishments and problems with
this concept. They did, however, state that they were experimenting
with electronic control of EGR, air injection, and idle speed. Electronic
control inputs would be engine speed, manifold vacuum, coolant tem-
perature, barometric pressure, humidity, ambient temperature, engine
knock, and engine surge.
A number of vehicles were assembled to evaluate electronic controls.
All the following vehicles had electronic ignition timing and EGR control,
while some use choke, AIR, and idle speed control. These vehicles were
targeted to an emission level of 0.41 HC, 3.4 CO, 1.0 NOx.
7-136
-------
Table GM-22
Electronic Control Vehicle Data*
Emissions
(gin/mi)
Vehicle HC
Pontiac 0.23
151/3000//
Buick 0.26
231/3500//
Oldsmobile 0.24
350/4000//
Oldsmobile 0.29
403/4500//
Cadillac 0.25
425/4500//
CO
2.5
2.3
1.3
1.9
1.9
NOx
0.76
0.71
0.67
0.68
0.76
Fuel Economy
(mi/gal)
City
20.7
17.9
14.8
13.0
11.1
Hwy
26.2
23.5
20.4
18.3
16.6
Comp .
23.2
20.1
16.9
14.9
13.0
Electronic
Controls
Choke & idle
speed
AIR (modulated)
Idle speed
Choke & idle
speed
Choke & idle
speed
* All had electronic control of spark timing and EGR in addition to
those specified.
One vehicle employing exhaust manifold reactors as well as a production
catalyst, electronically controlled spark timing, EGR, cold enrichment,
and idle speed produced the following results: 0.25 HC, 1.2 CO, 0.75 NOx
with 13.2 MPG , 18.6 MPG, , and 15.2 MPG .
u h c
GM mentioned briefly that they were developing an engine knock limiter
to take advantage of increased engine compression ratio by optimizing
spark advance through electronic control over the entire operating range
of the engine. The system uses a transducer to sense engine knock and
uses this signal to control spark timing in order to maintain an acceptable
level of knock with a given octane fuel.
Engine "surge" is being considered as an input for electronic control.
No details were given.
GM feels electronic control has potential for achieving 0.41 HC, 3.4 CO,
1.0 NOx without the need for reducing catalysts.
7-137
-------
Staged EGR
The staged EGR system being developed utilizes a variable EGR orifice
sized to provide two discrete EGR rates, one for first and second gear
operation, and the second rate for third gear operation. The results
shown below are for a vehicle targeted for 2.0 NOx.
FTP Emission, gm/mi Fuel Economy
System
BPEGR
Staged EGR
HC
0.50
0.46
CO
3.6
3.7
NOx
1.5
1.5
MPG
14.1
14.3
MPGh
19.1
20.0
MPG
16.0
16.4
Cold Spark Advance/Retard Units
When used with leaner choke scheduling, the concept of advancing spark
timing during cold engine operation has improved driveability and reduced
emissions. A drawback is that this reduces the warm-up rate of catalysts
and/or reactors. GM has added some vacuum retard spark to the Cold
Spark Advance (CSA). This reduces total spark advance during light load
engine operation and increases the warm-up rate.
The special spark timing schedule is only used for the first few minutes
of engine operation. When the engine is warmed-up, conventional vacuum
spark advance is used. During the warm-up period, the CSA/retard unit
schedules spark timing opposite to current production technique, i.e.,
as engine vacuum levels drop, spark timing is advanced. Thus, during
high load operation, the increased spark advance improves driveability,
while at light load the decreased spark advance increases the exhaust
temperatures which increase warm-up rates. The CSA/retard spark system
requires additional hardware on the vacuum advance unit and a coolant
temperature sensor. Three Chevrolets with 1977 Federal emission controls
and equipped with 350 CID V-8 engines and 260 cu in. underfloor catalysts
have been tested with CSA and with CSA/retard. The results are shown as
follows:
7-138
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Table GM-23
CSA and CSA/Retard Results
Chevrolet: 350 CID V-8, CVS, EGR, no AIR, 260 cu in. Underfloor Catalyst
FTP Emissions—gm/mi Fuel Economy
System HC CO NOx MPG^ MPG^ MPGc
CSA 0.27 • 1.5 1.2 11.2
CSA/Retard 0.22 1.3 1.1 11.6 16.7 13.4
Chevrolet: 350 CID V-8, Lean Burn, no EGR, no AIR, 120 cu in. reactors,
260 cu in. Underfloor catalyst
FTP Emissions—gm/mi Fuel Economy
System
CSA
CSA/Retard
HC
0.21
0.16
CO
0.94
0.82
NOx
1.1
1.0
MPG
11.3
11.7
MPGh
16.5
16.5
MPG
13.2
13.5
Chevrolet: 350 CID V-8, AIR, EGR, 260 cu in. Underfloor Catalyst
FTP Emissions—gm/mi Fuel Economy
System HC CO NOx MPG^ MPG^ MPG^
CSA 0.25 3.61 1.42 12.5
CSA/Retard 0.19 3.02 1.34 12.4
As shown, the CSA/retard system reduced HC emission with no major effect
on fuel economy.
Improved Catalyst Warm-up Program
The objective of this program is to study methods of conserving engine
exhaust heat in order to provide more rapid converter warmup. Use of an
air-gap (double walled) exhaust pipe was successful in reducing catalyst
light off by a factor of 2.92 and reduced HC by 30%, CO by 40% and
increased NOx by 3.3%.
7-139
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Another study evaluated the effect of catalyst location and type on
exhaust emissions. The results are summarized as follows:
For every 25 inches the production pelleted oxidation catalyst is moved
downstream from the manifold take down (a) the time required to reach
600°F increases by 20 seconds (b) HC emissions increase by 0.03 gm/mi
and CO emissions increase by 0.3 gm/mi. Comparing a monolithic catalyst
to a pelleted catalyst at the same location, the time to reach 600°F
is reduced by 40 seconds.
7.1.4.2 Systems to be Used at Various Emission Levels
Table GM-1 lists the fuel economy percentage losses and MPG ranges for
each of the proposed standards which GM perceives will be associated
with meeting these levels.
1.5 HC, 15 CO, 2.0 NOx
At this level, GM will continue to use its present configuration of
oxidation catalysts, BPEGR and engine modifications. GM indicated there
was a 5% fuel economy loss in 1977, compared to what could have been
achieved at the 1976 standards (1.5 HC, 15 CO, 3.1 NOx), EPA calcula-
tions indicate there was a 10.4% gain in fuel economy for GM with all
changes considered and a 3.2% fuel economy gain due to system optimization
at lower emission levels.*
0.9 HC, 9 CO, 2.0 NOx
Additional AIR would be added to the system used at the previous emission
levels. GM maintains that lead time is insufficient due to shortage of
production capacity to produce enough air pumps for use in 1978. Lead
* "Light Duty Automotive Fuel Economy-Trends through 1977; J. D. Murrell,
et al., SAE Paper 760795, October 18-22, 1976, page 8.
7-140
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time for construction of new production facilities precludes using this
system in 1978 across the board, according to GM. GM predicts no fuel
economy penalty at this level.
0.41 HC, 9 CO, 1.5 NOx (1977 California Levels)
Systems to meet these levels would be similar to 1977 California systems
consisting of an oxidation catalyst, BPEGR, air injection, and improved
carburetion. Limited introduction of a closed-loop 3-way catalyst
system is planned for two engine families in California. Fuel economy
penalty for the former systems can be as much as 11% on a composite
sales weighted average, according to GM. Low mileage 3-way catalyst
system results (Table GM-7) show a modest fuel economy improvement
over comparable 1977 durability vehicles. GM stipulates that it would
be impossible to use the 1977 California system nationally in 1978 due
to lead time needed to contract new air pump and EGR valve facilities.
GM cited differences in the certification procedure between California
and EPA as a factor which may preclude use of the 1977 California system
on a national basis.
0.41 HC, 3.4 CO. 2.0 NOx
At these levels, GM feels that an oxidation catalyst, BPEGR, AIR, (or
PULSAIR), improved carburetion, and the use of lean reactors will be the
first choice system. However, improved catalyst performance and precise
air-fuel ratio control are necessary to meet these standards.
0.41 HC. 3.4 CO. 1.0 NOx
GM's system choices at these levels and at the following levels, are
either: 1) oxidation catalyst, AIR, EGR (limited to vehicles with high
power-to-weight ratios), 2) 3-way catalysts, EGR, and closed loop
7-141
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air-fuel ratio control. Those vehicles which attempt to reach 1.0 NOx
without reducing catalysts have exhibited large fuel economy penalties
and poor driveability, according to GM. GM continues to maintain that
technology does not exist which demonstrates that reducing catalyst
systems can be viable at these levels without fuel economy penalties.
0.41 HC. 3.4 CO, 0.4 NOx
Systems that employ the use of a reduction catalyst would be used at
this level according to GM. Again GM maintains the unknowns associated
with deterioration, durability, etc. limit both the demonstration and
development of these systems at this level except on an individual
vehicle basis.
7.1.4.3 Durability Testing Programs
Since GM assumed that the 1978 model year vehicles would be carryover
from 1977 vehicles, with the exception of more stringent evaporative
emission controls, they apparently have not conducted any sizeable pre-
certification durability fleet testing of prototype 1978 vehicles.
Table GM-24 summarizes those vehicles which GM reported to be on ex-
tended mileage accumulation.
The first three vehicles (63294, 63295, and 65343) in Table GM-24 reflects
GM's durability evaluation of a monolithic catalyst rather than their
current production underfloor pelleted catalyst. Preliminary data
indicates these systems appear capable at levels of 0.41 HC, 3.4 CO, 2.0
NOx. No fuel economy data were presented for the extended mileage
tests. GM plans to run a 43 car fleet to assess monolithic catalyst
durability in the field.
7-142
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Of the 3-way catalyst equipped vehicles, vehicles 64384 and 65375 were
reported in last year's status report. The mileage accumulation is now
complete to 50,000 miles. At levels of 0.41 HC, 3.4 CO, 0.4 NOx, vehicle
65375 failed to meet the NOx standards at 35,000 miles while failing CO
at 45,000 miles. This vehicle failed all three pollutant levels at
50,000 miles. Vehicle 64384, equipped with an Engelhard 3-way monolithic
catalyst, failed to meet all these levels at lower mileage.
No explanation was given for the difference in fuel economy between the
two vehicles. Vehicle 65344 is a durability test with a larger engine
using a pelleted 3-way catalyst. Both NOx and CO remain a problem with
this vehicle.
Vehicle 64534 represents all of the mileage accumulation data to date on
the Oldsmobile Diesel engine.
Vehicle 46145 and 46262 are mileage accumulation data on the turbocharged
V-6 Buick engine planned for 1978 introduction at 1977 emission levels.
GM reported that it was their intention to get 301 CID engine performance
with the fuel economy of a naturally aspirated 231 CID engine by turbo-
charging their 231 CID engine. Vehicle 46145 did not use the ESC
(knock limiter) system incorporated on the certification durability
vehicles. GM selected the AiResearch turbocharger because of lower
cost and better production availability.
No mention was made of any large scale emission control system fleet
testing as GM has done in the past with their Corporate Durability Test
Fleet. GM orally reported that they have less than 300 vehicles under
all types of testing.
7-143
-------
Table GM-24
Durability Vehicles
VIN
63294
63295
Control
Model CID System Mileage (103)
Nova 305 Monolith 5,000
OC 10,000
15,000
20,000
22,500
22,500
25,000
30,000
35,000
40,000
Nova 305 Monolith 5,000
OC 210 cu in. 10,000
15,000
20,000
22,500
22,500
25,000
30,000
35,000
40,000
45,000
HC
0.25
0.28
0.36
0.30
0.34
0.37
0.33
0.36
0.28
0.28
0.28
0.32
0.35
0.40
0.40
0.44
0.42
0.41
0.42
0.42
0.44
CO
1.2
2.1
2.3
1.8
1.9
2.0
1.6
2.4
2.0
2.2
0.8
1.0
0.8
1.1
1.2
0.9
1.2
1.0
1.0
1.2
1.3
NOx MPG MPG,
u n
1.55
1.50
1.50
1.60
1.65
1.60
1.55
1.70
1.25
1.10
1.07
1.07
1.20
1.20
1.30
1.30
1.10
1.20
1.20
1.25
1.40
7-144
-------
Table GM-24 (con't)
VIN
63343
65344
65375
Model CID System Mileage (10 ]
Nova 250 Monolith 0
OC (205 cu in.) 5,000
10,000
15,000
20,000
22,500
22,500
25,000
Nova H/B 350 3-way (pelleted), 0
closed loop 4bbl, 5
0» sensor, BPEGR 10
15
20
22.5
22.5
30
Vega 2.3 EFI, 0_ sensor, 0
litre 9.0 CR 0
BPEGR, 5
10
10
15
15
20
22.5
22.5
22.5
25
30
30
35
) HC
0.28
0.36
0.34
0.30
0.32
0.34
0.52
0.32
0.30
0.22
0.25
0.25
0.26
0.25
0.29
0.31
0.18
0.19
0.26
0.23
0.17
0.20
0.18
0.22
0.29
0.22
0.18
0.18
0.20
0.21
0.23
CO
2.0
1.6
1.6
2.2
2.3
3.2
3.3
1.2
3.41
5.67
5.3
5.37
5.50
5.20
3.40
3.75
2.42
2.36
3.81
4.38
2.35
3.49
3.18
2.82
4.60
3.92
2.81
2.94
3.88
3.10
3.10
NOx
1.40
1.40
1.50
1.55
1.65
1.45
1.55
1.45
0.33
0.34
0.52
0.62
0.63
0.68
0.57
0.45
0.21
0.26
0.39
0.64
0.37
0.38
0.27
0.32
0.32
0.55
0.39
0.35
0.36
0.40
0.68
MPG MPG,
u h
12.6
12.6
13.0
13.0
13.0
12.8
13.3
13.3
16.9 23.5
17.6
17.7
-
17.1
18.1
17.9
17.7
18.1
18.2
17.4
17.4
19.0
19.3
18.7
7-145
-------
Table GM-24 (con't)
VIN Model
64384 Vega
64534
CID System Mileage (10 )
35
40
45
45
50
New cat 50
2.3 Same as 64375 0
litre exc. w/Engelhard 0
monolithic 3-way 5
catalyst 10
10
10
10
15
15
20
22.5
22.5
30
35
35
37.5
40
43
50
350 Diesel Engine 0.5
5
10
15
20
25
7-146
HC
0.18
0.27
0.38
0.33
0.57
0.20
0.26
0.24
0.22
0.21
0.21
0.29
0.24
0.30
0.32
0.30
0.68
0.29
0.34
0.48
0.31
0.32
0.36
0.38
0.33
0.80
0.60
0.80
1.05
0.85
1.00
CO
2.53
3.75
5.13
4.60
6.03
1.60
1.69
2.54
1.84
2.14
2.19
4.60
2.71
3.52
3.67
4.14
9.16
3.75
3.03
6.60
4.56
4.61
4.33
6.33
5.23
2.1
2.0
2.0
2.0
1.8
2.0
NOx
0.41
0.51
0.60
0.57
0.57
0.37
0.16
0.29
0.43
0.71
0.76
0.41
0.27
0.73
0.33
0.29
0.40
0.33
0.51
0.51
0.62
0.56
0.44
0.32
0.65
1.70
1.60
1.65
1.60
1.50
1.58
MPG
u
17.8
17.5
18.8
17.5
17.2
17.6
17.3
20.2
21.0
21.7
21.6
21.1
19.5
21.3
20.9
20.5
20.0
20.4
21.5
20.6
20.8
22.8
23.8
20.9
19.5
18.4
19.8
20.0
19.8
20.8
20.4
MPG,
n
23.5
26.8
28.8
29.6
29.5
29.7
28.6
-------
Table GM-24 (con't)
VIN
46145
Model CID System
Mileage (10 ) HC CO NOx MPG MPG.
Buick
231 Raj ay
Turbocharger
EFE, OC, EGR
46262
Buick
231 Same as 46145
exec. AlResearch
turbocharger
0
5
10
15
22
25
30
35
0
h 0
5
6.3
10
10.7
11.4
11.5
0.
0.
1.
1.
1.
1.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
53
83
08
70
43
05
85
69
52
62
43
60
62
78
73
72
6.
9.
23.
26.
16.
11.
11.
10.
6.
4.
2.
4.
3.
4.
3.
5.
0
3
0
1
0
5
2
2
4
8
5
4
9
8
8
1
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
60
40
43
49
22
70
65
56
38
48
78
72
72
80
69
55
17
18
16
18
18
16
16
16
16
17
17
18
17
18
18
18
u
.9
.1
.0
.2
.1
.4
.9
.9
.1
.4
.8
.3
.8
.0
.8
.8
7-147
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7.1.4.4 Progress and Problems Areas
Progress and Problems - 1978 Model Year
Because GM apparently believes that the 1978 emission standards will
remain at the 1977 levels, little progress towards meeting levels in
1978 lower than the current standards was noted. GM steadfastly main-
tains that any levels lower than 1.5 HC, 15.0 CO, 2.0 NOx are impossible
to meet nationwide in 1978. However, GM will be introducing 3-way
catalyst technology on a limited basis in California, but at NOx levels
no lower than 1.0 gm/mi, according to GM. There are also indications
\
that GM will be continuing their vehicle weight reduction program that
started in model year 1977.
According to GM, catalyst durability and the fuel metering quality
necessary for 3-way catalyst operation remain as the major development
problems for attaining statutory levels. Based on this year's status
report submission, GM apparently has had only limited success with
vehicular 3-way catalyst durability. GM also appears to have possible
problems with their closed-loop carburetion which is so necessary for
good 3-way catalyst operation.
Progress and Problems at Levels at Other than Statutory
At levels of 1.5 HC, 15 CO, 2.0 NOx, GM will have no difficulity and
will continue to raise their corporate fuel economy figure. GM main-
tains there will be difficulties encountered with the new evaporative
emission test and interaction of the evaporative emission control system
with exhaust emissions, but GM appears to have the capabilities of
resolving these difficulties. Work on the Oldsmobile Diesel has pro-
gressed at these emission levels. While it is encouraging to see the
7-148
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introduction of this fuel efficient engine, there appears to be a lack
of the aggressive development reported that may be needed to attain
lower emission levels.
GM will have to add AIR and recalibrate only some of their 1977 vehicles
to attain levels of 0.9 HC, 9 CO, 2.0 NOx as many of their 1977 vehicles
are well below these levels. GM maintains that the lead time needed to
build new production facilities for air pumps and BPEGR would preclude
expanded use of these systems in 1978. Here again, GM will have to
expend little effort to meet these levels other than the corporate
commitment to produce sufficient air pumps and EGR valves to meet pro-
jected sales levels.
In order to extend nationwide the present California levels, 0.41 HC, 9
CO, 1.5 NOx, GM would have to recalibrate many of their 49 state vehicles.
Using the calibrations found on the 1977 California vehicles may not be
directly applicable since those vehicles were allowed to line cross, had
a methane correction, and may have used the Federal deterioration factor
rather than their own (California system) deterioration factor. A
positive factor at these levels will be the introduction of two engine
families in California using closed loop 3-way catalyst technology.
At both 0.41 HC, 3.4 CO, 2.0 NOx and 0.41 HC, 3.4 CO, 1.0 NOx, GM has
made some progress with systems which have reduction catalysts and
systems using lean calibrations, lean reactors and oxidation catalysts.
However, lack of durability fleets using these concepts pose a problem
in projecting a time for the introduction of this technology.
GM provided scant cost data with this year's submission.
7-149
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7.2. Independent Developers
7.2.1. The Bendix Corporation
Bendix responded to EPA's request for a status report submission by
discussing Bendix's emission control development efforts since their
last testimony at the EPA Suspension Hearings in 1975. Bendix stated
that until approximately one year ago, Bendix's activities centered
around development of electronic fuel injection (EFI) on a system basis
in conjunction with industry efforts to meet emissions standards.
Recent revaluation of Bendix's engineering and marketing strategies has
resulted in a change from a system-only approach to that of a component
supplier as well. Consequently, Bendix has for the past year been
accelerating their efforts in the development of engine sensors, actuators,
and digital electronic control units (DECUs). See Figure Bendix-1.
The components supplied by Bendix consist of four major subsystems: (1)
fuel delivery, (2) air induction, (3) sensors, and (4) ECU. Bendix
described these subsystems thusly: The fuel delivery subsystem, as
installed in a vehicle, includes the fuel tank pickup and boost pump,
the electrically-driven, constant displacement, main fuel pump, a
filter, the fuel manifold, injectors for each cylinder, a fuel pressure
regulator, and supply and return lines.
The air induction subsystem includes the intake manifold and throttle
I
body assembly for primary air flow control, as well as an integral fast
idle air valve controlled by engine temperature and an electric heating
coil. The fast idle valve supplies increased cold starting air around
the closed primary throttles.
The sensor subsystem includes several primary engine sensors. An intake
manifold pressure sensor measures absolute pressure in the intake manifold
7-150
-------
DIGITAL CONTROL UNIT
•vl
I
Figure Bendix-1
-------
to provide a parameter for continously computing air flow to the engine.
An air temperature sensor is located in the intake manifold to provide a
correction for the computation of the engine air flow. A speed sensor,
mounted integrally to the ignition distributor, provides engine speed
data for volumetric efficiency corrections, computation of air flow, and
engine-phasing data for synchronizing injector timing. A temperature
sensor, installed in the engine coolant jacket, provides a signal for
computation of fuel enrichment requirements for cold start and engine
warm-up. A throttle position sensor provides information for accelera-
tion fuel enrichment (AE) and wide open throttle enrichment.
The electronic control unit receives information from the sensors and,
using a selected control logic, computes the exact fuel requirement
relative to air flow for each cylinder on each engine cycle. This is
translated into injector-open time signals which energize the solenoid-
type injector valve to deliver a specified quantity of fuel to each
cylinder. The ECU calibration is flexible enough to provide precise
fuel requirements over a wide range of engine performance requirements.*
Bendix has field experience with EFI equipped vehicles at both ends of
the vehicle weight spectrum. During MY '75/'76, Bendix provided EFI for
approximately 3200 Cosworth Vegas. They also supplied EFI units for
'75/'76/'77 MY Cadillacs. Bendix reported that while overall performance
and driveability were reported to satisfy most vehicle owners, there
were two problems which were driveability oriented; the tip-in response
off closed throttle sometimes contains a slight "hesitation" causing the
car to stumble slightly, and a hot restart condition which results in
noticeable engine speed oscillation between the hot restart and subsequent
driveaway.
* Development Status of Electronic Emission Controls at the Bendix
Corporation Electronic & Engine Control Systems Group, page 1-1, 1-2.
7-152
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In order to improve driveability with EFI, Bendix has conducted specific
test and development programs. The problem of tip-in anomalies will be
solved by use of an injection technique referred to as simultaneous
double fire (SDF). The hot start instability problems will be solved by
enriching the fuel injection calibration on a time decay basis as a
function of coolant temperature at the time of hot restart.
The present production system uses two-group injection, where each
cylinder receives the computed fuel requirement in a single injection
pulse for each engine cycle of two engine revolutions. With simul-
taneous double fire (SDF), the per-cycle fuel requirement for each
cylinder is delivered with two injection pulses (one for each engine
revolution). For steady state conditions, then, each pulse provides one
half of the cycle fuel requirement; however, during transients it is
possible to update the computation between the first and second injec-
tion and more closely match fuel to air flow. Apparently, the SDF
system, like the two-group system, does not control each injector in-
dividually.
SDF injection timing (and engine speed information) is obtained directly
from the ignition primary instead of from the two distributor-driven
reed switches presently used in production for group injection. This
requires added ECU circuitry for counting down but an overall cost
benefit is realized.
Results of the various programs generally show significant improvements
in throttle tip-in response and in other transient modes with some idle
roughness penalty. A 5500 Ib IW vehicle with a 500 CID engine was
converted from the 2-group to SDF injection mode with the results shown
in Table Bendix-1.
Table Bendix-1
SDF Versus 2-Group Injection
HC CO NOx MPG
2-Group 0.967 15.79 1.617 10.46
SDF 0.59 9.30 2.20 10.75
7-153
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Bendix reported that this vehicle demonstrated improved idle quality and
complete elimination of the off-closed-throttle tip-in hesitation and
hot restart rollout. The SDF emissions calibration had not been fully
optimized at the time the above emissions data were recorded. It is
fully expected that calibration development and possible intake manifold
modifications would achieve emissions and fuel economy at least equivalent
to that for 2-group injection.
All development programs at Bendix including forward model production
and potential customer programs are being done using the SDF injection
mode.
Bendix is also developing a closed-loop idle speed control subsystem
which is regulated by the ECU. This control maintains a relatively
constant warm engine idle speed and also provides idle speed control for
cold start and warmup.
Bendix has conducted several programs to investigate fuel economy improvements
using EFI systems. One of the programs is to determine the minimum
acceptable driveability for fuel cut-off on deceleration and for low
idle speed. Bendix reported fuel economy improvements between 3 and 7
percent but with aggravated tip-in hesitation and hot start instabilities.
Work continues on this program.
Bendix is also working with a potential customer in a program to apply
digital electronic spark advance for improvements in fuel economy. The
system replaces the distributor timing pickup, centrifugal advance,
vacuum motor, calibrated throttle port, and temperature overrides.
Ignition timing is controlled by digital electronics using the inputs
from a crank position sensor, a manifold absolute pressure sensor, and
7-154
-------
a coolant temperature sensor. In addition, the EGR subsystem is con-
trolled in an on/off manner as a function of coolant temperature, and
ignition timing corrections are made concurrently with this. Two systems
of a prototype configuration have been delivered to the customer for his
calibration development. The program is now nearing the demonstration
phase with a goal of model year 1979 production. Future addition of
full digital electronic EGR control is intended.
Bendix has also conducted development programs to assess exhaust emis-
sion improvements obtainable using an EFI system. Their development
work has again been in conjunction with the ultimate user of the system.
Zero mile testing of a 3-way catalyst, closed loop EFI, oxygen sensor,
and back pressure EGR system on a 350 CID, 4500 pound inertia weight
vehicle showed results of 0.45 HC, 6.58 CO, 1.21 NOx with fuel economies
of 12.1 MPG and 17.0 MPG, . These fuel economies compare to the Cadillac
u h v
Seville with 1976 fuel economy of 15 MPGu and 21 MPGh. Further work
continues to improve the closed loop techniques.
A vehicle equipped with a 350 CID engine, and a 3-way catalyst, tested
at 4500 IW, targeted at 0.41 HC, 3.4 CO, 1.0 NOx has demonstrated 0.45
HC, 2.9 CO, 1.0 NOx with 16.4 MPG at low mileage. Driveability was
rated very good.
Work with a vehicle equipped with a 140 CID engine, closed loop air
flow sensing EFI, a 3-way catalyst, tested at 3000 IW, targeted at
statutory emission levels has achieved zero mile emissions of 0.2 HC,
2.3 CO, 0.2 NOx.
Bendix also has supplied EFI systems to EPA for a heavy-duty engine
program at SwRI and to A. P. Parts (Questor) for development work with
the Questor-Reverter emission control system.
7-155
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The advanced development work reported by Bendix included work on a
digital ECU (DECU) and engine sensors. The principal reported advantages
of the digital controller over its analog counterpart include increased
accuracy in digital computation over the range of operating temperatures,
improved reliability, and lower cost. In addition, the DECU has the
ability to use more complex schedules for control of additional engine
variables such as spark timing and EGR.
Bendix has undertaken a major development effort in the area of engine
sensors. Table Bendix-2 displays the type of sensor and sensor concepts
under active investigation.
Table Bendix-2
Sensor Type
Concepts Under Investigation
Pressure
Air Flow
Temperature
Position
Exhaust
Strain Gage
Crystal
LVDT
Variable Capacitance
Potentiometric
Vortex Shedding
Turbine
Swirl
Deflecting Vane
Wire Wound
Thermistor
Metal Film
Solid State
Potentiometric
Reluctance
Hall Effect
Reed
Zirconium Dioxide (ZrO_)
Titania
7-156
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Samples of both the zirconium dioxide and titanium dioxide sensors have
been supplied to prospective customers for evaluation. See Figure
Bendix-2.
One of the more interesting advanced projects Bendix reported was their
efforts to develop single point electronic fuel metering concepts for
reduced costs and introduction for model year 1980. While initial work
has shown this system has problems inherent with carburetor systems,
i.e., fuel preparation and distribution, examples of improved cylinder
to cylinder air-fuel distribution and driveability have been achieved.
Further optimization work needs to be conducted while attempting to meet
presently legislated standards. A schematic of this concept will be
found in Figure Bendix-3.
7-157
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EXHAUST GAS SENSOR
I
I-1
IJ1
00
Zr02
BOSCH &
AUTO LITE
AUTOLITE
Figure Bendix-2
-------
I
M
Ln
vO
LOW COST FUEL CONTROL SYSTEM
PDM METERING
(v
ff
'
AIR
TEMPERATURE
SENSOR
SINGLE POINT
INJECTION
PACKAGE
INTANK
FUEL PUMP
MAGNETIC SENSOR
COOLANT TEMPERATURE
SENSOR
Figure Bendix-3
-------
7.2.2. Robert Bosch
Since one of the first demonstrated applications of closed loop three-
way catalyst operation incorporated Bosch fuel injection equipment and
oxygen sensor, Bosch was asked for a submission for this year's status
report. The potential importance of the three-way catalyst technology
necessitates an understanding of injection system and oxygen sensor
availability, technical difficulties, and system potential. The pro-
bability of three-way catalyst introduction may hinge on the avail-
ability of fuel injection equipment if feedback carburetion cannot be
developed in time to meet production deadlines of if feedback carburetion
is not capable of the required emission control.
The Bosch response to the status report submission request was dis-
appointing in that it failed to provide sufficient information to assess
the potential of fuel injection equipment availability, cost and demon-
strated performance. Bosch provided no cost, lead time, emission and
vehicle performance or fuel economy data. They suggested that this
information should come from the vehicle manufacturers rather than a
component supplier.
Bosch did reinterate that they felt that either their L or K-Jetronic
fuel injection system would be an improvement over presently available
carburetion systems. For the various emission levels, Bosch stated the
following:
A. At levels of 1.5 HC,15 CO,2.0 NOx, Bosch feels that port type
fuel injection in combination with EGR on engines up to 2 litre
displacement is sufficient. On engines over 2 litres, thermal
reactors, air pumps, and oxidation catalysts are necessary.
7-160
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B. For levels of 0.41 HC,3.4 CO,2.0 NOx, the use of oxidation
catalysts becomes mandatory, according to Bosch. Additionally lean
calibration, pulse air or air pumps are required on larger dis-
placement engines.
C. Bosch maintains that at levels of 0.41 HC,3.4 CO,1.0 NOx the
three-way catalyst with feedback fuel injection is superior to
either higher amounts of EGR or dual catalyst systems. This type
of system is what will be used on the 1977 California Volvo vehicles.
Bosch states that low mileage emission results of .2 HC,1.5 CO, 6
NOx have been achieved on a 4 cylinder, 2 litre engine. One difficulty
Bosch has encountered with their three-way catalyst work is finding
a suitable location for the 0_ sensor on opposed-cylinder and V-
type engines. One possible solution is to use two separate closed
loops with individual sensors for each engine bank. Bosch would
prefer not to use this solution due to cost. Bosch predicts no fuel
economy penalty at this level for four cylinder engines, but a
potential fuel economy penalty may exist for larger displacement
engines. Driveability is rated satisfactory, particularly without
EGR.
D. At levels of 0.41 HC,3.4 CO,0.4 NOx, Bosch reports difficulties
meeting the NOx standard over 50,000 miles. Bosch maintains the
good fuel economy which comes with stoichiometric control will
disappear at this level of NOx control. EPA believes that stoichio-
metric control may still be used at these levels, but EGR may be
required for many vehicles.
A benefit of a closed loop fuel injection system is the automatic
compensation for temperature and barometric changes, engine wear, and
system calibration shifts. Consequently, the vehicle owner has no
7-161
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obvious temptation to tamper with the fuel metering system, unlike the
present carbureted systems. Bosch feels their closed loop control is
ideally suited to maintain good driveability and to protect against
maladjustments at the expense of emissions.
While Bosch may have a parochial interest in furthering the closed loop
electronic control system, it is evident to EPA that while these systems
provide flexibility in controlling exhaust emissions there is much more
work necessary in optimizing all the controlling parameters in a pratical
application. Consequently, the following discussion is aimed at providing
a basic understanding of closed loop control systems as was provided by
Bosch.*
Figure Bosch-1 shows the components constituting closed loop system.
The time response of the closed loop system consist of:
the time response of the controller (normally referred to
as ECU)
the response of the fuel metering system
- the delay for the transport of the mixture from the metering
system to the intake valves of the engine
- the transport of the mixture through the engine
the delay for the transport of the exhaust from the exhaust
valve to the lambda ( X) sensor (commonly called 0- sensor)
- The time response of the lambda sensor.
* Application of Closed Loop Control to Fuel Metering, H. Eisele and
W. Vessel, Robert Bosch GmbH, Stuttgart, W. Germany, no date.
7-162
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It can be seen that the overall time response is a combination of six
individual and partially controllable time constants. How important are
each of these constants and what impact do these have on the overall
system time response?
The fuel metering system in most cases can be approximated by a first
order time delay with the frequency response.
FM 1 + sT
m
However T is normally small and can be neglected.
The transport delay representing the movement of the mixture from the
metering system to the intake valve depends on the applied metering
system. Bosch indicates that with a carburetor or a single point
injection system this time constant can be substantial. For an indi-
vidual port injection system with the injector mounted close to the
intake valves the transport time delay is very small and can be ignored
according to Bosch.
The transport of the mixture through the engine is a function of the
engine speed.
The movement of the exhaust from the exhaust valve to the lambda sensor
is also represented by a transport delay.
F_ = e~sTEx
Ex
The time constant T_ depends on engine speed, engine load and the
£jX
location of the lambda sensor in the exhaust system.
7-163
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The time response of the lambda sensor can be approximated by a first
order time delay with a very high gain. Figure Bosch-2 shows the output
signal of the sensor as a function of the normalized air-fuel ratio
lambda.
F
S 1 + sTs
Time constant Tc depends on the temperature of the sensor. Tc decreases
O O
with increasing sensor temperature. For practical purposes the input-
output characteristics of the sensor is of the ON-OFF type.
A further refinements of Figure Bosch-1 with appropriate annotated
transport delays can be seen in Figure Bosch-3.
Further simplification of Figure Bosch-3 can be achieved by various
substitutions for the time parameters TE and TE plus a summation of T
and T to equal T to total transport time through the engine combined
fjX 1
with the exhaust valve to lambda sensor transport time. The transport
delay Tp for a four stroke engine can be approximated by 3 engine strokes
consisting of the compression stroke, expansion stroke and approximately
50% of the intake stroke and exhaust stroke. Therefore, T is equal to
3/2 x 1/n, where n represents engine revolutions per unit time. The
delay T_ represents the time it takes the exhaust gas to reach the
lambda sensor after the outlet valve opens. This time delay depends on
engine speed, engine load and the volume of the exhaust system between
outlet valve and location of the lambda sensor. Measurements taken from
a typical four cylinder engine application allow the following crude
approximation:
T
Ex 4 1 n
With IL representing the normalized internal engine load; full load
corresponds to 1C = 1.
7-164
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As a further simplification of Figure Bosch-3, the first order time
delays of block F and block ¥„ can be compensated by lead time constants
in the controller. This simplification results in a control loop
consisting of a transport delay and a block F with a very high pro-
D
portional gain within a very limited operating range ending up in
saturation outside this narrow range. Therefore it is not possible
to treat this control loop using known linear techniques. Basically the
control loop consists of a transport delay and a block with ON-OFF
characteristic .
The frequency response of the controller selected must include an
integral portion to assure full compensation of any disturbances to the
fixed plant. Although in actual applications a more complicated fre-
quency response is used, a controller with pure integral response allows
a very accurate description of the basic behavior of the closed loop as
applied to vehicles. Figure Bosch-4 depicts the three essential blocks
of the closed loop with the frequency response of the controller, where
F =
c sT
Due to the non-linear ON-OFF type characteristic of the lambda sensor
the closed loop maintains an oscillation even under steady state conditions.
The frequency of the oscillation is determined by the phase shift of the
controller with integral response and the transport delay. With the
constant phase shift of 90° for the controller the total phase shift
results in
2irfTT
7-165
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According to feed back control theory a stable oscillation must be
expected at
0 = TT + r2ir with r = 0, 1, 2, 3, . . .
This means that the closed loop can oscillate at different frequencies.
From the above equations, the frequencies can be derived
= 0, 1, 2
This result can also be derived without any calculations from Figure
Bosch-5 which shows the output of the different blocks of Figure Bosch-4
for the frequencies f_ and f-. The lambda sensor changes the output
signal whenever the signal from the transport delay changes from rich to
lean mixture and vice versa. The integral controller moves corres-
pondingly to the lean side when the sensor shows rich mixture and towards
rich mixture whenever the sensor indicates lean.
For an ideal engine with perfect mixure distribution from cylinder to
cylinder, and no outside distrubances the closed loop would oscillate
with the frequency f-. Practical applications, however, show that
disturbances quite 'frequently cause the closed loop to change from
frequency f_ to frequency f, and lock in at the higher frequency f1.
Bosch reports higher frequencies than f.. have not been observed on four
cylinder engines in practical applications. This can be explained with
the reciprocating mode of the typical gasoline engine transporting
mixture on a per stroke basis.
The frequency of the osciallation as shown in the above equation is
independent of the integration time constant T of the controller. The
adjustment of the controller, however, determines the amplitude of the
oscillation under steady state conditions and the required time to
7-166
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compensate for a disturbance. As can be derived from Figure Bosch-5 the
amplitude A of the oscillation is determined by
T
A --£
A defines the deviation from the desired reference at X =0 to X=l or
y
vice versa.
For example, the equations derived, frequencies of the closed loop
oscillation for a four cylinder engine can be determined at KT =1 re-
presenting full internal engine load and K=l/3 corresponding to 33% of
full load.
Example:
At n = 900 1/min.
= 1
TT = 150 msec fQ = 1.66 Hz f = 8.3 Hz
TT = 250 msec FQ = 1 Hz f = 5 Hz
at n = 3000 1/min.
= I
TT = 45 msec fQ = 5.55 Hz ^ = 27.75 Hz
TT = 75 msec fQ 3.33 Hz
16.66 Hz.
7-167
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The calculated frequencies in this example are close to the measured
values from an actual application.
The amplitude of the oscillation under steady state conditions varies
with engine speed and engine load. For a controller with a constant
intergration time constant T the maximum amplitude occurs at idling of
the engine. Therefore the actual value of the air-fuel ratio can
deviate substantially from the set point at lambda =1, although the
controller maintains the desired stoichiometric air-fuel ratio with high
accuracy on an average basis. For proper operation of the 3-way catalyst
concept if is necessary to achieve an adequate mixing of the exhaust gas
from different cylinders in the exhaust manifold and the catalyst over
at least a cycle of the closed loop oscillation. The required averaging
effect is simplified if the amplitude of the oscillation is kept small,
which is also a necessary condition for stable idling of the engine.
This means that the time constant T of the controller should be large.
There are however the contradicting requirements for a controller with
fast response to compensate quickly for disturbances, and with slow
response to keep the amplitude of the oscillations small, in particular,
at low engine speed. The obvious answer is the application of a self-
adaptive controller with a variable time constant T . During operation
the time constant is adjusted depending on engine conditions.
A combination of the above information shows that variation of the
amplitude A dependent on engine speed and engine load can be derived.
Ay = 2~n~T (1 + "2lT)
y T-
The above equation also defines the necessary automatic adjustment of T
if for instance A should be kept constant over the full operating
range.
7-168
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Actual emission tests, however, show that a less sophisticated adjust-
ment is sufficient. A one step change of the integration time constant
dependent only on engine speed results in a good compromise for stable
idling and low emissions.
From the discussion of the closed loop operation it is obvious, however
that the proper functioning of the system must be checked at the low
frequency f_. This assures automatically adequate performance at the
higher frequency f1.
The lambda sensor is only operational at temperatures exceeding approxi-
mately 300°C. Therefore it is necessary to operate at lower sensor
temperatures open loop and to keep the integral contoller output clamped
at a selected preset level. This low temperature condition always
occurs for a short time after starting a cold engine, and it can also be
observed on certain engines during extended periods of idling if the
sensor is mounted too far downstream of the outlet valves. For initiali-
zation of the closed loop lambda sensor is warm enough to generate the
required proper feedback signal. One possibility in this case is to
check the source impedance of the sensor which decreases with increasing
temperatures as shown in Figure Bosch-2. This check is complicated
becasue it is unknown whether the engine is operating lean or rich with
respect to a stoichiometric air-fuel ratio. One possible approach for
the checking procedure is shown in Figure Bosch-6.
After a cold start a checking current is fed through the sensor. The
measured voltage decreases with warm-up of the sensor because of the
decreasing source impedance. Curve A represents the situation for rich
mixture and curve B for lean mixture. In the figure the initialization
for lean mixture is shown. As soon as the measured voltage goes below
a preset bias voltage, the controller is started. At the same time the
7-169
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reference voltage of the integral controller, which was held at the bias
level, starts to decrease until the value representing warm engine is
reached.
After the controller is intialized, the operation of the closed loop is
monitored on a continuous basis. This is relatively simple because of
the existing oscillating mode of the operation under steady state
conditions. It is sufficient to monitor the time between two changes of
the sensor output voltage indicating rich or lean mixture. If this time
exceeds a preset value, then the controller is clamped and the open loop
mode is selected. In this case the initialization check is restarted in
order to go back to closed loop operation whenever the necessary con-
ditions are again met.
It is sometimes desirable to operate the system at a point other than at
stoichiometry. The lambda sensor Figure Bosch-2 shows a very steep
characteristic at stoichiometric air- fuel ratio. This ON-OFF type
behavior allows the desired accurate control at lambda = 1 for the 3-way
catalyst concept. For certain emission control concepts it is inter-
esting, however, to operate accurately at an air-fuel ratio different
from stoichiometry. Electronic means in the controller afford the
desired reference adjustment within about plus or minus 5% of lambda =
1.
One obvious way to obtain a reference adjustment with an integral
controller is shown in Figure Bosch-7a which depicts the output of the
integral controller. The integration time constant is asymmetrical.
The slope going up is different from the slope going down. The achieved
reference adjustment on an average basis is given by the following
equation:
AX = T (— - ~ )
yi y2
7-170
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Unfortunately this reference adjustment is dependent on the transport
delay which changes with the operating condition of the engine. Another
possibility which avoids this drawback is shown in Figure Bosch-7b. In
this case the reference adjustment is independent of the transport delay
T as given by the next equation
y
The integrator is forced to continue for a defined time interval t
z
after the sensor output changes.
The reference adjustment decreases the frequency of the closed loop
oscillation and causes an increase of the amplitude. The influence of
frequency and amplitude on idling stability and emission was discussed
before and must be carefully considered if reference adjustment is
applied.
Consequently, Bosch summarizes that closed loop control compensates
automatically for:
tolerances, wear and drift of the engine and the fuel
metering system
- changes in the composition of the fuel
- variation of the atmospheric pressure due particularly to
different elevations.
Considering these effects, an output range of the controller from
lambda = .8 to 1.25 with respect to rated conditions is necessary. The
limited range of the controller output allows emergency operation of the
engine if a catastrophic failure of the control loop - which cannot be
7-171
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corrected by clamping of the controller should occur.
The previous discussion by Bosch indicates that the engine emission
control designers are now faced with not only the normal engine para-
meters of air-fuel ratio, speed, load, etc. but a myriad of electronic
controls which must be tailored for engine operation over the entire
speed/load range. While this may seem a formidable task for the design
engineer, it indicates the extreme flexibility that electronic controls
allow potential for custom tailoring of engines for both good fuel
economy and low emission levels.
7-172
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Controller
Fuel
Metering
Engine
System
X- Sensor
Figure Bosch-1
Closed Loop Engine Control System
INTERNAL AND EXTERNAL SURFACES
PLATINUM PLATED
ZIRCONIUM DIOXIDE
^-SENSOR1
VOLTAGE I
^-SENSOR i
SOURCE I
IMPEDANCE
RICH STOICH LEAN
— A
TEMPERATURE
Figure Bosch-2
Lambda Sensor
7-173
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tl
FM
Fc Fc
E Ex
Figure Bosch-3
Block Diagram of the Closed Loop
System
\u*n
0. i
RICH
MIXTURE
LEAN
MIXTURE
Figure Bosch-4
Simplified Block Diagram
A
/ \ OUTPUT TRANSPORT
OELAY
\
0 S
-------
VOLTAGE] \\
\\*
\ \ SENSOR VOLTAGE LIMITS
RICH MIXTURE
BIAS
VOLTAGE
VA
\ \ ' SENSOR
\
\
^v
N
V
X
/ VOLTAGE
x
\J
••^^^ /
^-^
^^
^
"~*~
~— ».
rn
—
REFERENCE
- INTEGRAL
CONTROLLER
START
ENGINE
Figure Bosch-6
Initialization of the Closed Loop
CO
— t
Figure Bosch-7
Reference Adjustment
7-175
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7.2.3. Dresser
Dresser Industries is a multi-divisional company which produces a variety
of products including gas station pumps, tools, safety valves, and oil
drilling equipment. Since 1970 Dresser has been involved in the devel-
opment of a sonic carburetor known as the "Dresserator". Dresser felt
the potential for the carburetor system, which was formerly under
development at Stanford Research Institute, was sufficient to allow them
to eventually obtain licensing fees from the automobile industry for its
use.
The Dresser concept is an attempt to achieve fine fuel atomization over
a wide range of operating conditions by maintaining a choked flow
condition in the carburetor throat. By metering fuel upstream of the
throat, the fuel must pass throught the shock wave that occurs when the
flow goes sub-sonic in the diffuser which is located downstream of the
throat. The extremely fine droplet sizes reportedly created by the
Dresserator (10 micron diameter) allow uniform air-fuel ratios (A/F) to
be achieved during warm-up and transient conditions that cause A/F ratio
variability problems with conventional carburetors. The wall wetting
that occurs with conventional carburetors is less of a problem for the
Dresserator. The coarser droplet size and heavier wall wetting that is
characteristic of a conventional carburetor results in significant
variations in air fuel ratio from cylinder-to-cylinder and from one
cycle to the next cycle (successive intake charges for the same cylinder).
To prevent lean misfire in a conventionally carbureted engine, this is
counteracted by richening up the overall mixture so that the lean
cylinders are not too lean. This has prevented the achievement in
practice of the theoretical benefits of lean (18-19:1 A/F ratio) operation.
The achievement of sonic flow in a carburetor is not a new accomplish-
ment. Conventional carburetors experience sonic conditions at idle and
extremely light load operation when the ratio of manifold to ambient
7-176
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pressure is less than 0.528. The Dresser carburetor, however, maintains
sonic conditions over most of the engine's operating range including
modes where intake manifold pressure approaches ambient pressure. This
is accomplished by the variable area, converging-diverging geometry of
the Dresserator. Figure Dresser-1 is a schematic of the Dresserator
geometry. Movement of a slider between two fixed jaws accomplishes the
throat area changes necessary as the engine's air requirement changes.
Previous versions of the Dresserator have employed moveable jaws without
a slider and annular geometry with a vertically moveable cone to vary
throat area. Figure Dresser-2 is a prototype Model III Dresserator
completely assembled.
To regulate the fuel flow rate Dresser has relied in the past on a low
pressure metering technique. This system increased the fuel pressure
during cold start to provide the needed enrichment. This system worked
fairly well but was handicapped to some degree by the cost of the pump
and regulating device required. The sonic carburetor design is compatible
with virtually any type of fuel metering method, and Dresser has devoted
a lot of attention in the past year to studying alternate systems.
These systems include: vacuum (float fed), electronically controlled
pressure metering, and electronically modulated, float fed models. Most
of this work has been done on the Model III units.
Three fundamental operating modes are forseen by Dresser for their sonic
carburetors. These are:
a. Very lean, 18-19:1 air-fuel ratio
b. Stoichiometric, open loop with 3-way catalyst
c. Stoichiometric; closed loop with oxygen sensor,
3-way catalyst
No emission data has been reported yet by Dresser for the 3-way catalyst
modes but they have reached an agreement with Engelhard to work together
7-177
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Incoming Air
Figure Dresser-1
Fuel/Air Mixture
to Engine
Figure Dresser-2
7-178
-------
on this concept. It is understood that the open loop stoichiometric
mode will be the primary objective for the initial phase of this work.
Dresser has a licensing agreement with Ford and Holley Carburetor Division
of Colt Industries. The Ford arrangement has been in effect for several
years. Ford has evaluated Dresser supplied units in the past, but most
of Ford's work has been directed at developing their own version of a
sonic carburetor. Ford has utilized electronically controlled fuel
metering on their most recent units. Dresser reported that one of these
units had been selected by Ford for 1979 model year introduction but was
later shelved in favor of a less expensive, non-sonic, unit. The sonic
unit was Ford's "D" body which resembles the Dresser Model II pivoting
jaw unit. This Ford sonic unit used two electronically controlled
injectors and was intended for use with a 3-way catalyst system. This
system was targeted at the 1.0 NOx level.
Holley is working on a float fed unit which incorporates compensation
features for enrichment during cold start, acceleration and large
throttle openings. A unit incorporating these features was evaluated in
a contract between Holley and EPA. This was a Model III unit and it was
mounted on a 1975 California model Dodge Dart. The emission performance
of the vehicle in the baseline condition and with the sonic carburetor
is shown in Table Dresser-1. When the sonic carburetor was added, the
air injection system was removed.
7-179
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Table Dresser-1
1975 Dodge Dart, oxidation catalyst, EGR
Three Test Average for
System
Baseline
HC
0.53
CO
2.6
NOx
1.0
Each Case
MPG
u
16.0
MPG,
n
22.6
Sonic
carburetion* 0.41 6.4 1.0 15.1 21.2
Sonic
carburetion** 0.47 5.3 1.2 15.9 23.3
* Test results at Holley
** Test results at the EPA laboratory in Ann Arbor, MI.
Dresser reported that they have outfitted three small cars with sonic
carburetors. These were two Capris, a 2800 cc V-6 and a 2600 cc V-6,
and a 2000 cc 4 cylinder Triumph. Only steady state emissions and fuel
economy data were presented but these appeared to show very significant
emission reductions for the Capris with fuel economy equivalent to the
baseline vehicles. Very limited data was provided for the Triumph, but
the fuel economy was claimed to have been improved by 30%, according to
Dresser.
Dresser reported the start of a program to build, evaluate, and ultimately
market a retrofit model. This would be a float fed Model III unit using
constant depression fuel metering. Dresser feels that they can provide
a 10% to 15% gain in fuel economy on a retrofit basis.
Progress and Problems
The results to date from a vehicle equipped with a Dresser carburetor
that had the subsystems generally thought to be necessary in a practical
system (cold start enrichment, acceleration enrichment and power enrich-
ment) have not been significantly better (in fact they have been some-
what worse) than the results from a conventional system. With the
7-180
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great interest being shown now in feedback control of conventional
carburetion, it appears that systems employing the Dresser principle
will have to show improvements in emissions and fuel economy over and
above that demonstrated to date before the system will become widely
used.
The Dresser principle may offer some potential if operated in a feedback
mode, due to the possibility that the air-fuel mixing may be better than
with conventional systems. However, data are not now available to show
this. A feedback Dresser carburetor may receive significant competition
from single-point feedback fuel injection systems in the future.
7-181
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7.2.4. Engelhard
7.2.4.1. Systems Under Development
Virtually the entire Engelhard submission was devoted to the testing and
development of monolithic and pelleted 3-way catalysts. The efforts
included studies of 1) space velocity effects, 2) noble metal loading
effects, 3) Pt/Rh ratio effects, 4) conversion efficiency deteriora-
tion as related to feedgas conditions, 5) conversion efficiency de-
terioration as a function of fuel contaminant levels, and 6) catalyst
regeneration.
Monolithic 3-Way Catalysts
Figures Engelhard-1 and Engelhard-2 show the effects of space velocity
and Pt/Rh ratio on NOx conversion efficiency. Though not stated by
Engelhard, these efficiencies apparently are gross NOx conversion, and
neglect the formation of ammonia. Ammonia formation however, may be low
at stoichiometry. NOx efficiency was increased by reducing the space
velocity (or increasing catalyst volume) and by reducing the Pt/Rh
ratio. It should be noted that increased catalyst volumes at mine-mix
Pt/Rh ratios (% 19/1) can provide nearly equivalent gross NOx conversion
at 25,000 miles as smaller catalyst volumes at much lower Pt/Rh ratios.
The 19 (mod) and 3 (mod) points apparently indicate modified catalyst
formulations. Engelhard did not discuss these points; however, NOx
conversion of the 19/1 Pt/Rh catalysts are equivalent to the 3/1 Pt/Rh
catalysts when tested at 500°C inlet temperature. At 600°C inlet temp-
erature, the 19 (mod) results are much like the mine-mix catalysts
without this unidentified modification.
The importance of Pt/Rh ratio for monoliths is also shown in Figures
Engelhard-3 and Engelhard-A. Over 20% difference in maximum NOx con-
version at 25,000 miles is shown between the lowest and highest Pt/Rh
ratios. Figure Engelhard-3 also shows the relationship of crossover
1-182
-------
Figure Engelhard-1
Effects of Space Velocity and Pt/Rh Ratio
- 500°C Inlet Temperature
100
o
I
1
\6
ID
i
CO
AFTER 25,000 MILES ENGINE DYNAMOMETER AGING.WITH
1977 (COMMERCIAL FUEL)
NOx CONVERSION AS A FUNCTION OF Pt/Rh RATIO
AT FOUR SPACE VELOCITIES, 520 M.V., 500°C
ENGINE DYNATCttETER
SIX Pt/Rh RATIOS 19/1—^ 3/1 PLUS 19/1
(Mod.) and 3/1 (Mod.)
7-183
-------
Figure Engelhard-2
Effects of Space Velocity and Pt/Rh Ratio
- 600°C Inlet Temperature
\00
.1
1
• -
o-
A-
+ •
• •
-a
A HSOOO
.4. 119000
_L
4.
Q
t
1
AFTER 25,000 MILES ENGINE DYNAMOMETER AGING WITH 1977 (COMMERCIAL) FUEL
«•,
NOx CONVERSION AS A FACTION OF Pt/Rh RATIO
AT FOUR SPACE VELOCITIES, 500 M.V., 600°C
ENGINE DV;:AMCMETER
SIX Pt/Rh RATIOS 19/1—> 3/1 PLUS 19/1
(Mod.) and 3/1 (Mod.)
7-184
-------
Figure Engelhard-3
HC/NOx CROSSOVER
After 5,000 miles aging. Evaluated on Engine Dynamometer
at 1600 RPM, 10-11" manifold vacuum, 620°C inlet temperature,
and VHSV = 112,000 All catalysts loaded to 5Q gm/cu. ft.
IOO
ft: 90
o
80
CC LJ
o >
x O
O o 70
o ^
60
50
j_
_L
I
_L
0 10 20 30 40 50
RHODIUM AS % BY WT. OF PRECIOUS METAL
'77 Fuel = Commercial Fuel
'75 Fuel = 1975 Fuel (0.025 q/gal Pb)
7-185
-------
Figure Engelhard-4
TWC CATALYST EFFICIENCY VS
DURABILITY MILEAGE
EVALUATION ON ENGINE DYNAMOMETER AT 1600 RPM, 10-11" MANIFOLD VACUUM,
620°C INLET TEMPERATURE AND VHSV=112,000
100 -
cc
LJ
O
O
701-
O 60
0-19
A-15
*>-IO
- O-7.5
X-5
D-3
! t T
! t
10
15
20 25 30
XiO3 MILES
Fuel 1977
7-186
-------
efficiency (the maximum conversion efficiency for the simultaneous
conversion of all three pollutants). The crossover efficiency is later
illustrated in Figure Engelhard-8 and is a very important indicator of
3-way catlyst performance. The crossover efficiency of Engelhard
catalysts is generally limited by HC and NOx, but this is not true of
all catalysts as CO and NOx are limiting in some cases.
The effect of Pt/Rh ratio on maximum HC efficiency is seen in Figure
Engelhard-5. The Pt/Rh ratio did not affect the maximum HC efficiency.
It should be noted that only 5,000 miles were accumulated on the catalysts
in Figure Engelhard-5 as opposed to 25,000 miles on the catalysts in
Figures Engelhard-1, 2, and 4. Engelhard reported that the accumulation
of 5,000 miles on the 1975 certification-type fuel (.025 gm/gal Pb)
yielded more catalyst deterioration than the accumulation of 25,000
miles on 1977 certification-type fuel (less than 0.005 gm/gal Pb).
Sulfur and phosphorus levels of the fuels were 250-550 ppm sulfur and
less than 1 ppm phosphorus.
The effects of noble metal loading are shown in Figures Engelhard-6 and
Engelhard-7 for the TWC-19 catalyst (11/1 Pt/Rh ratio). The loadings
were reduced to 40% of the original (unspecified) loading. Both the
maximum HC and NOx efficiencies were always within about 10% of the
highest values at all loadings. Further mileage accumulation, higher
catalyst temperatures, or higher fuel contaminant levels could change
this apparent lack of change in maximum HC or NOx efficiency with reduced
noble metal loadings. Crossover efficiencies were not given for the
TWC-19C.
Studies were conducted to determine the relative conversion efficiencies
versus air-fuel ratio which resulted from high temperature aging (at
1800°F for 24 hours) under nearly stoichiometric conditions (0.8%
oxygen), highly oxidizing conditions, and highly reducing conditions.
The conversion efficiencies of HC and NO were generally higher when aged
at high temperature at stoichiometry or under oxdizing conditions, and
lower when aged under reducing conditions. This ranking of efficiency
7-187
-------
Figure Engelhard-5
MAXIMUM CONVERSION OF HC OR NOx
AFTER 5000 MILES AGING
Evaluation on Engine Dynamometer at 1600 RPM. 10-11" manifold
vacuum. 620°C inlet temperature and VKSV =112,000* All catalysts
loaded at 50 gm/cu. ft.
100
90
^ ^
t
2 80
o
CO
o:
u
o
o
70
60
50
NO, '77
0 10 20 30 40 50
RHODIUM AS % BY V/T. OF PRECIOUS METAL
NOx '77 and HC '77 = 1977 Conmercial Fuel
NOx '75 and HC '75 = 1975 Fuel (0.025 g/gal Pb)
7-188
-------
Figure Engelhard-6
TWC CATALYST EFFICIENCY VS.
DURABILITY MILEAGE
TWC 19C,600°C,|I2,CCO VHSV
z
o
CO
C£
UJ
>
z
o
o
100
90
80
70 'r
60
50
P M LOADING
O
D
i.o
0.8
0.6
0.4
10
Aged at 650
15 20 25 30
XIO3 MILES
Fuel 1977
7-189
-------
Figure Engelhard-7
TWC CATALYST EFFICIENCY VS.
E
DURASILITY MILEAG
TWC I9C,600°C, 112,000 VHSV
£
z
o.
CONVERSI
o
X
X
2
100
90
80
70
60
50
i i i i i -i
'§2 — "" u ~~^ — —
^
PM LOADING
O l.O
D 0.8
^ °'6 Aged at 650°C
O 0.4
1 1 1 i t 1
5 10 15 20 25 30
XIO3 MILES
Fuel -1977
7-190
-------
versus aging condition was reversed for CO. The conversion of NOx
to ammonia was generally minimized when the catalyst was aged under
reducing conditions and generally maximized when aged under oxidizing
conditions for an after aging air-fuel ratio test range of 14.2 to 14.7.
These tests also suggest that substantial losses in surface area of the
washcoat or noble metals of the TWC-9 catalysts did not result from
these high temperature excursions.
Catalyst regeneration was accomplished by disconnecting one spark plug
wire which caused the catalyst temperature to increase. Apparently,
the high catalyst temperature caused some of the catalyst contaminants
to be released. NO efficiency was greatly increased by the regeneration,
HC efficiency was slightly increased, and CO efficiency appeared to be
slightly reduced.
Pelleted 3-Way Catalysts
The effects of two different space velocities are shown in Figures
Engelhard-8 to Engelhard-11 for the TWC-13B catalyst (10/1 Pt/Rh). The
reduction in space velocity from 228,000 to 112,000 per hour did not
show much of a benefit on the operational 3-way catalyst window. The
effect of noble metal loading is also seen when Figures Engelhard-8 and
Engelhard-9 are compared to Figures Engelhard-10 and Engelhard-11. The
noble metal loadings were 15 gm/cu. ft. in the first two figures and
45 gm/cu. ft. in the next two figures. The crossover efficiencies of HC
and NOx increased somewhat with increased loading, but of equal importance
is the increased window width (at 60% efficiency) with higher loadings.
Engelhard does not like to place too much emphasis on window width because
of the difficulties in obtaining accurate values of X. EPA agrees that
accurate measurements of HC, CO, NOx, C0» and 0_ are needed, but EPA also
believes that window width is an important parameter in the evaluation
of low mileage catalysts, particularly when the evaluations are done
on engines with closed loop air-fuel metering systems.
7-191
-------
Figure Engelhard-8
TWC-13B with 15gm/cu. ft. Loading at a Space Velocity of 112,000 per Hour
.94
100
80
60
20
• ."• 1 \ ..-I'
1.02
Operating Conditions;
Inlet Temperature = 600°C
Manifold Vacuum = 12 in. Hg
MPH = 23
Sensor Controlled Aging
. _ • Aged 5,000 Miles
-•—Groesover
j '- -Bfftciency
1975 Durability Fuel
Pb = .020-.025 g/gal.
Figure Engelhard-9
TWC-13B with 15gm/cu. ft. Loading at a Space Velocity of 228,000 per Hour
LAMBDA
.94 .96 .98
1.02
100
80
60
40
20
\j .... j . jV--
Operating Conditions;
Inlet Temperature = 700°C
Manifold Vacuum = 6 in. Hg
MPH = 39
Sensor Controlled Aging
Aged 5,000 Miles
1975 Fuel
7-192
-------
Figure Engelhard-10
TWC-13B with 45gm/cu. ft. Leading at a Space Velocity of 112,000 per Hour
.94
100
BO
60
20
LAMBDA
.98
1.02
Operating Conditions:
Inlet Temperature = 600°C
Manifold Vacuum = 12 in. HG
MPH = 23
Sensor Controlled Aging
Aged 5,000 Miles
1975 Durability Fuel
Pb = .020-.025 g/gal.
Figure Engelhard-11
TWC-13B with 45gm/cu. ft. Loading at a Space Velocity of 228,000 per Hour
100
80
60
40
20
.94
LAMBDA
-98
1
1.02
*C*T;
• I. I .,-... .i
Operating Conditions:
Inlet Temperature = 700°C
Manifold Vacuum = 6 in. Hg
MPH = 39
Sensor Controlled Aging
Aged 5,000 Miles
1975 Fuel
7-193
-------
Figure Engelhard-12 shows the effect of Pt/Rh ratio on the crossover
efficiency for HC and NOx for the TWC-18 catalyst. At the minimum Pt/Rh
ratio, the pellets showed poorer efficiency than the previously mentioned
monoliths, but at higher Pt/Rh ratios near mine-mix, the pellet was
superior in crossover efficiency when compared to the monoliths in
Figure Engelhard-3. The respective aging conditions of the catalysts
were not discussed by Engelhard, and may have been different.
It should be noted that the crossover efficiencies are warmed-up
efficiencies and do not necessarily represent FTP conversion efficiency.
Although the pellet may have higher warmed-up efficiency, the monolith
may still have better FTP efficiency because of better light off char-
acteristics.
As a final comparison, the best reported pelleted 3-way catalyst had
about 82% HC/NOx crossover efficiency and the best reported monolith
also had about 82% HC/NOx crossover efficiency. Both of these results
are at 5,000 miles on the 1975 fuel but the precise aging conditions may
have been different. The monolith used a mine-mix Pt/Rh ratio. The
Pt/Rh ratio of the TWC-13B pellet was 10/1. The monolith was the TWC-
9D. The TWC-9D is considered by EPA to be inferior to the TWC-19 and
TWC-16 series monolithic catalysts from Engelhard, particularly for net
NOx efficiency. Efficiency plots were not presented for either of those
two catalysts.
Testing with the Holley Feedback Carburetor
Low mileage testing of a Pinto with a 2.3 litre engine, which used a
Holley feedback carburetor, was conducted at Engelhard in a joint development
effort between Holley and Engelhard. The vehicle was a 1976 model at
2750ipounds inertia weight (10.8 horsepower at 50 MPH) with an automatic
transmission and did not use EGR or AIR. These test results are shown
in Table Engelhard-1.
I
7-194
-------
Figure Engelhard-12
CONVERSION CROSSOVER OF HC/NOx AND
MAXIMUM CONVERSION OF HC OR NOx
AFTER 5000 MILES AGING ON 1975 FUEL
EVALUATION ON ENGINE DYNAMOMETER AT 1500 RPM,ir-l3" MANIFOLD
VACUUM, 600° C INLET TEMPERATURE AND VHSV = 112,000
100 -
80
CO
en
tu
o
o
60
5/1
TWO- 18
O-NOx
Q-HC
A-HC/NOx CROSSOVER
! 1
15/1
Pt/Rh RATIO
20/1
7-195
-------
Table Engelhard-1
Testing of 2.3 litre Pinto
1
0
0
FTP Test
HC
.15
.31
.26
Results
9
2
2
CO
.84
.86
.31
(gm/mi)
NOx
5.27
1.39
0.83
Catalyst
HC
73.
77.
0
4
Efficiency
CO
—
70
76
.9
.5
W
NOx
—
73.6
84.3
Catalyst
None
TWC-9B
TWC-16
The TWC-9B accumulated 10,000 miles of AMA durability with fuel containing
0.020-0.024 gm/gal Pb (4-5 times as much Pb as used in the Engelhard
1977 certification-type fuel). The TWC-16 accumulated 9,800 miles with
commercial unleaded fuel. Thus it appears for the TWC-9B catalyst that if
the carburetor can maintain its stoichiometric calibration, conversion
efficiencies of 70% or greater for all three regulated pollutants may be
achieveable at 50,000 miles.
7.2.4.2. Durability Testing
Other vehicle testing reported by Engelhard used a Toyota Crown Mark II
vehicle with a 2.0 litre engine and an automatic transmission. Vehicle
test results were reported at 3000 pounds IW. Each of the two catalysts
had been used on a vehicle that had accumulated 20,000 durability miles.
The test results are shown in Table Engelhard-2.
Table Engelhard-2
Toyota Vehicle FTP Test Results Fuel Economy
Catalyst HC CO NOx MPG
- - • - - • ' ----™ jj
Dummy 2.07 14.01 3.59 16.7
TWC-16 0.38 2.18 0.47 17.2
TWC-9B 0.40 2.36 0.55 16.9
7-196
-------
The FTP conversion efficiencies were over 80% for all three pollutants
for both catalysts at 20,000 miles.
7.2.4.3. Progress and Problem Areas
Vehicle tests conducted by Engelhard, and by others using Engelhard
catalysts, have shown that a great deal of progress has been made in
increasing the crossover efficiency and window width of 3-way catalysts.
Based on the Engelhard submission, and submissions from vehicle manufacturers,
Engelhard appears to be a leader in 3-way catalyst technology.
Problems for Engelhard include the lack of data on the effects of MMT
and 0.03% sulfur in the fuel and the lack of complete studies of unregulated
emissions from their 3-way catalysts.
7-197
-------
7.2.5. Ethyl Corporation
The Ethyl Corporation continues to develop the Turbulent Flow System
(TFS) in pursuit of an non-catalytic emission control system. During
the past year, Ethyl has concentrated on Turbulent Flow Manifold (TFM)
modifications and improvements, the effects of EGR with TFS, heat
conservation and lean reactor development, compression ratio, TFS in
combination with an electronic spark advance system, port liners, and
extended system durability up to 100,000 miles.
The significance of the TFS continues to be the use of heat conservation
and lean reactor technology rather than operation of an engine solely
with lean calibrations.
Ethyl continued to refine and improve their TFM during the past year.
Results from two vehicles equipped with the TFM indicate that carburetor
production tolerances and misadjusted idle mixtures have no detrimental
effect on the cylinder to cylinder air-fuel spread. Work also continues
on refining the air-fuel distribution capabilities, increasing heat
transfer to the conditioning chamber for improved cold start operation,
and the effect of EGR introduction into the TFM.
Further work was conducted on the benefits of port liners, both individually
and in combination with a lean thermal reactor. Ethyl's reactor work
centered on the investigation of the emission reduction potential of
three types of reactors: open, baffled, and a cored model. Their tests
indicate that the cored reactor was superior under simulated transient
conditions and further vehicle tests will be conducted using this reactor
to confirm their results. Much of the previously mentioned testing was
engine dynamometer testing rather than vehicle testing.
7-198
-------
Ethyl reported work on a proprietary system which is an extension of
their TFS. The development work was conducted on one of their previously
reported lower inertia weight vehicles. The significance of this work
lies in the demonstration of results indicating levels of 0.41 HC, 3.4
CO, 2.0 NOx are possible with a thermal, as opposed to a catalytic,
aftertreatment system.
Results from these vehicles are shown in Table Ethyl-1 and compared to
similar vehicles and 1977 model year vehicles.
Table Ethyl-1
Vehicle
IW
Trans
Development #1
Baseline
Development //2
Baseline
2500
2500
2750
2750
Comparable Certification
1973-2bbl
-2bbl
-FI
-FI
1977-FI + TR +
EGR + AIR
-FI + AIR +
EGR
2500
2500
2500
2500
2750
2750
2750
2750
2750
M4
M4
A3
A3
Vehicles
M4
A3
M4
M4
M4
M4**
A
A
M4
FTP Results (gm/mi)
HC
0.10
3.29
0.09
2.42
1.9
2.1
2.4
2.9
0.18
0.35
0.32
1.00
1.13
CO
2.34
25.10
1.90
37.59
22.0
27.0
23.0
24.0
6.3
8.5
8.5
8.5
8.6
NOx
1.52
2.54
1.86
2.24
1.9
1.5
1.7
1.1
1.02
0.80
1.09
1.31
1.49
Fuel Economy
MPG
u
20.0
22.8
21.5
23.7
22.4*
22.8*
23.0*
23.5*
19.6
18.0
19.7
18.7
20.2
* 1973 Certification vehicle fuel economy originally measured on the 1972 FTP.
Results adjusted to 1975 FTP equivalent by a factor of 1.045.
** High Altitude vehicle
7-199
-------
This system may have potential for combination with other emission
control techniques such as electronic spark advance, electronic EGR,
etc. which could improve both NOx emissions and fuel economy.
Ethyl also reported on their continuing study of the effects of compression
ratio on emissions and fuel economy. The study involved raising the
compression ratio one unit on two different vehicles. The results
indicate that the predictable composite fuel economy benefits of as much
as 6.2% can be achieved at the expense of increased hydrocarbon emissions.
Ethyl feels the use of exhaust port liners could keep this hydrocarbon
increase to 6% for a one unit increase in compression ratio. Representative
data for one of the vehicles are shown in Table Ethyl-2.
Table Ethyl-2
Effect of Port Liners and Compression Ratio
on Emissions and Fuel Economy
1974 360 CID Plymouth Fury III
5000 Ib Inertia Weight
TFS, Carter 4-Barrel Carburetor
1975 FTP Emission Fuel Economy O.N.
(gm/mi) (MPG) Req't
Configuration HC CO NOx MPG MPG, MPG (FBRU)
M — — u_ h c
8.0 CR + Exh. 1.06 9.34 1.87 11.3 18.3 13.68 92
Port Liners
9.0 CR + Exh. 1.22 6.34 1.88 11.5 19.2 14.05 100
Port Liners
(Unadjusted Performance)
Same as above 1.38 6.98 1.69 11.8 19.7 14.40
(Equal perf. to 8.0 CR)
Table Ethyl-2 shows higher HC emissions, higher octane requirement,
lower CO, lower NOx, and improved fuel economy for the higher compression
ratio case.
7-200
-------
Table Ethyl-3*
Exhaust Emissions
1974 Dodge Coronet, Car #857
360 CID V-8 Engine
TFS with Exhaust Port Liners and Exhaust Reactors
Test
Miles
0
3,000
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
45,000
50,000
50,000-Miles
Deterioration
Factor
1975 CVS Emissions,
gm/mi
HC
0.22
0.24
0.30
0.35
0.34
0.43
0.49
0.41
0.48
0.37
0.41
0.43
CO
Phase
3.33
4.29
4.61
5.05
4.93
4.66
6.33
5.77
5.70
5.06
5.95
6.07
NOx
I
1.26
1.66
1.83
1.77
2.13
2.02
1.78
1.79
1.97
1.75
1.82
1.93
1.28
1.26
Average
1.00
Phase II
55,000
60,000
65,000
70,000
75,000
80,000
85,000
90,000
95,000
100,000
0.33
0.50
0.37
0.35
0.41
0.48
0.42
0.43
0.47
0.38
5.09
6.50
5.96
6.24
5.65
7.09
4.88
5.83
5.93
7.13
1.57
2.24
2.03
1.86
1.65
1.95
1.58
1.54
1.79
1.41
Ave
Fuel
Economy,
MPG
10.
10.
11.
11.1
10.7
11.3
11.1
11.3
11.9
11.1
11.2
11.3
11.1
11.4
11.4
10
10
10
10
11.0
10.
11.
10.9
10.9
* Ethyl data reported in Status Report submission page VI-14
7-201
-------
Ethyl extended the durability testing of the TFS vehicle which they
reported last year. The extended mileage results were shown in Table
Ethyl-3. Ethyl performed some maintenance based on emission results
which is not allowed ,by EPA in official durability testing. On the
other hand, according to Ethyl, the maintenance intervals for plug
change and EGR system cleaning during the durability run were longer
than that recommended by the original vehicle manufacturer. The methane
and sulfate emissions as reported by Ethyl are shown in Table Ethyl-4.
No mileage is specified for the methane results.
Table Ethyl-4
Sulfate Emissions
TFS-Lean Reactor Car
50,000 miles
FTP Emissions, gm/mi
FTP
Highway
Sulfate
Cycle
HC
0.43
0.18
NA
CO
6.07
2.49
NA
NOx
1.93
2.59
NA
H2S°4
0.021
0.013
0.009
Fuel
Economy ,
MPG
11.3
18.8
NA
Percent
Conversion
H2S°4 *
1.0
1.0
0.6
* Based on 0.03% sulfur in test gasoline
Methane Emissions**
FTP, gm/mi
FTP Bags, gm
Cold Transient
Hot Stabilized
Hot Transient
TFS-Lean Reactor Car
HC
0.27
2.91
0.43
0.67
FTP
CO
5.29
55.77
9.63
10.68
Emissions
NOx
1.26
5.73
4.28
4.74
CH4
0.011
0.120
0.025
0.015
Percent
CH4
4.1
4.1
5.8
2.2
** Methane was measured using a Baseline Industries Gas Chromatograph
Series 1000 B.
7-202
-------
Ethyl reported other proprietary development work that leads to the
estimation that TFS in combination with other known emission control
techniques could result in achievement of levels of 0.41 HC, 3.4 CO, 1.0
NOx or lower without catalytic aftertreatment. However, this system
would initially be limited to smaller vehicles and not be available
until model year 1981. This combination system's fuel economy remains
to be evaluated.
Ethyl did not discuss their work on the control of particulate emissions
and driveability of lean reactor equipped vehicles. Ethyl does not
routinely use a driveability test that results in a quantifiable numerical
rating. Vehicles are rated by a subjective procedure which, according
to Ethyl, has resulted in vehicles considered by Ethyl to have commercial
driveability also considered to be acceptable in driveability by some
automotive manufacturers.
Ethyl's work with particulate traps has been concentrated on the non-
domestic market and is centered on European, Australian, and other
potential users of particulate trap technology.
7-203
-------
7.2.6. Holley
The Holley Carburetor Division of Colt Industries has developed a
feedback carburetor which will be used by Ford in the 1978 certification
of their Pinto with a 2.3 litre engine for California. While Holley is
known to be developing feedback carburetion for other engines also,
their report to EPA primarily discussed an experimental Pinto with a
2.3 litre engine system.
The Holley system is relatively uncomplicated as shown in Figures
Holley-1 and Holley-2. During warmed-up operation, the oxygen sensor
output is compared to a reference signal in the ECU to yield an ECU
output signal to the vacuum control valve. The vacuum control valve
in turn modulates vacuum from the vacuum storage canister to the twin
diaphrams in the carburetor. The variable air bleed has the potential
to keep the system at stoichiometry during idle and off idle operation.
The auxiliary main metering system provides for stoichiometry in the
part throttle operating range. The auxiliary main metering circuit is a
refinement of what previously was the power enrichment circuit, according
to Holley.
The ECU output was said to be a square wave. The width of the square
wave is variable and depends on the input from the oxygen sensor.
The system runs in the open loop mode during both wide open throttle and
engine warm-up conditions.
Holley indicated that an adjustment of the ECU can be made to maximize
HC, CO, and NOx control by modifying the relationship of the ECU output
to input. Additionally, circuit gains and time constants can be modified
to achieve relatively uniform engine-out CO levels over the operational
range of the engine. Figure Holley-3 shows that the Holley system can
provide stable air-fuel metering under rich and lean conditions as well
as at stoichiometry. Holley did not reveal which, if any, of these
adjustments to the ECU will be required on a production vehicle.
7-204
-------
Figure Holley-1
HOLLEY ELECTRONIC METERING CARBURETOR
THREE-WAY CATALYST APPLICATION
VACUUM REGULATOR
CONTROL VALVE
IS)
O
Ui
VACUUM
STORAGE
CANISTER
ELECTRONIC '
CONTROL UNIT
CARBURETOR
ENGINE WATER
TEMPERATURE
SENSOR
CATALYSTS
_D THROTTLE
OPERATION
SENSOR
02 SENSOR
AIR PUMP
-------
Figure Holley-2
FEEDBACK CARBURETOR SCHEMATIC DRAWING
to
o
FEEDBACK CONTROLLED
IDLE AIR BLEED
CONTROL VACUUM
CONNECTION
FIXED IDLE
AIR BLEED
MAIN METERING JET
FEEDBACK CONTROLLED
MAIN SYSTEM FUEL
-------
Figure Holley-3
. I
NJ
o
HOLLEY FEEDBACK CARBURETOR PERFORMANCE
.09
at .08
3
UJ
£
3.07
I
Q
-06
.05
FEEDBACK SYSTEM CONTROL OF
CARBURETOR FLOW AT VARIOUS
LEVELS OF CONTROL VACUUM
CONTROL
VACUUM
IN
IN. Hg
0
2.5
LL
5 10 20 30 40 50 60 70 80 100 120 140 160 180
AIRFLOW-SCFM
-------
Vehicle tests were reported on a modified 1976 Pinto at 2750 pounds IW
with the 2.3 litre engine, an automatic transmission, and a 3.18 rear
axle. Emission control equipment included the Holley feedback carburetion
system, backpressure EGR, AIR, and a 3-way plus oxidation catalyst
system. The vehicle had accumulated less than 3000 miles. These low
mileage test results are shown in Table Holley-1.
Table Holley-1*
Low Mileage Testing of 2.3 litre Pinto
EC
0.152
0.165
0.136
0.166
CO
3.29
2.79
2.56
3.22
NOx
0.436
0.434
0.420
0.502
MPG
u
20.48
21.37
21.65
21.42
Average 0.15 2.96 0.45 21.43
The similar fuel economy vehicle** from 1977 Federal certification
achieved 23.0-23.4 MPG .
u
The driveability of the vehicle with feedback carburetion was said to be
improved over the driveability of the vehicle in its original 1976
California configuration, except at idle. Apparently, engine surge was
experienced with feedback idle operation. The elimination of lean
stretchiness at part throttle was said to be the biggest improvement in
driveability.
*From Holley Status Report, December 1976, pages 3 and 4.
**VIN 7Y1-2.3-F-43.
7-208
-------
Holley will provide only the carburetor and vacuum control valve to
Ford. The carburetor will cost 5-10% more than the similar open loop
carburetor which is being replaced and the vacuum control valve will
cost less than $5.00, according to Holley.
Lead time requirements for the modification of an existing carburetor to
feedback control ranges from 18 to 30 months, depending on the necessary
design changes and availability of prototype tooling. Holley also indi-
cated that they would need two model years to introduce feedback modifi-
cations for all their production carburetors.
The developmental efforts of Holley have made production feasible,
feedback carburetion available to many vehicle manufacturers for the
first time. Consequently, data which can be used to directly compare
feedback carburetion to feedback fuel injection may now become avail-
able.
Perhaps the biggest problem for the Holley system is the apparent lack
of demonstrated durability. It appears that if the feedback carburetors
are durable and can provide reasonable emissions and fuel economy when
compared to fuel injection, the domestic vehicle manufacturers will
probably continue to use carburetion because of the cost differential
between carburetion and injection. Thus the slower system time response
which is associated with intake manifold wall wetting will probably
continue to be accepted by the industry.
7-209
-------
7.2.7. Matthey Bishop Inc. (MB)
Matthey Bishop Inc. is the U.S. subsidiary of Johnson Matthey Chemicals,
Ltd. Their major activity in the automotive emission control area is
the development and manufacture of catalysts. They have tended to
specialize in monolithic substrate catalysts and their major customer
has been the Ford Motor Company.
MB responded to EPA's request for information with some interesting
reports on progress in the areas of oxidation catalysts and 3-way
catalysts.
i
Along with the other catalyst manufacturers, MB has been striving to
reduce the amounts of noble metal and washcoat in their catalysts.
Significant reductions in these items have already been made on pro-
duction catalysts since the large scale introduction of catalysts in
1975. For example, a representative monolithic substrate noble metal
loading for 1977 model year catalysts is approximately 25 gm/cu ft.,
whereas in 1975 the loading was in the area of 40 gm/cu ft. MB is
striving to reduce the loading still further and initial results indicate
that from a low mileage activity point of view this may be possible.
However, their testing has shown that maintaining high catalyst efficiency
at high mileage may be the limiting factor.
Two types of laboratory aging testing have been performed. The first
type was poisoning with fuel containing 0.024 gm/gallon of lead. This
poisoning resulted in some reduction in activity as shown in Table MB-1.
7-210
-------
Table MB-1
Effect of Catalyst Aging on a Cycle Emphasizing Poisoning
System
Standard
Low NM
Low WC
Low WC
Loadings
Washcoat Noble Metal
gm/cu in. gm/cu ft.
1.75
1.75
1.2
0.8
25
15
25
25
Steady State Conversion Eff.
35
HC
94
91
89
89
hrs
CO
100
100
100
100
127
HC
92
88
87
88
hrs
CO
100
100
100
100
293
HC
84
78
80
80
hrs
CO
100
100
100
100
MB also presented data showing the effect of high temperature on the
durability of catalysts like those in Table MB-1. The aging cycle
presented the catalysts with an 800°C (1472°F) inlet exhaust gas temperature
for half of the time. The results are shown in Table MB-2. These
results indicate that low noble metal and low washcoat formulation do
not hold up nearly as well under high temperature operation.
Table MB-2
Effect of Catalyst Aging on a Cycle
Emphasizing
System
Standard
Low NM
Low WC
Low WC
' Loadings
Washcoat Noble Metal
gm/cu in. gm/cu ft.
1.75
1.75
1.2
0.8
25
15
25
25
Thermal
Degradation
Steady State Conversion Eff.
HC
78
72
75
68
SOhrs
CO
99
97
96
95
100
HC
76
69
69
63
hrs
CO
96
94
93
93
200
HC
66
57
58
46
hrs
CO
94
93
90
63
300
HC
60
51
52
30
hrs
CO
92
88
79
21
7-211
-------
MB presented some very interesting and potentially significant information
on metal substrate catalysts. Current monolithic catalysts use ceramic
substrates. Metal substrates offer the promise of improved shock and
vibration resistance along with reduced size. This last advantage may
be the most important. This is because on some installations requiring
a "close coupling" of the catalyst to the exhaust manifold, a limiting
condition may be available space. Close coupling is advantageous because
the exhaust gas is at a higher temperature when it arrives at the
catalyst. This has advantages in the areas of quicker light-off and
improved conversion efficiency. Close coupling is particularly important
for start catalysts and 3-way catalysts. MB claims that by using a
metal substrate, the cell wall thickness can be reduced to as low as 2
mil (0.002 in.). This allows a metal substrate catalyst of 400 cells
per square inch (CPSI) to be fabricated and coated with ease of a 300
CPSI ceramic monolith. MB indicated that their calculations show that a
metal substrate catalyst need only be half the volume of a ceramic
substrate catalyst to give equivalent performance, assuming the same
noble metal content for both. Conversely, a conventional catalyst could
be replaced by a metal substrate catalyst of the same volume to yield
improved catalyst efficiencies. Table MB-3 compares the performance of
a 34 cu in. metal substrate with a 75 cu in. ceramic substrate, using an
aging cycle which included severe mechanical and thermal shock.
7-212
-------
Table MB-3
Metal Substrate vs. Ceramic Substrate
Conversion % Eff.
Catalyst Type Hours Aged HC CO
34 cu in. 0 81 91
400 CPSI, Metal 100 61 87
Pt/Pd ratio 2:1 200 68 88
56 gm/cu ft.
300 64 86
75 cu in. 0 84 93
300 CPSI, Ceramic 100 69 90
Pt/Pd ratio 2:1 200 69 86
25 gm/cu ft.
300 64 89
MB reported progress in 3-way catalyst development. They indicate that
their development approach has emphasized the importance of air-fuel
ratio perturbations of controlled amplitude and frequency. All of MB's
reported work on 3-way catalysts involved formulations containing an
11:1 Pt/Rh ratio and a 40 gm/cu ft. noble metal loading. Table MB-4
contains CVS test results (assumed to be 1975 FTP) for two of their
formulations. Table MB-5 contains steady state conversion efficiency
data for some later formulations. These later formulations appear to
perform quite well.
7-213
-------
Table MB-4
3-Wav Catalyst Test Results (VW Beetle with Bosch L-Jetronic EFI)
K>
Catalyst
TWC-1
TWC-2
TWC-1
TWC-2
TWC-1
TWC-2
on FulJL— Sized
Pollutant
NOx
NOx
HC
HC
CO
CO
Catalysts (at
11:1) Aeed
0 Hour Emissions
(gm/mi)(75 FTP)
Baseline Sum Wt.
2.82
2.82
1.05
1.05
12.9
12.9
0.77
0.69
0.33
0.21
2.88
1.92
by a 3-Way
% Conv.
77
76
69
80
78
85
Catalyst Cycle
265 Hour
(gm/mi)
Baseline
2.82
2.79
0.86
0.94
12.0
12.6
Emissions
(75 FTP)
Sum Wt.
0.92
0.93
0.22
0.21
2.93
2.56
% Conv.
67
67
74
78
76
80
-------
Table MB-5
Steady State Efficiencies MB 3-Way Catalysts
after 300 Hours Dyno Aging by 3-Way Catalyst Cycle
Perturbation = 1 A/F at 1 Hz
A/F = 14.6
Catalyst Gross NOx HC CO
TWC-3 62 94 92
TWC-4 75 94 92
TWC-5 77 95 97
TWC-6 80 93 97
A/F = 14.5
TWC-3 68 94 84
TWC-4 85 94 87
TWC-5 93 95 92
TWC-6 87 93 92
7-215
-------
MB reported some interesting data on the sulfuric acid emission char-
acteristics of platinum/rhodium catalysts. Their test data show a
dramatic drop off in sulfuric acid emission following a cool down period.
The catalyst had been run continuously for 500 hours, with periodic
sulfuric acid emission testing, prior to this cool down. After the cool
down the sulfuric acid emission level dropped to one fourth its former
level. MB indicates that this may result from a catalyst surface enrichment
in rhodium that occurs during the cool down.
MB reported data on the effect of noble metal content and air-fuel ratio
on HCN emissions. Note that data show the net increase in HCN over the
catalyst. Table MB-6 shows this data.
Table MB-6
Net HCN Production by Various Matthey Bishop Catalysts at 500°C
50,000 hr SV, as a Function of A/F Ratio (Stoich. = 14.7)
*HCN Produced, ppm, at A/F ratio of
14.7 14.9
1.0 1.0
1.5 1.0
1.5 1.0
1.5
0.5 0.5
* Inlet HCN (baseline): 5 ppm
** Major component of all systems is platinum
MB is in active competition with the other leading catalyst manufactur-
ers in the development of 3-way catalysts. They are presently concentrating
on an 11:1 platinum/rhodium ratio which appears to show fairly good
results.
7-216
System**
100 /
33 %
2.5 /
7.5 5
15 %
I Pt
Pd
I Rh
I Rh
Rh
14.0
1.5
2.0
3.0
32
9
14.3
1.0
1.0
1.5
17
4
14.5
1.0
1.5
1.5
2.0
1.0
-------
7.2.8. Questor
7.2.8.1. Systems Under Development
Questor's Reverter System entails a three-step process involving limited
thermal oxidation of CO, HC, and H2; catalytic reduction of NOx; and
then further oxidation of remaining CO, HC, and H2< The system can be
thought of as a rich thermal reactor, followed by a NOx catalyst,
followed by a lean thermal reactor. This is basically the same system
as the one reported in last year's status report.
The system operates moderately rich (13.0:1 t;o about 14.2:1 A/F ratio)
using limited port air injection via an air pump for nominal 0_/CO
ranges of 0.05 to 0.4, a rich thermal reactor where exhaust gas temperatures
range from 1550-1750°F, a base metal catalyst with a combination of Cu,
Cr, and Nl powder sintered to a base metal substrate, and finally,
secondary air injection into another lean thermal reactor section in an
amount roughly equal to that injected at the ports. These three steps
correspond to areas A, B, and C, respectively, in Figure Questor-1.
A Reverter system is being installed at Chrysler on a 318 CID equipped
B-body vehicle incorporating open loop, electronic fuel injection (EFI) .
An identical system will be installed on a 318 CID Cordoba with EFI
owned by Houston Chemical. Houston Chemical is a manufacturer of lead
additives for gasoline. They have an interest in lead-tolerant emission
control systems, and the Questor system appears to be one. Test results
from these systems will be compared to results using engines equipped
with conventional carburetors. Previous work shows deviations in CO
results partly due to carburetor air-fuel ratio drift.
The Houston Chemical vehicle is intended for use in continuing their
lead tolerance testing. Previous testing involved use of a Reverter
7-217
-------
AIR
INJECTION
to
oo
EXHAUST
GAS
OUTLET
Figure Questpr-1
Questor's Reverter System
-------
equipped Pinto. Though somewhat limited testing was performed, hot
start tests showed that as lead content increased, HC, CO, and NOx
emissions increased with little or no effect on fuel economy. These
tests were performed on the same day using the same driver and ana-
lytical equipment. Averaged emission results are presented in Table
Questor-1. Exhaust gas temperatures taken in the first reactor, 1/4 in.
ahead of the NOx catalyst, showed decreasing exhaust temperatures
Table Questor-1
Lead Tolerance Test Results of the Questor Reverter System
1974 Pinto Wagon, 2.3 litre, 3000 Ib IW
CVS hot start bags 2 & 3, 11.3 hp setting
avg gm/mi
Pb. gm/gal (nominal) HC CO NOx MPG
^ 0 0.058 2.678 0.205 17.1
0.5 0.073 2.975 0.351 16.8
1.5 0.115 4.468 0.344 16.9
3.0 0.190 6.115 0.414 17.3
(as much as 200°F, 3 minutes into hot start) with increased fuel lead
content. Questor indicated that additional use of lead retards the
reaction rates of the partial oxidation zone disturbing the operating
states of not only the partial oxidation zone (step 1), but also catalytic
reduction and final oxidation (steps 2 and 3, respectively).
7.2.8.2. Systems to be Used at Various Emission Levels
0.41 HC, 3.4 CO, 0.4 NOx
The Questor Reverter System was developed to meet statutory emission
levels. Emissions performance to date have been generally promising,
7-219
-------
however, CO control shows some inconsistency. This may be due to the
inability of the carburetor to hold the desired air-fuel ratio. Some
emission results are presented in Table Questor-2 and Table Questor-3.
The loss of CO control at zero mileage and the fluctuating level of NOx
at 5000 miles in Table Questor-3 could not be explained by Questor.
Table Questor-2
Emission Results with Questor's Third Generation Reverter
Vehicle
Date
1974 Pinto 11/24/75
2.3 litre 11/26/75
2V Garb 12/01/75
Veh. //HC-33 12/04/75
12/05/75
12/08/75
12/09/75
12/15/75
12/17/75
12/18/75
1/12/76
Lab
—
AP
AP
AP
GM
GM
GM
GM
GM
GM
GM
GM
Fuel HC
— ~--
Indolene 0.03
Clear 0.08
0.04
0.00
0.05
0.05
0.06
0.06
0.05
0.04
0.05
CO
2.32
2.50
1.85
4.90
3.90
4.00
3.70
5.70
2.80
2.70
4.70
NOx
1
0.26
0.25
0.24
0.26
0.25
0.14
0.15
0.21
0.28
0.22
0.19
MPG
u
16.2
16.0
16.0
14.9
15.4
16.0
16.2
14.5
15.8
15.8
15.9
Average
0.05 3.55 0.22
12/19/75 GM
1/08/76 GM
Indolene 0.07 3.9
30 0.10 6.6
Average
0.08 5.2
0.34
0.25
0.30
15.7
15.6
MPG,
18.7
19.2
19.4
19.5
7-220
-------
Table Questor-3
Emission Results with Questor's Third Generation Reverter
Vehicle
1973 Pinto
2.3 litre
2-V Garb
Date
1/14/76
1/15/76
1/16/76
2/27/76
3/01/76
3/02/76
3/02/76
3/03/76
7/12/75
7/14/75
7/15/75
7/15/75
Mileage
Zero
5000
je Lab
AP
AP
AP
Ford
Ford
Ford
Ford
Ford
Average
Ford
Ford
Ford
Ford
Fuel HC
Indolene 0.12
Clear 0.12
0.08
0.09
0.08
0.09
0.13
0.08
0.10
Indolene 0.07
Clear 0.07
0.09
0.07
CO
3.21
2.98
2.80
2.93
2.39
4.34
3.68
5.24
3.45
3.08
3.10
4.58
2.66
NOx
0.25
-
0.27
0.23
0.25
0.18
0.38
0.16
0.25
0.42
1.05
0.27
0.68
MPG
u
,5
,7
16.
16.
17.0
15.6
15.1
15.8
16.2
16.0
16.1
16,
16.
16.
Average
0.08 3.36 0.60
16.4
16.5
Inspections of the Reverter hardware and its air management controls
showed no apparent malfunctions. Testing is to continue to the 10,000
mile interval where NOx control will again be examined. Fuel economy
continues to be a problem with the Reverter system primarily due to the
richer than stoichiometric air-fuel ratios used. Typical 1977 Pinto
certification results show average urban fuel economy of about 21.5 MPG
compared with the Questor Pinto which is averaging about 16.3 MPG .
7.2.8.3. Durability Testing
Other than the data reported in Table Questor-3, no durability data were
presented. The Chrysler B-body test vehicle described above is being
equipped with a Reverter system and is designated to undergo durability
testing. To help increase system durability, the geometry of this
7-221
-------
system was kept as simple as engine space constraints would allow to
reduce the magnitude of residual stresses created through complex
forming operations. Electron beam welding is also used to help alleviate
residual stresses. Installation and initial testing were expected to be
completed in January 1977, thus no test data were reported.
7.2.8.4. Problems and Progress
As mentioned above the fuel economy of vehicles equipped with Reverter
systems continues to be a problem. This may be primarily due to the
rich carburetor settings used in this system. CO results have been
somewhat inconsistent possibly due to carburetor air-fuel ratio drift.
Results from EFI equipped vehicles will be compared with previous
results for possible improvements in both fuel economy and emissions
over carbureted vehicles.
A total development program of the Reverter system cannot be pursued by
Questor for financial reasons. As interest is generated in the automotive
manufacturers and others, financial backing from these parties can be
used for further development.
7-222
-------
7.2.9. Universal Oil Products. Inc. (UOP)
7.2.9.1. Systems Under Development
Oxidation Catalysts
Though no data were presented, UOP has done work on developing a monolithic
start catalyst. These are presently available on a commercial basis.
No further effort was reported by UOP.
3-Way Catalysts
Three-way catalyst development was the largest area of effort reported.
UOP has been directing their 3-way catalyst development programs with an
objective of reaching a platinum/rhodium ratio of 20-30:1 and a total
noble metal loading of 25-40 gm/cu ft.
The noble metal loadings in catalysts (A" dia x 6" long monolithic
substrates having 300 cells/sq in.) which have been prepared and eval-
uated by UOP are described in Table UOP-1. Catalyst #PZM-360911 is
roughly within the above objectives of UOP.
Table UOP-1
Noble Metal Loadings in UOP Catalysts
Noble Metal Loadings (gm/piece)
Catalyst
PZM-35106
PZM-36039
PZM-36089
PZM-360911
Pt
1.89
2.50
1.60
1.14
Rh
0.31
0.25
0.16
0.06
Pt/Rh Ratio
6:1
10:1
10:1
19:1
gm total
loading
2.20
2.75
1.76
1.20
gm/cu ft.
50.42
63.03
40.34
27.50
7-223
-------
A steady state dynamometer procedure is used to evaluate these catalysts.
Table UOP-2 shows aging data using catalyst //PZM-360911. UOP indicates
Table UOP-2
Steady-State Dynamometer Evaluation
of Catalyst //PZM-360911
Test
Hours
0
60
120
180
240
NO/CO
Intercept
%
74.5
77.9
75.5
71.8
72.7
NO/HC
Intercept
%
85.7
80.7
82.5
80.8
76.3
Maximum Efficiencies
%
HC
88
83
84
83
79
CO
83
84
85
82
84
NOx % Efficiency
Under Rich
NOx Conditions (2% CO)
97
94
91
88
88
90
73
47
26
13
that zero mile conversion efficiencies should be between 80-90% for HC,
CO, and NOx over the '75 FTP with this catalyst. The durability of low
rhodium catalysts is presently unknown to UOP. Programs to obtain this
information using actual vehicle testing are expected to be concluded
within the next six months. No data were reported for the other catalysts
listed in Table UOP-1.
UOP is also involved in the preparation and evaluation of pelleted 3-way
catalysts. Though no data were reported, additional work is presently
being directed toward increasing the Pt/Rh ratio (from the 9:1 ratio
which UOP reports is available commercially at present), and improving
HC and NOx activity and durability.
Some testing of catalysts having Pt/Rh ratios of from 4:1 to 18:1 has
been performed to study the effect of Pt/Rh ratio on the production of
sulfuric acid emissions. No data were reported.
Other Development Efforts
Another program to study the production of HCN under rich conditions
using a laboratory test procedure has been established by UOP. No
results are available.
7-224
-------
7.2.9.2. Systems to be Used at Various Emission Levels
No specific system to be used to meet any particular emission level was
identified by UOP.
7.2.9.3. Durability Testing
No data were reported.
7.2.9.4. Progress and Problems
The supply of rhodium was discussed briefly by UOP. They reported that
recent information (Metals Week, 31 January 1977, page 2) indicates that
South African platinum mines would be able to supply 33,000 troy ounces
of rhodium per year to the U. S. automobile industry. This figure is
5.5% of the platinum supplied to automakers, and would require a ratio
of platinum to rhodium of about 18:1 if 3-way catalysts were to be
employed on all vehicles. Assuming a figure of ten million vehicles/model
year, the allowed rhodium loading per vehicle would be 0.1 gm if all
vehicles were equipped with 3-way catalysts. An alternative situation
would involve half the vehicles (5 x 10 vehicles) being equipped with
oxidation catalysts and the remainder being equipped with 3-way catalysts.
This situation would theoretically permit the use of 0.2 gm of rhodium
per vehicle for those equipped with 3-way catalysts. The platinum to
rhodium ratio could also be reduced to about 10:1 under these conditions
if this were necessary.
UOP's objectives to reduce total catalyst loadings and increase Pt/Rh
ratios are admirable, but UOP did not report any vehicle test results to
EPA that would indicate how UOP's catalysts compare with those of other
catalyst manufacturers.
7-225
-------
7.2.10. Walker Manufacturing
Submissions for this year's status report were requested from the
Manufacturers of Emission Controls Association (MECA) of which Walker
Manufacturing is a member. Walker furnished parts for the GM oxidation
catalyst and is assembling the Ford oxidation catalyst in their Ohio
plant. Research and development is carried in Walker's Grass Lake,
Michigan Engineering and Research Laboratories.
Walker submitted a response to the MECA request which outlined their
test results of selected monolithic catalysts in comparison to production
pelleted catalysts. After evaluations using an engine dynamometer,
Walker decided to use a Matthey-Bishop 3C oxidation catalyst for their
vehicle comparison testing. These monolithic catalysts were on a W. R.
Grace substrate with a cell density of 306 cells per square inch, a
Pt/Rh 40 gra/cu ft. loading level, 0.0854 troy ounces of precious metal,
and an effective volume of 96 cubic inches. The vehicles selected for
durability testing were three 454 CID equipped, full sized Chevrolets
(EVT-1,2,3) and a 140 CID Vega (EVT-6) . The Vega and two of the Chevrolets
were driven 30,000 non-AMA durability miles and the other Chevrolet was
driven 50,000 miles. Emission tests were performed every 5,000 miles
and before and after any significant maintenance. These emission results
can be found in Table Walker-1. Sulfate or hydrogen cyanide emissions
were evaluated nor any high altitude or non-FTP temperatures and speeds
evaluated. Additional tests are scheduled for these vehicles.
Walker placed the following constraints on the catalyst selection: (1)
the converter must be packaged within the location of the original
equipment converter, (2) production substrates and catalysts must be
used, and (3) the vehicle emission control system would remain unchanged.
Operating within these constraints, Walker attempted to determine how
long and to what levels tailpipe emissions could be controlled, and
7-226
-------
Table Walker-1
TABULATED CVS RESULTS *
ETV-l/AM-33
CATALYST KTLES
0
0
0
5k
10k
15k
18.5k
'18'.5k
2Ck
2Ck
25k
25k
25k
3o:<
33k
3Ck
30k •
3Ck
35k
4Ck
4Ck
43k
>j <5lc
I • 5Gk
'K> 50k
fO ' • 50k
^J 5 Ok
E7V-2/AM-34
CATALYST MIL2S
0
0
0
Sk
10k
15k
18.5k
18.5k
20k
25k
25k
3Ck
3Ck
30k
30k
• 30k
30k
KC
1.66
1.70
0.17
0.34
0.34
0.31
0.33
0.43
0.37
0.36
0.45
0.53
0.51
0.43
0.40
0.41
1.37
1.47
0.53
1.C4
0.54
0.49
. 0.51
0.5S
1-74
l.si
HC
1.31
1.46
0.21
0.30
0.33
0.33
0.39
0.34
0.35
0.61
0.66
0.43
0.4S
0.63
0.51
1.32
1.43
CO
11.30
11.03
1.37
3.20
3.32
2.42
2.14
• 1.41.
5.09
1.29
2.54
2.30
. 3.44
3.15
3.18-
3.37
13.95
12.14
2.71
12.63
3.09
2.50
NO TEST
2. S3
3.35
12.36
12.77
CO
28.8
26,1
2. 65
2.71
2.60
3.21
3.19
3.37
3.46
5.23
4.34
3.84
5.11
9.42
6.83
33.91
33.45
NOv
3.09
2.73
2.73
2.75
2.58
2.66
2.55
2.54
2.66
2.88
3.C4
2.84
2.76
2.67
2.66 '
2.71
2.71
2.93
2.53
2.61
3.36
3.54
2. CO
2.73
3.07
2.80
NO,
2.45 •
2.69
2.02
1.99
2.14
2.R3
2.30
2.25.
2.57
2.42
2.1£
2.29 •
2.12
2.05
2.03
2.29
2.17 .
COM.VESTS
Baseline
Baseline
Before Maintenance .
After Maintenance
Invalid Cold Start
After Maintenance
After Maintenance, repeat
Jtepeat
Repeat
Baseline .
Baseline
Defective Air Pump
After Air Pur.p Replaced
After Maintenance
Repeat
Baseline
Baseline
COMMENTS
Baseline
Baseline
Before Maintenance
After Maintenance •
After Maintenance
Repeat '
Repeat
Repeat
Baseline
Ba.-.eline
ETV-3/AM-35
CATALYST MILES
0
0
0
0
5k
5k
10k
15k
18.5k
18.5k
20k
20k
25k
25k
. 30k
• 30k
30k
'30k
30'.:
ETV-6/AM-44
CATALYST MILES
0
0
0
5k
10k
15k
15k
18.5k
18.5k
20k
25k
25k
30k
30k
30k
30k
30k
30k
HC
2;76
2.92
0.22
0.21
0.23
0.38
0.57
0.63
0.55
0.59
0.63
0.78
0.92
0.86
0.99.
1.04
0.99.
2.73
2.63
KC
2.26
2.26
0.45
0.43
0.51
0.76
0.52
' 3.73
1.02
0.99
0.95
0.90
1.11
1.08
1.04
1.06
2.37
2.17
CO
8.36
7.43
1.82
1.14
1.43
2.26
1.14
1.48
1.76
1.61
1.63
1.53
2.06
2.68
2.59
3.32
3.18. "
10.93
19.53
CO
11.79
12.14
8.59
8.67
7.47
10.23
10. :o
9.79
10.53
11.28
• 11.93
11.53
10.41
11.24
10.44
. 9.26
14.62
13.95
KOv
4.43
3.13
3.26
3.09
2. £2
3.42
2.90 •
. 2.83
3.31
3.94
2.92
3.62
2.72 •
2.77
2.77
2.82
2.83
3.04
2.89
KOv
2.63
2.67
1.62
1.67
1.41
1.31
1.25
1.44
1.65
1.46
1.49
1.65
1.57
1.82
. 1.73
1.92
2.37
2.17
COK2S7S
Baseline
Baseline
After idle reset
After idle reset
Before K2intenar.ee
After Maintenance
Retest-tininc. reset
After Maintenance
Repeat
Repeat
Baseline
Baseline
COMXSKTS
Baseline
Baseline
After Idle Reset
Before Xainter.ar.ce
After Xaiaieaar.ca
After Maintenance
Repeat
Repeat
Repeat
Baseline
Baseline
*From Walker Manufacturing Status Report
submission, page Figure 9.
Walker Manufacturing Co.
12/15/76
-------
to determine how Inlet emission levels (engine-out) affect the choice of
catalyst volume. Consequently, Walker made the following tentative
conclusions based on the data accumulated by Walker to date:
1. The minimum catalyst volume required to meet any emission
standard is dependent on feedgas composition (See Figure Walker-1).
2. The volume of catalyst required to just meet a tailpipe emission
standard on an individual vehicle may be quite small. Feedgas
concentration tolerance spread requires relatively large catalyst
volumes to ensure all vehicles of a particular production group
meeting standards.
3. Figures Walker-1 and Walker-2 imply that, at a given feedgas
concentration level, increasing catalyst volume beyond the knee in
the curves is an inefficient and costly method to further reduce
tailpipe emissions.
A. Figures Walker-1 and Walker-2 together show that feedgas
concentration level reductions have a much more pronounced effect
on tailpipe emission reductions than do large catalyst volume
increases.
5. Figures Walker-3 and Walker-4 indicate that specific activity
variations exist on typical catalyst-substrate combinations in the
fresh state. Presumably this is true in the aged state also,
although this has not been determined. It is noteworthy in any
case, that large volume increases are necessary (greater than 2
times) to attain the final 10 to 15% increase in conversion efficiency.
7-228
-------
Figure Walker-1
CVS Test Results as a Function of
Catalyst Volume (AM-34 at 30, 000 miles)
For Two 454 CID Chcvrolets
W
£
u
3.2
2.8
2.4
SH
(U
a
0)
a
cd.
WJ
o
•s
a)
o
O
2.0
1.6
D
O
ETV-2
ETV-3
HC
— CO
W. n. Grace Substrate. 200 cells/in*
3. CO-" x C. GG" oval cross section, C. 0" lone
. Maltlicy Uisliop 3C catalyst, -10 g/CK
191i Chevrolet. 454 CIH
With secondary air.
49 State calibration,
Unmodified except for catalyst.
MileaEc accumulated over simulated
.AMA durability route.
Fed. Std.
1.2!
32.0
28.0
24.0 4-
• *-:
E
20.0
16. 0
12.0
8.0
4.0
64
80
96
Catalyst Volume (In. 3)
c
tr
r
r.
I-
t
r.
•c
c
t:
c.
c
r-
T
r.
C
Walker Manufncturln.T C.r>
12-16-76
7-229
-------
Figure Walker-2
t-c
0)
a
V)
6
rt
M
bfl
.
ri
u
E.
•O
to
>
U
• CVS Test Results as a Function of
Calalynt Volume for the ETV-l/AM-33
System (AM-33 at 50, 000 Miles)
W. ri. Crntc Subblratc. 205 cells/In*
». GO" x 6. CU" oval cross section. 6.0" lonf
Miitlhcy Iiiohop 3C calalysi, 40 e/CF
1075 Clicvrolct, 4S4 C1Q
With nrcoitdary air.
49 Slulr r:ilibralion,
UnnioJifioil rx-crpl for catalyst.
Mltra|;r nrctiiuulatcd over simulated
AMA Ournbillly route.
n H.C
O CO
l.C
Fed. Std.
1.2
Calif. Std.
0.8
0.4
U)
tf
•O
W
01
fn
20.0
16.0
12.0
8.0
4.0
16
32 48 64
Catalyst Volume (In3)
80
96
o>
o.
10
I.
(-1
to.'
G
•c
•^'
X
t
ir-
r\
C
f
re
U
u
Walker Manufacturing Co.
12-16-76
7-230
-------
Comparison of Carbon Monoxide Hot
Conversion Efficiency versus Substrate Volume
for Four Fresh Catalyst/Substrate Systems
Dynamometer tests at 120 SCFM Carburetor Air Flow
100 -
90 -
80. -
70 -
60 -
50 -
40
Code
o
Substrate
CroBO-
Scctlon
Cells
In.2
Conversion efficiency - ~fes X 100
Cat.ilvst
W. R. Grace 3. CC" x 6. GO" 290 Mallhoy Bishop - 3C
3.'?5" xC.GG" 235 U.O.P.
' S. CC" x C. CC" 200 Matthey Elshop -3C
A Corning
O Corning
• O Corning
4.66"
200 Engclhard
40
60
80
100
120
140
Substrate Volume (In. )
Figure Walker-3
Walker Manufacturing Co
E.S. 12-15-76
7-231
-------
100 J
90 -
80 -
70 -
60 -
50 -
40 -
(
Comparison of Hydrocarbon Hot
Conversion Efficiency versus Substrate Volume
for Four Fresh Catalyst/Substrate Systems
Dynamometer tests at 120 SCFM Carburetor Air Flow
• Convercion efficiency =
Inlet-Outlet
Cross-
Section
Cells
In.2
W. R. Grace 3. GG" x 6. CG" 290
S. 75" x 0.66" 236
3. 66" x 6. 66" 200
4.66"
Corning
Corning
Corning
200
Catalyst
Mnllhcy Bishop - 3C
U. O. P.
Mattlicy Bishop -3C
Engelhard
60
8
10
0
Substrate Volume (In. 3)
Figure Walker-4
Walker* Manufacturing Co.
7-232
-------
6. An effective catalyst system to meet the statutory emission
levels of 0.41 HC, 3.4 CO requires reductions in feedgas concen-
trations and in feedgas variation between identical vehicles.
As indicated above, the six statements are conclusions made by Walker.
An interesting result of the Walker study lies not in the effects of a
monolithic oxidation catalyst versus a pelleted catalyst, but in their
conclusion that closer control of engine out emissions has a more
beneficial effect than increasing oxidation catalyst volume. Therefore,
if techniques were applied to reduce engine-out emission variability,
like using improved fuel metering and air injection systems, then the
emission reduction load on the catalyst can be reduced with subsequent
lowering of precious metal loading or catalyst volume. The conclusion
that large catalyst volumes are inefficient and costly may be in error
as a 10-15% improvement in efficiency is not small. The cost and
efficiency of the utilization of larger catalyst volumes must be compared
to both the incremental degree of emission control required to achieve a
given emission goal, and the cost of alternate solutions to the accomplish-
ment of the emissions goal before such a conclusion can be drawn.
The Walker results should also be interpreted in light of the basic
constraints placed on the program. It is not apparent that retrofitting
GM's pellets with monoliths using the same car with no changes in the
vehicle's emission control system is what would actually be done to
achieve lower emissions.
One of the more important conclusions to be drawn from the Walker results
is that larger catalyst volumes reduce emissions. A bigger monolithic
catalyst is better, in other words. The largest catalyst volume to
engine displacement ratio reported by Walker was 0.21 (96/454), and in
general the curves indicated that even larger catalysts would have had
7-233
-------
even lower emissions. This indicates that higher catalyst volume to
engine displacement values may be needed in the future to achieve low
emission levels, and some manufacturers are examining catalyst volume to
engine displacement ratios closer to 1.0, compared to the 0.21 ratio
examined by Walker.
7-234
-------
7.3. Foreign Manufacturers
7.3.1. Bayerische Motoren Werke (BMW)
7.3.1.1. Systems Under Development
After an absence of a year, BMW submitted a report concerning the
systems they have under development to meet the various proposed exhaust
emission standards. Unfortunately, most of the systems that BMW has
under development were included in a confidential cost section which
precludes discussion of these developments in this report. However, BMW
did mention that they were working on a 3-way catalyst system for levels
of 0.41 HC, 3.4 CO, 1.0 NOx and lower. At levels higher than these, BMW
will continue to update their 1977 systems with the exception of the
320i model vehicles which will use an oxidation catalyst, secondary air
injection and EGR for 1979.
3-Way Catalyst System
BMW briefly discussed their progress in developing a 3-way system for
their vehicles. BMW is optimizing the time delay of the closed loop 3-
way system to improve both HC and CO emissions and driveability. To
date, BMW reported results of 0.255 HC, 4.338 CO and 0.267 NOx with a 20
millisecond (ms) time delay and 0.257 HC, 3.486 CO, and 0.382 NOx with a
10 ms time delay. Additional work is being carried out to optimize
warm-up and driveability. All the previous work was conducted using an
Engelhard TWC-14 catalyst. BMW is also determining 0. sensor location
for optimum sensor life, warm-up, and system control. The BMW 3-way
catalyst system schematic is shown in Figure BMW-1.
The only development emission data BMW supplied for the 3-way catalyst
on the 3 litre-530 model vehicle were average FTP results of 0.6 HC, 5.0
CO, and 0.4 NOx with fuel economies of 14.4 MPG and 22.5 MPG, . BMW
u h
stated more work is necessary on the selection of catalyst volume to
7-235
-------
ENGINEERING EMISSION CONTROL
MIXTURE CONTROL
UNIT
K-JETRONIC FUEL INJECTION
WITH K-PROBE SYSTEM ON
BMW 4-CYL. ENGINE
EM-G 177
Figure BMW-1
-------
lower HC and CO levels. Work is to start in January 1977 to complete
this optimization. BMW did supply data developed on the Japanese 10 and
11 mode test cycles for their 1977 model year vehicles.
7.3.1.2. Systems to be Used at Various Emission Levels
The systems BMW presently offers for model year 1977 and the corres-
ponding emission levels and fuel economies can be found in Table BMW-1.
BMW plans to have the following systems available for 1978 model year
vehicles at emission levels of 1.5 HC, 15.0 CO, and 2.0 NOx.
Family CID Systems Model Sales
120.8 121.3 FI,EGR,TR,AP 320i, iA Cal.
120.9 121.3 FI,EGR,AP 320i, iA 49 states
130.8 182.0 EFI,EGR,TR,AP 530i, iA 50 states
133.8 196.0 EFI.EGR.TR.AP 733i, iA 50 states
633i, iA 50 states
FI = K-Jetronic Fuel Injection
EFI = L-Jetronic fuel injection
A = Automatic Transmission
EGR = Exhaust Gas Recirculation
TR = Thermal Reactor
AP = Air Pump
As previously stated, BMW plans to use a three-way catalyst system for
all vehicles at emission levels lower than 0.41 HC, 3.4 CO, 1.0 NOx.
7.3.1.3. Durability Testing
BMW submitted no durability test data in this year's submission.
7.3.1.4. Progress and Problems
It is difficult to assess the extent of BMW's progress towards meeting
emission levels lower than 0.9 HC, 9 CO, 2.0 NOx due to the paucity of
data presented by BMW. Apparently BMW has not decided on the required
volume for their 3-way catalyst system nor the precise control approach
for their feedback control system.
7-237
-------
Table BMW-1
BMW 1977 Model Year Durability and Data Vehicle Results
VIN
661
BMW 120.8,
320i
683
BMW 120.9
3201
017
£ BMW 130.8
» 5301 H
5 400 001
5 400 001
5 460 001
5 470 002
5 420 004
4 375 045
System CID
AIR,FI,TR,EGR 121.3
2750 IW
AIR,FI,EGR 121.3
2750 IW
AIR,FI,TR,EGR 182.0
. 3000 IW
AIR,EGR,FI,TR 121.3
M4, Low Alt.
AIR,EGR,FI,TR 121.3
M4, Hi Alt.
AIR.EGR.FI.TR 121.3
A, Low Alt.
AIR.EGR.FI 121.3
A, Low Alt'.
AIR.EGR.FI 121.3
M4, Low Alt.
AIR,EGR,FI,TR / 182.0
0
Miles (10 )
5
50
Range
5
50
Range
5
50
Range
4
4
4
4
4
4
FTP
HC
0.35
0.36
0.25-.37
1.46
0.97
0.90-1.46
0.43
0.27
0.27-.71
0.18
0.35
0.32
1.00
1.13
0.20
Results (gm/mi)
CO
6.6
5.9
5.3-8.0
11.1
8.5
8.2-13.7
12.5
8.1
6.7-13.7
6.3
8.5
8.5
8.5
8.6
4.7
NOx
1.39
1.42
1.13-1.42
1.91
1.57
1.57-1.91
1.80
1.60
1.27-1.84
1.02
0.80
1.09
1.31
1.49
1.06
Fuel Economy
MPG MPG,
u h
18.6
18.6
17.2-19.5
18.9
18.7
17.8-19.5
13.5
14.6
12.5-14.6
19.6 25.0
18.0 27.3
19.7 25.0
18.7 24.8
20.2 . 29.5
13.1 18.1
A, Low Alt.
-------
Table BMW-1 (con't)
~J
NJ
VIN
5 Oil 506
4 375 046
4 375 046
5 031 418
System
AIR.EGR.FI.TR
M4, Low Alt.
AIR,EGR,FI,TR
M4, Low Alt.
AIR,EGR,FI,TR
M4, Hi Alt.
AIR.EGR.FI.TR
A, Low Alt.
CID
182.0
182.0
182.0
182.0
Miles (10 )
4
FTP Results (gin/mi)
HC CO NOx
0.36
0.30
7.2
8.7
0.50 14.2
0.42 14.8
1.04
1.62
1.48
1.38
MPG
Fuel Economy
MPG,
13.5
14.5
14.4
14.5
20.1
27.6
21.9
20.3
-------
Evidently BMW will need to conduct accelerated testing to meet emission
levels at or near statutory levels in the near term. Reduction of HC
and CO emissions from the BMW 3-way system will apparently have to be
their prime concern. Since they supplied no details on 3-way catalyst
system selection and optimization programs, it remains unclear how BMW
plans to obtain low emissions and good fuel economy in the future.
7-240
-------
7.3.2. British Leyland (BL)
7.3.2.1. Systems Under Development
BL cites the uncertainty of the 1978 emission standards as a difficulty
in concentrating on one particular emission control system. For 1978,
BL intends that one of two courses of action will be taken; either to
use carryover of existing 1977 systems, or for certain vehicle models to
use a 3-way catalyst with a feedback fuel injection system. BL indicates
that beyond 1978 all their divisions exporting to the U. S. are working
on 3-way catalysts with feedback fuel injection since at the present
this system appears to be the most technically desirable solution from
BL's viewpoint. BL is actively developing feedback carburetion to
offset the cost of fuel injection which BL indicates is too high (approxi-
mately $260, according to BL).
Oxidation Catalysts
During the past year BL has investigated newer oxidation catalyst substrates
and thermal insulation in hopes of improving catalyst warm-up, efficiency,
and durability. They have been successful with durability and efficiency,
but still have difficulties with their large vehicle's warm-up charac-
teristics. BL's work with metallic substrates has produced one substrate
with a satisfactory material but an insufficiently active and durable
catalyst, while the second substrate has a poor material but a satisfactory
catalyst. BL plans to incorporate the beneficial characteristics of
both of these catalysts into their 3-way catalyst work.
BL continues to experiment with thermal insulation between the catalyst
substrate and the catalyst container. Work continues to optimize and
select an insulation material suitable for production.
7-241
-------
BL indicates that oxidation catalysts have no future below 1.5 gin/mi NOx
levels either by themselves or in combination with reduction catalysts.
Fuel economy problems with dual catalyst systems were given as part of
the reason.
BL will be testing the effects of MMT on their oxidation catalysts.
No further work is being carried out with manifold catalysts.
3-Way Catalysts
Three-way catalyst systems are under active development for all British
Leyland models planned to be marketed in the U. S. after 1978. BL anti-
cipates that at least one model (unspecified) will be equipped with a 3-
way catalyst for the 1978 model year and probably others for the 1979
model year. The 3-way catalysts tested have a Pt/Rh ratio range from
about 3/1 to 12/1.
BL reports that some vehicles will be fitted with fuel injection for
reasons of fuel economy and performance, and that on these vehicles the
extra cost of the feedback system required is not excessive. In the
case of smaller, cheaper vehicles currently fitted with carburetors, the
additional cost of feedback fuel injection is considerable. For this
reason two other types of system are being investigated in addition to
conventional fuel injection and feedback fuel injection.
The first alternative is feedback control of carburetors. This program
is being pursued in two areas: firstly, in co-operation with the current
outside supplier of carburetors and secondly, as an internal program
with a BL carburetor division and an outside electrical supplier. The
fuel injection required for the main program of 3-way catalyst work is
being actively pursued in conjunction with several European and British
manufacturers.
7-242
-------
A research program is examining a third alternative, i.e., normal
carburetion plus a 3-way catalyst followed by an oxidation catalyst fed
with air by an air pump. BL reported no test results or durability data
for a 3-way plus oxidation catalyst system.
BL revealed that they have an extensive 3-way catalyst screening process
underway with several catalyst manufacturers, and a 3-way catalyst
development program with one catalyst manufacturer. BL is impressed
with the oxygen storage components of some of the catalysts. BL also
noted that catalyst warm-up was still a problem and this produced cold
start driveability problems.
Testing to date has concentrated on determining the effect of metal
loading, rhodium content, oxygen storage capacity, etc. with a vehicle
equipped with a 2 litre engine for emission testing and on 4.2 litre
engine for durability testing. More promising catalyst candidates are
scheduled for further work.
Typical 4,000 mile results for a 250 CID six cylinder engine with a
current best 3-way catalyst are 0.3 - 0.6 HC, 4.5 - 7.0 CO, and 0.6 -
1.0 NOx. Poor warm-up characteristics with this catalyst have been a
problem. Further optimization of the catalyst sensor location is
underway on this catalyst system.
BL notes that there is a significant improvement in fuel economy by
using a 3-way catalyst system. They report urban fuel economy of 14.3
MPG compared with '77 Federal levels of 12.9 and '77 California levels
of 12.1 MPG . Current European specification vehicles give 14.4 MPG
but have a slightly higher compression ratio than U. S. versions.
A durability test of 20,000 miles has shown BL that 3-way catalysts have
little emission deterioration although the emission levels were reported
7-243
-------
at 0.57 HC, 7.30 CO, and 1.3 NOx. Armed with this knowledge and a zero
mile test on a 120 CID four cylinder engine of 0.10 - 0.20 HC, 1.5 - 3.0
CO, and 0.1 - 0.4 NOx, BL indicates that further intensified work is
necessary with this concept.
Dual Catalysts
Only one dual catalyst durability test was conducted by BL last year.
According to BL, efforts toward developing this concept have diminished
for two reasons: firstly, a reduced interest on the part of catalyst
suppliers, and secondly, the increased effort being put into 3-way
catalysts and the associated feedback fuel injection systems.
The results of the dual catalyst durability test are shown in Table BL-
1; but it should be stressed that this test run involved more than the
permitted amount of maintenance for certification testing., The NOx
result was 0.35 gm/mi which is too near the 0.4 NOx standard to be
considered acceptable to BL, particularly in view of the additional
maintenance involved. The HC and CO results were much less impressive,
particularly for CO. Even taking only the results for the second oxidation
catalyst (after a change at 18,600 miles) the CO level was 13.4 gm/mi.
The fuel economy on the urban cycle was 15-16 MPG for a 2,500 Ib. IW
Marina. A total catalyst volume four times that of the current oxidation
volume typical for that engine family was used.
A second series of tests at zero miles was carried out on a vehicle with
a V12 engine. The best results were 0.73 HC, 4.78 CO, and 0.53 NOx. This
vehicle used a total catalyst volume twice that of the "oxidation only"
system, whereas the Marina used a factor of four times the volume. The
fuel consumption of this system was 8.6 MPG for the urban driving cycle
compared with 10 MPG for the current oxidation only system and a
similar figure for a prototype 3-way catalyst system. All systems used
fuel injection, the last system incorporating feedback control.
7-244
-------
Table BL-1
Dual Catalyst Durability Results
Vehicle: 1.8 litre Marina, EGR, 1976 California specifications
Oxidation catalysts: 2 Johnson-Matthey 206 catalysts, 4" diameter x
4 1/2" long
Reduction catalyst: NM 201 I.C.I
Copper-Nickel-Platinum catalyst, Corning 300
cell substrate, 4" diameter x 4 1/2" long
_ FTP Results (gm/mi)
Miles (10 ) HC CO NOx MPG Remarks
____—.___——_ .— — —L -•- • U "
0 0.16 3.2 0.15 16.5
7 0.38 4.8 0.32 15.4
18 0.88 12.4 0.31 14.8 Before Cat. change
19 0.10 3.6 0.35 14.2 After Cat. change
27 0.36 7.5 0.32 14.2 Before Maintenance
27 0.32 4.5 0.43 14.1 After Maintenance
32 0.31 12.4 0.30 15.1 Before Maintenance
32 0.43 6.5 0.35 15.4 After Maintenance
41 0.48 6.6 0.35 16.0 Before Maintenance
41 0.25 3.1 0.34 15.7 After Maintenance
51 0.45 4.0 0.28 15.9
7-245
-------
BL considers the dual catalyst system as a backup to the 3-way system,
the only advantage being initial cost on vehicles which have carburetion
rather than fuel injection, according to BL.
Other Systems
British Leyland has stopped work on rich thermal reactor systems because
of poor fuel economy. They have reduced their efforts with lean thermal
reactor systems, and only consider this system for use with their European
and stratified charge engines.
Work on the Shell Vapipe has been stopped. A concept which is similar
to the Vapipe is being considered.
BL is improving their analytical capabilities to measure non-regulated
pollutants.
A sulfate trap consisting of calcium carbonate pellets was tested for
17,000 miles on a 110 CID engine. There was no loss of the absorbent
after the accumulated mileage. Further tests are in progress.
BL is working on a transonic carburetor, a sonic idling carburetor, as
well as a feedback carburetor. No emissions or fuel economy data were
presented for these concepts.
Other Development Concepts
Research work has continued on the three-valve stratified charge engine
which was previously reported. BL noted that the three valve engine has
higher HC emission than practical for reduction by use of thermal reactors.
BL reported that hot engine driveability is good, but cold start and
warm-up conditions need refinement.
7-246
-------
Typical emissions from this engine are 8.0 HC, 9.0 CO, and 0.50 NOx.
These HC results are an order of magnitude higher than those reported by
other manufacturers examining the three-valve stratified charge engine.
However, must other manufacturers have used some form of aftertreatment
such as thermal reactors or catalysts. The fuel economy was 23 MPG .
By comparison, a similar size and weight vehicle gave approximately 16
MPG with dual catalysts and up to 23 MPG in the 3-way catalyst con-
figuration.
Further work continues with the three-valve stratified charge concept on
another engine type, but unfortunately the HC emissions were also high
on this engine. Basic research on this concept continues.
BL has done work with a high compression ratio engine (12:1), but has
reported high HC emissions. BL does not plan to introduce this concept
in the U. S. unless they can achieve statutory NOx levels with the use
of a lean mixture only.
Little work has been reported on Diesel engines by BL. A research
program is aimed at achieving NOx levels below 1.0 gm/mi without increased
smoke or HC levels. This work investigates injection timing, EGR, and
high fuel injection rates.
BL provided no cost or lead time information.
7.3.2.2. Systems to be Used at Various Emission Levels
While not entirely clear from the BL submission, BL apparently intends
to use their 1977 emission control system of EGR, oxidation catalysts,
air injection, and fuel injection on specific models. For future emission
levels, BL apparently will introduce a 3-way catalyst system with fuel
injection as a first choice and feedback carburetion as a second choice.
7-247;
-------
Attached to BL's submission was their response to NHTSA's request for a
fuel economy position. Table BL-2 indicates the fuel economy penalties/
improvements BL associated with various proposed emission levels.
7.3.2.3. Durability Testing
BL provided the durability data listed in Tables BL-3 and BL-4.
7.3.2.4. Progress and Problems
BL has made progress since last year with their 3-way catalyst system,
adoption of fuel injection for some vehicle models, and refinement of
their oxidation catalyst. While these efforts are encouraging, the data
presented by BL also indicate that further efforts are necessary to
achieve statutory emission levels. Data from the 3-way catalyst testing
indicate that on their larger displacement engines work must be conducted
to bring NOx levels closer to the required levels. HC and CO levels on
the smaller displacement engine remains higher, thereby reducing confidence
in achieving the required control during the entire durability test.
Fuel economy improvements are encouraging.
Whether BL will be able to meet statutory emission levels in the near
future is impossible to determine with the information that was supplied.
To date, it appears that the early 1980s is the most optimistic date of
that occurrence.
7-248
-------
Table BL-2
Fuel Economy Effects at Various Emission Levels*
VO
MODEL YEAR 1976
Emission Targets
Less than 4 Seats Models: MG Midget, Tr Spitfire
MGB, TR6 and TR7 2V
MG Midget - higher compression
TR Spitfire - higher compression
4 Seats
5 Seats
MODEL YEAR 1977
Models: Jaguar XJS
Models: Jaguar XJ6 and XJ12
XJ6 (small engine changes)
MPG Improvement over Previous Model Year
1.5 HC, 15 CO. 3.1 NOx 1.5 HC. 15 CO. 3.1 NOx
+3 MPG
+3 MPG
+1 MPG
1.5 HC. 15 CO, 2.0 NOx
1.5 HC. 15 CO. 2.0 NOx
Less than 4 Seats Models: MG Midget, Tr Spitfire,
MGB, TR7 2V and TR7 V8 (Production
ends on TR6)
MG Midget ) Lower compression &
Tr Spitfire) Catalysts fitted for emissions
TR7 2V) Engine tune changed and
MGB ) Catalysts fitted for TR7 V8 (new model)
special version of TR7 with 3.5 litre V8 engine
fitted in place of 2 litre 4 cyl. fuel consumption
difference 5 MPG less for V8.
-2 MPG
-2 MPG
+1 MPG
-3 MPG
4 Seats
5 Seats
Model: Jaguar XJS (no change)
Models: Jaguar X16 and LJ12 (no change)
-------
Table BL-2 (con't)
MODEL YEAR 1978
Less than 4 Seats
1.5 HC, 15 CO, 2.0 NOx
0.41 HC, 3.4 CO, 0.4 NOx
Models: MG Midget, TR Spitfire,
MGB, TR7 2V, TR7 V8 (no change)
MG Midget)
Tr Spitfire) Large change in
MGB) severe emission
TR7 2V) standards hence
TR7 V8) MPG changes
Models: Jaguar XJS (no change)
XJS
Models: Jaguar XJ6 and XJ12 and
Rover 3500 (SD1) (new model)
XJ6 (now on PI)
XJ12
Rover 3500 (SD1) Compare with XJ6 (note not in competition)
Inertia Weight Rover 3500 Ibs Jaguar 4500 Ibs
Engine Size Rover 3.5 litre V8 Jaguar 4.2 litre 6 cyl
Fuel consumption Rover 19 MPG Jaguar 16 MPG
4 Seats
ts> 5 Seats
o
+2 MPG
-2 MPG
-4 MPG
+1 MPG
-1 MPG
-2.5 MPG
-0.3 MPG
+2 MPG
-0.3 MPG
-------
Table BL-2 (con1t)
MODEL YEAR 1979
Less than 4 Seats Models: MG Midget, Tr Spitfire,
TR7 2V, TR7 V8 (Production ends MGB)
TR7 2V) Both change to
TR7 V8) Petrol injection
4 Seats Models: Jaguar XJS and Lynx (new model)
LYNX compare XJS (note not in competition)
Inertia Weight LYNX 3000 Ibs Jaguar 4500 Ibs
Engine Size LYNX 3.5 litre V8 Jaguar 5.3 liter V12
Fuel Consumption LYNX 19 MPG Jaguar 11 MPG
5 Seats Models: Jaguar XJ6 and XJ12
Rover 3500 (SD1) (no change)
1.5 HC, 15 CO, 2.0 NOx
+3 MPG
+3 MPG
0.41 HC. 3.4 CO, 0.4 NOx
+4 mpg
+5.5 MPG
MODEL YEAR 1980
Less than 4 Seats Models: Tr Spitfire, TR7 2V,
TR7 V8 (Production ends MG Midget)
0.9 HC. 4.0 CO. 2.0 NOx
0.41 HC. 3.4 CO. 0.4 NOx
4 Seats
5 Seats
TR Spitfire (more severe lenient emissions)
Models: Jaguar XJS and LYNX (no change)
Models: Jaguar SJ6 and XJ12 and
Rover 3500 (SDl) (no change)
-1 MPG
* BL's Submission to NHTSA Request for Fuel Economy Effects at Various Emission Levels.
-------
NJ
Ul
Table BL-3
BL 3-Way Catalyst Selection Emission and Fuel Economy
Durability Data
TR 7 Vehicle with Fuel Injection, 0- Sensor, 3-Way Catalyst
Approximately 2500 miles
VIN
ACL 2
ACL 2
ACL 2
ACL 693
Catalyst
"A"
"X"
"X"
"X"
HC
0.155
0.12
0.115
0.11
CO
2.85
2.85
2.45
3.30
NOx
0.29
0.40
0.27
0.43
MPG
u
20.0
20.7
20.9
20.8
1978 Federal and California XJ6 (Jaguar) Vehicles at 4000 Miles
XJ31-22 "A" 0.55 7.93 1.21 13.2
13.4
14.4
14.5
13.7
1979 XJ12 (Jaguar) Vehicles at 4000 Miles
XJ32-7 "A" 0.61 7.7 1.35 9.3
"A." 0.49 5.4 . 0.85 10.2
"XZ" 0.49 4.4 1.1 9.8
"A"
"A^1
"A,"
"A^"
"X
0.55
0.37
0.32
0.35
0.34
7.93
5.63
3.69
3.87
3.80
1.21
1.15
0.61
0.66
0.43
-------
Table BL-4
BL 1977 Model Year Durability Vehicle Emissions and Fuel Economy
VIN/CID Trans.
TR7* M4
MRW 277P
(122 cu in.)
TR7* M4
MRW 278P
(91 cu in.)
i
K TR7-V8* M5
w MRW 273P
(215 cu in.)
TR7** M4
DU 576P
(122 cu in.)
TR7-V8** M5
DU 577P
(215 cu in.)
Spitefire** M4
MRW 274P
(91 cu in.)
Spitefire** M4
MDV 533P
(91 cu in.)
System
OC/EGR/AI
EW2/20G
OC/EGR/AI
EW2/20G
OC/EGR/AI
EW23/20G
OC/EGR/AI
EW2/20G
OC/EGR/AI
EW2/20G
OC/EGR/AI
EW2/20G
OC/EGR/AI
EW2/3C/4
•3
Mileage (10 )
0
50
50***
0
50
0
50
0
50
0
50
0
50
0
50
FTP Results (gm/mi) Fuel Economy
HC
0.38
0.85
0.70
0.34
0.73
0.37
0.51
0.23
0.35
0.14
0.32
0.34
0.40
0.26
0.67
CO
3.41
5.75
4.40
3.59
3.55
1.50
3.45
4.21
6.11
4.55
6.91
1.45
4.12
2.82
5.96
NOx
1.64
1.54
1.31
1.79
1.55
1.55
1.13
1.10
1.28
0.64
0.56
1.24
0.96
1.63
1.36
MPG
u
19.5
19.3
22.4
21.3
22.8
13.3
14.3
18.3
20.0
11.7
14.9
18.7
21.6
17.4
20.0
-------
Ta,ble BL-4 (cont)
FTP Results (gm/mi)
Fuel Economy
I
K>
VIN/CID
TR7**
MDV 532P
(122 cu in.)
XJ6 Fed.
XJ33-11
(258 cu in.)
XJ12 Fed.
XJ 32-31
(236 cu in.)
Rover
3500 S
TR7-V8
ACL 391
Rover V8
ACL 444
Trans. System Mileage (10 ]
M4 OC/EGR/AI
EW2/3C/4
A AI/OC/EGR
A FI/AI/EGR/OC
EW 20/2G
EW 23/20/4
EW 23/20G/4
0
50
5
50
5
5
25
15
50
1 HC
0.44
0.81
0.46
0.40
0.71
0.65
0.60
0.70
0.91
CO
4.52
6.88
3.43
3.88
5.56
6.38
1.18
0.79
2.73
NOx
1.67
1.35
2.60
2.01
1.74
1.71
0.36
1.92
1.96
MPG
u
21.1
20.3
15.8
13.5
9.4
10.0
—
-
-
* 1977 Federal Specifications 1.5 HC, 15 CO, 2.0 NOx
** 1977 California Specifications 0.41 HC, 9 CO, 1.5 NOx
*** EPA Test
-------
7.3.3. CitroSn
7.3.3.1. Systems Under Development
3-Way Catalysts
Citroen*s current efforts utilizing 3-way catalyst systems include fuel
injection with feedback control by an oxygen sensor. No data were
presented because it is claimed these efforts are not at a stage where
results are meaningful.
Other Systems
Citroen has a Diesel engine option for one of its currently manufactured
European vehicles. Table Citroen-1 includes emission and fuel economy
results from such a vehicle. The 3500 IW vehicle is equipped with a 4
cylinder, 2.5 litre engine and a manual transmission. No information
about the emission control system, if any, on the vehicle was reported.
This vehicle was involved in a correlation program with EPA.
Table Citroen-1
Citrogn Diesel Results
Exhaust Emissions (gin/mi)
Lab HC CO NOx
Citroen
Citroen
EPA
EPA
Lab
EPA
EPA
0.37
0.37
0.46
0.39
MPG
25.5
24.2
1.66
1.51
1.72
1.75
Fuel Economy
— h
32.2
31.9
1.59
1.61
1.46
1.61
MPG
28.1
27.2
7-255
-------
7.3.3.2. Systems to be Used at Various Emission Levels
0.41 HC, 3.A CO, 0.4 NOx
A 3-way catalyst system is under development to meet these emission
levels. No data were presented. The Diesel engine described above is
another candidate to meet these levels but substantially better NOx
control will be required.
7.3.3.3. Durability Testing
No durability testing was reported.
7.3.3.4. Problems and Progress
Citroen does not now market vehicles in the U.S. and does not intend to
do so in the immediate future. All of Citroen's efforts are concentrated
on meeting statutory standards. Since no data were presented for their
candidate 3-way catalyst system, no progress can be reported.
For their Diesel engine, Citroe'n feels that a NOx standard below 1.5
gin/mi could not be met in the immediate future on production vehicles,
that a 1.0 gm/mi NOx standard would require extensive research with
unpredictable results, and a 0.4 gm/mi requirement can simply not be
achieved. They have imposed a temporary moratorium on Diesel emissions
research until promulgation of definite, stabilized standards at which
time they will reevaluate their Diesel program. Without detailed
information concerning the type of the emission controls used with the
Diesel, little can be stated as to the nature of problems confronting
Citroen.
7-256
-------
7.3.4. Daimler-Benz
7.3.4.1. Systems Under Development
The Daimler-Benz (DB) status report submission indicated that DB an-
ticipated that the 1977 emission standards would be applicable in 1978.
Consequently, DB will be ultilizing many of the systems found on their
1977 model year vehicles. A review of these systems will be detailed
under the section on various systems to be used at various emission
levels. DB reported development progress on some specific systems,
namely the 3-way catalyst system, while providing only scant details on
other systems.
Oxidation Catalysts
DB plans to use their present oxidation catalyst through levels of 0.41
HC, 3.4 CO, 2.0 NOx. DB reported no new programs to improve their
oxidation catalysts. The results of DB's efforts using oxidation
catalyst technology can be found in Table DB-1. With the exception of
the M115, MHO California, and Diesel engine families, the remaining
vehicles utilize only oxidation catalysts. DB will have no difficulty
achieving emission levels down to 0.9 HC, 9 CO, 2.0 NOx with this
technology on most of their low altitude vehicles.
3-Way Catalysts
DB provided data outlining their selection process for determining a
production-feasible 3-way catalyst for model year 1979 vehicles. They
did state, however, that the selection was not finalized nor had the
questions concerning 0- sensor durability needed for closed loop 3-way
operation been resolved. DB stated that further work was necessary for
system optimization. Research vehicle low mileage test results can be
found in Table DB-2 while the 3-way durability results can be found in
7-257
-------
Table DB-1
Certification Durability and Data Vehicle Emission and Fuel Economy Results
Engine Family
Ml 15, Carb.
DBC,AI,EGR
(141 CID)
Low Alt.
High Alt.
MHO, FI
OC,AIR,EGR
(168 CID)
49-state
Low Alt.
Low Alt.
High Alt.
MHO, FI
DBC,AIR,EGR
(168 CID)
Calf.
Low Alt.
Low Alt.
High Alt.
Mileage (103)
5
50
Range
4
4
5
50
Range
4
4
4
5
50
Range
4
4
4
HC
0.30
0.34
0.25-.37
0.23
0.48
0.62
0.85
0.62-.90
0.59
0.57
0.99
0.30
0.34
0.29-.40
0.37
0.18
0.69
FTP Results
CO
4.4
5.0
4.2-5.8
4.8
12.2
5.9
9.5
5.9-10.0
4.7
4.2
5.2
3.1
4.6
3.0-5.6
1.6
1.1
11.9
NOx
1.29
1.48
1.29-1.48
0.96
0.99
1.80
1.74
1.51-1.97
1.54
1.71
1.77
1.14
1.34
1.12-1.48
1.20
1.08
1.02
Fuel
MPG
u
17.67
18.41
17.38-18.49
17.2
15.8
14.75
15.38
14.61-15.45
14.3
14.4
13.2
14.54
15.50
14.38-15.98
14.5
14.7
13.3
Economy
MPG,
h
-
20.6
-
19.0
18.5
18.2
-
18.1
18.8
-------
Engine Family
M117, FI
AIR.OC.EGR
(276 CID)
49-state,
Hi Alt. Calf.
Mileage (10 )
5
50
Range
Table DB-1 (con't)
FTP Results
HC
0.56
0.77
0.49-.77
CO
4.2
7.0
4.2-7.1
NOx
1.82
1.76
1.60-1.93
Fuel Economy
MPG
u
11.22
12.17
10.96-12.17
MPG,
t_n
vo
Low Alt.
High Alt.
M117, FI
AIR.OC.EGR
(-276 CID)
49-state
Range
4
4
5
50
0.38
0.39
0.52
0.70
0.51-.75
5.2
3.6
5.5
7.3
5.4-7.7
1.72
1.75
1.72
1.71
1.45-1.91
12.8
12.5
11.70
12.84
11.52-12.84
18.3
18.0
-
Low Alt.
0.87
5.2
1.69
13.2
18.5
M117, FI.AIR
OC,EGR
(276 CID)
Calf.
Low Alt.
High Alt.
M117, FI.AIR
OC.EGR
(276 CID)
Range
Range
5
50
i
4
4
5
50
0.27
0.36
0.27-.40
0.24
0.34
0.27
0.35
0.22-.40
3.6
5.0
3.6-5.4
1.7
5.1
4.1
5.1
3.8-5.6
1.47
1.42
1.34-1.50
1.28
1.25
1.39
1.31
1.28-1.50
11.26
12.46
11.15-12.46
12.0
12.3
11.35
12.65
11.35-13.25
—
-
™
17.3
18.2
.
-
-
-------
Table DB-1 (con't)
FTP Results
i
ro
Engine Family
Low Alt.
High Alt.
M100, FI
AIR,OC,EGR
(417 CID)
Low Alt.
High Alt.
OM616
Diesel (240D)
50-state
(147 CID)
Low Alt.
High Alt.
Low Alt.
OM617
Diesel (300D)
50-state
Low Alt.
High Alt.
Mileage (1QJ)
4
4
Range
Range
Range
5
50
4
4
5
50
4
4
4
5
50
4
4
HC
0.25
0.39
0.27
0.36
0.27-.38
0.25
0.23
0.30
0.34
0.27-.34
0.36
0.15
0.37
0.25
0.20
0.19-.25
0.29
0.48
CO
2.7
7.4
3.4
6.1
3.4-6.1
3.8
2.1
1.7
1.6
1.5-2.1
0.9
1.5
1.2
1.3
1.1
1.1-1.3
1.0
1.4
NOx
1.28
1.04
1.43
1.41
1.31-1.47
1.25
1.59
1.40
1.27
1.27-1.51
1.65
1.62
1.43
1.85
1.70
1.67-1.85
1.70
1.81
Fuel Economy
MPG
U
12.8
11.8
10.36
10.56
9.6-11.47
10.5
10.1
23.75
20.05
20.05-26.83
25.9
25.3
24.8
24.30
22.75
21.82-24.32
22.2
22.9
MPG,
17.6
14.3
14.5
30.2
33.5
-------
Table DB-2
DB 3-Way Catalyst plus 0~ Sensor Research-Vehicles Emission and Fuel Economy Data
Average FTP Results
i
ts>
o\
VIN
R107-E45-66
ii
W116-E69-139
11
W116-E69-55
W116-E45-113
R129-E45-51
W116-E28-97
CID
276
417
417
276
276
168
Emission
Target
2
2
2
2
3
3
4
4
No. of
Tests
4
7
2
7
1
15
1
2
HC
1.124
0.410
0.814
0.399
0.381
0.304
0 . 186
0.337
CO
17.689
3.73
16.05
4.32
3.336
2.956
3.173
2.987
NOx
1.242
0.310
0.802
0.348
0.967
0.580
0.338
0.243
Fuel Economy
MPG
u
11.61
12.47
10.23
10.78
10.67
12.35
11.93
15.83
MPG,
n
18.42
_
-
15.12
-
19.01
20.58
Targets
1 = 1.5 HC, 15 CO, 2.0 NOx
2 = 0.41 HC, 9 CO, 1.5 NOx
3 = 0.41 HC, 3.4 CO, 1.0 NOx
4 = 0.41 HC, 3.4 CO, 0.4 NOx
-------
Table DB-10 in the system durability section. No mileage is specified
for the durability test results, nor were there any durability vehicles
targeted for emission levels lower than 0.41 HC, 9 CO, 1.5 NOx.
3-Way Plus Oxidation Catalyst
DB provided no discussion of their efforts with a 3-way catalyst plus
oxidation catalyst system. However in their data submission the follow-
ing data from a research vehicle was noted.
Table DB-3
Data from Research Vehicle R107-E45-51 (450SL,276CID)
Equipped with a EFI/O-S/TWC/AI/OC System
Targeted at 0.41 HC. 3.4 CO, 1.0 NOx
FTP Results (gm/mi) Fuel Economy
Date HC CO NOx MPG MPG,
u n
13.54* 17.80**
13.92
13.78
13.75
14.15
14.05
13.89
* Fuel economy improvement over current engine families.
** Average two tests.
It is evident that further work is necessary to reduce the NOx levels
from this system if 0.4 NOx is to be achieved with this approach. DB
reported test data from one vehicle (W114 V28-156) which incorporated
EGR and air injection with a 3-way catalyst. NOx levels remained high
(3 gm/mi) while there was a fuel economy improvement of 3 MPG for this
vehicle. Work was stopped on this concept in April 1976. No reason was
given.
7-262
3-26-76
4-6-76
4-8-76
4-12-76
4-21-76
4-22-76
4-23-76
0.105
0.289
0.324
0.316
0.290
0.299
0.308
2.532
2.533
2.806
2.955
2.312
2.746
2.965
0.606
0.505
0.585
0.519
0.814
0.592
0.517
-------
Dual Catalysts
DB uses a system containing a reduction catalyst on some 1977 model year
vehicles and plans to continue this practice into 1978. A description
of their production dual catalysts can be found in the footnotes to
Table DB-9. A review of DB's flow curves in their Part I submitted to
the Certification Division apparently indicates that those engine
families which use the dual catalyst system are calibrated lean. These
flow curves were for part load operation and indicated production tolerance
A/F ratios between 15.2 to 17.0. If the flow curves are correct, it is
difficult to determine how DB expects to maintain a reducing atmosphere
thereby enabling the reducing catalyst to function properly. The reduc-
ing portion of the dual catalyst may be used during those portions of
vehicle operation on the FTP when the air-fueled ratio has an excursion
to the rich side of stoichiometric, thereby creating a reducing atmosphere.
DB did not provide enough discussion to ascertain the reason for the
expected results or technical discussion on the selected catalysts to
make a judgement on the benefit of the system. A review of the certification
data in Table DB-1 apparently indicates that the MHO family with the
dual bed catalyst has lower NOx emission levels than the same family
with an oxidation catalyst. It is difficult to determine if this system
has potential below 1.0 gin/mi NOx, however.
Dual Bed catalyst research vehicle data can be found on Table DB-4 and
the durability results in Table DB-11. There were no durability mileages
given.
7-263
-------
Table DB-4
DB Dual Bed Catalyst Research Vehicle Emission and
VIN
CID
130 141
62 276
Fuel
Emission
Target
2
4
Economy
No of
Tests
41
4
Data
Avg.
HC
0.248
0.200
FTP Results
CO
3.64
1.564
NOx
1.093
0.274
Fuel Economy
MPG
u
15.29
11.05
MPG,
Targets
1 = 1.5 HC, 15 CO, 2.0 NOx
2 = 0.41 HC, 9 CO, 1.5 NOx
3 = 0.41 HC, 3.4 CO, 1.0 NOx
4 = 0.41 HC, 3.4 CO, 0.4 NOx
Other System Developments
Stratified Charge Engine
DB did not discuss their work on this engine concept in their submission.
They did present data on this engine are is detailed in the following
table.
7-264
-------
Table DB-5
DB Stratified Charge Engine Tests
Average FTP Results
VIN
W115 V24-132
MB240
L W115 V24-248
Ul
No.
EC Target of
CID System Stds . Tests
L-4/147 CIS/02S/TWC 0.41 HC, 3.4 CO, 1.0 NOx 10*
L-4/147 Pt/Rh Cat. 0.41 HC, 3.4 CO, 1.0 NOx 101+
HC CO
0.157 4.63
0.576 0.988
NOx
0.974
1.69
Fuel Economy
MPG MPG.
19.82 22.10**
20.25 21.57**
* Hot Start Tests
** 10 tests
*** 9 tests
+ None of the tests achieved target emission levels
-------
The tests of Table DB-5 were conducted over the period of one year and
reveal a potential for low HC and CO control with an approximately 18%
urban cycle fuel economy gain over the present engine in the MB 240
model vehicle. DB did not provide sufficient details to properly
evaluate this concept.
Diesel Engines
Daimler-Benz has been one of the leaders in the production of Diesel
engine powered automobiles since the 1930s. Their 240D and 300D series
vehicles along with the Peugeot vehicles have been the only Diesel
powered vehicles available in the U.S. However, the introduction of
Diesel powered vehicles by GM and Volkswagen may increase the competition
in this area.
Up to now, DB has steadfastly insisted that the NOx barrier of 1.5 gm/mi
would preclude the mass introduction of Diesel vehicles in inertia
weight classes above 3500 pounds IW. The development work necessary to
lower NOx emission below 1.5 NOx necessitates use of other concepts
besides the simple reverse flow damping valve currently used in the DB
injection system. DB did provide information on both the use of EGR and
turbocharging of their Diesel engines.
Diesel EGR Concepts
DB reported on two modulated EGR concepts for their Diesel engines
targeted at achieving 1.0 gm/mi NOx. These concepts are the differ-
ential pressure control system and the air fuel ratio control system.
1) Differential Pressure Control System
The exhaust manifold and intake manifold are connected by an EGR pipe
which can be closed by an EGR valve mounted at the exhaust manifold.
The EGR valve is operated by a vacuum motor. The recirculation rate is
7-266
-------
determined by the pipe diameter and the valve lift, depending on the
differential pressure of the intake manifold and the exhaust manifold.
The vacuum motor is loaded by a pneumatic pilot valve which in turn is
governed by a lever. At a lever position corresponding to 4/5 load, the
pressure on the valve is released and vacuum valve is closed by a spring.
At cold start there is no EGR. Results to date range from 0.5 to 0.7
NOx on a laboratory basis. DB reports a corresponding HC rise and
significant CO and smoke increase with this system. Fouling of the
intake manifold and lubrication oil was also reported. There has been
no durability testing of this system.
2) Air Fuel Ratio Control System
DB is working in cooperation with Bosch to develop an EGR system which
operates in principle as an air fuel ratio (Lambda) control. DB describes
the system thusly:
"This EGR system consists of fuel and air metering devices which are
actuated by a servo assisted throttle valve. A modified fuel pump
produces the servo pressure which is needed to actuate the throttle
valve.
Thus, in dependence of the fuel flow of the injection pump, a coordina-
tion between injected fuel amount and aspirated air volume can be
realized, and for the smallest lambda which is possible, the reduced air
volume can be substituted by exhaust gas. At full load, there is no
EGR.
The adjustment of the air volume meter at idle speed will be done in
dependence of the CO- volume of the exhaust gas.
At testing of such a pilot system, analogous experiences as described in
the EGR system before, were noted. Under actual driving conditions, and
special consideration of good engine starting, smoke emission and diesel
7-267
-------
knocking, NOx emission values from 0,7 .... 0,8 gm/mi can be reached as
an optimum.
Durability results from this system are not available, since this
prototype had many corrections, and maintenance jobs required."*
Tests results of EGR equipped Diesel engine powered research vehicles
can be found in Table DB-6 and the durability vehicle results can be
found in Table DB-12 in the durability section.
Turbocharged Diesel Engine
DB has been working on a turbocharged Diesel engine in the recent past.
One concept, the Comprex supercharger, has received interest by both DB
and EPA. EPA has tested this vehicle and reported the results in an EPA
report.** DB is losing interest in this concept and is now concentrating
on an unspecified turbocharged version of the 300D series vehicles.
These engines are targeted for 1.5 HC, 15 CO, 2.0 NOx and will possibly
be introduced in model year 1978. Data from DB research Diesel vehicles
i
targeted at 0.41 HC, 3.4 CO, 2.0 NOx can be found in Table DB-7. DB
presented no durability data for these vehicles.
DB' displayed data (Table DB-8) which are presented here for comparison
purposes with both the aforementioned concepts and other Diesel engine
powered light duty vehicles. Details of vehicle calibrations, etc.,
were not provided by DB. A greater than 10 MPG difference in highway
fuel economy exists between two 300D vehicles (W115-D30 276 and W115-D30
116) on Table DB-8, for example. Data to explain this difference were
not provided.
* Daimler-Benz Status Report, October 1976, Vol. I, pages 77-78.
** Test results on Mercedes-Benz 220D Diesel Sedan equipped with a
Comprex Pressure Wave Supercharger, TAEB Report No. 76-2 GS, August
1975.
7-268
-------
Table DB-6
Emissions and Fuel Economy Results
From a DB Diesel Powered Research Vehicle
Equipped with EGR
VIN
W115 D24-140
W115 D30-176
W115 D30-176
j W115 D30-256
^
5
CID
147
147
183
183
Emission
Target (s)
0.41 HC, 3.4 CO, 2.0 NOx
0.41 HC, 3.4 CO, 1.0 NOx
0.41 HC, 3.4 CO, 1.0 NOx
0.41 HC, 3.4 CO, 1.0 NOx
FTP
No. of
Tests HC
1 0.169
11 0.209
6 .0.225
6*** 0.167
Results
CO
2.370
2.19
1.78
1.45
(gin/mi)
NOx
0.922
0.916
0.941
1.76
* 8 valid tests
** 13 valid tests
*** None of the tests achieved target emission levels
**** 5 valid tests
Fuel Economy
MPG
u
MPG,
23.96 32.66
22.81 29.57*
24.47 32.09**
22.04 27.74****
-------
I
N>
Table DB-7
Turbocharged Diesel Engine Emission and Fuel Economy Data
(Emission Target 0.41 HC, 3.4 CO, 2.0 NOx)
Average FTP Results Fuel Economy
VIN
W116
W123
W116
W116
D30A-71
D30A-90
•D30A-119
D30A-149
CID
183
183
183
183
No. of
Tests H<:
15
2
3
4
0.142
0.151
0.086
0.090
0.
1.
0.
0.
CO
895
12
79
88
NOx
1.
1.
1.
1.
57
33
66
86
MPG
u
25
26
24
22
.23
.87
.01
.97
MPG,
h^
28.16*
35.27
26.78**
26.24*
* 3 valid tests
** 4 valid tests
-------
(300D)
W115 D30-276
(300D)
W123 D20-126
(200D)
W123 D20-136
(200D)
Table DB-8
DB Diesel Power Vehicles
VIN
W123 D24-64
(240D)
W123 D30-194
(300D)
W115 D30-243
(D300D)
W115 D30-281
(300D)
W115 D30-235
(300D)
W115 D30-273
CID
147
183
183
183
183
183
Emission
Targets
1
1
1
1
1
1
Research
or
Durability Vehicle
R
R
R
R
D
D
No. of
Tests
3
7
.13
1
4
5
Avg.
HC
0.085
0.189
0.130
0.117
0.132
0-168
FTP Results
0.
1.
1.
1.
1.
1.
CO
882
33
14
66
22
64
NOx
1.74
1.43
1.47
1.73
1.84
1.56
183
122
122
R
0.118 1.24 1.64
11 0.102 1.03 1.24
3* 0.517 1.74 1.58
Fuel Economy
MPG
u
MPG,
23.16 25.20
22.60 28.90
22.95 30.10
22.87 30.32
22.81 31.10
24.67 35.17
24.03 36.67
26.64 30.74
24.99 31.52
-------
Table DB-8 (con't)
Research
Avg. FTP Results
VIN
W115 D20-195
(200D)
W115 D24-258
(240D)
W123 D30-94
(300D)
W116 D30-116
V (300D)
NJ
M W115 D30-219
(300D)
W115 D30-224
(300D)
W115 D30-236
(300D)
W116 D30-130
(300D)
Legend: Emission
1 = 1.5 HC,
2 = 0.41 HC,
CID
122
147
183
183
183
183
183
183
Targets
15 CO, 2.
3.4 CO,
Emission
Targets
2
2
2
2
2
2
2
2
0 NOx
2.0 NOx
or No.
Durability Vehicle Test
R 1"
R 13
R 3
R 3
R 3
R 2
R 5
D 8
HC CO
NOx
1* 0-491 2.17 1.32
0.158 1.29 1.51
0.128 1.09 1.67
0.109 0.78 1.71
0.223 1.25 1.29
0.126 1.15 1.79
0.185 1.07 1.69
0.080 0.80 1.72
Fuel Economy
MPG MPG,
u h
22.68 29.43
25.36 32.70
23.57 26.90
25.95 26.49
24.23 30.50
22.96 29.21
23.61
23.70 27.68
* None of the data achieved target emission levels.
-------
7.3.4.2. Systems to be Used at Various Emission Levels
The Daimler-Benz system that will be used at various emission levels can
be found in Table DB-9.
7.3.4.3. Durability Testing
DB provided the durability test results shown in Tables DB-10 through
12. There were no mileage figures given with any of the durability
tests, thereby making it difficult to assess their progress in meeting
future emission levels.
DB reported a test on a high mileage Diesel vehicle. The vehicle tested
was a randomly selected German 300D taxicab. The emissions results were
0.14 HC, 1.3 CO, 1.9 NOx. At the time of the test, the vehicle had
220,000 miles on it.
7.3.4.4. Progress and Problems
Daimler-Benz's progress with 3-way catalyst system lags the progress
other foreign manufacturers and some demestic manufacturers have exhibited.
While DB has demonstrated the low mileage potential to meet 0.4 NOx, the
lack of durability data for this system casts doubts upon its immediate
introduction. Because of the poorly described durability data, a
projection on lead time for introduction of 3-way catalyst systems on DB
vehicles is difficult to make.
Like others, DB's 3-way catalyst systems tests indicate that control of
CO will be a problem even at low mileage. This difficulty may be
overcome with better 3-way catalyst selection and refined engine cali-
brations. DB's 3-way catalyst work to date demonstrated no fuel economy
penalty for most vehicles and a slight (M).5 MPG) fuel economy improve-
ment for others. DB will need considerable work with this concept
7-273
-------
Table DB-9
Daimler-Benz Emission Control Systems at Various Emission Levels
Model
Year
1978
1.5 HC,
15 CO,
2.0 NOx
Engine
Type
M115
MHO
MHO
M117
M117
MHO
OM616
OM617
OM617A
Appl.
50 state3
49 state
Calf.
49 state
'Calf.
50 state
50 state
M
II
CID
141
167.5
167.5
276
276
417
147
183
183
Ind.
System
Carb
Bosch
K-Jet .
ii
it
ii
ii
Diesel
Inj
"
..
Engine
Mods
X
X
X
X
X
X
Pre
Chamber
it
..
EGR
X
xe
xe
X
X
X
-
-
—
Air Dual
Inj. Cat. Ox. Cat. 0™ Sensor 3-way Turbo
xb xcd - -
xf - xd -
xb x8 - - -
Asp. - Xh - - -
x - x1
x - x1 - -
_ _ _ _ _ . •
_ _ _
J
-------
Table DB-9 (con't)
Model
Year
1979/80
0.41 HC,
3.4 CO
2.0 NOx
1981
0.41 HC,
3.4 CO,
1.0 NOx
Engine
Type Appl.
M115 50 state
MHO 49 state
MHO Calf.
Mil? 49 state
Mil? Calf.
M100 50 state
OM616
OM617
OM617A
M115 50 state
MHO
M117 "
OM616 "
OM617
OM617A
CID
141
167.5
167.5
276
276
417
147
183
183
141
167.5
276
147
183
183
Ind.
System
Garb
Bosch
K-Jet .
"
it
ii
n
Diesel
Inj
»
»
Garb
Bosch
K-Jet .
II
Diesel
Inj.
•'
-
Engine
Mods
X
X
X
X
X
X
Pre
Chamber
n
»
X
X
X
Pre
Chamber
it
n
EGR
X
xe
xe
X
X
X
-
-
-
X
-
A
A
A
Air Dual
Inj. Cat. Ox. Cat. Q Sensor 3-way Turbo
xb xcd - -
xf - xd -
? xcd - -k -k
Asp. - X - - -
i k k
X - X1 - - -
X - X1 -
_ _
_ _
_ _ J
xb xcd - -
X - - - ? X1
X ? X1 -
- - - -
- - - -
- - B
-------
Table DB-9 (con't)
Legend:
a Differs from MY 77 version with regard to breakerless transistorized
ignition system, high altitude adjustments and modification to
evaporative system.
b Air switched: t < 62.5°F and t > 122°F air is injected ahead of
oxidation catalyst 62.5°F < t > 122°F air is injected directly
into the exhasut port.
c Reduction Catalyst d Oxidation Catalyst
Platinum + Rodium Platinum + Palladium
1.7 gra Pt 0.73 gm Rh 1.831 gm Pt 0.915 gm Pd
516 gm 1076 gm
Monolith Monolith
5.78" x 3.03" 5.78" x 3.03"
2.9.2" long 6" long ^
NSV 58,000 ti NSV 35,000 h
e BPEGR
f Manifold air injection
g Same loading as M 115 catalysts, only reduction catalysts
mounted underhood, oxidation catalyst underfloor
h Vehicle Models M 117/W 116 to use 2 catalysts
6x4 693 gm loading same as note d ,
Vehicle Models M 117/R/C 107 Federal to use one
5.78 x 3.03 x 6 inch catalyst with 1.45 g Pt +
0.17 gm Rh, 1064 gm total loading.
I
i Larger catalyst volume than Federal version, 1425 g total loading
j May have a turbocharged version
k For MY 80 California version will possibly have no EGR,
AIR, and use a 3-way catalyst - not determined yet.
1 No details
A Two EGR systems under development
Differential Pressure Modulated EGR
Air Fuel Ratio Control Modulated EGR
B "The lower standards for HC and CO emissions can be met with
the turbocharged engine in the weight (4000 Ibs) class."**
**Daimler-Benz Status Report, page 81.
7-276
-------
I
NJ
VIN
R107 E45-71
W116 E45-123
W116 E69-52
Table DB-10
DB Three-Way Catalyst and 00 Sensor Durability Vehicle Results
CID
276
276
417
Emission
No. of
Tests
13
3
1
Targets
Avg.
HC
0.313
0.213
0.862
0.41 HC,
9 CO, 1.5
FTP Results
CO
2.96
2.03
9.357
NOx
0.693
0.362
0.642
NOx
Fuel
MPG
u
11.71
11.73
11.16
Economy
MPG,
n
-
-
15.0
-------
before they reach the demonstrated achievement of other manufacturers.
The dual catalyst work, in which DB reported using a NOx catalyst at
lean air-fuel ratios, was unusual and differed from conventional practice
in this regard. The technology assessment of DB's dual catalyst system
remains perplexing due to scarcity of technology descriptions and
durability test data.
DB's efforts on the stratified charge engine show fuel economy benefits
and potential for emissions levels of 0.41 HC, 3.4 CO, 1.0 NOx. Again,
the lack of technical description and further data precludes further
discussion of this concept.
The use of EGR on a Diesel engine has been tried by DB and the results
to date have been mixed. There are indications that EGR has the potential
of lower NOx levels below 1.0 gm/mi without adverse effects on HC, CO,
or fuel economy. The effect on smoke levels or particulate emissions
cannot be determined from DB's submission. Since DB did not report
durability mileages it is impossible to determine the durability effects
of EGR. <
Also, DB did not reveal any information or data on Diesel engines targeted
to meet the statutory levels of 0.41 HC, 3.4 CO, 0.4 NOx. This may have
been intentional, since DB steadfastly maintains that 1.5-2.0 gm/mi NOx
must be the limit for Diesel powered vehicles. Previous submissions
from DB have indicated developmental Diesel powered vehicles have the
capability to achieve 0.4 NOx. The lack of any data on Diesel systems
targeted toward 0.4 NOx may indicate that DB does not consider this
emission level to be a real future requirement.
7-278
-------
Table DB-11
DB Dual Bed Catalyst Durability Vehicle Results
Emission Targets 0.41 HC,
Avg. FTP Results
VIN
W115
i
^J W115
VO
W116
R107
R107
W116
V23-213
V23-222
E28-167*
E28-63*
E45-72
E69-74
CID
141
141
-
168
168
168
417
No. of
Tests
2
1
3
1
6
2
0.
0.
0.
0.
0.
0.
HC
331
394
400
388
385
255
CO
1.
1.
1.
1.
3.
1.
93
45
98
57
36
40
9 CO, 1.5 NOx
Fuel Economy
NOx
1.
1.
1.
1.
0.
1.
24
18
24
03
96
29
MPG MPGU
14.
15.
14.
12.
13.
10.
U 11
83
47
47
72
38 18.19
37
* EGR also
-------
oo
o
Table DB-12
EGR Equipped Diesel Durability Vehicles Emission and Fuel Economy Results
Emission Target 0.41 HC, 9 CO, 1.5 NOx
Avg. FTP Results Fuel Economy
Emission No. of
VIN CID Targets Tests HC CO NOx
W115 D30-272 183 0.41HC, 3. 4 CO, 1.0 NOx 7* 0.148 1.17 1.45
W115 D30-275 183 0.41 HC, 3. 4 CO, 1.0 NOx 4 0.213 1.41 0.92
MPG MPG,
u h
23.15 26.99+
24.11 29.84*
* None of the tests achieved target emission levels
+ 6 valid tests
** 9 valid tests
-------
7.3.5. Fiat
7.3.5.1. Systems Under Development
3-Way Catalyst Systems
Fiat is apparently doing some 3-way catalyst screening on bench setups
and engine dynamometers. Additional evaluations are being conducted on
vehicles at "zero" miles to determine the influence of various engine
operating conditions on conversion efficiency and in defining the width
of the catalyst window. As no data were submitted, no measure of the
status of this program can accurately be determined.
Other Systems
Various Otto cycle, 4-cylinder, prechamber engines are currently under
development by Fiat, but few details were presented. One mechanically
fuel injected, 2000 Ib IW, manual transmission vehicle has had pre-
liminary emission levels averaging 1.3 HC, 4.5 CO, 1.2 NOx. Further
improvement of the fuel injection system has yielded levels of 1.25 HC,
3.35 CO, 1.2 NOx on this vehicle. No fuel consumption data were reported.
A lean reactor system has been designed and is now under construction in
an attempt to further reduce HC and CO. A turbocharged version of this
engine is currently being installed in a vehicle. Work on a tridimensional
cam was reported but no details were presented.
Carbureted versions of the prechamber concept are also under development.
Initial results using a 2500 Ib IW vehicle have been about 2 HC, 7 CO,
0.9 NOx. With a thermal reactor (uninsulated and without secondary air)
results have been about 0.8 HC, 4.5 CO, 0.9 NOx. With a pelleted, noble
metal catalyst (without secondary air) results have been about 0.6 HC,
2.5 CO, 0.9 NOx. Further work is being conducted to optimize the
calibration between the main and auxiliary carburetors. The most recent
7-281
-------
engine configuration has a prechamber volume of about 10% of total
volume, 8:1 compression ratio, and runs at an average air-fuel ratio of
about 18:1. A prototype version of this engine is currently being
installed in a 2500 Ib IW vehicle. In a parallel effort a new dual
chamber thermal reactor is also being constructed. No details or
emission data for these recently developed systems were reported.
Other results have been reported in the literature* concerning Fiat's
prechamber engine. The engine employs a spherical prechamber which
ignites the charge from the center of the prechamber. The naturally
aspirated engine yields 105 BMEP, and turbocharging increases this to
150 BMEP. The compression ratio is 11:1. There is no ignition control,
the timing is fixed at 5° BTDC. Naturally aspirated, the octane require-
ment is 77 in terms of primary reference fuels, and the turbocharged
engine has an octane requirement of 86. Using Indolene Clear fuel, the
emissions were 1.54 HC, 3.75 CO, 1.24 NOx, 26 MPG . The engine is also
reported to have low noise levels.
Fiat is also studying a thermal reactor for this engine. The thermal
\
reactor has a center tube that is composed of a nickel and copper-
containing surface catalyst.
Fiat is also developing three, 4-cylinder, prechamber Diesels of 1.8,
2.0, and 2.4 litres and one 4-cylinder, open-chamber Diesel of 3.5
litres. The 1.8 litre engine is being installed in vehicles of 2250 and
2500 Ib IW. Some average emission results from the 2.0 and 2.4 litre
prechamber engines are presented in Table Fiat-1.
* Champion Ignition and Engine Performance Conference,
Vienna Austria, 1976.
7-282
-------
Table Fiat-1
Average Diesel Results
Engine
2.0
litre
2.0
litre
2.4
litre
Power
60 hp
at 4400
60 hp
at 4400
72 hp
at 4200
IW
2750
RPM
3000
RPM
3000
RPM
HC
0.53
0.41
0.76
FTP emissions, gm/mi Fuel Economy
CO NOx MPG MPG,
-
2.03 0.78 27 34
1.78 1.32 28 36
2.43 1.07 26 35
A total of 13 vehicles, seven 2750 Ib IW vehicles (two with manual
transmissions) and six 3000 Ib IW vehicles, equipped with 2.0 litre
engines have satisfactorily accumulated over 30,000 miles in testing
designed to study the mechanical reliability of this engine. No emission
results were presented.
Fiat also reported work on fumigation for Diesels. Fumigation is the
name given to a technique of altering the usual method of introducing
fuel in a Diesel engine. In the usual approach, all of the fuel is
introduced into the cylinder via the high pressure fuel injection
system. Fumigation consist of introducing some of the fuel mixed with
air as a premixed charge into the cylinder during the intake stroke,
like with a conventional gasoline engine. The rest of the fuel is
introduced in the usual manner. Fumigation has the potential to increase
the Diesel's air utilization and also to reduce ignition delay. Fiat
has tried fumigation on a 2.4 litre, indirect injection engine and a 3.5
litre direct injection engine. Based on the results to date, Fiat
concluded:
1. Oxides of Nitrogen can be reduced from 10 to 30%.
2. Wide-cut fuels can be used without losing thermal efficiency.
3. Combustion noise can be appreciably reduced.
7-283
-------
Fiat will continue work in this area to find a practical way to obtain
the fumigation, and to study the fumigated air-fuel ratio that is best
for HC and CO control.
Other Development Efforts <
Other efforts include work on a feedback controlled EGR valve, exhaust
gas sensors, low thermal inertia exhaust manifolds, and microprocessor
controlled electronic fuel injection. Most of these developments represent
early efforts and little detail was provided.
7.3.5.2. Systems to be Used at Various Emission Levels
1.5 HC, 15 CO, 2.0 NOx
Fiat's systems for 1978 will be substantially the same as for 1977.
These are described in Table Fiat-2. Fiat did not provide any information
on systems to meet any other emission standard.
7.3.5.3. Durability Testing '
Fiat did not provide any durability test data.
7.3.5.4. Progress and Problems
Other than some encouraging results from Diesel engines and other
efforts with prechamber engines, it appears Fiat has much work to do in
order to meet any emission level much lower than 1977 California .standards
(0.41 HC, 9 CO, 1.5 NOx). Fiat's other development efforts are in the
early stages of development and they appear to be far behind other
manufacturers in many of these same areas, particularly in the area of
durability testing of prototype emission control systems. The lack of
adequately reported data prevented a more comprehensive assessment of
the progress and problems of Fiat.
7-284
-------
Federal
California
Federal
California
Table Fiat-2
1978 Emission Control System Descriptions - 1.5 HC, 15 CO, 2 NOx
Engine Carb
l,289.7cc 2-V
A-cyl Weber
8.5:1 C.R.
l,289.7cc 2-V
4-cyl Weber
8.5:1 C.R.
1,755.5 cc 2-V
4-cyl Weber
8.0:1 C.R.
1,755.5 cc 2-V
4-cyl Weber
8.0:1 C.R.
IW
2250,
2500 Ib
2250 Ib
•2500,
2750,
3000 Ib
2500,
2750,
3000 Ib
Trans
4-spd
man
4-spd
man
5-spd
man,
3-spd
auto
5-spd
man,
3-spd
auto
Axle
Ratio
3.765:1,
4.416:1
3.765:1
4.077:1
4.1:1,
4.214:1
4.3:1,
4.357:1,
4.444:1
3.929:1
4.1:1,
4.214:1,
4.3:1,
. 4.357:1
4.444:1
N/V
61,
66,
72
61,
66
53,
56,
57,
59,
66
53,
55,
56,
59,
66,
67
Ignition
System
HEI,
mech. and
vac . adv .
HEI,
mech. and
vac. adv.
HEI,
mech . and
vac. adv.
HEI,
mech. and
vac . adv .
Air
EGR Injection
none belt driven
pump, port
injection
none belt driven
pump, port
injection
port vac belt driven
controlled pump, port
injection
port vac belt driven
controlled pump, port
injection
Catalyst
UOP
underflow
pelleted
ox. cat.,
1.144 gm
Pt,
2.2 litre
vol.
UOP
underf loaf
pelleted
ox. cat.,
1.144 gm
Pt,
2.2 litre
vol.
-------
7.3.6. Fuji Heavy Industries (Subaru)
7.3.6.1. Systems to be Used
Fuji departs from conventional technical approaches in many aspects of
their vehicle engineering. For example, their engine layout, a horizontally-
opposed, four cylinder, water cooled configuration is unique. Their
emission control systems, likewise, are unconventional. Fuji relies
upon heat conservation techniques combined with air injection to control
HC and CO. The heat conservation techniques include exhaust port liners
along with double wall insulated exhaust manifolding and piping. Fuji's
exhaust port liner is shown in Figure Fuji-1. The air injection system
utilizes an aspirator valve and injects the air quite close to the
exhaust valve for maximum effectiveness. All of these measures serve to
promote the after-reaction of HC and CO. A ported EGR system is used to
control NOx. Fuji indicates that this non-catalytic system with modification
and recalibration of its major components will be capable of meeting
emission standards as low as 0.41 HC, 3.4 CO, and 1.0 NOx.
Figure Fuji-1
to Exhaust
Manifold
• Cylinder Head
-Port Liner
-Air Layer
• Exhaust Port
7-286
-------
Fuji reported last year on an EGR system designed for the 1.0 NOx level
that included two EGR valves: one in the carburetor and another in the
intake manifold. No diagrams or detailed information were provided.
They now report that this system achieved well below the 1.0 NOx level
but at a considerable penalty in driveability and fuel economy. The ,
system appears to have been dropped.
Fuji does not describe any systems targeted at the 0.41 HC, 3.4 CO, 0.4
NOx level but they did indicate that they are considering the 3-way
catalyst approach for future emission levels. Their approach would
apparently be to combine heat conservation measures with a 3-way catalyst.
7.3.6.2. Systems to Meet Various Emission Levels
Fuji indicates that at the 0.41 HC, 3.4 CO, 2.0 NOx level, they will
modify and/or recalibrate their exhaust manifold, distributor, and EGR
valve. The air-fuel ratio will be richened to approximately stoichio-
tnetric or slightly richer. Fuji did not provide cost information for
this system. Table Fuji-1 shows emissions and fuel economy data for
this system.
For the 0.41 HC, 3.4 CO, 1.0 NOx level, Fuji will use a slightly rich
airfuel ratio combined with heat conservation, AIR (aspirator), and EGR.
The major difference between this system and the 2.0 NOx system previously
discussed is EGR flow rate, which is substantially higher. Emissions
and fuel economy for this system are also shown in Table Fuji-1.
7-287
-------
Table Fuji-1
E,llia.SSJ-L)Il
Target
0.41 HC,
3.4 CO,
2.0 NOx
0.41 HC,
3.4 CO,
1.0 NOx
Trans .
M
A
M
A
HC
0.30
0.31
0.32
0.26
CO
3.26
3.62
3.20
4.00
NOx
1.28
1.44
0.91
0.96
MPG
u
22.8
20.9
22.6
20.4
77 Fed.
28
24
28
24
u 77 Cal.
22
22
22
22
* Certification results from comparable vehicles.
7.3.6.3. Durability Testing
Fuji did not report any durability .testing information.
7.3.6.4. Progress and Problems
Fuji has extracted a great deal out of their heat conservation approach.
This type of system, however, may be approaching its practical limit at
the 0.41 HC, 3.4 CO, 1.0 NOx level, unless more NOx control can be
achieved from the basic engine. Fuji's system, in conjunction with a
twin-plug cylinder head, like that reported by Nissan, might show
promise for emission levels lower than 0.41 HC, 3.4 CO, 1.0 NOx.
7-288
-------
7.3.7. Honda
7.3.7.1. Systems Under Development
Honda Motor Company reported no information on systems other than their
Compound Vortex Combustion Chamber (CVCC) engine system. A schematic of
the CVCC engine can be seen in Figure Honda-1. Honda states emphatically
that "...we (Honda) are not convinced to adapt catalysts on the CVCC
system vehicle."* Therefore, there will be no discussion of Honda's
attempts to work with 3-way, oxidation, or reduction catalysts.
7.3.7.2. Systems to be Used at Various Emission Levels
1.5 HC, 15 CO, 2.0 NOx
Honda stated that for model year 1978 they will be targeting for emission
levels of 1.5 HC, 15 CO, and 2.0 NOx for their 49-state cars, and 0.41
HC, 9 CO, and 1.5 NOx for their California vehicles. Both the 49-state
and California vehicles will be refinements of Honda's 1977 model year
offerings. For the 49-state vehicles (the 1.5 litre Civic CVCC and the
1.6 litre CVCC Accord) Honda will improve the fuel metering and distri-
bution system, adopt the double wall exhaust port liners from their 1977
California vehicles, and incorporate a new evaporative emission control
system. Honda will still market vehicles using the 1.2 litre conventional
engine and air injection in the 49-states. They are expecting some
engine performance improvements, but provided no details on how this
will be obtained. Honda anticipates that the 1978 emission levels and
fuel economy of the CVCC will be similar to their 1977, 49-state CVCC
vehicles. The same is true for their ve.hicles with conventional engines
and air injection although they expect a fuel economy increase in 1978
for this engine. The 1977 fuel economy and emission levels of Honda
* Honda Motor Company, Status Report Honda's Emission Control Systems,
December 15, 1976, page 15.
7-289
-------
Figure Honda-1
Auxiliary Intake Valve
Spark Plug
Anxlllary
Combustion Chamber
Strcl Cup
Auxiliary
Intake Passage
Exhaust Passage
Port I.incr
Exhaust Valve
Main
Corihus t; j on Chamber
7-290
-------
vehicles can be found in Table Honda-1. Honda stated the cost increase
for 1978 would be 15 to 20 dollars due to new evaporative emission
controls needed on the CVCC engines.
Table Honda-1
Vehicle
Civic CVCC
Sedan, 1.5 litre
Civic CVCC
Wagon, 1.5 litre
Accord CVCC
1.6 litre
Civic, Conventional 4M
Engine, 1.2 litre
' Federj
Trans
AM
5M
2A
4M
2A
5M
2A
4M
2A
il Certif:
Exhaust
HC
1.4
1.4
0.9
0.9
0.4
1.3
0.5
0.8
0.6
Lcation Resu
t 7c
Emissions
CO
6.3
6.2
3.8
4.6
4.4
5.2
4.5
11.2
8.1
Its
T?TP____.
NOx
1.5
1.4
1.7
1.8
1.5
1.4
1.7
1.4
1.7
Fuel Economy
MPG
u
39
41
32
30
27
38
26
28
23
50
54
37
41
32
48
31
43
29
0.41 HC, 9 CO, 1.5 NOx
Honda foresees that their present 1977 California system will meet these
levels as they do presently. Both the 1.5 litre and 1.6 litre CVCC
engines will be offered in California with improvements identical to the
49-state vehicles. Honda predicts that there will be no trouble meeting
these levels and the vehicles will have an improved driveability and
engine performance over comparable 1977 models. Again the cost increases
7-291
-------
will be due to evaporative emission controls. The 1977 certification
data for California vehicles are given in Table Honda-2.
Table Honda-2
Vehicle
Civic CVCC
Sedan, 1.5 litre
Civic CVCC
Wagon, 1.5 litre
Accord CVCC,
1.6 litre
Exhaust Emissions(gm/mi)
Fuel Economy
'rans
4M
5M
2A
AM
2A
5M
2A
HC
0.29
0.30
0.27
0.25
0.27
0.28
0.21
CO
2.6
2.8
3.2
3.1
4.1
2.4
3.2
NOx
1.3
1.2
1.4
1.2
1.2
1.2
1.3
MPG
u
35
34
28
28
25
33
25
MPG,
n
46
51
34
37
32
47
32
0.41 HC, 3.4 CO, 2.0 NOx
Honda expects that they would use the system described above at these
levels.
0.41 HC, 3.4 CO, 1.0 NOx
To comply with these standards, Honda would use basically the same
system as the 0.41 HC, 9.0 CO, 1.5 NOx system with recalibration of the
carburetion and optimization of the auxiliary combustion chamber configuration.
No EGR or oxidation catalyst is considered necessary by Honda to obtain
these levels. Prototype vehicles at 2000 Ib IW with 4 speed manual
transmission have obtained 0.32 HC, 2.9-3.1 CO, 0.9 NOx with 31-32
MPG .
u
7-292
-------
0.41 HC, 3.4 CO. 0.4 NOx
Honda has continued their low NOx study on the CVCC that has been reported
the past two years. Work has apparently been stopped on the 2.0 litre
engine in favor of assessing low NOx levels and basic understanding of
the CVCC process on the 1.5 litre engine. Honda remains convinced these
levels are attainable without the use of catalysts on the CVCC system.
Basic research has resulted in improved combustion chamber configurations
and carburetion which were reflected in the new engine results presented.
The 1.5 litre engine is in a 2000 Ib IW vehicle with a four speed trans-
mission and achieves 0.3 HC, 3.0 CO, 0.3 to 0.4 NOx. Urban fuel economy
is 25 to 26 MPG . Fuel economy and driveability is said to have improved
over the past year. Work also continues to improve the fuel economy of
this engine.
7.3.7.3. Durability Testing Programs
Again, Honda failed to supply durability test data on their proposed
emission control system. However, in 1977 certification durability
testing, the Honda CVCC system exhibited deterioration factors of less
than 1.0. No durability problems for the CVCC system are expected.at
any of the emission levels considered.
7.3.7.4. Problems and Progress
Honda continues to display leadership in the development of 3 valve,
carbureted, pre-chamber, stratified charge engines. However, their
reliance on the thermal reactor approach for aftertreatment may require
significantly improved thermal reactor efficiency in order to meet
future stringent emission standards with good fuel economy.
The work reported to date has shown the ability to meet any of the
proposed emissions levels but at a substantial fuel economy penalty at
statutory emission levels over the present CVCC vehicles. Honda's
7-293
-------
aggressiveness to meet the 0.4 NOx goal is hard to ascertain, given the
lack of development and durability test details. It appears that
Honda's biggest development task is one of improving fuel .economy at low
emission levels, rather than just attaining those levels. Honda reported
their ability to meet the 0.41 HC, 3.4 CO, 0.4 NOx levels as early as
1973. In the four years since then, Honda has not reported much in the
way of their development progress to EPA. Honda results with their
current aftertreatment show a definite HC/fuel economy relationship. In
order to maintain their good fuel economy performance, it is expected
that Honda might have to explore sophisticated EGR and/or improved
thermal reactors and/or catalytic control.
7-294
-------
7.3.8. Mitsubishi
7.3.8.1. Systems Under Development
Oxidation Catalysts
Oxidation catalyst systems currently under development at Mitsubishi are
combined with their MCA-JET system described below. Samples of candidate
pelleted and monolithic oxidation catalysts are screened and durability
tested for attrition resistance and conversion efficiency deterioration
before being selected for vehicle durability tests. No test data were
presented. It is of some interest that last year's status report included
testing of monolith catalysts but apparently no vehicle testing of
monolithic catalysts is currently in progress at Mitsubishi.
3-Way Catalysts
Mitsubishi has tested 3-way catalyst systems but has not achieved what
they feel are satisfactory results. No test data were presented.
Dual Catalysts
Two vehicles equipped with reduction plus oxidation catalysts are being
developed and are undergoing testing at Mitsubishi. This is virtually
the same system reported in last year's status report. The engine is
based on their current 97.5 CID, 4-cylinder engine with modifications
made to the compression ratio, combustion chamber shape, valve timing,
bore, stroke, and spark plug location. Detailed descriptions of these
modifications were not provided. Except for an improved fuel metering
system which maintains the air-fuel ratio at a point slightly richer
than stoichiometry, and a new dual-cam choke system (described below),
the intake system is basically unchanged from the 1977 system. The EGR
system also remains substantially unchanged except for increased flow
7-295
-------
rates. Two types of air injection techniques are used depending on the
NOx catalyst type and location. In one vehicle a reducing catalyst
containing ruthenium is located in the exhaust manifold with air injected
downstream just ahead of the oxidation catalyst. This NOx catalyst
location is being examined for light-off/durability trade-offs with an
alternate underfloor location. No air is injected ahead of the ruthenium
catalyst because of its poor durability in an oxidizing environment.
With another NOx catalyst (substantially base metal plus a small quantity
of noble metal) located underfloor just ahead of the oxidation catalyst,
an air switching mechanism directs air to the exhaust ports and uses the
NOx catalyst as an oxidation catalyst during cold start operation.
During hot operation the air is diverted to a point between the catalysts.
NOx is then reduced in the first catalyst and the HC and CO combine with
oxygen and are oxidized in the second catalyst. In an effort to reduce
ammonia formation in the NOx catalyst, Mitsubishi is developing a method
to bleed some of this air through a nozzle into the exhaust just ahead
of the NOx catalyst. This is done to maintain a CO to 0_ ratio of
around 2:1 at which Mitsubishi indicated that ammonia formation is
minimized. They are still encountering some difficulty with this split
air system in effectively controlling the amount of air metered to the
NOx catalyst. (Further description of these vehicles can be found in
the section discussing Mitsubishi's system to be used at 0.41 HC, 3.4
CO,. 0.4 NOx.)
Other Development Efforts
A dual-cam automatic choke system has been devised by Mitsubishi.
This system has a starter cam and a warm-up cam in place of the fast-
idle cam in a conventional automatic choke system. The starter cam
provides a wider throttle opening during cold start. A coolant temper-
ature sensing wax-element controls the warm-up cam which in turn controls
the throttle opening during warm-up. As coolant temperature increases
7-296
-------
the throttle is gradually closed providing a smooth reduction in engine
speed until the engine is thoroughly warmed-up. Mitsubishi claims
improved cold start emissions with this system and prevention of catalyst
overheating during prolonged engine idling.
A system to control the switching and modulation of secondary air has
also been developed by Mitsubishi. During cold start air is injected
into the exhaust ports. As coolant temperature increases above 131°F,
the air is gradually diverted to a point just ahead of the oxidation
catalyst and is modulated with an air control valve by sensing manifold
vacuum and air pump discharge pressure. When catalyst(s) temperature
becomes excessively high, a relief valve opens discharging the air to
the atmosphere away from the catalyst(s).
Port liner development and other heat conservation programs have been
suspended at Mitsubishi. Current efforts are being focused on their new
lean burning MCA-JET system. When used with an oxidation catalyst,
Mitsubishi indicated that this system does not require high exhaust
temperatures as do current 1977 models without the MCA-JET. The need
for heat conservation techniques to be used with the MCA-JET system to
meet statutory emission levels was not addressed by Mitsubishi.
Electronic fuel metering development has been slowed because Mitsubishi
indicated EFI has a cost to benefit ratio which is too high. They are
continuing to use EFI as a research tool. Similarly, they have no plans
to use electronic spark advance control systems from a cost/benefit
point of view. Electronic ignition systems remain limited to Mitsubishi's
luxury models which are sold in Japan.
7-297
-------
Other Systems
Mitsubishi has recently developed a new emission control system called
the MCA-JET. It was originally designed to meet 1978 Japanese emission
standards but will probably be used to meet U.S. standards as well.
Compared to conventional engines with a single intake valve per cylinder,
this new system using two intake valves has revealed much improved fuel
economy on an equivalent emissions basis. The MCA-JET is pictured in
figure Mitsubishi-1. This system is reported to have enhanced accept-
ance of leaner air-fuel ratios and greater EGR rates. To keep drive-
ability at an acceptable level, further refinements in EGR control may
be required.
Additional air passage
Air cleaner
Figure Mitsubishi-1
Mitsubishi's New MCA-JET System
7-298
-------
The smaller Jet valve is operated simultaneously with the conventional
intake valve by a common rocker arm. Air enters the passage above the
throttle at approximately atmospheric pressure and passes through the
Jet valve into the cylinder. Increased swirl induced by this stream of
air improves combustion by increasing flame speed and thus provides the
potential for reduced emissions, according to Mitsubishi. At low throttle
openings the swirl is greater because of the greater pressure differential
across the Jet valve. Better fuel economy has been noted especially
under these low load/low speed conditions. As the throttle opening
increases, the amount of air inducted through the Jet valve is reduced.
To compensate for this, the mixture supplied through the conventional
intake valve apparently becomes correspondingly leaner. Under high load
conditions, the combustion process is usually good enough without the
additional swirl. Mitsubishi notes an extension of the lean limit and
increased EGR tolerance with this system. They are currently studying
the fuel flow characteristics to obtain better trade-off between emissions,
driveability, and fuel economy. No FTP emission data were presented
(only 10-mode Japanese data with steady state fuel economy at 37.3 mph
of about 45 to 49 MPG using an oxidation catalyst plus EGR.)
Limited information comparing the 1978 MCA-JET system's first cost and
operating costs to that of the 1977 conventional engine was presented by
Mitsubishi and is shown in Table Mitsubishi-1. The only apparent differ-
ence in costs is in the fuel economy benefits which will appear to yield
a significant savings of about $140 to the consumer during 50,000 miles
of operation. The only increase in cost may come from catalyst replace-
ment at some point after 50,000 miles of operation.
7-299
-------
Table Mitsubishi-1
Mitsubishi's 1978 Federal and Calif. MCA-JET Models vs. 1977 Federal and Calif. Models
Federal Calif.
First Cost:
Operating Costs:
o
o
Additional cost of Jet valve
mechanism approximately offset
by elimination of secondary air
system (detailed cost data not
reported).
Fuel - $140 savings (based on
50,000 miles operation,
$0.65 per gal., and 32.5
MPG for 1978 model versus
28.§ MPG for 1977 model).
c
Lubricant - no expected change
Maintenance - no expected change
Catalyst replacement - catalyst:
container:
gaskets:
labor:
(1.5 hr at
$14/hr)
Not reported (same as Federal
configuration except for slight
cost increase due to increased
catalyst volume).
Fuel - $270 savings (based on
50,000 miles operation, $0.65
per gal., and 30.0 MPG for
1978 model versus 24.0°MPG
for 1977 model). C
Lubricant - no expected change
Maintenance - no expected change
$10 Catalyst replacement - catalyst: $20
5 container: 8
1 gaskets: 1
21 labor: 21
$37 (1.5 hr at $50
$14/hr)
-------
Before the MCA-JET system was developed, three other systems were
candidates to meet the 1978 Japanese emission standards but further
development of these systems has apparently been suspended.
The first of these systems is a lean/rich thermal reactor system with
air injection and EGR. This is shown in Figure Mitsubishi-2. The
center two cylinders receive a rich mixture (about 13:1 at 25 mph) from
one barrel of the carburetor while the outer two cylinders are fed a
separate lean mixture (about 17:1 at 25 mph) from the other barrel of
the carburetor. This was done principally to reduce NOx formation. Air
injection was required primarily to treat CO and HC during transient
operation. No FTP emission data are available. Japanese 10-mode emission
data were presented with steady state fuel economy at 60 km/hr (37.3
mph) ranging from about 35 to 38 MPG in a 2,200 Ib IW vehicle.
The second system is a rich thermal reactor with air injection plus EGR.
NOx formation is reduced by rich operation and further reduced by EGR
while HC and CO emissions were oxidized in the thermal reactor with the
aid of port liners and air injection. Again, no FTP data are available,
but Japanese 10-mode data were presented with steady state, 60 km/hr
(37.3 mph) fuel economy of about 39 MPG.
The third system is a dual catalyst system substantially the same as
that described above in the Dual Catalyst section. No FTP data were
presented, but again 10-mode Japanese data with steady state fuel economy
at 60 km/hr (37.3 mph) ranging between about 38 and 42 MPG.
7.3.8.2. Systems to be Used at Various Emission Levels
1.5 HC, 15 CO. 2.0 NOx
Mitsubishi's systems to meet this emission level are described in Table
Mitsubishi-2. One of the engines reported, the 97.5 CID 4-cylinder,
uses the new MCA-JET system with EGR plus an oxidation catalyst located
in the exhaust manifold. The other engine is a 121.75 CID 4-cylinder
7-301
-------
Air FuniD
Air Control Valve
Thermal Reactor
Rich Mixture Barrel
Lean Mixture Barrel
Carburetor
EGR Control Valve
Figure Mitsubishi-2
Schematic nr^ng of Lean/Rich Thermal Reactor System
7-302
-------
Engine
Table Mitsubishi-2
Emission Control System - 1978: 1.5 HC, 15 CO, 2.0 NOx
System A
121.75 CID,
4-cylinder,
cast iron block,
alum. head
System B
97.5 CID,
4-cylinder,
cast iron block,
alum, head,
MCA-JET
OJ
o
u>
Induction System
Exh Manifold
Ignition System
EGR System
Air Injection
Catalyst
staged 2-V carb, auto choke
alum, int man
exh heated air bi-metal
control valve
4-port, cast iron
breaker point,
mech and vac adv
spk port vac, int
man modulated, coolant
temp sensing control valve
reed valve air
induction
none
staged 2-V carb, modified
mixture control, auto choke,
exh heated air bi-metal
control valve
4-port, cast iron
with radial flow ox cat
located in exh man
breaker point,
mech and vac adv
spk port vac, int
man modulated, coolant
temp sensing control valve
none
Evap System
charcoal storage, 41.4 cu in,
purge thru control valve
by int man vac
pellet, oxidizing, y-
substrate, 0.8 gm Pd,
56,833 sq ft total surface area,
location: exh man
mfr: Cataler Co., Ltd.
charcoal storage, 41.4 cu in,
purge thru control valve
by int man vac
-------
with EGR and reed valve air injection into the exhaust ports with
possible further refinement of EGR flow rates, spark advance, and/or
other control parameters. Mitsubishi plans to seek certification at
these emission levels for the 1978 model year.
0.41 HC. 9 CO. 1.5 NOx
The two engine-systems to meet this level are described in Table Mitsubishi-
3. These systems are substantially the same as described in Table
Mitsubishi-2 except: System C uses a thermal reactor, increased spark
retard and decreased EGR flow compared to System A; and, System D uses
increased spark retard, increased EGR flow, and a catalyst with approxi-
mately double the surface area and noble metal loading as compared with
System B.
0.41 HC. 3.4 CO. 2.0 NOx
These levels are planned to be met for the 1979 and 1980 model years
using systems similar to system B, the MCA-JET, in Table Mitsubishi-2.
Detailed information as to the exact nature of the planned systems was
no,t presented other than some refinement in carburetion will be necessary
as will an increase in catalyst volume.
0.41 HC. 3.4 CO, 1.0 NOx
The MCA-JET system is Mitsubishi's candidate to meet these emission
levels for the 1981 model year. Again, detailed information about this
system was not presented, but it will be substantially the same as that
planned for the 1979-80 model years. They mentioned that increased EGR
rates may be necessary to meet the lower NOx level and further refinement
of EGR control may be required to keep driveability at an acceptable
level.
7-304
-------
Table Mitsubishi-3
Emission Control Systems - 1978: 0.41 HC, 9 CO, 1.5 NOx
u>
o
Ul
Engine
Induction System
Exh Manifold
Ignition System
EGR System
Air Injection
Thermal Reactor
Catalyst
Evap System
System C
121.75 CID,
4-cyl, cast iron
block, alum head
staged 2-V carb, auto choke
alum int man, exh heated
air bi-metal control
none
breaker point, mech adv and
vac adv with dual-diaphragm
(decreased flow vs. System A)
spk port vac, int man
modulated, coolant temp
sensing control valve
(decreased flow vs. System A)
reed valve air induction
yes
none
charcoal storage, 41.4 cu in.,
purge thru control valve
by int man
System D
97.5 CID,
4-cyl, cast iron
block, alum head,
MCA-JET
staged 2-V carb, modified
mixture control, auto choke,
exh heated air bi-metal
control valve
4-port, cast iron with
radial flow ox cat located in
exh man
breaker point, mech adv
and vac adv (increased retard
vs. System B)
spk port vac, int man
modulated, coolant temp
sensing control valve
(increased flow vs. System B)
none
none
pellet, oxidizing, Y~alumina
substrate, 1.6 gm pd, 113,666 sq. ft.
total surface area, location: exh man
mfr: Cataler Co, Ltd.
charcoal storage, 41.4 cu in.,
purge thru control valve
by int man
-------
0.41 HC, 3.4 CO. 0.4 NOx
A dual catalyst system Is continuing to be developed by Mitsubishi to
meet statutory emission standards. This is substantially the same
system previously discussed in the Dual Catalyst section. Durability
emission data are presented in the Durability Testing section below.
Low mileage emission results look promising with vehicle number 206 (NOx
catalyst located uriderfloor), however, testing was suspended at 20,000
miles of durability testing due to an increase in emissions in excess of
statutory levels. The second vehicle, number 502 (NOx catalyst located
in the exhaust manifold), is continuing to be tested at 21,250 miles
even though emissions are exceeding those of the first vehicle. Spark
retardation is being considered by Mitsubishi as a means to reduce
engine out HC, CO, and NOx levels and also to get better light-off of
the catalysts. A modified EGR valve is being adopted in an effort to
reduce the need for retarded spark and the associated fuel economy
penalty.
The MCA-JET system is also a prospective candidate to meet statutory
\
emission levels primarily because of its ability to accept leaner air-
fuel ratios and increased EGR rates. Mitsubishi feels further refine-
ments over conventional EGR may be required to further reduce NOx and
maintain acceptable driveability. No specific development effort to
achieve statutory levels with the MCA-JET system was reported. This
system is being developed, however, to meet future 1978 model year
Japanese standards.
7.3.8.3. Durability Testing
The two dual catalyst vehicles described above and an MCA-JET vehicle
represent the only durability data reported. These are presented in
Table Mitsubishi-4. No other durability data were presented although
7-306
-------
Table Mitsubishi-4
Dual Catlayst and MCA-JET Durability Data
Veh.
206
I"
2750
502
2750
509
2750
Engine
and
Drive Train System
97.5 CID, dual cat, split
man trans, secondary air with
3.889 axle switching and air
ratio control, EGR
(NOx cat located
underf loor)
97.5 CID, dual cat
man trans secondary air
3.889 axle control, EGR
(NOx cat located
in exh man)
97.5 CID, ox. cat
MCA-JET, located in exh. man,
man trans. , EGR
3.889 axle ratio
System
Mileage
0
600
5 , 000
10,000
15,000
20,000
0
8,000
15 , 600
15,600
18,750
21,250
21,250
0
4,000
10,000
16 , 000
22,000
25,000
30,000
37,000
HC
0.24
0.34
0.45
0.56
0.39
0.49
0.85
0.79
0.85
0.65
0.68
0.82
0.83
0.20
0.28
0.26
0.28
0.27
0.30
0.25
0.28
0.36
0.31
0.28
CO
54
88
00
72
3.55
3.79
4.49
6.82
6.75
6.43
6.07
6.86
6.35
60
53
83
36
12
3.51
10
89
70
16
3.97
NOx
0.32
0.35
0.46
0.69
0.63
0.69
0.34
0.54
0.45
0.41
0.62
0.61
0.59
1.14
0.95
,10
.07
.21
,08
,11
,02
0.84
0.76
0.99
MPG MPG. Comments
u h :
22.9
24.2
26.9
36
test run suspended
due to increase
in emissions
before .maintenance
after maintenance
before maintenance
after maintenance,
testing continuing
before maintenance
after maintenance
before maintenance
after maintenance
before maintenance
after maintenance
testing continuing
-------
another vehicle using the MCA-JET has just begun testing and Mitsubishi
expects to add more vehicles in the future.
7.3.8.4. Problems and Progress
Mitsubishi's recent efforts have been directed toward development of
their MCA-JET system to comply with Japan's 1978 emission standards.
For the U.S. market, however, substantial development of this system
still appears necessary to meet levels of 0.41 HC, 3.4 CO, 1.0 and 2.0
NOx as well as statutory levels. The dual catalyst systems designed to
meet statutory emission levels show some promise but durability is a
problem. Development efforts directed toward combinations of Mitsubishi's
innovative control techniques such as the MCA-JET and the dual-cam choke
systems may show good potential. Durability and fuel economy results of
the MCA-JET system will be especially interesting. Mitsubishi will have
to overcome problems in such areas as precise control of fuel metering,
EGR flow, spark advance, and secondary air modulation without the aid of
electronic control which they feel is undesirable from a cost/benefit
standpoint.
7-308
-------
7.3.9. Nissan (Datsun)
7.3.9.1. Systems Under Development
3-Way Catalyst System
The Nissan 3-way catalyst system is shown in Figure Nissan-1. The
system uses L-Jetronic electronic fuel injection, an oxygen sensor,
backpressure EGR (up to 12%), and a 3-way catalyst. System optimization
testing was directed at statutory emission levels and was conducted on a
3000 pound IW vehicle (VIN 8D-740) equipped with a 2.8 litre engine and
a manual transmission. The best reported results were 0.27 HC, 1.75 CO,
0.32 NOx, 17.9 MPG . The fuel economy of the similar 1977 Federal data
vehicle was also 17.9 MPG , and the fuel economy of the similar durability
vehicle ranged from 17.2 to 18.2 MPG .
A number of promising pelleted and monolithic 3-way catalysts were
evaluated in laboratory and engine dynamometer testing at Nissan. Some
of the better candidates are shown in Figures Nissan-2 through Nissan-5.
From Figures Nissan-2 and Nissan-5, it can be seen that the high temper-
ature laboratory aging of 100 hours results in greater catalyst deter-
ioration than the equivalent of 30,000 km on the engine dynamometer.
The Z value on the figures is defined as:
Z = (02 + 0.5 NO)/(0.5 CO + 0.5 H2 + 1.5 HC) where HZ = 1/3 CO.
Catalysts JB 1101 and AB 318 are particularly impressive in the laboratory
testing. After 100 hours of aging, they were reported to have HC/NOx
crossover efficiencies of 96% and 94% respectively.
7-309
-------
Switch
Temp. Sensor
Starter Injector
U)
I—"
o
Silencer
Fuel Pump
Fuel Filter
Injector
DftTSUN
fuel Tajik
mm \o\li!lfoi /Q//Q//
BWoytitoid.
O2 Sensor
Feedback
CorjtroL
MtainMisfftet
Cwtster \
Air Regulator
Throttie. Switch
Air Flow Meier
Air Temp. Sensor
Figure Nissan-1*
3WAY CATALYST SYSTEM
WITH ELECTRONIC FUEL INJECTION
* from Nissan Status Report, December 1976, page IV-3
-------
Figure Nissan - 2*
, ]""' I ' i i I i. i - I• i I'' ; i •!•••! ' I'-!'! •
•LLuabo. rotcrVjE vcitu'atj on'"of 3-Way i
1 i ; ; • • • I '• • • \ '• • x>'_. i _:i . _ i I
Tl
r
sLX;PA1213_
1' i I '. ' I • i • i : ' t I i i :l i ' I I i
""Durability'""t'dhdi't'ibh's""!""""]"'""!"" i""
I •>«IBM*!^••^•^••^•^^•IBI^B^™™**^^^^""""^^™"^^*^ • I , • . _ I
Cdtqlyst ;-| •:-{ •
110 0 K_o a_en gin ?_dy n.amQ.mei er
Inlet! gas
""Space'" ve[ocify^jTE273;OOer)T
: V • i ! I : ! : r i- I !' -I ! i ' !
""""
EvdluQtibniTt'est"
"lrjletLNp'""c6nc;..:.
f—Inletr'gas -jtempr
--r
-HC: composition
:.5"OQ pprrf
:25,5:oo;h
: ethylene-:
__L.NO Fresh
'NO
"1
-LJ..i i i !.!..-_ i":.' .i..".lLiIlZlL
*from Nissan Status Report, December 1976, page V-14.
7-311
-------
Figure Nissan - 3*
_LabQrabryLEvalJjaii JDnil
i • : ; •'::.•! i • i i ; •
T
""Calaiysry J BTI01"(monblifR).: I...i_
! ' J \ • , : . I . I : ; . : | . .
T
Uu rab'i It t y :cohd It i bhs:. j ,!.;...
"TOO h ~ph jehgThe dynarnometer
-Inlet
.Space:.. .velQ(:LtyLZ_iJLj2.?3,000_lii
! * • 1 ' '^i:l 1 !
lEvaluatibn ! tesilLl-.
±inletiviD.i.
T"n ! ~
_500; ppriL
AOO 'C:
Inlet gas temp.
"Spacer velocify" :.i .;"25,500 h~!1
7 H C";c6mposi6nTT7ZjI~^thylehe~~1
propane
i i _i
i i . i
ii:j_x-..:-.2-;-.±±±t±t-.ti±
* from Nissan Status Report, December 1976, page V-16.
7-312
-------
Figure Nissan - 4*
- ... ....
_..
••
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.
...
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c
(I)
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80
60
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; T"i"
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i
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1
Ui
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— :....
i
)ry
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jra
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Ink
Spc
/all
Eva
1 i ;
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k. AB
bility
, 1 ij. !.!..[ L..L
luation
Of.. i_a
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. |.:.L. J.1...I....L7 :..:
i
318
1 :
T'rrjbn"
CohcJitibr
; • i •
h ;on! engine. <
?t! gas- ; temp.:
icei...yel6.city.ull
jation test !""i"
Inlet JN
Inlet g<
Space v
HC'comp
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e
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f
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as temj
elocity
jositi
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t
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i
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t
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1.5.
D.
[
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atalys.r.
i . ! ;
5HThi
s
jyn
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: 5
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00
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thy
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omete
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* from Nissan Status Report, December, 1976, page V-17.
7-313
-------
Figure Nissan - 5*
;_:i
I Engine
,- i = i i
mr
..Dynamb.me.ter" Evaluation.!
-H-f i of 3rWgy Catalyst H--j
jCbtd lyst;. i J A i 12.13.(pel LetjlIi±jZ
Durability : test rriociej."'. jl
i,' j...i,.4_,..l ,__.._.
! I : | •
._Proposed Japan MOT mode_
I on engine dynamometer
"Inlet ;gas"'temD7ii"J50-700°C
I ' ! : : , : : i ! •
-- -4—
Evaluation test i .. i ;
concr:r500ppm
-Inlet1 gas temp;:-^ A50°C ~-
..Space; velocity :..:!_27,O.Q.O h'l
* from Nissan Status Report, December 1976, page V-20.
7-314
-------
Fast Burn System
The Nissan fast burn system, shown in Figure Nissan-6, demonstrates a
unique approach toward meeting statutory emission levels without catalytic
NOx control. The system utilizes two spark plugs per cylinder which
greatly increases the burn rate of the air-fuel charge. Then large
amounts of EGR (up to 30%) are added to reduce NOx to statutory levels.
The high EGR rates in turn slow down the burn rate, but the desired NOx
control is achieved. As shown in Figures Nissan-7 and Nissan-8, the
conventional engine does not have the high EGR tolerance (or good fuel
consumption) of the fast burn engine. Figure Nissan-9 shows that at the
same NOx level, the conventional engine experiences combustion stability
problems. High HC emissions are the result of incomplete combustion at
the low IMEP levels.
Since only NOx emissions are controlled by combustion in the engine, HC
t
and CO control is being attained with air injection and an oxidation
catalyst.
Optimization testing has been done on a 2750 pound IW vehicle with a 2.0
litre engine and a manual transmission (VIN 8D-946). The best reported
results are shown in Table Nissan-1. The catalyst was reported to be a
95 cu in., all platinum monolith. The noble metal loading of the catalyst
and engine-out emissions were not reported.
.Table Nissan-1*
Test Results of the Vehicle
Using the Fast Burn System
HC CO NOx 'MPG MPG, MPG
— — u h c_
0.17 1.85 0.35 21.9
0.22 2.09 0.38 22.2 33.1 26.1
0.24 2.01 0.37 22.6 33.4 26.4
*from Nissan Status Report, December 1976, Page IV-31.
7-315
-------
I
10
Auto. Temp. Conk fiir
finti Backfire Valve
Sub EGR
Control l&Vc
/Main E6R Control Valve " J
\_
7o. DisfHbutor
Figure Nissan-6*
NISSAN FAST BURN SYSTEM
* from Nissan Status Report, December 1976, page IV-19.
-------
O'OU
<• — »,
r.
^ "s/, f)
J1 v/ *-!• \J
•^.^^
^320
Q_
l/j
"C~^— ^
CONVENTIONAL
ENGINE^-''
s^^^ * "~*
,/'
EAST BURN
ENG|N§^.
/
^s**
1AOO rpm
3 kgm
A/E : 145 to 1
MBT
X.
a
30
20
10
0
0
\
CONVENTIONA
\ ENGINE
ALLOWABLE STABILITY
LIMIT
FAST BUR!
ENGINE
10
20 30
EGR RATE (°/0)
Nissan-7* IMPROVEMENTS OF EGR LIMIT AND B.S.F.C.
* from Nissan Status Report, December 1976, page IV-24
50
-------
100
u>
M
oo
H-
z:
cc
ID
CD
z:50
o
cc
Li_
CO
CO
FAST BURN ENGINE
0 LJ
-45
1400 rpm
3 kgm
A/F:i4-5 to 1
MBT
CONVENTIONAL ENGINE
80
135
CRANK ANGLE (deg.ATDC)
Nissan- s* INCREASE OF COMBUSTION RATE IN FAST BURN ENGINE
* from Nissan Status Report, December 1976, page IV-28
-------
80-
U)
60
0
CONVENTIONAL ENGINE FAST BURN ENGINE
1400 rpm
3 kgm
A/F : 145 to 1
MET
NOx LEVEL : 6%
I.M.E.R (kg cm2)
Nissan-9* IMPROVEMENT OF COMBUSTION STABILITY IN FAST BURN ENGINE
* from Nissan Status Report, December 1976, page IV-29
-------
Nissan reported that power output of the fast burn engine is similar to
current models, but some loss in driveability has been noted due to the
necessity of introducing EGR sooner than desirable after the cold start
to achieve the required NOx control. Nearly all vehicle manufacturers
delay the introduction of EGR until after the engine has warmed up to
retain good cold start driveability.
For the purposes of comparison to Table Nissan-1 the comparable 1977
Federal certification fuel economy vehicle achieved 23.0 MPG , 34.1
MPG , and 26.9 MPG . The urban fuel economy of the comparable 1977
Federal durability vehicle ranged from 21.4 to 22.8 MPG . Thus, the
fast burn vehicle has virtually equivalent fuel economy while achieving
statutory emission levels.
Other Components Under Development
A 3-way catalyst system using a feedback carburetor is now being durability
tested at Nissan to determine its ability to comply with the 1978
Japanese emission levels. The carburetor uses feedback control to an
I
air bleed as shown in Figure Nissan-10. One vehicle was reported to
have completed 30,000 km. The major problem with the carburetor was
said to be durability of the air bleed actuator.
7.3.9.2. Systems to be Used at Various Emission Levels
1.5 HC, 15 CO, 2.0 NOx
If the 1978 emission standards remain at these levels, the emission
control system of Nissan will not change greatly from those of 1977.
Table Nissan-2 shows the planned systems.
7-320
-------
Figure Nissan-10*
Electronically Controlled Carburetor
..--. AIR
SMALL VENTURI fl MAIN N
OZZLE
\
ACTUATOR (E.5.V.)
MAIN AIR BLEED
FLOAT
MAIN JET
THROTTLE VALVE
* from Nissan Status Report, December 1976, page V-4,
7-321
-------
Family
L280F
L240F
L200F
A140F
A141F
Table Nissan-2*
1978 Federal Emission Control Systems
Configuration
1-6
1-6
1-4
1-4
1-4
CID
168
146
119
85
85
IW
3000
3000
2750
2250
2250
Emission Control
System
EFI + EGR
EFI + EGR
AIR -I- EGR
AIR + EGR
RAIR** + EGR + OC
* From Nissan Status Report, Dec. 1976, p. 1-3
** RAIR = reed valve air induction system
The EFI system on the vehicles with six cylinder engines is the Bosch L-
Jetronic system. All EGR systems are backpressure modulated for EGR
control which is somewhat proportional to load. A new configuration of
the small inline four cylinder engine is planned, which incorporates a
system using pulse AIR, EGR, and an oxidation catalyst. Nissan has
previously used oxidation catalysts only in California.
Fuel economy of these vehicles will be improved, according to Nissan,
due to some vehicle weight reductions and recalibrations. The change in
initial cost of these models is expected to range from a $10 reduction
to a $40 increase. Increased costs are due to the addition of breakerless
ignition and low-maintenance batteries on some models. The reduced
costs are for a reduction in cost of the breakerless ignition for vehicles
already with breakerless ignition, apparently due to increased volume
purchases. Maintenance costs are going to be reduced in 1978 by about
$90 to $125 (Nissan stated this as $34 to $50 plus 4 to 5 hours of
maintenance time).
0.41 HC, 9 CO. 1.5 NOx
While stating that they could certify vehicles in 1978 on a Federal
basis at this emission level, Nissan indicated that there was insufficient
lead time remaining to procure an ample supply of oxidation catalysts
from their supplier.
7-322
-------
Configuration
1-6
1-6
1-4
1-4
CID
168
146
119
85
IW
3000
3000
2750
2250/2500
Emission Control
System
EFI + EGR + Ox. Cat
EFI + EGR + Ox. Cat
AIR + EGR + Ox. Cat
AIR + EGR + Ox. Cat
The systems planned for California in 1978 are described in Table
Nissan-3. High altitude vehicles will be identical to the California
vehicles.
Table Nissan-3*
1978 California Emission Control Systems
Family
L281C
L241C
L201C
A140C
* From Nissan Status Report, Dec. 1976, p. 1-3.
Initial cost of the 1978 California vehicles is to be reduced by $50 to
$70 despite the addition of the low maintenance battery (not really an
emission control device), because of cost reductions in other emission
components. One example is a reduction in noble metal loading of the
catalyst. Maintenance costs will be reduced by an amount similar to
that of the Federal vehicles for 1.5 HC, 15 CO, 2.0 NOx.
The difference in initial cost between the currently planned Federal and
California systems was said to be $85 to $95.
0.9 HC. 9 CO. 2.0 NOx
Since current Federal vhicles from Nissan generally do not use oxidation
catalysts, their emissions would not comply with the 0.9 HC, 9 CO, 2.0
NOx emission levels. The current California vehicles would easily
achieve these levels. Emissions of the Federal vehicles are suffi-
ciently close to these levels that Nissan could possibly recalibrate
these vehicles and achieve 0.9 HC, 9 CO, 2.0 NOx without catalytic
aftertreatment.
7-323
-------
0.41 HC, 3.4 CO. 2.0 NOx
Nissan said that they have not yet fully developed systems for this
emission level. Their work for California indicates that CO may be
their biggest problem. The data to support this contention apparently
were developed by installing high mileage catalysts, which had been run
about 50,000 miles, on low mileage vehicles. The results of this
testing are shown in Table Nissan-4.
Nissan further substantiated their CO problem with evidence that EPA
testing generally shows higher CO levels than found at Nissan on the
same vehicles. Nissan mentioned that CO control on high altitude
vehicles is of even more concern, and considerable lead time would be
necessary to resolve the problem.
The Nissan analysis may have been too conservative. The vehicles in
Table Nissan-4 were not calibrated for 3.4 CO. Considerable enleanment
of the systems is still possible based on the engine-out emissions shown
in Table Nissan-4, particularly for the vehicle with the 85 CID engine.
Other manufacturers have reported lower engine-out CO emissions at
stoichiometric operation than reported here by Nissan. Also the cat-
alysts used by Nissan in this testing, despite their high loading, are
not considered to be the best technology available. Apparently Nissan
did not test catalysts from their usual supplier on this vehicle. All
but one of their 1977 California durability vehicles have already
completed 50,000 miles with emission levels below 0.41 HC, 3.4 CO, 1.5
NOx.
7-324
-------
VIN
A-458
AK-363
BK-340
£ F-503
CID
85
119
146
168
IW
2250
2750
3000
3000
Trans
A
M
A
A
System
AIR+EGR+OC
AIR+EGR+OC
EFI+EGR+OC
EFI+EGR+OC
Table Nissan-4*
Vehicle Testing for 0.41 HC, 9 CO, 1.5 NOx
Emission Control Catalyst** With Catalyst Without Catalyst
Corning 3M HC O) NOx HC CO NOx
X
X
X
X
0.29
0.34
0.23
0.29
0.37
0.29
0.31
2.69
2.64
2.69
3.22
2.64
3.70
4.12
0.82
1.14
1.16
1.15
1.17
1.08
1.14
1.43
1.46
1.41
1.54
0.93
21.0
19.8
14.2
11.8
10.8
1.01
1.23
1.37
1.18
1.29
* from Nissan Status Report, December 1976, page 11-4
** noble metal loading of 78 gm/cu ft.
-------
0.41 HC. 3.4 CO. 1.0 NOx
A 1.0 NOx development program for 1981 has not yet been conducted by
Nissan. They indicated that at 1.0 NOx, their 0.4 NOx systems would
probably be used. Those systems are a 3-way catalyst system and their
fast burn system. Further efforts on the oxidation catalyst systems
could make them feasible for lighter weight vehicles, according to
Nissan.
0.41 HC. 3.4 CO. 0.4 NOx
The Nissan 3-way catalyst system and fast burn system are being developed
for statutory emission levels. The development status of these systems
was discussed under the section entitled Systems Under Development.
The fuel economy of these systems was seen to be equivalent to 1977
Federal Nissan vehicles. Initial costs and maintenance costs of the two
systems were not discussed by Nissan.
I
7.3.9.3 Durability Testing
A single 3-way catalyst vehicle was durability tested at Nissan. The
vehicle is the previously described vehicle number 8D-740 (see Systems
Under Development). The catalyst was described as a 3 litre, pelleted
catalyst which was mounted underfloor. No further catalyst description
was given. The durability results are shown in Table Nissan-5. HC and
CO control appear to be deteriorating at the 30,000 mile point.
7-326
-------
Table Nissan-5
3-Way Catalyst Durability
Mileage HC CO NOx MPG Comments
__ __ ____ u —————-
0 0.27 1.75 0.32 17.9
5,000 0.45 3.30 0.42 17.7
0.31 3.25 0.38 17.7 After Maintenance
10,000 0.54 2.82 0.43 18.4
0.34 2.83 0.43 18.1 After Maintenance
15,000 0.28 2.99 0.41 18.3
20,000 0.40 2.62 0.47 18.3
25,000 0.40 3.35 0.37 17.9
30,000 0.53 4.23 0.41 17.9
Two oxidation catalyst vehicles were reported to be undergoing durability
testing for 0.41 HC, 9 CO, 1.5 NOx. Vehicle BK-342 was a 3000 pound IW
vehicle with a 146 CID engine and an automatic transmission. It was
equipped with an EFI + EGR + OC system. The catalyst was a monolith of
about 100 cu in. with a loading of 40 gm/cu ft. Vehicle F-560 was a
3000 pound IW vehicle with an automatic transmission and a 168 CID
engine. It also has an EFI + EGR + OC system. This catalyst was about
100 cu in. with a 25 gm/cu ft. loading. The test results of both
vehicles are shown in Table Nissan-6.
7-327
-------
Table Nissan-6*
Oxidation Catalyst Durability Vehicles
VIN Mileage
BK-342 0
3,245
4,000
10,171
10,185
12,418
15,191
F-560 0
4,000
10,000
12,500
15,000
20,000
HC
0.28
0.31
0.31
0.27
0.36
0.33
0.27
0.29
0.31
0.27
0.39
0.36
0.39
CO
3.3
3.4
4.0
3.0
3.7
3.3
2.8
4.9
3.0
3.9
3.7
3.1
3.1
NOx
43
68
22
01
25
03
09
20
46
46
35
05
MPG
Comments
After Maintenance
1.33
From Nissan Status Report, December 1976, pages II-6 and II-7.
The fuel economy of similar 1977 Federal certification vehicles is shown
in Table Nissan-7.
Table Nissan-7
I
Fuel Economy of 1977 Federal Certification Vehicles
Which are comparable to the Oxidation Catalyst
Vehicles in Table Nissan-6
Comparable to
BK-342
F-560
or
Durability
Vehicle
FE
D
FE
Fuel Economy
MPG MPG,
u
17.1-17.5
16.8-17.8
17.6
21.8-24.2
22.5
MPG
18.9-20.0
19.5
7-328
-------
7.3.9.4. Progress and Problem Areas
Nissan appears to have the capability of achieving emission levels as
low as 0.41 HC, 3.4 CO, 1.0 NOx with three different emission control
systems; oxidation catalyst/conventional burn, oxidation catalyst/fast
burn, and 3-way catalyst systems. At 0.41 HC, 3.4 CO, 0.4 NOx, only the
oxidation catalyst system with the conventional burn engine would be
eliminated from consideration.
The reported testing demonstrates excellent progress by Nissan toward
the simultaneous achievement of good fuel economy and low exhaust
emissions. The testing of the fast burn system represents one of the
few times that a vehicle with a conventional, spark ignited engine has
achieved the statutory emission levels without catalytic reduction of
NOx. In addition, the fast burn vehicle had excellent fuel economy. The
testing of a vehicle equipped with a 3-way catalyst system at statutory
emission levels also revealed excellent fuel economy, but the system
durability did not yet appear adequate. Other 3-way catalysts have been
identified by Nissan in laboratory and engine dynamometer testing which
may be considerably more active than the one tested on the durability
•vehicle.
The biggest problem remaining for Nissan is to demonstrate that the
durability of their fast burn and 3-way catalyst systems are adequate.
Should their durability be adequate, Nissan could then devote their
development efforts to improved fuel economy. The lack of reported
development of electronic spark and EGR systems is one area which could
have an adverse impact on Nissan's fuel economy improvement potential in
the future.
7-329
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7.3.10. Peugeot
7.3.10.1. Systems Under Development
Peugeot also anticipates that the 1978 model year emissions standards
will remain at the 1977 model year levels. The Peugeot submission also
addressed the levels proposed in the House-Senate Conference bill and in
the same time frame as proposed in that bill. Consequently, Peugeot did
not discuss their engineering efforts to attain levels of 0.41 HC, 3.4
CO, 0.4 NOx in their status report. This latest submission was less
informative than previous Peugeot submissions.
For 1978, Peugeot will offer two gasoline engines for the low altitude
and high altitude areas plus the same two engines recalibrated to meet
the 1977 California standards. The 120.3 CID four cylinder engine will
power the 504 series vehicles both sedan and station wagon, while the
163 CID V-6 engine will power the 604 series vehicles. The XD 4.94 138
CID Diesel engine will be offered on a 49-states basis for the 504
series vehicles. No mention was made concerning the use of the Diesel
engine in California.
The 1977 Certification results for durability vehicles are shown in
Table Peugeot-1.
7-330
-------
Table Peugeot-1
FTP Results (gm/mi)
VIN
77-261
Family XD
77-601
Family XNAC
Cal
77-650
Family
112.9 DA
Federal
77-651
Family
112.9 DA
Cal
System Miles (103) HC
Diesel
AIR, OC
EGR, EM, Decel Valve
604 Sedan
AIR, OC, EGR, EM
Decel Valve
Same as 77-650
5
50
5
50
5
50
5
50
0.39 ;:
0.41
DF 1.02
0.23
0.19
DF 1.00
0.23
0.27
DF 1.22
0.32
0.42*
DF 1.23
CO
0.80
1.30
1.45
4.40-
5.00
1.34
2.90
3.20
1.09
3.80
5.00
1.15
NOx
0.72
1.19
1.26
0.86
0.81
1.00
0.68
0.80
1.23
0.99
0.94
1.14
MPG
u
33.6
25.9
0.72
18.3
19.4
1.04
15.24
17.23
1.16
16.77
17.80
1.06
* Exceeds the numerical value of the California 1977 Standards.
7-331
-------
3-Way plus Oxidation Catalyst System
Peugeot is presently working on a fuel injected engine with an emission
control system which incorporates an oxygen sensor, a 3-way catalyst,
and, an oxidation catalyst with air injection before the oxidation
catalyst. Little details were provided concerning the status of this
development effort. Initial test results were about 0.41 HC, 7 CO, and
1 NOx. The vehicle will be started on durability testing soon.
No other systems were discussed.
Diesel Engine
Peugeot will be able to market their 138 CID Diesel engine in their 504
series vehicles at levels of 1.5 HC, 15 CO, 2.0 NOx. This engine
incorporates a Ricardo Comet V combustion chamber and the Peugeot
retardation system to reduce combustion noise and a declutching fan to
improve fuel economy. Engine noise remains a major concern to Peugeot.
Peugeot maintains that at levels below 0.41 HC and 2.0 NOx, their Diesel
engine will experience problems in attaining these levels simultaneously.
Efforts to improve this situation include studies of a max-min governor
rather than an all speed governor, a new improved injection pump, and
modifications to the basic engine. These modifications include thermal
insulation of the combustion pre-chamber, improved air induction, modified
combustion chamber shape, and suppression of secondary fuel injection.
Peugeot reported that their initial results with the thermally insulated
combustion pre-chamber were disappointing. The apparent lack of success
is attributed to reduced compression ratio stemming from a poor heat
barrier between the main combustion chamber and pre-chamber. Further
thermal insulation work is contemplated.
7-332
-------
Additional development work is underway to improve the air induction
by modifying the intake and exhaust camshaft profiles. Also, reduced
piston cavity volume will be studied.
All of the above developments, except thermal insulation, have been
incorporated into a test vehicle which produced the following zero mile
results: 0.25-0.30 EC, 1.63 CO, 2.1 NOx when using French fuel oil.
Using 2D fuel could cause the values for HC and NOx to be higher.
Durability testing has been started.
No cost or fuel economy data were presented for future Peugeot systems.
7.3.10.2. Systems to be Used at Various Emission Levels
At levels of 1.5 HC, 15 CO, 2.0 NOx, Peugeot will use the same systems
for both their gasoline and Diesel engines as were marketed in 1977.
At 0.9 HC, 9 CO, 2.0 NOx, Peugeot did not address this level but it is
clear these levels can be attained by the present 1977 vehicles.
t
The 0.41 HC, 9 CO, 1.5 NOx levels should not present any difficulty
for Peugeot1s gasoline engines, but Peugeot is very close to the 0.41 HC
level with their Diesel durability vehicles now at high mileage.
To achieve levels of 0.41 HC, 3.4 CO, 2.0 NOx, Peugeot will use the same
systems they plan to use at California levels for 1978, i.e., oxidation
catalyst, EGR, air pump, a deceleration throttle opening system, and a
new carburetor. The location of the catalyst and composition of the
catalyst may be modified, and an automatic enrichment shutter for cold
starting will also be incorporated.
7-333
-------
Fuel economy and costs will be comparable to 1977 model vehicles.
At levels of 0.41 HC, 3.4 CO, 1.0 NOx, Peugeot will use a fuel injection,
3-way catalyst, 0 sensor plus oxidation catalyst system. They anticipate
that the 0 sensor will have to be replaced every 15,000 miles. Fuel
economy is predicted to be 1 MPG better than the present California
vehicle fuel economy range of 16.7-17.8 MPG on the urban cycle when the
technology is developed. The increased costs for this system is intended
to be 10%. There was no discussion of the Diesel engine at these levels
nor any discussion of levels more stringent than those for either the
gasoline or Diesel engine.
7.3.10.3. Durability Testing Program
Peugeot did not report any durability test data. A summary of the 1977
Certification durability test data can be found in Table Peugeot-1.
Problems and Progress
Peugeot's progress during the past year has been disappointing as
compared to the promise shown in last year's status report. The ag-
gressiveness shown previously in attempting to lower HC and NOx emissions
from Diesel engines seems to be lacking. The reported HC penalty
encountered with the thermally insulated combustion chamber may have
been a disappointment to Peugeot.
It was difficult to assess Peugeot's progress towards achieving statutory
standards due to their report brevity, but it is encouraging to note
their efforts with 3-way plus oxidation catalyst system.
Peugeot may have difficulty meeting emission levels of 0.41 HC and 1.5
NOx with their Diesel engine. They also will have to improve the basic
calibration on the 3-way plus oxidation catalyst system to achieve
statutory levels.
7-334
-------
7.3.11. Renault
7.3.11.1. Systems Under Development
Renault indicates that they expect that the 1977 model year emission
standards will be applicable in the 1978 model year. Consequently, much
of the emission control hardware Renault used in 1977 will be used again
in 1978 and possibly post-1978 model years. Renault uses air injection,
EGR, and oxidation catalysts in combination as standard emission control
equipment. The proposed 1978 model year systems offered by Renault are
shown in Table Renault-1.
3-Way Catalysts
Renault was an early leader in 3-way catalyst technology and Renault
continues to specify the 3-way catalyst as their first choice for a
system to meet emission levels of 0.41 HC, 3.4 CO, 1.0 NOx and lower.
There was no evidence in the Reanult submission that any other system is
under active consideration, with the exception of the possible use of a
I
3-way plus oxidation catalyst plus air injection. Renault has not
determined if it will be necessary to use this latter system.
7-335
-------
Table Renault-1
1978 Model Year Systems
Engine
Family
810R
843R
843FIR
140RC
810RC
843RC
140RCA
CID
79
101
101
163
79
101
163
49-State or
California
49s
49s
49s
49s
Cal.
Cal.
Cal.
Fuel
System
Carb
Carb
EFI*
FI+
Carb
Carb
FI+
AIR
yes
yes
yes
no
yes
yes
yes
EGR
yes
yes
yes
yes**
yes
yes
yes**
Ox. Cat.
no
no
no
yes
yes
yes
yes
* Bosch L-Jectronic
** Proportional EGR
+ Bosch K-Jectronic
While the details of Renault's work on 3-way catalyst systems remained
sketchy, they did report data which showed the results of laboratory
test program for 3-way catalyst selection.* This screening program
culminated in the apparent selection of an Engelhard TWC-16 as the
production 3-way catalyst. There were data that indicated that other
potential 3-way catalysts had higher conversion efficiencies but were
rejected for durability reasons. No details concerning the composition
of the catalysts used in the screening test were provided.
Hot start CVS testing of 3-way systems have shown the following results.
* During the discussion of the 3-way catalyst screening tests, Renault
provided information which indicated that several platinoids (platinum,
palladuim, ruthinium, rhodium) and oxides of transition metals such
as nickel, iron, cobalt, copper, chrome/cerium and other rare earth
metal are mounted on a large surface aluminum support which may or
may not be stabilized by other oxides such as lanthanum, barium, and
magnesium.
7-336
-------
Table Renault-2
3-way Catalyst Test Results
Hot Start FTP (gm/mi)
Engine HC CO NOx MPG Remarks
79 CID
101 CID
it
163 CID
0.06
0.2
0.3
0.4
2.5
2.0
2.33
3.4
0.59
0.30
0.38
1.32
-
22-23
20.9
14.5
L-Jetronlc EFI
20K miles
K-Jetronic FI*
* Attempt to adapt the Volvo system to Renault 30 vehicles, no
system optimization.
Renault presented no data concerning 0? sensor durability or system
optimization to achieve levels of 0.41 HC, 3.4 CO, 0.4 NOx.
7.3.11.2. Systems to be Used at Various Emissions Levels
The systems Renault plans to use at the various emission levels are
found in Table Renault-3 along with their fuel economy estimates.
Renault indicated that these various levels could be met in the time
frame indicated in the House-Senate Conference bill. No mention was
made of developments or systems targeted at statutory levels.
7.3.11.3. Durability Testing
Renault reported no durability test data. Renault presented the 1976
and 1977 durability and data vehicle emissions and fuel economy results
which can be found in Table Renault-4.
7-337
-------
Table Renault-3
Systems to be Used at Various Emission Levels
Level
1.5 HC
15 CO
2.0 NOx
0.9 HC
9 CO
2.0 NOx
0.41 HC
9 CO
1.5 NOx
0.41 HC
3.4 CO
2.0 NOx
0.41 HC
3.4 CO
1.0 NOx
0.41 HC
3.4 CO
0.4 NOx
Model Model line/
Year Eng. (CID) System (s)
1978 5/79 Carb, AIR, EGR
12/101* Carb, AIR, EGR
17/101 EFI, AIR, EGR
30/163 EFI, EGR, OC
Not specifically addressed
Assumed same model line would
be offered in 1978
1978 Would use 1977 California
only vehicles at this level
1979- 5/79 Carb, AIR, EGR, OC**
1980 17/101 EFI, AIR, EGR, OC
30/163 EFI, AIR, EGR, OC
1981 5/79 Carb, 3-way, 0 sensor
17/101 EFI, 3-way, 0 sensor
30/163 EFI, 3-way, 0^ sensor
? No discussion at this level
Fuel Economy
Penalty
Baseline
No penalty
5%
No penalty
5 to 7%
improvement***
No penalty
* To be dropped after 1979 model year
** Lower compression ratio
*** If system development is completed
-------
Table Renault-4
1976 A 1977 Durability and Data Vehicle Emissions Level and
MX
391
367
345*
Model/CID
5/79
17/101
5/79
Trans
MA
M5
MA
HC
Mileage Mileage
A or 5K 50K Range
1.27 1.33 1.12-1.38
0.95 0.97 0.84-1.14
0.381 0.539 .26 3-. 570
Fuel Economy
CO
Mileage Mileage
A or 5K 50K Range
12.2 13.1 11.3-13.6
11.7 12.4 8.6-13.0
3.46 3.31 2.49-3.76
HOx
Mileage Mileage
4 or 5K 50K Range
1.81 1.71 1.65-1.84
1.60 1.75 1.60-1.93
1.63 1.65 1.39-1.82
Mileage
4 or 5K
27.7
18.6
23.8
MPC MI'J;,
U ll
Mileage Miltvij;'
50K R.-mgt- 4K
27. {) 26.0-27.7 -
19.7 17.4-19.8 -
25.8 23.0-25.fi -
*California
target
A IK , EGR
TP 751
TP 750
373
TP 95
TP 96
O.A1 HC/9 CO/2
,OC
5/79
5/79
17/101
30/163
30/163
.0 NOx
MA
MA
M5
A3
MA
1.34
1.20
1 . 32
0.93
1.31
11.8
13.3
7.9
6.2
7.9
2.00
2.02
1.53
1.74
1.91
25.6
24.5
20.8
15.4
15.0
41.0
4O.6
3ft. 0
20. R
24.6
-------
7.3.11.4. Problems and Progress
It was difficult to ascertain from the Renault status report the progress
Renault has made during the past year. While it appears that Renault
has made some progress with their 3-way catalyst system, much more
durability testing is required before their capability to meet low
emission levels can be determined. Indeed, EPA only has Renault's
assurances that emission levels more stringent than the present levels
can be met. A positive note was the statement by Renault that they were
working with Volvo on perfecting a 3-way catalyst system.
7-340
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7.3.12. Rolls-Royce (RR)
7.3.12.1. Systems Under Development
Rolls-Royce Motors is a comparatively small company with annual sales in
the USA of about 1100 cars. Therefore, they have concentrated on projects
which offer good prospects for success with priority given to meeting
standards to assure continuity of production. RR's aim is to adapt and
develop proven techniques resulting from basic research carried out by
the major manufacturers who have the necessary financial resources.
Close liaison is maintained with component suppliers and other car
manufacturers.
RR also assumes that the 1977 legislated standards will be applicable in
1978. Hence, they plan to continue marketing their conventional V-8
(412 CID) engine, with twin SU carburetors, HEI, air pump, BPEGR, and
dual Johnson Matthey 23G oxidation catalysts. The systems that RR is
presently working on are discussed below.
Oxidation Catalyst
RR introduced a rhodium/platinum oxidation catalyst with their 1977
vehicles. Because they intend to use this catalyst at the present
emission levels of 1.5 HC, 15 CO, 2.0 NOx, they have not conducted
additional development efforts on this catalyst other than system
optimization with increased EGR rates to meet 0.41 HC, 3.4 CO, 1.0 NOx.
1977 Certification levels can be found in Table RR-1. A vehicle with
this catalyst was tested for hydrogen cyanide at EPA Research Triangle
Park. The results are summarized in Table RR-2.
7-341
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HC
0.197
0.186
0.41
0.18-.33
0.705
CO
1.293
1.578
5.9
1.5-2.9
0.972
NOx
1.97
1.10
1.56
0.90-1.35
0.775
MPG
u
10.7
8.7
8.7
8.22-9.
1.103
MPG
n
12.3
11.4
11.4
13 -
_
Table RR-1
RR 1977 Certification Test Results
FTP Results (gm/mi) Fuel Economy
Engine
Family
IF 49 states
1C Calif.
IF 49 state high alt. 0.41
Durability vehicle
DFs
Table RR-2
HCN Testing of RR Production Catalysts
Freeway test: Normal operation 0-0.79 mg/mile
Malfunctioning 4.89 - 31.0 mg/mile
(Air injection
disconnected)
EPA tentative max.
permissable limit 300 mg/mile
Garage test: Normal operation 0
Malfunctioning 0 - 0.934 mg/mile
(Air injection
disconnected)
EPA tentative max.
permissible limit 15 mg/mile
7-342
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3-way Catalysts
At levels of 0.41 HC, 3.4 CO, 0.4 NOx, RR has selected as their first
choice system the new aluminum V-8 444 CID engine, Bosch K-Jetronic fuel
injection, a Bosch ()„ sensor for closed loop electronic control, HEI,
BPEGR, and an unspecified 3-way catalyst. Low mileage vehicle results
were 0.25 HC, 2.5 CO, and 0.25 NOx with a city fuel consumption of 8.5
MPG. Cold driveability was considered poor.
Work continues on evaluating Johnson Matthey, Engelhard, and Degussa 3--
way catalysts along with various engine compression ratios and induction
system features. RR feels that the fuel injection system could not be
introduced into production before 1980 model year even on a crash basis.
RR projects 1982 as the time frame for introduction of this system. No
costs were estimated. Production system durability is targeted to start
in September 1977.
3-way Catalysts plus Oxidation Catalyst
Since the last status report, RR has evaluated a prototype 3-way catalyst
plus oxidation catalyst system with switched air injection. They reported
the results were disappointing. RR will continue to work on this
system but they feel other methods were more promising. No emissions or
fuel economy results were reported.
Other Systems
Start Catalysts
RR now is concentrating their start catalyst work in association with
their fuel injection and their 3-way catalyst efforts. To date they
have not seen any emissions benefits using start catalysts and air
7-343
-------
switching with their 3-way catalyst system.
EGR System
RR evaluated the Deutsche Vergaser Gesellschaft (DVG) EGR system in
comparison to the Rochester Products BPEGR system. DVG system produces
no advantage, according to RR, over the Rochester system.
Dual Fuel System
RR has abandoned work with the Mobil LEF system due to better results
with their 3-way system and the LEF's increased complexity.
Modulated Air Injection System
Work on a modulated air injection system with closed loop control from
an oxygen sensor in the exhaust system has reached only the project
design stage. Efforts have been concentrated on other work and this
project remains in the formative stage.
I
7.3.12.2. Systems to be Used at Various Emission Levels
The systems RR would use at the various emissions levels can be found in
Table RR-3 along with explanatory remarks from the RR status report
submission.
7-344
-------
I
U)
js-
Table RR-1
Systems to be Used at Various Emission Levels
Level
1.5 HC, 15 CO, 2.0 NOx
0.9 HC, 9 CO, 2.0 NOx
0.41 HC, 9 CO, 1.5 NOx
System
Present 1977
system for
49 states both high
and low altitude
Same as above
Present 1977 California
vehicle calibration
achieves these levels
Projected
Fuel Economy Penalty
Base
Introduction
Date
1978
0
18.7% City
7.3% Highway
0.41 HC, 3.4 CO, 2.0 NOx Oxidation catalyst Present 1977 system
+ EGR
0.41 HC, 3.4 CO, 1.0 NOx Oxidation catalyst,
EGR, and new
444 in engine
0.41 HC, 3.4 CO, .4 NOx 3-way closed
loop EFI, 0. sensor
durability vehicle meets
these levels with a fuel
consumption range of
8.2 - 9.1 (15 - 23% loss
from fuel economy vehicle)
20%
1978
1978
1978 ?
1980 ?
1982
Remarks
No difficulty in
achieving these
levels
No difficulty
Cannot be met at
high altitude at
present. Lead time
of 12 months needed to
introduce nationally
Both 1977 Federal &
California vehicles
meet these levels now.
Cannot meet levels
at high altitude.
Needs adequate
lead time
Achieved
experimentally
-------
7.3.12.3. Durability Testing
RR presented no durability data for any of their experimental systems.
7.3.12.4. Problems and Progress
At NOx emission levels higher than 1.5 gm/mi, it would appear that RR
has the capability of achieving sufficient HC and CO control to certify
vehicles at low altitude with their present 1977 model year emission
control system. Additional work will be necessary to achieve NOx levels
of 1.0 gin/mile while reducing the presently high fuel consumption penalties
associated with their first choice control system for 1.0 NOx.
RR is experiencing problems with 3-way catalyst and 0 sensor durability
which makes them pessimistic about achieving statutory levels prior to
1982.
7-346
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7.3.13. Saab
7.3.13.1. Systems Under Development^
During the past year, Saab has continued to aggressively pursue 3-way
catalyst technology. Saab, with their low inertia weight model line and
the already accepted cost penalty for fuel injection, is in a position
to actively develop 3-way catalyst systems. Saab has also introduced a
3-way catalyst system on their 1977 model year California vehicles.
Consequently, Saab has not addressed systems other than the 3-way
catalyst system. In fact they state, "The basic reason why other
possible systems have been abandoned is that we (Saab) are convinced
that the 3-way catalyst system offers the best solution for meeting very
stringent emission levels and it does this without requiring any com-
promise with respect to driveability and fuel economy."*
Saab feels that stratified charge engines are not feasible for two
reasons, namely low sales volume which cannot justify large investments
in development and tooling and the stratified charge engine's non-
compatibility with a 3-way catalyst system.
Saab also has not tested lean burn systems "because lean mixtures
always imply a risk of bad driveability, loss of performance and fuel
economy and it has not been proven that 1.0 gm/mi NOx can be obtained at
the same time as performance and driveability are at an acceptable
level."**
3-Way Catalyst System
Since Saab feels that a 3-way catalyst system is the only acceptable
solution to meet stringent emission standards, they have concentrated on
* Saab-Scania AB 1976 Status Report, page A.
** ibid.
7-347
-------
developing this system. In terms of emissions, Saab has changed the
engineering design goals from 50% of any emission level to 70% on prototype
vehicles. Saab also has engineering targets to improve fuel economy to
meet prescribed mileage levels, to maintain good driveability and to
minimize the system cost impact. Saab feels that compared to their
present 1977 systems, the 3-way catalyst system's only drawback will be
cost. Compared to an uncontrolled engine, the 3-way catalyst will have
a performance loss of 10-15%, fuel economy penalty of 10%, and be 300
dollars higher on the sticker price, according to Saab.
Saab presently has three 3-way catalyst system vehicles and two turbo-
charged 3-way catalyst system vehicles under component and system testing
at their Trollhatten assembly plant, headquarters for Saab's Passenger
Car Division. They also have four 3-way catalyst vehicles, one of which
is at Engelhard and one at Bosch, plus three turbocharged engines with
3-way catalyst vechicles under system testing at Sodertalje, their
engine assembly plant and laboratory. Three other vehicles are used
specifically for durability testing of 3-way catalyst systems. Two of
these vehicles, numbers 745 and 797, have completed 50,000 miles and the
third vehicle has completed at least 40,000 durability miles using the
proposed production Engelhard TWC-16 3-way catalyst. Prior to these
latest test results, these vehicles had accumulated mileage using the
Engelhard TWC-9B 3-way catalyst. The test results can be found in Table
Saab-1. Saab noted that the problems of worn exhaust valve guides and
seats have been solved by using sodium-cooled exhaust valves.
Saab described the driveability rating of their 3-way catalyst vehicles.
The driveability ratings for model year 1975 to 1981 vehicles are
summarized in Table Saab-2.
7-348
-------
Table Saab-1
Saab Three-Way Catalyst Durability Test Fleet*
VIN
745
Test No. 130
System
EFI, 0_ sensor
TWC-9B
Auto Trans.
i
U)
VO
797
Test No. 131
800
Test No. 132
EFI, 0- sensor
TWC-9B7
Auto Trans.
Worn exhaust valves
EFI, 0- sensor
TWC-9B7
Manual Trans.
Cold start problems
Miles (10 )
0
4
5
11
16
21
24
27
31.8
0
5
10
15
21
25
27.5
0
2.5
5
6.7
11
13
30
32
35
40
FTP Results (gm/mi)—
HC CO NOx
0.07
0.10
0.18
0.23
0.14
0.14
0.14
0.18
0.31
0.13
0.25
0.23
0.30
0.32
0.65
2.47
2.70
2.71
6.48
3.96
2.70
2.70
2.72
2.83
2.14
2.70
4.95
5.85
4.50
4.50
0.96
1.73
1.65
0.90
0.87
0.80
0.85
0.73
0.70
0.97
0.82
0.90
0.90
1.12
1.27
0.83
8.02
0.90
0.21
0.21
0.32
0.24
0.23
0.43
0.27
0.29
0.30
0.45
4.06
2.97
2.80
2.25
1.80
3.15
3.60
3.70
3.70
8.13
0.35
0.60
0.98
1.13
1.15
1.15
1.05
0.75
0.98
0.60
MPG
20-22
21-22.5
20-23
-------
Table Saab-1 (cont.)
VIN
745
Test No. 133
797
Test No.
134
System
EFI, 0- sensor
TWC-16
Auto Trans.
Cyl. heads
changed 6 & 36K
miles
Before maintenance
After maintenance
EFI, 0- sensor
TWC-16
Auto Trans.
U)
Ul
o
800
Test No.
135
800
Test No.
136
EFI, 0- sensor
TWC-16
Man. Trans.
Exh. Valve failure
Ignition cables broken
ii ii it
EFI, 0- sensor
TWC-16
Man. Trans.
Miles (10 )
0
2
6
11
14
22
27
36
36
42.5
50
0
4
8
14
19
24
28
34
39
43
48
50
0
1.6
3
. 4.6
7
11
14
0
5
11
25
31
40
HC
CO
NOx
MPG
0.03
0.16
0.51
0.23
0.25
0.28
0.29
0.65
0.16
0.18
0.39
0.15
0.23
0.37
0.25
0.26
0.27
0.26
0.27
0.26
0.25
0.26
0.23
0.21
0.38
0.21
0.47
0.30
0.57
0.50
0.18
0.27
0.16
0.30
0.31
0.46
2.77
2.80
7.20
3.60
2.25
5.85
5.40
5.40
2.25
3.60
5.93
3.06
4.23
8.10
5.40
5.40
5.85
5.40
5.50
5.50
5.40
5.90
4.35
4.54
5.40
2.30
6.80
4.50
5.85
7.40
2.11
3.78
5.85
5.60
5.90
6.73
0.09
0.60
0.25
1.05
0.45
0.30
0.30
0.45
1.05
0.90
0.95
0.22
0.30
0.33
0.35
0.38
0.38
0.38
0.75
0.90
0.75
0.70
0.95
0.10
0.28
0.45
0.75
0.83
0.45
0.65
0.08
0.15
0.15
0.23
0.15
0.33
u
* All vehicles targeted to 0.41 HC, 9 CO, 1.5 NOx.
-------
Table Saab-2
Driveability For Different MY Vehicles*
MY
'75
'76
'77
'78
'79-'80
'81
Federal
Cold
5.5
6.5
6.5
6.5
5.0
5.0
Warm
6.0
7.0
6.5
6.5
8.0
8.0
California
Cold
5.5
6.5
6.5
6.5
5.0
5.0
Warm
5.0
5.5
8.0
8.0
8.0
8.0
Acceleration Performance Comparison
Cal
Acceleration
Range
Improvement
MY 1977
0
to Cal MY 1976
- 60 MPH
5.9 sec
(automatic gearbox)
30 - 60 MPH
7.2 sec
1/4 mile
2.4 sec
Part throttle
Improvement 3 sec 1.5 sec 1.1 sec
Full throttle
* Driveability Ratings
1-3 Very Bad
4 Bad
5 Limit
6 Acceptable
7 Well acceptable
8 Good
9 Very good
10 Excellent
7-351
-------
For Federal cars the achieved performance improvement was somewhat
offset by the necessity to use proportional EGR on all model year 1977
cars. The 3-way catalyst system for California model year 1977 gives a
pronounced warm engine driveability improvement compared to the model
year 1976 system. For model years 1979 to 1980 driveability will be
impaired by the necessity to use lean air-fuel ratios at cold start.
The driveability ratings for model year 1979 to 1981 are anticipated
values as the final specifications have not yet been determined.
Saab also presented data comparing the emission results between the TWC-
9D and the TWC-16 at various noble metal loading and Pt/Rh ratio. These
results are presented in the table below.
Table Saab-3
CVS - results with TWC-16 and TWC-9D, 15gm/cu ft.
loading, aged to 600 hrs = 50.000 miles
Conditions
Without catalysts
TWC-16, 50 gm/cu ft.
aged 600 hrs 0.278 4.68 0.214 21.6
TWC-16, 15 gm/cu ft.
aged 370 hrs 0.291 5.73 0.752 20.8
aged 625 hrs 0.357 6.67 0.786 21.6
TWC-9D, 15 gm/cu ft.
aged 370 hrs 0.218 5.92 0.769 20.6
aged 625 hrs 0.431 7.01 0.790 21.6
CVS Results
HC
1.29
CO
16.0
NOx
2.74
Fuel Economy
21.0
- MPG *
u
*Reported as (l/10km) in the Saab Status Report and converted to MPG
assuming these were corresponding CVS test results.
7-352
-------
The test results with the different catalysts show that the TWC-16 with
50 gm/cu ft. loading gave the best overall results. If the TWC-16
tested by Saab is like other TWC-16 catalysts, the Pt/Rh ratio should be
5/1. The data in Table Saab-3 show that both Pt/Rh ratio and loading
are important, with Pt/Rh ratio being possibly less important than total
loading. If one compares the results from the TWC-9D (19/1 Pt/Rh) and
the TWC-16 at 15 gm/cu ft. the results are fairly close at 625 hours:
0.431 HC vs 0.357 HC, 7.01 CO vs 6.67 CO, 0.790 NOx vs 0.786 NOx. These
results show almost no difference for NOx and a slight HC and CO advantage
for the catalyst with the higher Rh content (TWC-16). Comparing the two
TWC-16 catalysts, it can be seen that the results for NOx are much
different (0.214 NOx vs 0.786 NOx) with a decided advantage for the more
highly loaded catalyst. To complete the comparison, results on a 50
gm/cu ft. TWC-9D catalyst would have been helpful. However, Saab did
not report these results.
Saab also tested the influence of manganese additives on catalyst and
oxygen sensor aging. Their results show a very small effect on the
catalyst but the sensor shows a slight deterioration. In CVS-testing
this gives somewhat higher HC and CO emissions and lower NOx emissions.
Fuel specification and test results are shown in Table Saab-4. Saab
also has tested their 3-way catalyst for sulfate emissions and measured
H2SO, content as 0.00 gm/mi in all tests. Saab does not have the facility
to test for hydrogen cyanide.
Fuel economy figures from Saab's durability test vehicles are shown in
Table Saab-5.
7-353
-------
Table Saab-4
CVS-results with TWC-16, loading 15 gm/cu ft. and 50 gm/cu ft., aged on
motor-bench for 600 hours (about 50,000 miles) with fuel containing
manganese additives
Fuel Certification fuel - 77 but with 0.5 gm MMT/USG
(0.125 gm Mn/USG) added
Test cars: 658, auto., CVS-results without catalyst (gm/mi).
HC = 1.05 CO = 14.8 NOx = 3.32
686, manual, CVS-results without catalyst (gm/mi):
HC = 1.38 CO = 16.0 NOx = 2.83
Results After 350 hours, car 658
50 gm/cu ft. 15 gm/cu ft.
HC CO NOx HC CO NOx
Normally aged cat. 0.28 4.01 0.64
and 0 sensor
Mn-aged cat. and 0.34 5.83 0.56 0.46 6.00 0.99
0 sensor
\
After 600 hours, car 686
50 gm/cu ft. 15 gm/cu ft.
HC CO NOx HC_ CO NOx
Normally aged cat. 0.25 3.78 0.22 0.36 6.67 0.79
and 0 sensor
Mn-aged cat. and 0.23 4.66 0.24 0.28 5.85 0.78
normal 0~ sensor
Mn-aged cat. and 0.23 5.27 0.20 0.31 6.15 0.64
0 sensor
* 600 hours
7-354
-------
Table Saab-5
Saab Fuel Economy Data from Various Test Vehicles
EGR + Pulse Air
Vehicle No.
230
455
536
014
716
771
Emission
Targets Trans. MPG
1 M 18-20
A
16-18
A
M
A
M
Norm
MPG,. MPG Drive*
25-26 20.5-22.5 23-24
21-22 18-20 21-22
20.7
20.5
22.4
Mean Over
Miles
300-600
300-600
21,000
33,000
37,000
Compared to MY 1977 EPA Result (Saab reported)
MPG MPG, MPG
M
A
21
19
31
23
25
20
3-Way Catalyst Vehicles
658,686
018
019
059
745**
797**
800**
839***
168**
4
4
4
4
3
3
3
4
4
A,M
M
A
M
A
A
M
M
M
19-21
26-28
22-24
23-25
21.6
18.9
22.6
21.6
22.6
23.5
18-19
25-26
20.5-21.5
23.5
300-600
18,000
16,000
15,000
84,000
88,000
87,000
800
Compared to MY 1977 3-way cat. EPA Results (Saab reported)
u
M
A
MPG
i
23
21
33
25
MPG
c
27.5
22.8
* Measured fuel consumption on non-AMA durability test route.
** Durability vehicle.
*** Turbocharged engine
Emission Targets
1.5 HC/15 CO/2.0 NOx = 1
0.9 HC/9 CO/2.0 NOx = 2
0.41 HC/9 CO/1.5 NOx = 3
0.41 HC/3.4 CO/2.0 NOx = 4
0.41 HC/3.4 CO/1.0 NOx = 5
0.41 HC/3.4 CO,/ 0.4 NOx = 6
7-355
-------
Saab presented, in the following table, the first cost of the emission
control components of the model year 1978 and model year 1979-81 systems.
These costs are increased over the 1974 system except for the cost for
the turbocharged version. In that case the cost increments are to be
compared with the European version (uncontrolled) of the turbocharged
vehicle.
Table Saab-6
Model
Federal
__
—
—
—
—
11
24
(14)
—
2
3
40
(30)
$60
(45)
Year 1978
California
105
15
14
81
4
—
—
—
—
2
5
226
$339
Turbo.
105
15
—
85
4
—
—
—
12
2
7
230
$345
Model Year
1979-81
50 State
105
15
14
81
4
—
—
—
—
2
5
226
$339
Item
Closed loop control
Oxygen sensor
Exhaust manifold
3-way converter
Heat shield
Pulsair
EGR-proportional
Alternate EGR
Decel. system
Service Ind.
Assembly costs
Value Added
Sticker Price
Operating Costs
1. Fuel and Lubricant Costs
A comparison of composite fuel economy (miles/gallon) for
the Saab engine families as compared to model years is
given in the following table:
Engine Family
Manual, Federal
Automatic, Federal
Manual, California
Automatic, California
1977
25
20
27.5
22.8
1978
22
20
27.5
22.8
1979-81
24
Note: California fuel economy is better than Federal fuel economy
due to improved emission control technology.
7-356
-------
Table Saab-6 (cont)
Based on the previous information, the following shows fuel
costs for 50,000 miles of operation, assuming a fuel cost of
$.60/gallon:
1977 1978 1979-81
Manual, Federal $1,200 $1,360
Automatic, Federal 1,500 1,500 $1,648
Manual, California 1,086 1,086
Automatic, California 1,314 1,314
There will be no change in lubricant costs.
2. Maintenance Costs Other than Catalyst Replacement
The anticipated maintenance costs for 1977 and 1978 through 1981
as compared to 1974 models are given as follows:
1974 1977 1978-81
Parts Labor Parts Labor Parts Labor
Federal $188 14 hrs $193 26.4 hrs $241 26.4 hrs
California $188 14 hrs $241 26.4 hrs $--
The maintenance cost includes 3 changes of the oxygen sensor at
15,000 mile intervals at a cost of $16/change.
3. Catalyst Replacement Cost
The estimated life of the 3-way catalyst used in the ()„ sensor
control closed loop system is over 50,000 miles.
The initial cost of the catalyst, including the container, is
approximately $70. Although the replacement cost has not yet
been determined, it is estimated to be about $200. One-third
of an hour labor would be required for replacement of the catalyst.
7-357
-------
Turbocharged Engine
Saab maintains that the idea behind the turbocharged engine is not
basically to improve emissions and fuel economy but to maintain those
properties at a higher performance level. When the 3-way catalyst
system was adapted to the turbocharged engine, it was found that very
few changes were necessary, indeed the exhaust emission results were
very similar to the non-turbocharged version. Saab speculates that the
reason for this is that the exhaust inlet temperature at the catalyst is
lower than on the non-turbocharged which is compensated for by the lower
gear ratio in the turbocharged vehicle. Typical emission and fuel
economy data are shown in Table Saab-7. It should be noted that these
cars have not yet been optimized with respect to emissions. Saab plans
to test market 50 of these vehicles in the near future.
Table Saab-7
Turbocharged Vehicle Emissions and Fuel Economy Results
VIN
839
170
186
System
Turbo , no cat .
3 tests
w/ 3-way cat.
18 tests
839 w/new engine
wrong decel valve
setting, 4 tests
839 w/eng.
tune
w/ 3-way cat
w/o cat
w/ 3-way cat
FTP
HC
1.09
0.40
0.35
0.24
0.33
0.23
0.98
0.30
Results
CO
16.2
3.1
4.2
4.2
4.0
2.6
13.9
3.5
(gm/mi)
NOx
2.16
0.86
1.02
0.62
0.75
0.54
3.14
0.22
Fuel Economy
MPG MPG, MPG
u ' h c
17.2
17.2 23.4* 19.2*
18.5 25.2 21.1
17.7
18.2 24.5 20.6
- -
- -
* Two test results
7-358
-------
7.3.13.2. Systems to be Used at Various Emission Levels
The systems Saab plans to use at the various emission levels can be
found in Table Saab-8. Saab did not address levels of O.A1 HC, 3.A CO,
0.4 NOx directly but did indicate that the 3-way catalyst system has
potential at this level.
7.3.13.3. Durability Testing
The durability test results of vehicles equipped with a 3-way catalyst
system are shown in Table Saab-1. Since Saab plans to introduce the 3-
way catalyst system in California in May 1977, the durability testing
for certification of this system is well underway. Typical test results
for both the Federal and California vehicles can be found in Table Saab-
9. It appears that Saab will have little difficulty achieving the 1977
emission levels and in fact may have a good chance to meet statutory
levels in the very near future.
Durability testing of the turbocharged engine is just starting with none
of the six vehicles presently under test having accumulated more than
6,000 miles. One additional vehicle is planned for durability testing.
Since Saab feels that the 3-way catalyst's durability will not be a
problem, they have concentrated on solving the apparent durability
problems of the 0 sensor. Saab has developed four tests to establish
durability under high engine temperature conditions, ceramic failure at
low temperature, thermal shock, and normal vehicle road testing. To
date Saab reports that the production released sensor has reported few
failures on the various test cycles or vehicle durability tests. Those
sensors which have drifted, drifted to the rich side of stoichiometric.
Durability test fleet mileages on oxygen sensors have ranged from
11,000 to 50,000 miles on durability vehicles.
7-359
-------
I
L->
O*
o
Table Saab-8
Systems to be Used at Various Emission Levels
Naturally Aspirated Engines
Item
Compression ratio
-8.7
-9.25
Exhaust manifold
-Single
-Two-branch
Air Injection
-Pulsair
1978
1978
1979-80
1981*
1.5 HC, 15 CO, 2.0 NOx 0.41 HC. 9 CO, 1.5 NOx 0.41 HC, 3.4 CO, 2.0 NOx 0.41 HC, 3.A CO, 1.0 NOx
EGR
-Proportional
-Double port
alternative**
Catalyst 3-way
Catalyst location;
-Under floor
-Close to engine
Closed loop control-EFI
Fuel load enrichment
Service interval indicator
Turbocharged Engines
X
X
X
The turbocharged engines will be equipped with the same exhaust emission control
system as used on the naturally aspirated engine with the following differences:
-Compression ratio will be 7.5:1
-Full load enrichment will not be
used after 1978
-A new deceleration control system will be used.
(X)
X
X
(X)?
X
(X)
X
X
(X)?
X
* Saab did not address 0.41 HC, 3.4 CO
0.4 NOx directly but feels the three-way
system has potential to meet these levels.
** A vacuum reservoir keeps the EGR valve
open for 6 seconds on high load accelerations
and at sustained high Loads EGR is shut off.
( ) To be determined.
-------
Table Saab-9
1977 Durability and Data Vehicle Test Results*
Durability Vehicles, 99 GL Sed., 4 speed, 3000# I.W. , 3.89 Rear Axle
VIN
99-086
99-109
System
FI/EGR/PAIR
FI/3-way**
•j Data Vehicles Same as durability
u>
M
99-121
99-087
99-187
99-188
Trans.
M
M
vehicles
Miles (10-
5
50
Range
5
45
Range
except some
, FTP Results
) HC
1.34
0.90
0.7-1.42 5.
0.15
0.35
0.15-0.45 2.
equipped with
CO
6.4
5.4
4-9.6
2.7
5.0
7-6.4
NOx
1.81
1.87
1.72-1.98
0.71
0.82
0.38-0.93
Fuel Economy
MPG
u
17.7
14.5
14.5-17.7
18.7
17.6
15.5-19.6
MPG,
n
23.3
22.1
22.7
automatic transmission
FI/EGR/PAIR
FI/3-way
M
A
M
A
4
4
4
4
0.89
1.29
0.12
0.18
8.0
8.8
3.1
2.4
1.70
1.91
0.38
0.32
21.9
14.4
17.7
16.5
31.0
22.3
24.1
24.6
* Difficulties have been encountered with the Saab certification test results. Data have been
discovered where Saab failed to record background emission levels during the FTP testing along
with failure to comply with the 20 minute time limitation on measuring the bag emissions between
Bags 2 and 3. Correction factors are being developed by the Certification Division to correct
these data for the apparent anomalies.
** Three 0~ sensor changes approximately 15,000 miles each.
-------
In order to stress the oxygen sensor at low ambient temperature con-
ditions, a cold start test was conducted where the car was started
three times a day from a cold state and driven hard until the engine
reached normal operating temperature. Then the vehicle was stopped, the
engine was cooled down to ambient temperature and the cycle repeated.
The test was stopped after 221 cycles. The following test results were
noted.
Before HC 0.14 CO 2.36 NOx 0.19 gm/mi
After (221 cycles) HC 0.24 CO 4.88 NOx 0.57 gm/mi
7.3.13.4. Progress and Problems
Saab has experienced exhaust valve sealing problems during the durability
testing of the 3-way catalyst system. The inclusion of sodium cooled
valves has helped avoid excess HC emissions on subsequent tests. Improved
ignition cables were also necessary to alleviate a misfire problem also
noticed during durability testing. Other than these minor problems,
Saab has not reported the durability problems other manufacturers reported
for the 3-way catalyst system. They have reported, like other manufacturers,
that CO levels at 3.4 do not increase the chances of the 3-way catalyst
sustaining emissions below statuatory levels for 50,000 miles.
Because Saab has already accepted the cost of fuel injection and produces
vehicles with relatively low inertia weight, it is conceivable that Saab
will be able to meet exhaust emission levels of 0.41 HC, 3.4 CO, 0.4 NOx
in the near future. Saab's work to date indicates that they should have
no trouble meeting levels below 1.0 gm/mi NOx with improved driveability
and potentially improved fuel economy. Saab has aggressively developed
the 3-way catalyst system and consequently has the potential for meeting
the lowest emission levels proposed.
7-362
-------
7.3.14. Toyo Kogyo (TK)
7.3.14.1. Systems Under Development
Rotary Engine
TK is pursuing the development of three rotary engine concepts. These
are:
1. Lean Combustion System (LCS)
2. Compound Induction Step Control (CISC)
3. Rotary Stratified Combustion (ROSCO)
The LCS is the current production rotary used in both 49 state and
California vehicles. It is used on their 3000 IW vehicles. The LCS
replaced the older concept rich thermal reactor rotaries which suffered
from poor fuel economy. The current LCS engine is a twin rotor, 80 cu
in. unit with air injection, thermal reactor, and proportional EGR.
TK is working on several improvements to the LCS. These include im-
proved gas seals, modified combustion chamber, and HEI. TK indicates
that the LCS is capable of achieving emission standards as low as 0.41
HC, 3.4 CO, and 1.0 NOx. Table TK-1 shows emissions from an advanced
version of the LCS.
Shown in Figure TK-1, the CISC is a carbureted engine that achieves a
charge stratification by utilizing the natural swirl of the rotary and
introducing the intake charge through a novel porting arrangement. As
with the LCS, the CISC is equipped with air injection, thermal reactor,
and EGR. TK indicates that the CISC is capable of NOx emissions in area
of 0.7 to 0.8 gm/mi. It competes with advanced versions of the LCS at
the 1.0 gm/mi NOx level where it reportedly has improved fuel economy
and driveability over the LCS. Cost and producibility considerations,
however, cause TK to favor the LCS at this level.
7-363
-------
Table TK-1 shows emission and fuel economy results for the LCS and CISC
calibrated for the 1.0 NOx level.
Figure TK-1*
Compound Induction Step Control (CISC)
VALVE PERIPHERAL POUT
* Automotive News, 10 January 1977, page 23.
Table TK-1
Rotary Engine Emissions
IW HC CO
System
LCS
CISC
ROSCO
CID
80
80
80
NOx
3000 0.21-.28 2.2-2.98 0.85-.90
3000 0.25 2.0 0.68
3000 0.3 3.1 0.34
19.4 31.8
20.0 31.0
17.0 29.5
The ROSCO engine accomplishes charge stratification by injecting fuel
into the natural swirl of the rotary. The ROSCO system includes fuel
injection, air injection, thermal reactor, and EGR. TK indicates that
the ROSCO is capable of achieving statuatory emissions. Table TK-1 shows
emission results for a ROSCO system calibrated at this level. TK indicates
7-364
-------
that the current fuel economy penalty of the ROSCO can be reduced by the
application of the improved gas seals and HEI that are currently being
developed for the LCS. At present the ROSCO suffers about a 10% fuel
economy penalty at the 0.4 NOx level. The driveability of the ROSCO at
this level is reported to be good.
Figure TK-2*
Rotary Stratified Combustion (ROSCO)
PERIPHE-UI. PORT
SIOEPOBT
* Automotive News, 10 January 1977, page 23.
Conventional Engines
TK's previous first choice system for NOx levels below 1.0 gm/mi was
their Divided Chamber Stratified Charge (DISC) system. This system
resembled the Honda CVCC. TK now reports, however, that a new system
called the Stabilized Combustion System (SCS) has supplanted the DISC
system for meeting the 0.4 NOx level. The SCS system is a derivitive of
TK's system to meet the domestic Japanese 1978 emission standards. This
system uses a proprietary technique to substantially increase EGR
tolerance. This reportedly allows higher EGR rates with a resultant
improvement in NOx control without accompanying HC or driveability
7-365
-------
penalties. TK has also designed a new EGR system to be used in conjunction
with the SCS system. This EGR system has more proportional flow characteristics.
TK intends to use a 3-way catalyst along with the SCS at the statutory
emission level. This would be a carbureted, open loop system. TK
reported laboratory screening tests of many 3-way catalyst formulations.
7.3.14.2. Systems to Meet Various Emission Levels
Table TK-3 shows TK's first choice systems to meet the various emission
levels for rotary and conventional engines.
7.3.14.3. Durability Testing
TK provided no durability test data.
7.3.14.4. Progress and Problems
TK appears confident that it has a firm grip on the technology needed to
\
meet any of the various future standards under consideration. Questions
do remain in TK's mind concerning cost, fuel economy, and development
and production schedules.
The SCS system for the conventional engine is an example of TK's technical
talents and willingness to expend resources on research and development.
One weak point for TK is their lack of durability testing on their
advanced systems such as the ROSCO and SCS.
7-366
-------
Table TK-3
First Choice Systems to Meet Various Emission Levels
Level Engine
HC CO NOx
0.41 9 1.5 Rotary
Conv. 98 cu in.
Conv. 77 cu in.
0.41 3.4 2.0 Rotary
Conv. 98 cu in.
77 cu in.
0.41 3.4 1.0 Rotary
Conv.
0.41 3.4 0.4 Rotary
Conv.
LCS
AIR
AIR
LCS
AIR
AIR
LCS
AIR
System Fuel Economy*
: Thermal Reactor + AIR + EGR -1 to -10%
+ Exhaust Port Liners 0 to -15%
(aspirator type) + Ox. Cat. + EGR 0 to -15%
: Thermal Reactor + AIR + EGR -1 to -10%
+ Ox. Cat. + Exhaust. Port liners + EGR 0 to -15%
+ Ox. Cat. + EGR 0 to -15%
: Thermal Reactor + AIR + HEI + EGR 7 to 15%
+ Ox. Cat. or 3-way (open loop) + EGR
Cost
$5-9
$30-$60
$30-$60
$30-$60
$30-$60
-
-
ROSCO: Fuel Injection + Thermal Reactor + AIR 2 to 10%
SCS
+ 3-way (open loop) + EGR
-
* 1977 Federal emission standard is fuel economy base.
-------
7.3.15. Toyota
7.3.15.1. Systems Under Development
Toyota has several different types of systems under development to meet
future standards. These systems are shown in Table Toyota-1, along with
an indication of how they will be referred to in this report.
Table Toyota-1
Systems Under Consideration
Toyota System EPA System
Designation Description Designation
P2 EM+AI(AS)+EGR+CCo Oxidation Catalyst
P3 EM+AI+EGR+TR+CCo Thermal reactor plus
Oxidation Catalyst
P6 EM+AI+EGR+CCr+CCo Dual Catalyst
P7 EM+EFI+EGR+CCro 3-Way Catalyst
EM = Engine Modifications, AI = Air Injection, AI(AS) = aspirator,
EGR = Exhaust Gas Recirculatiori, TR = Thermal Reactor, CCo = oxidation
catalyst, CCr = reduction catalyst, CCro = 3-way catalyst with feedback
system, EFI = Electronic Fuel Injection
Toyota is adapting these systems to three basic engines, described in
Table Toyota-2.
Table Toyota-2
Basic Toyota Engines Types
Arrangement,
Toyota Designation Displacement, CID (litres) Number of Cylinders
2TC 96.9 (1.6) In-line, 4
20R 133.6 (2.2) In-line, 4
4M 156.4 (2.6) In-line, 6
7-368
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The Toyota engines will be referred to as the 1.6 litre-4, the 2.2
litre-4, and the 2.6 litre-6 in this report.
Oxidation Catalyst Systems
According to Toyota, 60 to 80% of the HC and CO emissions come from the
first peak of the emission test for catalyst equipped vehicles. The
primary reasons for this are: (1) the engine is still operating under
cold start enrichment, thus the HC and CO out of the engine are high,
and (2) the catalyst has not reached a high enough temperature to convert
HC and CO efficiently. This is shown in Figure Toyota-1.
As can be seen from Figure Toyota-1, the catalyst has not reached its
operating temperature of approximately 450° C until about 300 seconds
into the test. Note that during the first peak or "hill" of the driving
cycle (from zero to about 150 seconds), the catalyst temperature is less
than about 200°C, too low for good conversion of the high HC and CO
emissions being emitted from the engine.
Toyota has examined several ways to try to improve catalyst "light-off"
(bring the catalyst up to temperature quicker). Several approaches were
tried.
Thermal reactors were examined, in order to compare them to more
conventional exhaust manifolds. The concepts are shown in Table Toyota-
3.
7-369
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Figure Toyota-1
Catalyst Bed Temperature During the LA-4 Driving (3K-C for 49-States)
20- - :•
63r
100
200
300
400
soo
600 700
Tine (sec)
800
900
1,000
1,100
1,200
1,300 1,372
-------
Table Toyota-3
Manifold/Reactor Comparison
Description Weight (kg) Volume (litres) Insulated ?
Exhaust Manifold A 4.3 2 no
Thermal Reactor A 10.0 1.5 yes
Thermal Reactor B 4.8 1.3 yes
Exhaust Manifold B 7.4 2 no
The results of the testing are shown on Figure Toyota-2.
Figure Toyota-2 indicates that the A-type exhaust manifold generally had
the best effect on promoting catalyst light-off. However, this does not
necessarily mean that the emissions would be the best for this configuration.
This is because it is important to know what the emissions were before
the catalyst lit off. Toyota ran emission tests on the four configurations.
The results are shown in Table Toyota-4.
Table Toyota-4 shows that the B-type thermal reactor was about the same
in tailpipe (after CCo) emissions as the A-type exhaust manifold.
\
The reactor-out emissions from the B-type thermal reactor were actually
lower than the manifold-out emissions from the A-type exhaust manifold.
Toyota chose the A-type manifold for further considerations, because the
catalyst inlet temperatures were too high with the B-type thermal
reactor, according to Toyota.
The results shown on Table Toyota-4 are interesting because they show
that the parameters of thermal reactor/manifold volume, weight, and
insulation characteristics are all important. Toyota did not provide
enough data on the engine calibrations for all the cases to be able to
determine if the emission results shown can be attributed to only the
parameters studied. The results do indicate that lightweight, large
thermal reactors are more effective than heavier, smaller ones.
7-371
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Figure Toyota-2
The Effect of Exhaust Manifold and Thermal Reactor
on the Temperature in the Exhaust Svstem (2T-C)
i
CO
1.000—i
900 —
800—
700 —
600 —
I
I
500 —
400
300 —
200 —
100 —
0 -
Exhaust Manifold A
Thermal Reactor A
Thermal Rcacor B
Exhaust Manifold B
-------
Table Toyota-4
The Effect of Exhaust Manifold and Thermal Reactor on
the FTP Emission Test Results
Type
Ex.
Manifold A
Thermal
Reactor A
Thermal
Reactor B
Ex.
Manifold B
Before CCo
After CCo
Before CCo
After CCo
Before CCo
After CCo
Before CCo
After CCo
Composite (g/mile)
HC •
0.570
0.072
0.861
0.136
0.445
0.074
1.026
0.108
CO
11.783
1.624
17.241
2.737
8.804
2.175
17.377
1.649
NOx
0.854
0.844
0.813
0.754
0.776
0.728
1.025
1.040
Cold (g/test)
HC
3.317
0.835
5.675
1.881
3.344
0 . 997
5.729
1.300
CO
60.496
19.450
99.274
36.84
64.951
26.063
99". 4 34
19.71
NOx
5.071
4. 804
4.789
4.347
4.629
4.197
6.081
5.863
Hot 1 (g/test)
HC
1.826
0.128
2.538
0.136
1.137
0.069
3.558
0.144
CO
40.664
2.757
56.783
3.490
21.319
2.965
59.895
2.977
NOx
2.126
2.140
1.960
1.894
1.897
1.861
2.419
2.520
Hot 2 (g/test)
HC
1.788
0.098
2.618
0.131
1.337
0.093
2.931
0.178
CO
38.062
1.858
52.346
2.094
29.439
3.751
48.550
1.600
NOx
3.672
3.683
3.644
3.318
3.390
3.148
4.653
4.835
Fuel Economy
(mpg)
17.08
17.53
17.74
18.18
I
U>
-------
Toyota has also looked at the effects of air pump flow rate. Two air
pumps were studied, one with 150 cc/rev and one with 220 cc/rev. The
emission results are shown on Table Toyota-5 for a vehicle with the 1.6
litre-4 engine, and the effect on catalyst light-off is shown on Figure
Toyota-3.
Table Toyota-5
Effect of Air Pump Displacement
Air Pump Grams Emitted During Bag 1
HC (tt NOx
150 cc/rev 3.84 65.8 8.97
220 cc/rev 1.13 24.3 9.99
The results shown on Table Toyota-5 imply significant reductions in the
HC and CO emissions from the whole test, since Bag 1 includes the cold
start portion of the test and accounts for most of the emissions. Reductions
of about 40 to 50% in HC and CO could be expected on the whole test,
however Toyota did not report the results from the complete test.
Figure Toyota-3 shows why the HC and CO emissions are reduced. The
catalyst lights off much faster with the larger air pump. Toyota
indicated that because of the NOx increase seen in Bag 1 they would try
to offset that by making the air-fuel ratio richer, which will be
another reason to use the larger air pump. At light loads under warmed-
up conditions, there will be too much air injected which might quench
the reactions in the manifold. Toyota plans to divert some of the air
pump discharge into the air cleaner during these conditions.
The effect of air pump volume was also examined on a 3000 IW vehicle
equipped with a 5-speed manual transmission and the 2.2 litre-4 engine.
Hot start tests were run, because the vehicle was apparently 0 deficient
on the second hill of the test. The results are shown in Table Toyota-6.
7-374
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I
u>
~J
IJ1
Figure Toyota-3
The Effect of Air Pump Volume on the Temperature in the Exhaust System (2T-C)
1,000—1
900 —
100
700—
600—
« soo—
400— —
300—
200 —
100—
Air pucp 220 cc/rev.
Air pump ISO cc/rev.
120
-------
Table Toyota-6
Effect of Air Pump Displacement
Air Pump Emissions - Hot Start 1972 FTP
Displacement HC_ CO NOx
220 cc/rev 0.056 0.812 1.605
375 cc/rev 0.049 0.523 1.576
Table Toyota-6 indicates that the CO benefit for the larger displacement
was the greatest, although all three pollutants were lowered with the
larger displacement air pump.
Air injection system modifications have also been explored by Toyota.
Current systems divert some of the injected air into the air cleaner
during deceleration and shifting to eliminate backfiring. A different
approach is to inject the air right in front of the catalyst during
these modes. The results are shown on Figure Toyota-4.
Figure Toyota-4 shows some CO benefits on the hot start test. The HC
impacts are not consistent. The HC emissions went up with an aged
catalyst, for example.
A control technique that is similar to increasing the vacuum break was
explored. This system was activated by coolant temperature.
As shown on Table Toyota-7 the Bag 1 emissions were reduced for HC and
CO but increased for NOx, much in the same manner as the larger air
pump. Toyota also reported that the driveability with the increased
choke opening was poorer.
7-376
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Figure Toyota-4
The Effect of Air Injection Before CCO
on the HC and CO Emission (2T-C)
0 10 •-
008
OOfi __
OA A ,__
• U<1 ""'
OH9
PI Y7\ r— i
! \\\
With fresh catalyst
01 n
Ono. ..
00,6
0.04—
0 02 ...
—
-• t
'"<$
II
'•^i
H
• -^.
—
1
With aged catalyst
1.0 —
00
Ofi ...
0.4 _
00
n
n
'•''•••• - f?3 -
1 1 -
'"M S-f
.'•• ^
'.V.i; •>•
Oi ^
Without catalyst
CJ
Direction of air injection at the time of deceleration
_E3. Air cleaner \
%& Before catalytic converter
II Exhaust port
CO Emission (g/mile)
Oc
. 3 —
OA
. t — •
00 _
n 2
0.1 —
•S -ffl
I 1
n
With fresh catalyst
0.5—j
0.4 —
0-1 _
0.2 —
0.1 —
n
rr
—
'" ' '.f
^•, ••
i
......
—
, — ,
....
—
With aged catalyst
25—
^ U —"
15—
10 —
5 —
o
p?
-
-
\
I
-
.....
Without catalyst
7-377
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Table Toyota-7
Effect of Choke Opening
Grams Emitted During Bag 1
System HC CO NOx
Older system 1.89 43.3 8.7
Newer system 1.13 24.3 9.9
Spark retard and increased idle speed are other techniques to promote
fast warm-up. Toyota's results with this approach are shown on Table
Toyota-8.
Table Toyota-8
Effects of Idle Speed and Retard
Emissions, 1975 FTP*
Idle Speed/Retard? HC CO NOx
2400 rpm - no 0.285 1.40 1.65
3400 rpm - yes 0.171 0.971 1.49
* assumed to be on 1975 FTP - not specifically stated by Toyota.
Toyota did not quantify the effects of the vacuum spark retard and
increased idle speed on fuel economy. Directionally, both approaches
tend to make fuel economy poorer. The actual extent of the fuel economy
impact will depend on how much these techniques are employed during the
test.
Results from tests run to examine the effects of a catalyst volume were
also reported. Toyota examined the effect of increasing the catalyst
volume on two vehicles. Only the transmissions on the vehicles were
specified. The results are shown in Table Toyota-9.
7-378
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Table Toyota-9
Effect of Catalyst Volume
Emissions - 1975 FTP
Catalyst Volume Vehicle HC CO NOx MPG
2.5 litre 5-speed manual 0.10 2.30 0.60 16.0
3.0 litre 5-speed manual 0.10 2.03 0.63 16.2
2.5 litre 3-speed auto 0.08 1.92 0.67 16.2
3.0 litre 3-speed auto 0.06 1.64 0.64 17.1
Table Toyota-9 indicates that the larger catalyst volume reduced HC and
CO somewhat. The small improvement in fuel economy with the larger
catalyst may or may not be a real effect. Toyota did not report details
of the calibrations or the number of tests run.
Toyota has experimented with several different ways to improve the warm-
up emission performance of their vehicles. Due to the lack of specific
vehicle calibration and description, it is not known if the results
reported in the Toyota submission, especially the durability vehicles,
used any of these technical approaches.
Toyota also reported information about how the spark timing, air-fuel
ratio, and EGR rate vary during the emission tests. These results are
shown on Figures Toyota-5, Toyota-6, and Toyota-7.
These figures indicate that the air-fuel ratio control used on some
current systems permits wide swings in air-fuel ratio ranging from A/F
values of 30 or more to A/F values of 10, depending on the mode. This
wide range in air-fuel ratio may point to the need for improved fuel
metering on future vehicles.
3-Way Catalysts
Toyota considers the 3-way catalyst system to be their best candidate to
meet future stringent emission standards. Toyota has an extensive
7-379
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„»!<>
~J
1
UJ
oo
o
_ 60
5
1
E
v°
a
u
220
o
«M
c
f)
z
1
"1
-
1.
1
1
.
1
1
'
1
1
:il
;i.
!i
: il
Figure Toyota-5
EGR Rate During the LA-4 Driving Using
the Computer Simulation Model (3K-C for for 49-States)
ou
60
40
100
200
300 <00 500
600 700 800
Time (sec)
900
1.000 1,100 1,200 1,300 1,372
-------
I
u>
oo
Figure Toyota-6
Spark Timing During the LA-A Driving (3K-C for 49-States)
100 200 300 400 500 600 700 800
Tine (sec)
900 1,000 .1,100 1,200 1,300 1,372
-------
Figure Toyota-7
Air-Fuel Ratio During the LA-4 Driving (3K-C for 49-States)
CO
oo
NJ
30r
10«-
^^
100
200
300
400
500
600
700
800
900
1,000 1,100 1,200 1,300 1,372
Time (sec)
-------
catalyst screening program underway to evaluate potential 3-way catalyst
candidates. The results from a Toyota-developed 3-way catalyst are shown
on Figures Toyota-8 and Toyota-9.
No details of the catalyst were provided by Toyota, except to say that
this catalyst was a Pt/Rh pelleted catalyst. Catalyst "T" is the best
catalyst for which data were reported by Toyota. Efficiency information,
read from Figure Toyota-9 is shown on Table Toyota-10.
Table Toyota-10
Parameters from Aged Catalyst "T"
Parameter Efficiency Location
HC Max - 95% lean 14.8/1 A/F
CO Max - 98% lean 14.7/1 A/F
NOx Max Net - 97% slightly rich 14.55/1 A/F
HC/NOx crossover 93% approx. 14.6/1 A/F
CO/NOx crossover 91% approx. 14.6/1 A/F
The window width at 50% conversion efficiency is about 0.1 A/F units,
from approximately 14.5/1 to 14.6/1. This type of aged 3-way catalyst
performance is much better than the other 3-way catalysts reported by
Toyota, and appears to be competitive with the better 3-way catalysts
reported to date. However, differences in the type of catalyst aging
tests among those examining 3-way catalysts make absolute comparisons
difficult.
Toyota has also examined "stabilized" Ru catalysts, but the results have
not been good, indicating that Ru is lost under oxidizing conditions.
Toyota is experimenting with pelleted 3-way catalysts containing Pt/Rh on
vehicles. The catalyst loading was not supplied by Toyota. Apparently
Toyota is concentrating the development on vehicles with the 2.6 litre-6
engine because that may be the most difficult combination to control.
7-383
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CATALYST: T FRESH
100
ol
u
55
u
H
O
H
Ex.
U
O
K
W
>
13.0 13. k 13.8 1^.2
15.0 15. '<
A/F
Figure Toyota-8
Catalyst Dynamometer Testing
7-384
-------
CATALYST T AGED
(after 600Hrs. durability test)
O
w
O
H
b.
Cc.
U
O
M
K
U
>
6
o
A/F
Figure Toyota-9
Catalyst Dynamometer Testing
7-385
-------
At the 1.0 NOx level HC and CO have been more difficult to control than
NOx, according to Toyota. They examined the influence of fresh versus
aged components in the 3-way catalyst system. The testing was conducted
on a 3000 IW vehicle, equipped with the 2.6 litre-6 engine and a 4-speed
manual transmission. The results are shown on Table Toyota-11.
Table Toyota-11
Effect of Fresh and Aged Components
Catalyst
Condition
Fresh
Fresh
Aged
Apparently, the aged catalyst had the biggest effect on emissions. Bag
data reported by Toyota indicated that cold-start control was the major
problem. To attempt to solve this, Toyoto examined several approaches.
The first approach involved the use of a quick warm-up manifold. Tempera-
tures during the test are shown in Figure Toyota-10.
Directionally the quick warm-up manifold should yield lower emissions,
because the catalyst is warmed up quicker.
As is the case with oxidation catalyst systems, the influence of catalyst
volume is also an important parameter. Toyota studied two catalyst
volumes. The results are shown on Table Toyota-12.
on 3-Way Catalyst
Sensor
Condition
Fresh
Aged
Aged
System Performance
Emissions - 1975
HC CO
0.24 2.07
0.24 1.81
0.41 2.89
FTP
NOx
0.42
0.44
0.73
7-386
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Current type
manifold
Warm-up
manifold
exhaust gas temperature
catalyst bed temperature
exhaust gas temperature
catalyst bed temperature
1
460°C
190°C
530°C
200°C
2
490°C
240°C
570«C
260°C
3
530°C
280°C
600«C
320°C
1st Peak of the LA*4
Figure Toyota-10
7-387
-------
Table Toyota-12
Effect of Catalyst Volume
Emissions - 1975 FTP
Catalyst Volume HC C£ NOx
2.5 litre 0.23 2.20 0.56
3.0 litre 0.24 2.10 0.55
The emissions were not improved very much. The bag data indicate that
light-off was not improved with the larger catalyst. It is not known if
either catalyst was oxygen deficient on the cold start.
In order to improve the warm-up characteristics, Toyota tried a start
catalyst in conjunction with the 2.5 litre catalyst. The start catalyst
was a monolithic oxidation catalyst 30 mm (a little more than 1 inch) in
length, located directly under the exhaust manifold. The main catalyst
was a 3-way catalyst.
The results are shown in Table Toyota-13.
Table Toyota-13
Effect of a Start Catalyst
Emissions - 1975 FTP
Catalyst System Type HC C0_ NOx Fast Idle Speed
2.5 litre 3-way 0.22 1.78 0.56 1800 rpm
catalyst
2.5 litre 3-way 0.17 2.30 0.24 1800 rpm
catalyst + start catalyst
2.5 litre 3-way 0.21 2.74 0.31 1200 rpm
catalyst + start catalyst
7-388
-------
Some HC reduction was observed, but the CO performance was not as good
with the start catalyst. The NOx emissions were much lower with the
start catalyst. Toyota did not provide enough information to determine
the precise reason. The engine calibrations could be different (i.e.,
richer) with the start catalyst system, or the start catalyst could be
using up some of the oxygen making the air-fuel mixture into the main
catalyst oxygen deficient. However, these reasons are just conjecture,
because Toyota did not provide enough detail to properly explain the
results. In general, the use of a start catalyst would not have been
expected to have had as great an impact on the NOx emissions from a 3-way
catalyst system as are indicated in Table Toyota-13.
Figure Toyota-11 shows the transient temperature performance of the
systems described in Table Toyota-13.
Reductions in HC and CO from zero to 20 per cent using air injection on
start-up only were reported by Toyota, but no further details were reported
and Toyota apparently does not consider the technique to be cost
effective.
Dual Catalyst Systems
Toyota has worked for several years on dual catalyst systems. Not a
great deal of information concerning low mileage system testing was
reported by Toyota on this type of system. The majority of the Toyota
results with dual catalyst systems are reported in the section on durability
testing.
Other Systems
If 0.4 NOx had to be achieved without the use of catalytic control of
NOx, Toyota believes that this would require engine specific NOx emissions
of 0.5 to 1.0 grams per indicated horsepower-hour under any operating
7-389
-------
Figure Toyota-11
Exhaust Gas and Catalyst Bed Temperature
During the 1975 FTP (w/Start Catalyst-4M)
i
u>
VO
o
[Notes] Fast Idle-Base line : 1200rpm
Fast Idle up : ISOOrpm
500-
400-
300-
200-
100- -
CCatalyst Bed Temperature]
Catalyst+2.51 Main C
Idle-standard)
-^Start-Catalyst + 2.5(2. Main Catalyst
(Fast Idle up)
talyst
-------
conditions. As far as emissions are concerned, this would be equivalent
to an open furnace type of combustion that is below 100 to 150 ppm NOx.
Toyota stated:
"There may be some approaches for achieving such a low NOx emission in
the cylinder of an engine."
According to Toyota, the approach that uses stoichiometric fuel metering
plus high EGR rates seems to have the highest potential.
Toyota stated that when EGR is studied, the amount of EGR is not the
most important parameter. They feel that the burned gas ratio (BGR) is
the important parameter to study. The burned gas in the cylinder is
defined by Toyota to be the sum of the residual gases and the EGR in the
cylinder. Figure Toyota-12 shows the relationship among BGR, EGR, NOx,
ISFC, and IMEP as a function of manifold pressure.
Figure Toyota-12
Effect of EGR and BGR on NOx, IMEP and ISFC under
Various Charge Efficiencies (Engine B, Engine Speed 2000 rpm,
Spark Timing 0.95 MET)
300 400 500 600 700
Manifold Pressure mmlll« ahs-
7-391
-------
Toyota indicated that Figure Toyota-12 shows that EGR as a constant
proportion of intake air (proportional EGR) is not the best way to
control NOx. The values of constant BGR in Figure Toyota-12 (assumed to
be the dashed lines in the lower portion of the figure) do show a more
direct relationship to ISNOx, for all manifold pressures.
It appears that BGR values of 25% or more may be needed to achieve the
0.5 to 1.0 ISNOx values. Toyota did not indicate how this could be
achieved in a practical system. It might be accomplished by having the
EGR rate increase as manifold pressure increases, which can be inferred
from Figure Toyota-12.
Toyota uses some heat conservation techniques on some of their current
vehicles. Port liners and thermal reactors are two examples. A cast
case, stainless steel outer core, stainless steel inner core thermal
reactor was used on the 1976 Land Cruiser model. Temperatures increased
by 200°F resulting in a sharp HC reduction, but it is expensive and
difficult to produce, according to Toyota. Toyota also used a ceramic
liner cast on the branches of a thermal reactor. A schematic of this
system is shown on Figure Toyota-13.
Figure Toyota-13
Thermal Reactor Configuration
Insulatior
ies Pick-up Port
-------
Toyota also reported that they are working on ceramic port liners.
Current ones are metal. A schematic of the port liner is shown in
Figure Toyota-14. No details were presented.
Figure Toyota-14
Exhaust Port Liner
Ex. Port
Portliner
The use of ceramics may also be extended to piston heads and cylinder
liners. Previous attempts to reduce HC in the quench layer by use of
stainless steel were not effective and caused a torque loss and spark
knocking.
Other Engines
Toyota has two engines under development that utilize a small Turbulence
Generating Pot (TCP) in the combustion chamber to increase turbulence
and thereby extend the lean limit. The TCP is a small alloy steel
cavity located adjacent to the spark plug. The spark plug tip is
located at the mouth of the cavity and after the mixture is ignited the
outrushing gas from the TCP greatly increases the combustion chamber
turbulence. Toyota has two versions of this concept, the TTC-V and
TTC-L. The TTC-V is similar in principle to the Honda CVCC. It has an
7-393
-------
intake valve located in the TCP which is fed a richer air-fuel ratio
than the main chamber. Toyota reported a limited amount of development
work on the TTC-V. This was in the area of engine modifications and
heat conservation measures. These were intended to increase turbulence
and conserve exhaust gas heat and thereby allow further enleanment to
better optimize emissions, fuel economy, and driveability. These
modifications were: a cast in place exhaust port liner; increased
compression ratio (from 8.0 to 8.3); added squish area in combustion
chamber; and insulated exhaust manifold. Toyota did not present U.S.
emission test results for a system incorporating these changes.
The second version of the TCP concept is the TTC-L. Shown in Figure
Toyota-15, the TTC-L is a simpler engine. This engine has the TCP but
does not have an intake valve located in it. Thus the TCP receives the
same air-fuel ratio as the rest of the chamber. Toyota reported that
development work was proceeding on the TTC-L in the following areas:
improved ignition system; modified TCP; investigation of main chamber
configuration; improvement of mixture distribution; and addition of an
oxidation catalyst. No U.S. emission test results were provided on this
work.
Figure Toyota-15
TTC-L Engine
turbulence f
generati
exhaust
valve
exhaust
port liner
7-394
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Fuel Economy
Toyota reported fuel economy results comparing some developmental
systems targeted toward stringent emission standards to some current
(model year 1977) vehicles. Figure Toyota-16 shows the results for
manual transmission vehicles and Figure Toyota-17 shows the results for
vehicles equipped with automatic transmissions. Note that these are
steady state fuel economy results.
The prototype vehicles in Figures Toyota-16 and Toyota-17 are Corona
vehicles, targeted for 0.41 HC, 3.4 CQ, 1.0 NOx. In general, the
prototype vehicles targeted toward much more stringent standards show
much improved fuel economy over the 1977 Corona models, although some
axle ratio differences are apparent.
These results are also important because they show that the Corona
prototype vehicles have better fuel economy than some of the Corolla and
Celica models for 1977. The Corona vehicle is typically a 3000 IW
vehicle, whereas the Corolla is generally 2250 IW and the Celica is 2750
IW. Thus, the prototype vehicles returned better fuel economy on this
test than some current lighter weight Toyota vehicles.
The only vehicle that significantly bettered the prototype vehicles was
the 1977 3 K-C Corolla. The 71 CID 3 K-C engine was dropped from the
U.S. market for 1975. It was re-introduced in 1977 as part of a fuel
economy package. Toyota claims that more stringent standards will cause
this engine to be dropped again. Toyota presented no data on any system
optimization of this engine for future standards, so the reasons behind
their claim cannot be examined. The certification results from the 3 K-
C do not appear to indicate major problems.
These fuel economy results indicate that Toyota has the potential to
improve fuel economy and emission control over their current systems.
7-395
-------
Figure Toyota-16
Comparison of Fuel Economy of 1977 and Prototype
(0.41-3.4-1.0) Model Steady State Drive Pattern (2)
[Manual Transmission]
(km/£)
Ns, .Vehicle
'Vi No.
•*o
Vehicle •fvsl
speed (mphKO
30
35
40
50
60
70
60
RT- FF *
'.. -10
2 , 909-
15.5
14.4
13.2
11. S
10.4
RT- PF *
.. -18
3,727
16.7
15.1
13.6
12.3
10.9
'77 3K-C
Corolla
(5M/T)
4,100
(4th)
18.9
17.1
15.9
13.4
11.0
9.3
•77 3K-C
Corolla
(4M/T)
3 , 90<»
18.5
17.1
16.1
13.7
11.3
•77 2T-C
Corolla
(SM/T)
.1 , 009
(4th)
16.1
14.7
13.1
12.0
10.3
'77 2T-C
Corolla
(WT)
4,] 00
(4th)
15.6
14.7
13.2
12.1
10.6
•77
Celica
(5!'./T)
3,583
(4th)
12.3
12.6
12.3
11.0
10.1
8.7
•77 |
Corona
(4M/T)
3,583
13.1
12.9
12.9
12.1
11.6
9.4
8.3
Prototype (0.41-3.4-1.0)
18 •
IT •
16-
I !SH
~ 14 1
o
w L'2 -
-------
Figure Toyota-17
Comparison of Fuel Economy of 1977 and Prototype
(0.41-3.4-1.0) Model on Steady State Drive Pattern (1)
{Automatic Transmission]
(km/A)
i1
o
0
o
w
• -a
>cicl
-------
7.3.15.2. Systems to be Used at Various Emission Standards
1.5 HC. 15 CO. 2.0 NOx
For these emission levels, Toyota would apparently keep the same systems
as the ones in current (1977) use. One exception is the 1.6 litre-4
engine family. This would be modified to incorporate higher compression
ratio, a different camshaft, a smaller intake port diameter, and a 1.5
litre catalyst. This is done to improve fuel economy, driveability, and
engine performance, according to Toyota.
0.41 HC. 9 CO. 1.5 NOx
Toyota reported that they would have no problems technologically in
meeting this standard. Their vehicles could comply on a Federal basis,
according to Toyota. If the methane exclusion would not be permitted
for 0.41 HC, then Toyota would adopt double wall exhaust pipes to
improve the HC performance. Toyota did not indicate if they would
include this potential improvement for increased HC emission control,
which might permit a better fuel economy calibration, if the methane
credit was given.
Toyota's major problems with this standard are cost and lead time. Lead
time is just about gone for 1978, according to Toyota, due primarily to
the need to get air pumps and catalysts from vendors.
0.41 HC. 3.4 CO, 1.0 NOx
Toyota has run evaluation tests on their oxidation catalyst and thermal
reactor plus oxidation catalyst systems targeted toward this level.
Some results are shown in Table Toyota-14. The vehicle is a 2750 IW
Corona with the 2.2 litre-4 engine.
7-398
-------
Table Toyota-14
Potential 0.41 HC. 3.4 CO. 1.0 NOx Systems
System
Oxidation catalyst
Thermal reactor plus
oxidation catalyst
Oxidation catalyst
Thermal reactor plus
oxidation catalyst
Catalyst Input Emissions - 1975 FTP
HC CO NOx
0.749
0.583
11.08
11.09
1.2
1.28
Tailpipe Emissions - 1975 FTP
HC CO NOx
0.219
0.208
3.95
4.85
1.10
1.13
7-399
-------
Toyota attributed the better CO performance of the oxidation catalyst
system to quicker warm-up. The NOx performance shown in Table Toyota-14
does not appear to be sufficient for a 1.0 NOx standard for either
system.
Although Toyota has done much work with oxidation catalyst and thermal
reactor plus oxidation catalyst systems targeted for 1.0 NOx, they now
are concentrating on the 3-way catalyst approach for 0.41 HC, 3.4 CO,
1.0 NOx.
A system incorporating electronic fuel injection is receiving the most
attention although Toyota did indicate that they are working on a
carbureted back-up system, even though the carbureted package is
considered by Toyota to be less promising from an emission control
standpoint.
0.41 HC. 3.4 CO, 0.4 NOx
Toyota has investigated three systems for this emission standard.
They reported that they were able to attain the required emission
levels at low mileage with the thermal reactor plus oxidation catalyst
system, but the durability is not considered adequate by Toyota. The
fuel economy and driveability performance of this system is also not
good, according to Toyota.
Toyota's experiments with dual catalyst systems have indicated a lack
of durability for the NOx catalyst. Ammonia formation and warm-up
characteristics also remain a problem. Toyota is concentrating their
efforts in the area of NOx catalyst development now. System work will
await further catalyst improvements.
Toyota will concentrate their efforts toward meeting 0.41 HC, 3.4 CO,
0.4 NOx on 3-way catalyst systems.
7-400
-------
7.3.15.3. Durability Testing
Toyota's plans for durability testing are shown on Figure Toyota-18.
Figure Toyota-18 indicates that Toyota has completed durability testing
on some systems. The most current durability testing is targeted toward
0.41 HC, 3.4 CO, 1.5 or 1.0 NOx, according to Figure Toyota-18, not 0.41
HC, 3.4 CO, 0.4 NOx.
Toyota reported durability test data from 23 vehicles. The 3-way
catalyst and dual catalyst systems are of the most importance and are
reported in Table Toyota-15.
Table Toyota-15
Emissions Results from
Prototype Durability Vehicles
Highest Mileage Emissions
VIN System Reported HC_
TA-159 3-way 30,000 0.75
TA-159* 3-way 30,000 1.01
TA-158 3-way 28,100 0.28
TA-205 3-way 18,800 0.46
TA-204 3-way 20,000 0.39
TA-212 3-way 18,600 0.57
TA-212* 3-way 18,600 0.48
TA-213 3-way 31,100 0.60
TA-213* 3-way 31,100 0.65
MX-PF-302 3-way 15,000 0.41
MX-PF-10 3-way 15,000 0.40
TA-202 Dual 18,800 0.47
TA-208* Dual 18,800 0.43
TA-201 Dual 30,000 0.48
TA-201* Dual 30,000 0.40
TA-207 Dual 20,000 0.57
TA-215 Dual 18,600 0.20
TA-216 Dual 18,600 0.27 0.82
CO
27
42
91
63
70
18
26
97
4.62
2.23
28
30
05
86
90
48
06
5.
7.
1.
3.
3.
4.
3.
3.
NOx
0.64
0.41
0.90
0.97
0.60
0.38
0.37
1.00
0.37
0.62
0.78
,01
.25
0.70
0.55
0.92
1.42
1.75
2.
1.
* After maintenance
7-401
-------
Figure Toyota-18
1977 thru 1981 Test Program Status
1975
1976
1977
—T~
123456789
3 4
5 6 7 8 9 10 11 12
1 2 3 4 5 6 7 89 10 11 12
o
ts>
Phase 5
\ Phase 6-1
Phase 6-2
L
"VPhase 7
Deve
Step 1 Test
( , i initially Schedule
G • • .'.••; rescheduled
acutual
//'//\ estimated
lopment and Durability
of Preliminary Prototype
vehicles
[Emission Target : 0.41/3.4/0.4]
(1.0)
/ Developmen
Step 2 [ Testing of
and
proposed
[Emission Target
0.41/3.4/1.5])
(1.0)
c.
(2T-C)
^ (20R)
(4M)
-------
None of these prototype vehicles completed 50,000 miles of durability
testing. Typical of developmental durability testing, components were
replaced when necessary and recalibrations were performed during mileage
accumulation. No details of the systems or the catalysts were provided
by Toyota, so it is not known what types systems or catalysts (if any)
were used on these vehicles. Based on the results in Table Toyota-15,
it appears that Toyota has more difficulty controlling HC and CO than
NOx with 3-way catalyst systems at the 0.41 HC, 3.4 CO, 1.0 NOx levels.
7.3.15.4. Progress and Problems
Toyota has made some progress in developing systems to promote quick
warm-up of catalytically controlled emission control systems. They have
also made progress in identifying the basic system type that will be
investigated in an attempt to meet future emission standards. At least
one promising catalyst has been identified in Toyota's catalyst evalua-
tion process.
The lack of acceptable emission control from prototype vehicles at high
mileage appears to be one of Toyota's major problems. Toyota reported
problems with cold-start emission control, cost, and manufacturability
with several of their advanced concepts.
Toyota has apparently not combined and tested all of the components of
the emission control system, including, for example, the most promising
catalysts and cold-start control approaches. Therefore, this lack of
information about the capability of more advanced systems is a problem
in estimating Toyota's capability to comply with future emission standards.
The advanced control techniques under investigation by Toyota do show
promise, however.
7-403
-------
7.3.16. Volkswagen (VW)
7.3.16.1. Systems Under Development
Oxidation Catalysts
Volkwagen reported continued research on their improved oxidation
catalyst which was just reported to EPA last year. This new improved
oxidation catalyst is a 74 cu in. Johnson Matthey monolithic catalyst with
a specified Pt/Rh ratio ranging from mine mix (19/1) to the (5/1) ratio
employed on the Volvo vehicles. While this level of rhodium is unusual
for on oxidation catalysts, the range is too broad and might allow VW to
manipulate the Pt/Rh loading in production to be significantly different
from that in certification, with potential emission differences.
Because of this broad Pt/Rh range and the use of rhodium in VW's ox-
idation catalyst, VW is able to obtain some NOx control with their
oxidation catalyst. In response to a question from EPA, VW admitted
that it was their intention to use their oxidation catalyst to control
NOx during rich excursion from normal lean fuel metering operation, i.e.
power enrichment.
In addition to attaining NOx control, VW has agressively sought to
reduce their oxidation catalyst's size and now have reduced the catalyst
length from six inches down to three inches. Last year status indicated
that VW was experimenting with oxidation catalysts lengths as short as
one inch long. These one inch long oxidation catalysts showed power
poor NOx conversion efficiencies, but only slightly reduced HC conversion
efficiency. Last year's data indicates that VW's three inch long
catalyst may not be the smallest optimum length yet in light of VW's
increase of cell density from 200 to 300 per square inch.
For 1978 VW has introduced a mechanically actuated EGR valve on its
carbureted, water cooled, 49 state models and on its air cooled 49 state
and California models. The valve is shown in Figure VW-1. All
7-404
-------
of these systems provide a cooled exhaust gas input to the valve, which
should provide additional NOx control. The valve is actuated by a
mechanical linkage which is connected to the throttle. VW claims that
this system provides EGR at a rate proportional to intake air flow. As
with most EGR systems, the flow is cut off at idle and wide open throttle,
Figure VW-1
Mechanical EGR Valve
flo* ilrmtlm
Included with the VW mechanically actuated EGR description there was
mentioned an EGR filter. The VW submission was not clear whether the
EGR filter was applicable to both catalyst (unleaded fuel) and non-
catalyst (leaded fuel) vehicles. The VW Part I application indicates the
EGR filter is used only with the non-catalyst vehicles and on the catalyst
vehicle it is used as an EGR cooler by removing the filtration element
from the filter housing.
7-405
-------
What is significant about this filter is not its application to gasoline
powered vehicles, but the potential application of this type of technology
to Diesel powered vehicles. VW indicates in their Part I application
for certification that no maintenance is required on the EGR filter for
the gasoline engine for the entirety of the 50,000 durability testing.
This indicates that an EGR filter is now a reality for gasoline engines.
This type of technology might be able to be applied to Diesel powered
vehicles which may need EGR to achieve low NOx levels.
Figures VW-2 and VW-3 indicate the extent of reactive HC reduction
attainable from an oxidation catalyst. Those figures provide an example
of how difficult it is for an oxidation catalyst to reduce non-reactive
hydrocarbons.
3-Way Catalyst Systems
VW has previously reported work on closed loop, modulated air injection
for 3-way catalyst systems. They now report that this approach has been
deemphasized in favor of the more conventional modulation of fuel metering
approach. This decision was based upon the probable fuel economy advantages
of the latter approach. The fuel metering systems will include closed
loop controlled fuel injection (Bosch L-Jetronic and K-Jetronic) and
closed loop carburetion.
VW indicates that 3-way catalyst systems will be used for emission
levels of 0.41 HC, 3.4 CO, 1.0 NOx and below. VW also indicated that
they have obtained low mileage results with a 3-way catalyst plus EGR
system, but report they are not confident in this system's durability
for production.
VW reported data that appeared to show that a temperature related
correction factor should be applied to the oxygen sensor signal to
achieve optimal conversion of HC, CO, and NOx. See Figure VW-4. On the
7-406
-------
Figure VW-2
Exhaust emiusion chroma tog i-am at the inl^t ol' the
catalyst (column ii)
7-A07
-------
Figure VW-3
Exhaust 'emiuuion chr.-jiatograiu at the outlet of tho
catalyst (column IL^
7-408
-------
100
I
90 •
v -
\
\.
\
Exhaust Gas Temperatures
350 °C
400 °C
450 °C
500 °C
simulated A-sensor output signal ImV)
700
a>
o"
6SO
en
en
o"
600 550 450
I ! I
en
en
en
o"
o
in
o»
o
o
o
o
o
o
o
Optimal CO-NOX - Conversion - f
(Exhaust Gas Temperature)
Figure VW-4
-------
lean side of stoichiometry at A* = 1.0043 (Figure VW-5) NOx conversion
efficiency reaches 70% at 350°C and decreases with increasing inlet
temperature while the CO and HC conversion rates continue to increase.
At a rich air fuel ratio of X = 0.9875 (Figure VW-6), the CO conversion
reaches its maximum at 350°C and decreases at higher temperature. The
NOx and HC conversion rates increase at higher temperatures. These
above results were obtained with the sensor control voltage held constant
for each air-fuel ratio: 250 mV for for lean ratio and 700 mV for the
rich ratio. When the voltage was varied with temperature, the optimal
conversion rates for all three pollutants were obtained. The optimal
control voltage varied from 580 mV for 350°C to 637 mV for 500°C. VW
indicated that the optimal conversion profile as indicated in Figure VW-
7. This has important implications for optimizing 3-way catalyst per-
formance.
VW also reported the results of their investigation of using different
0_ sensor materials. VW concluded the most common type of platenum
sensor was the more suitable sensor for use when calibrating the 3-way
system to maintain a stoichiometric air-fuel ratio. However, as Table
VW-1 indicates, other sensor materials cannot only widen the control
range but also bias the sensor signal either richer or leaner than
stoichiometric. This indicates that depending on the manufacturers
calibration philosophy, there are other sensor materials available which
could allow air-fuel ratio control other than at stoichiometric.
* X = air-fuel ratio (actual)
air-fuel ratio (stoichiometric
7-410
-------
100
-90
7--80-
_CU 'f-
~o -.
ct -
C 2
.2 ~
in "
L_
Q)
>
O
70-
60-
50-
40
30-
20
10-
CO -::.:-.-;.-
'"-• HC -Conversion
' NOX-
200
25C
1—I—I
300
i—i—r
T—r
Exhaust Gas Temperature
Conversion CO.HC.NOX =f (Exhaust Gas
Temperature) at \ -1,0043 = 250mV
Figure W-5
-------
100-
t
o
cr
c
g
V)
i_
O)
c
o
o
80-
70-
20-
10
200
300
i i ,
•3 cm
O - ;- :-•-:--
HC - Conversion
NOX-
i i i i i i
i I i I
500
Exhaust Gas Temperature
Conversion CO.HC.NOX = f (Exhaust Gas
Temperature ) at X =0,9875 = 700 mV
Figure VW-6
-------
V
5
n
D
10Q
90-
80
70
60
50
40
30^
20
10
200
CO - :- :-:.:-.
HC -Conversion
NOX-
Exhaust Gas Temperat-jre
Sensor Voltage >
— Lambda
Optimal Conversion = f ( X and
Exhaust Gas Temperature)
Figure VW-7
-------
Table VW-1
Response Width and Maximum Response of
Different CL Sensor Materials
Maximal Rise
Sensor Response width (mV) Occurs Between
Pt-activated From 40-90 mV at X = 1.16 X = 1.03 and X =0.99
"spinell" up to 880 mV at X =0.84
Common type From 60-90 Mv at X = 1.16 X = 1.01 and X =0.99
with Pt-filter up to 840 mV at X = 0.84
Yttrium From 35-70 mV at X = 1.16 X = 1.04 and X = 1.0
up to 920 mV at X = 0.84
VW reported a limited amount of low mileage emission test data for
developmental 3-way catalyst systems. Table VW-2 shows the latest
reported emission results from systems targeted at the 0.41 HC, 3.4 CO,
1.0 NOx level.
Table VW-2
System HC CO NOx MPG
u
air cooled engine, L-Jetronic EFI, 0.23 2.83 0.46
0. sensor, 3-way catalyst
water cooled engine, K-Jetronic CFI, 0.25 2.20 0.40
02 sensor, 3-way catalyst
water cooled engine, feedback 0.27 2.80 0.87 22.8
carburetor, 0« sensor, 3-way catalyst
VW reported that the 3-way catalyst was developed in the same way as the
oxidation catalyst for MY 77 in that the substrate was increased from
200 cells per square inch to 300 cells per square inch. VW did not
report work on any 3-way plus oxidation catalyst or dual catalyst systems.
7-414
-------
Other Development Efforts
PCI
VW has been working on two divided chamber, stratified charge engines.
One of these is a three valve engine with a scavenged prechamber which
resembles in principle the Honda CVCC. The second engine of this type
uses an unscavenged prechamber and is call the Pre-Chamber-Injection
(PCI). The PCI is shown in Figure VW-8.
Figure VW-8
PCI Combustion Chamber
rlnjsct'on Nozzle
Prochcmber
^^^xir
^^&EH
-Spork Hug ^j
These concepts were originally tailored to their air cooled engines but
have, more recently, been adapted to their water cooled engines. VW's
current status report indicated that their interests and efforts have
shifted to the PCI concept because it has demonstrated significantly
better NOx control and lower fuel concumption than the three valve
concept. Figure VW-9 shows these relationships.
7-415
-------
Figure VW-9
Comparison of PCI and 3-Valve Engine
NOx
30
g/kWh
I
»]
01-
09
bs(c
g/kV/h
600
»]--- 4\\ -
l\\
---- 3-Valve
bsfc— -
.-...-],
sso
~v
t'.l 1.3 1.5
total relative air-fuel totio
QOCO
Comparison between PCI- one! 3-VoUe Engine
26<*> 'Pm- MBT SporV Advance 1
75 11 78
Data taken at the same operating conditions reveal the NOx advantage of
the PCI system, even at a lower brake specific fuel consumption according
to VW. This difference is most pronounced at a total relative air-fuel
ratio that is optimal for HC and CO oxidation in the exhaust system.
The indicated misfire limit for the PCI system is typical only for a
very late injection timing, according to VW.
7-416
-------
VW has added port liners to the PCI system to increase inlet temper-
atures to the lean thermal reactor incorported in the system. The
exhaust ports of the cylinder head were enlarged and modified so that
long port liners could be inserted without causing a significant flow
restriction. Because of the higher reactor inlet temperature, reactor
conversion, particularly at light engine load, can be significantly
increased or ignition timing can be chosen for less fuel economy loss.
Figure VW-9 shows that a temperature increase of 30° to 40° C resulted
in lower HC emissions of up to 50% at the same spark timing or in a
reduction in fuel consumption of 5 to 10% if the HC level was maintained.
Figure VW-9
HC
600 900 TOO
> 2160 rpm
, bnxp = 11 bor
700 900 q/kWh
2160 rpm
tamep
llbor
10 boi
igrttiGfi turtng
" 30 t>TOC
A 20 DlOC
• 10 mix
1UC
• 10 otDC
TIC eon g/kwh «»o bsfc
• with portliner
*ittx>jt portliner
Effect of Fbrthners on Exhaust Gas Temperature and HC-Emissons
76 11 81
Maximum engine power output is reduced by approximately 5-8%. This
stems primarily from modifications of the exhaust system, not as is
often assumed from a slower burn rate. The higher back pressure at the
exhaust ports caused by the reactor results in a noticeable reduction of
volumetric efficiency at high engine speeds.
7-A17
-------
VW claims that if regular fuel is used, the compression ratio should be
less than 9:1 to have a sufficient margin from the knock limit. This
will also keep combustion noise down to levels that are typical of Otto
engines. An analysis of cylinder pressure diagrams showed values for
the pressure gradient of 1 to 2.5 bar/degree crankangle under typical
operating conditions. Under extreme conditions, a value of approx-
imately 3 bar/degree crankangle was measured, still far below the values
of prechamber diesel engines.
Exhaust analysis for soot with the Bosch tester gave only than a few
tenths on the BOSCH-scale.
Various types of lean thermal reactors were built and tested. For
example, a design with a design with a cast iron casing, air insulation
for the inner core (Design A) with the provision to preheat the air-fuel
mixture by exhaust heat or, in the more conventional manner by the
engine coolant. In another effort, an all sheet metal design with
fiberfrax insulation (Design B and C) was chosen. A summary of emission
results obtained, and the fuel economy measured, is given in Figure VW-
Figure VW-10
HC CO
r. f
I } [>sgn AISAI'i v-vt,
HH llesqn A. V- 12b V[)
[ _ J DPS*)" I) *ilr,
Design D «••!•> Corp
[__J fte'.ign C
CICD
Effect of Reactor Design on '75-FTP- Results
76 II 83
7-418
-------
10. It shows the progress made in HC and CO emission by first increasing
the core volume of design A by approximately 25% and during the second
series of steps with the design B. In design C, heat losses of the
gases, when passing from the exhaust port into the reactor core, were
reduced by appropriate shields. It should be noted that the system with
the lowest emissions in Figure VVI-10 had the best fuel economy.
The significance of the warm-up behaviour following a cold start during
the FTP is convincingly expressed in Figure VW-11. Results were obtained
with the PCI-concept and without employing exhaust heat for mixture
preparation. The first and last 505 s are already weighted 43 to 57.
Particular attention is to be paid to HC and CO emissions from Bag 1,
which are 3 to A times greater than those in Bag 2. Here again, as in
practically all other cases shown, the major portion is caused during
the acceleration and cruise mode. Improvements through careful optimization
of the cold start phase will have a significant effect on the FTP results.
Only a very intensive application of exhaust heat to the intake manifold
will result in a quicker increase in mixture temperature when compared
with a water-heated intake manifold. This would, on the other hand,
require a control to limit the heat exchange at high engine load.
At the emission levels reported here, an evaluation of the driveability
gave good to very good ratings. No particular problems with vehicles
that are being tested under daily traffic conditions have appeared thus
far. However, no vehicle durability run has yet been made to determine
emission deterioration factors and cold start problems were encountered.
"May-Fireball" Combustion Process
VW reported on their ongoing evaluation of the "May-Fireball" combination
process. This process was developed by a research laboratory entitled:
"Antipollution Industrial Research S.A.". This engine reportedly produces
a high swirl rate and has a novel combustion chamber design. The combustion
chamber is positioned around the exhaust valve as shown in Figure VW-12.
7-419
-------
NOx
'75 FIP-Results
HC = 082
CO = /. 9
NOX : 0 79
f | A( ..Deration
jm oui'.f?
I I Oer.elprolKin
CO NOx
Bog l
Bog ?
Bag 3
COD
Analysis of '75-FTP- Emission Results
76 11 82
Figure VW-11
7-420
-------
n
20
Figure VW-12 "May-Fireball" Combustion Chamber
7-421
-------
It has been claimed that this process allows the compression ratio to be
increased to as high as 15.8 to 1.
VW has evaluated one engine of this type. This was a 90 CID Dasher
engine adapted to the May-Fireball process. It was equipped with K-
Jetronic fuel injection and installed in a Dasher. In a fuel economy
comparison between a carbureted version of the Dasher engine and a
Diesel version of this engine the May-Fireball was equivalent to the
Diesel and substantially better than the standard Dasher engine. See
Figure VW-13.
In emission testing the May-Fireball equipped Dasher measured 2.1 HC,
3.7 CO, 1.9 NOx. It is presumed that this was without the benefit of
any emission control components. It appears that the major emission
problem is HC. VW did not indicate whether or not this engine required
high octane fuel but with a compression ratio of 15.8 to 1, it is
likely that it did. The octane level requirements of 97-98 octane was
confirmed by the inventor, M. G. May, at the Champion Ignition and
Engine Performance Conference in Vienna, Austria. High octane require-
ments will complicate emission control of this engine since for example
they may necessitate leaded fuel which is not compatible with current
catalysts.
Diesel Engines
The following results are representative of results achieved by the VW
Diesels during MY 1977 Certification testing. The emission results
include DF of 1.0 for HC and CO and 1.308 for NOx.
Table VW-3
VW Diesel Results
Model
Dasher
Rabbit
Rabbit*
HC
0.46
0.30
0.78
CO
1.00
1.00
1.00
NOx
1.50
1.37
0.80
MPG
u
35
39
50
MPG
n
47
51
65
MPG
c
40
44
56
* Fuel economy improvement package, including different axle ratio.
7-422
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Figure VW-13 "May-Fireball" Fuel Combustion Results
__
-------
VW has been investigating the effect of injection retard and EGR, both
with and without cooling, on the Diesel engine emissions. Figure VW-14
presents data taken from their report.
VW did not report fuel economy or HC and CO data for the testing shown
in Figure VW-14. They did, however, present more complete emission data
for a series of CVS tests. Figure VW-15 portrays the results of this
testing which evaluated the effect of injection timing. VW did not
specify what engine or vehicle was involved in this testing, nor did
they indicate what type of CVS testing was conducted.
As can be seen from the above two figures, EGR and injection retard can
have potent effects upon NOx without seriously degrading HC, CO, or fuel
economy. VW indicated that cooled EGR was more promising than injection
retardation, but they were equally concerned about condensation and
deposit problems as well as the size and weight requirements of the EGR
intercooler used.
7.3.16.2. Systems to Meet Various Emission Levels
Table VW-4 shows VW's first choice systems to meet future emission
levels.
7-424
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I CONDITION OF RECYCLED GASES
HOT
: PErtCEHTACE o EXHAUST
.1..
RECYCLED
.. L. _......L .._.: .......
(% EGR = % REDUCTION IN VOLUME OF AMBIENT AIR FLOW INTO ENGINE)
Figure VW-14
7-425
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CO
7.2
0.25 *•
n
r.r
to
oe>
U2
-2P
NO,
-7' 5r +1
&f Jhe. injection
Figure VW-15
Emissions, Fuel Economy, and Injection Timing during CVS-Test
7-426
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i
*»
ts>
Engine
Air Cooled
L-Jetronic (EFI)
Water Cooled
Carburetor
Water Cooled
K-Jetronlc (CIS)*
1.5 HC
15 CO
2.0 NOx
Engine Mods
EGR
Table VW-4
Future Emission Control Systems
0.41 HC
9 CO
1.5 NOx
Engine Mods
EGR
Ox. Cat.
0.41 HC
3.4 CO
2.0 NOx
Engine Mods
EGR
Close coupled
Ox. Cat.
AIR
Ox. Cat.
EGR
Engine Mods
EGR
-
Engine Mods
EGR
Ox. Cat.
AIR
Ox. Cat.
EGR
Engine Mods
EGR
Ox. Cat.
0.41 HC
3.4 CO
1.0 NOx
Engine Mods
Oxygen Sensor
& Feedback
3-way catalyst
Engine Mods
Oxygen Sensor
& Feedback
3-way catalyst
Engine Mods
Oxygen Sensor
& Feedback
3-way catalyst
0.41 HC
3.4 CO
0.4 NOx
Engine Mods
Oxygen Sensor
& Feedback
3-way catalyst
Engine Mods
Oxygen Sensor
& Feedback
3-way catalyst
Engine Mods
Oxygen Sensor
& Feedback
3-way catalyst
* Continuous Injection System
-------
7.3.16.3. Durability Testing
VW reported the data in Table VW-5 which is assumed to indicate VW's
predurability calibrations on a system of K-Jetronic and improved oxidation
catalyst applied to their water-cooled engines from 1978 California
vehicles. What is significant about these data are the results indicate
that NOx levels approaching 1.0 gin/mi or below could be achieved on
smaller vehicles with fuel injection and an oxidation catalyst. It
should also be noted that as NOx is reduced HC and CO levels approach
the statutory levels of 0.41 and 3.4 and may not be sufficiently low
enough to assure certification at 0.41 HC, 3.4 CO, and 1.0 NOx.
Table VW-5
VW Durability Test Data at Low Mileage
Audi Fox, K-Jetronic + OC, M4
FTP - Results (gm/mi)
HC CO NOx
0.30 1.42 1.29
0.24 2.02 1.15
0.29 2.64 1.06
0.29 3.20 1.06
0.37 4.86 0.62
VW also reported two vehicle durability tests of systems targeted at the
0.41 HC, 3.4 CO, 1.0 NOx level. Table VW-6 shows the results of this
testing. No catalyst descriptions were provided.
7-428
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Table VW-6
Durability Testing
System
Air cooled eng., L-Jetronic,
0- sensor, 3-way cat.,
No EGR
Mileage
0
18,600
20,500
21,300
25,113
25,135
30,845
30,845
38,400
46,700
50,000
HC
0.45
0.30
0.43
0.41
0.53
0.95
0.20
0.33
0.40
0.29
CO
4.
4.
1.
3.
5.
7.
3.
3.
4.
70
00
56
22
67
65
26
60
60
NOx
1.16
0.48
2.27
.00
.03
.06
1.
1.
1.
3.56
0.47
1.30
0.90
0.89
While the above data is not that impressive, it was unclear why the
various tests reported varied so dramatically. A second vehicle assumed
to be equipped identically to the one above showed the following results
at low mileage:
Test 1
2
3
4
5
6
HC
0.21
0.17
0.15
0.15
0.14
0.13
CO
1.98
2.22
,78
,78
,54
NOx
0.50
0.46
0.
0.
0.
65
83
92
2.08
0.68
Test six may be a better indication of this system's potential.
7-429
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Table VW-6 (con't)
Water cooled eng., K-Jetronic,
02 sensor, 3-way cat.,
No EGR
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
0.18
0.25
0.23
0.78
0.87
0.39
0.13
0.16
0.18
0.30
0.97
1.03
0.96
1.83
1.26
8.73
13.42
2.20
1.24
1.17
1.59
3.10
13.81
14.46
0.72
0.55
1.12
0.66
0.92
1.46
1.22
1.13
0.63
0.33
0.27
0.40
Change X - sensor
Change X - sensor
VW also reported other 3-way data as shown in Table VW-7.
Table VW-7
3-Way Catalysts Zero Mile Test Results
FTP
Tests Performed At HC
0.18
Ingolstadt 0.23
0.26
0.15
EPA Ann Arbor 0.14
0.15
0.30
0.32
Ingolstadt 0.18
0.21
Results
CO
1.14
1.79
1.26
1.47
0.94
0.95
2.25
1.64
1.45
1.67
(gm/mi)
NOx
0.71
0.74
0.65
0.83
0.94
0.82
0.73
0.76
1.05
0.57
7-430
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7.3.16.4. Progress and Problems
VW has not shown much progress in the development and testing of 3-way
catalyst systems to meet lower NOx standards. However, the data presented
indicates that the potential for achieving 10.41 HC, 3.A CO, 1.0 NOx
with 3-way catalyst system exists for low inertia weight vehicles. Some
progress has been made on their PCI concept but this engine seems to be
a long way from production.
VW's progress in reporting and/or adapting EGR and other NOx control
measures to their Diesel engine has also been slow. Only a limited
amount of exploratory investigation and testing were reported in this
important area.
7-431
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7.3.17. Volvo
7.3.17.1. Systems Under Development
Oxidation Catalyst Systems
Volvo continues to work on oxidation catalyst systems. There are three
basic systems all employing oxidation catalysts and EGR. The systems
differ in the type of secondary air used. One system uses no additional
air injection, another uses a Saginaw (GM) air pump driven at 85% of
engine speed, and the third system uses a pulsair air introduction
system.
The no-air system is the current system used by Volvo for the Federal
standards. Apparently, only the air pump and the pulsair systems are
being developed for emission standards more stringent that the 1977
Federal standards.
Of the two systems (pulsair and air pump) Volvo prefers the pulsair
system, because Volvo sees fuel economy, cost, power, and possibly
sulfuric acid benefits with the pulsair system over the air pump system.
The pulsair system has been applied to both of Volvo's current engines,
the B21 (4 cylinder in-line configuration) and the B27 (6 cylinder -"V"
configuration). Results on the B21 have shown promise, but there have
been backflow and noise problems with the B27.
The Volvo pulsair system introduces about 20% air injection from idle to
1500 RPM, reduces this to 3% between 1500 and 2500 RPM, and remains 3%
from 2500 to 3500 RPM. Volvo did not indicate the basis for the deter-
mination of the percent air injection values. The system also contains
what Volvo calls an "NRV" (non-return valve) which is assumed to be a
check valve typical of pulsair systems.
7-432
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Volvo has experimented with different NRV configurations. Apparently,
the most effective one was with one NRV for cylinders 1 and 4 and one
NRV for cylinders 2 and 3.
The pulsair system was tested on a vehicle with a B21F engine, automatic
transmission, oxidation catalyst, and EGR.
The results of the testing, baseline compared to the most effective
pulsair system, are shown in Table Volvo-1.
Table Volvo-1
Effects of Pulsair*
HC
CO
NOx
MPG
u
Comments
2% idle CO, no air
2% idle CO, pulsair
3% idle CO, no air
3% idle CO, pulsair
* Volvo Status Report, page 59.
Testing has also been done with the B27 engine, apparently investigating
different NRVs. The results are shown in Table Volvo-2. The testing
was conducted on an unspecified vehicle equipped with a catalyst.
0.643
0.250
0.662
0.265
13.0
3.94
16.0
4.27
1.43
1.89
1.53
1.53
17.2
16.3
17.1
17.5
HC
0.23
0.18
CO
2.02
1.60
Table Volvo-2
Effects of Pulsair*
NOx
1.99
1.78
Comments
3 valve sytem, 2 APG, 1AC
3 valve system, AC valves
* Volvo Status Report, page 69, page 71.
7-433
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Tests were also run on vehicles equipped with B27 engines, apparently
testing different air injection systems. The different configurations
were labeled "standard air manifold" and "8mm air manifold". The results
are shown on Table Volvo-3.
Conf igurat ion
Standard
8mm
Standard
8mm
Table Volvo-3
Effect of Different Air Manifolds*
HC
0.35
0.34
0.26
0.21
CO
1.64
1.41
1.31
1.21
NOx
1.37
1.50
1.74
1.71
6
5
5
5
Comments
6 test ave, 1.8% CO
5 test ave, 1.8% CO
5 test ave, 1.7% CO
5 test ave, 1.7% CO
* Volvo Status Report, page 70.
Currently, Volvo uses an oxidation catalyst produced by Engelhard,
called by Volvo the PTX 514.5. For more stringent standards Volvo may
use the PTX 516. The catalysts are described in the following table.
7-434
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*>
OJ
Table Volvo-4
Volvo Oxidation Catalysts*
Type
PTX 514.5
PTX 516
Volume
77 cu ft.
102 cu ft.
Active
Materials, (Ratio)
Pt/Pd (2:1)
Pt/Pd (2:1)
Total Active
Loading Troy oz.
0.039
0.095
Dia/
Length
4.66/4.5 in
4.66/6 in
Loading, gm/cu ft
approx. 25
approx. 50
* Volvo part I, page VI 117, 118.
-------
As can be seen from Table Volvo-A, the two catalysts differ in both
length and specific loading (gm/cu ft.).
Volvo reported work on choke optimization with a 3500 IW vehicle equipped
with the 76 B27 engine, an air pump, EGR, and a PTX 516 oxidation catalyst.
Tests were run with choke times of 45, 62, 75, and 90 seconds. It
appears that the choke time of 75 seconds yielded the best results for
HC and CO. There was some scatter in the data, especially for HC. The
results are shown in Table Volvo-5. No data were provided to compare
the vehicle driveability at the various choke time settings.
Table Volvo-5
Effect of Choke Time*
Choke Time
Seconds
HC
CO
NOx
MPG
u
MPGL
MPG
Comments
45
45
ave
62
62
ave
75
75
ave
' 90
90
ave
0.09
0.25
0.17
0.24
0.15
0.20
0.04
0.06
0.05
0.29
0.18
0.24
1.21
1.63
1.42
1.39
1.33
1.36
1.12
1.12
1.12
1.70
1.49
1.60
1.26
1.38
1.32
1.66
1.35
1.51
1.64
1.49
1.57
1.55
1.55
1.55
14.3
14.1
14.2
14.0
13.5
13.8
13.2
13.7
13.5
13.6
13.2
13.4
19.1
19.1
22.8
22.8
21.8
21.8
23.6
23.6
16.0
16.1
16.9
16.8
16.5
16.3
16.5
16.6
1 Restart
1 Restart
* Volvo Status Report, page 67.
Volvo reported little development or durability testing with
other oxidation catalyst types.
7-436
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3-Way Catalyst Systems
Volvo has an extensive development program underway on 3-way catalysts.
Volvo's efforts in this area are so extensive, compared to other potential
systems, that it is concluded that Volvo is concentrating almost all of
their efforts for future emission control systems on the 3-way catalyst
system.
Volvo's emphasis on the 3-way catalyst system has resulted in the commercial
introduction by Volvo of a 3-way catalyst system. This system is the
one on the 1977 California vehicles equipped with a B21-engine.
This makes Volvo the world's first manufacturer to introduce a 3-way
catalyst emission control system on production vehicles.
The basic Volvo system consists of the 3-way catalyst, an oxygen sensor,
and a feedback controlled fuel injection system. Volvo uses a 3-way
catalyst manufactured by Engelhard. Volvo and Engelhard have worked
together closely in the development of the 3-way catalyst system. The
catalyst is the PTX 516, which apparently is also called the TWC-16. It
is generally like the PTX 516 oxidation catalyst described in Table
Volvo-4, except that its active materials are Pt/Rh in a 5 to 1 ratio.
Volvo states that because they are such a small consumer of precious
metals, the supply of Rhodium should be no problem for them, even though
the Pt/Rh ratio in their 3-way catalyst is higher than the naturally-
occurring or "mine-mix" ratio of approximately 19/1.
Volvo has completed much of the necessary development work for the 3-way
catalyst system for the B21 engine applications. When tested at EPA,
the emission data vehicles with the 3-way catalyst system produced the
results shown on Table Volvo-6.
7-437
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Table Volvo-6
Range of Low-Mileage (4000 mile)
Emission Data for Volvo 3-Way Catalyst Vehicles
HC CO NOx MPG MPG, MPG
— — u h c
0.17-0.22 2.4-3.3 0.07-0.18 18.0-18.7 25.4-31.4 21.1-22.4
These low mileage values, coupled with the DFs for this family of 0.824,
0.896, and 1.141 for HC, CO, and NOx respectively (I, 1, and 1.141 for
official purposes) might lead one to infer that the Volvo 3-way catalyst
car met the statutory emission levels of 0.41 HC, 3.4 CO, 0.4 NOx. This
is not exactly the case, because, in addition to the 4000 mile times DF
results being below the standards, the durability car cannot "line
cross". The line crossing prohibition means that the least squares line
through the durability car data points cannot exceed the standards at
4000 miles or at 50,000 miles. The Volvo 4000 and 50,000 (4K and 50K)
mile results are shown on Table Volvo-7.
Table Volvo-7
4K and 50K Results
For Volvo 3-Way Catalyst Durability Car
Mileage HC CO NOx
4K 0.27 3.83 0.37
50K 0.22 3.43 0.42
As can be seen from the above table, the Volvo durability car line
crossed at 4K for CO. There were no problems with HC. The NOx value
was very close to the standard of 0.4 grams per mile at the 50K point.
In fact, were the statutory NOx standard expressed as 0.40 grams per
mile instead of the official value of 0.4, the Volvo vehicle would have
line crossed at 50K for NOx.
7-438
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The important point about these results is that they show for the first
time, a vehicle run on official EPA certification durability that came
close to meeting the statutory standards of 0.41 HC, 3.4 CO, 0.4 NOx.
If the standards were 0.41 HC, 4.0 CO, 0.4 NOx instead, the Volvo vehicle
would have met them.
With much of the development work done for the B21, Volvo is now apparently
concentrating on the development of the 3-way catalyst system for the
B27 application.
Volvo will try to certify the B27/3-way catalyst system for California
for model year 1978. The catalyst to be tried will be identical to the
1977 catalyst for the B21. Volvo states that the reason for this is
that the B27 application can probably meet the assumed 1978 California
requirements of 0.41 HC, 9.0 CO, 1.5 NOx with the TWC-16, and having
only one 3-way catalyst simplifies certification and catalyst supply
problems. It should be noted that Volvo indicated that the B27 was
basically a higher emitting engine than the B21, and thus needed the TWC-
16 to reach the California-required levels. Since the B27 engine is
larger in displacement than the B21 (163 vs. 130 CID), in order to get
to lower standards than the California standards, it may be necessary
for Volvo to increase the loading and/or the volume of the 3-way catalyst
on the B27 in order to approach the performance already demonstrated
with the B21 applications.
An area of concern to Volvo in the B27 program is related to the "V"
configuration of the B27 engine. With two exhaust manifolds the crossover
pipe design, sensor and catalyst positioning, and light-off have been
important design/development areas.
The exhaust system has been modified on the 1978 California vehicle to
provide a shorter crossover so that the single oxygen sensor can
7-439
-------
be placed closer to the engine for rapid light-off. The catalyst location
is apparently not changed, from the oxidation catalyst system, being
approximately 38 inches from the exhaust manifold.
Volvo feels that this sensor/catalyst configuration will be sufficient
to give them enough control for the 0.41 EC, 9 CO, 1.5 NOx California
target values.
For future applications two approaches are being explored. The first is
the insulation of the current production exhaust system, and the second
is the so-called "super-short" exhaust system in which the left hand
exhaust pipe goes over the transmission. This configuration makes the
union between the two exhaust pipes even closer to the exhaust ports and
may allow for even faster sensor light-off. In addition, the super-
short system may allow for catalyst repositioning closer to the engine
next to the transmission.
The two approaches (insulation and the super-short exhaust system) show
"considerable potential" according to Volvo. They state that the proposed
1978 California system achieves sensor light-off in 30 seconds, compared
to 20 seconds for the B21 application. The advanced approaches may
allow the B27 to achieve sensor light-off as quickly as the B21, but the
driveability implications of very short sensor light-off (and sensor
cut-in) have not been fully explored by Volvo.
Volvo reported some data for the super-short configuration. The data
involved keeping the sensor voltage setting constant at 50 MV, and
varying "TV" and "1st", neither of which were explained. TV is assumed
to be a control system time constant, possibly the time delay between
the time that the signal from the 0_ sensor passes through the set point
value and the time that the fuel metering system begins to change the
7-440
-------
air/fuel ratio back toward stoichiometric. 1st is assumed to be a
pressure value that possibly controls the warm up regulator. The best
results were 0.15 HC, 4.02 CO, 0.24 NOx, 14.5 MPG with TV = 20 ms and
1st = 0.2. These results were obtained with a Dugussa catalyst. Since
the results were obtained with a catalyst that is not apparently Volvo's
first choice, the results are hard to interpret. They do not appear to
be as good as the low mileage results with the B21 application.
For future systems, Volvo plans to continue the use of the same fuel
injection type that is on the current vehicles. This fuel injection
type is the Bosch K-Jetronic or Continuous ^njection £>ystem (CIS)
system. Volvo previously used a Bosch electronic fuel injection system,
the D-Jetronic, before the switch over to the mechanical, K-Jetronic
system which Volvo feels offers advantages in cost, EGR tolerance,
driveability, fuel economy, and servicing.
The K-Jetronic system cannot, by itself, provide the proper control of
fuel metering required for successful 3-way catalyst operation, accord-
ing to Volvo. They claim that the spread of air/fuel ratio variations
is 40 times greater than is required. With the feedback control system,
Volvo stated that except for the first 20 seconds of engine operation,
their system will permit the 3-way catalyst to "operate continuously at
a conversion efficiency of 80% or better for all three major pollutants."
Other Catalytic Systems
Volvo did not report any development or durability tests with 3-way
catalyst plus oxidation catalysts or dual catalyst emission control
systems.
7-441
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Other Systems
Thermal Reactors
Volvo reported results from a thermal reactor program. Apparently, this
program is targeted toward a non-catalytic "lean burn" approach. The
project is being done with some assistance from Volvo Flygmotor, Volvo's
aeronautical division. Volvo Flygmotor provided the thermal reactors
and "combined swirl/squish", which is interpreted to mean a combustion
chamber modification. With the thermal reactors, a modified intake
manifold, 20 mm throttle valves, pulsair, and a lean choke, values of
0.4 HC, 4.5 CO, 2.7 NOx, 14 MPG were achieved. The vehicle description
was not provided. By itself the swirl/squish yielded 1.3 HC, 11 CO, 2.8
NOx, 14 MPG . Work in this area continues.
Diesel Engines
Early in 1974, Volvo contracted with Ricardo & Company, Ltd. to design,
develop and build 15 prototype Diesel engines for evaluation. Six
engines are now installed in various Volvo vehicles, including their
experimental taxicab for testing and in-house demonstration purposes.
Volvo has no plans to produce this engine.
The engine is a 6-cylinder in-line 145 cubic inch Diesel. It has a
Ricardo MK-V swirlchamber, and produces 70 hp at 4500 rpm and 98.4 Ib ft
of torque at 2400 rpm.
Volvo stated that they have contracted with VW for the development,
production, and supply of Diesel engines for Volvo's 240 series of cars.
This program will apparently be complete in late 1978 or early 1979.
Volvo stated that the introduction of Diesels for the U. S. market will
depend on the NOx standard. According to Volvo, certification will not
7-442
-------
be possible or economically feasible below 1.5 grams per mile NOx.
Volvo also discussed the application of EGR to Diesels. Problems claimed
were:
(1) At 1.0 NOx the fuel economy advantage over the
gasoline engine is lost.
(2) EGR pipework must be much larger due to the
unthrottled operation.
(3) Vacuum signals for EGR control do not exist.
EGR control must use another parameter.
No data on Diesel vehicles equipped with EGR were provided.
Backup data or analysis for the Volvo claims could not be found in their
status report. Because not one emission test of a Volvo/Ricardo or
Volvo/VW Diesel vehicle was reported, Volvo must be making their claim
based on information not reported to EPA. It is also curious that,
although all emission data run by Volvo were requested by EPA, the
Volvo/Ricardo 3-year program that resulted in 6 vehicles for test and
demonstration programs has not yet produced one emission test.
Other Development Efforts
B27 Engine Improvements
Volvo is conducting an extensive program to reduce the engine-out emissions
of the B27 engine. Work in the areas of (1) combustion chamber, (2)
spark plug position, (3) inlet ports and manifold, and (4) camshaft have
been conducted to investigate the effects of altered squish and swirl
conditions. Volvo did not report any data resulting from this program,
although "some potential for emissions reduction has been seen", according
to Volvo.
7-443
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From the extensive amount of what appears to be rather basic engine work
being conducted by Volvo on the B27 engine, it appears that even though
this is a relatively new engine (developed in conjunction with Peugeot
and Renault), emissions control is being studied as an after-the-fact
proposition, rather than being included in the original design of the
engine. The development program could also be one targeted toward fuel
economy improvements.
EGR Systems
The current B21 application does not use EGR. Since EGR is a well-known
NOx reduction technique, it is logical to expect that some 3-way catalyst
work would have been done by Volvo including EGR. Volvo did work in
this area some time ago. Development problems with unreliable EGR
systems and interactions between the EGR and the feedback systems slowed
the development of the 3-way catalyst system so much that Volvo dropped
the EGR in order to concentrate on the 3-way catalyst system. It should
also be noted that Volvo does not need EGR to meet 1.5 NOx, the target
for the 3-way catalyst B21 car in California. Because the performance
of the B21/3-way catalyst system has been so good, Volvo is "most unwilling"
to add EGR to this system. They predict losses in driveability, power
output, and a 10% loss in fuel economy if they have to add EGR. According
to Volvo this will be unsatisfactory from a customer standpoint and
"could well force Volvo out of the U.S. market on fuel economy considerations."
Because of higher priority projects, Volvo is expending little effort in
the area of EGR systems now. There would appear to be little need for
Volvo to do so, if the NOx standard is 1.0 NOx or above.
7-444
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7.3.17.2. Systems to be Used at Various Emissions Levels
Volvo provided the following table, labeled Table Volvo-8, as an indication
of their system approaches toward future emission standards. Volvo's
future systems are seen to be the major types, oxidation catalyst systems
and 3-way catalyst systems. Volvo did not specifically indicate what
systems would be targeted for the variety of possible emission standards
considered in this report, so the following discussion contains primarily
EPA estimates of the system choices.
1.5 HC, 15 CO, 2.0 NOx
Apparently, Volvo would stay with the current 1977 Federal systems,
which consist of an oxidation catalyst, no air injection, and EGR. This
basic system is also the same one that Volvo plans to use for the 1978
Federal vehicles, since Volvo is assuming that the standards will be set
to be carryover from the 1977 Federal standards.
0.9 HC, 9 CO, 2.0 NOx
Volvo will need somewhat more than their current Federal systems at this
level, since the B27 and B21 Federal durability cars line crossed for CO
at 4K. Either the current California oxidation catalyst/air pump/EGR
packages, or the pulsair/oxidation catalyst/EGR packages now under
development would appear to be adequate. It should be pointed out,
however, that Volvo stated in last year's status report that they favored
0.9 HC, 9 CO, 2.0 NOx as a level which might encourage Volvo to introduce
the 3-way catalyst system.
0.41 HC, 9 CO, 1.5 NOx
Volvo would use the 3-way catalyst system at these levels. It is
already in production for 1977 for California for the B21, and Volvo
7-445
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is trying to certify it for California at these standards for 1978 with
the B27 engine. Backup oxidation catalyst systems are also under consideration.
0.41 HC. 3.4 CO. 2.0 NOx
Volvo would probably tend to prefer the 3-way catalyst approach at these
levels, although they have not yet demonstrated the CO control needed at
the 3.4 gm/mi level with a durability vehicle. It should also be noted
that Volvo has already demonstrated control to this level with their
1977 California B27 durability vehicles, which are equipped with air
injection, an oxidation catalyst, and EGR.
0.41 HC. 3.4 CO. 1.0 NOx
Without EGR, Volvo indicated that this level is about the maximum control
that can be obtained from the 3-way catalyst system, expecially for the
B27 application. Volvo did not indicate any control systems other than
the 3-way catalyst approach that would be considered at these levels.
0.41 HC. 3.4 CO. 0.4 NOx
Somewhat reluctantly, Volvo would attempt to add EGR to the 3-way
catalyst system. Volvo indicated that this approach would result in
driveability and fuel economy penalties.
7.3.17.3. Durability Testing Programs
Volvo has conducted, and is conducting, extensive durability tests of
advanced emission control systems. Tests include investigation of
catalyst durability, oxygen sensor durability, and vehicle/system
durability.
7-447
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Catalyst Durability Tests
Volvo reported catalyst durability results obtained from operating a
vehicle on a dynamometer with periodic measurements of catalyst ef-
ficiency. The test is conducted for 1000 hours, with the vehicle
operating on Volvo's "open road" driving cycle. The vehicle used was
3500 IW, equipped with Bosch K-Jetronic, feedback control, and various
catalysts. The fuel contained no lead, no phosphorus, and less than 5
ppm sulfur. The catalysts tested are shown below, in Table Volvo-9.
Table Volvo-9
Catalysts Tested on 1000 Hr Test*
Catalyst
Manufacturer
Engelhard
Engelhard
Engelhard
Degussa
Designation
TWC-9B
TWC-16
TWC-16
OM 721
Substrate Washcoat
300 ce^ls N.R.
per in
Corning Ex20? N.R.
300 cells/in
ti n
Corning Ex 20 "L"
2 Bed-300 cells
/in
Pt/Rh
19/1**
5/1**
it
2/1
Total
Loading
Troy Ounces
N.R.
0.096
(3 grams)
ii
0.096
(3 grams)
Degussa
OM 721
5/1
* Volvo Status Report, page 73-78
** Not specified. Value assumed by EPA based on other information.
Volvo did not report the exact description of the test used to measure
conversion efficiency. It could be a simple catalyst efficiency test
at some air-fuel ratio, or it could be the results of a 1975 FTP test.
7-448
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The above limitations, coupled with the almost sterile fuel, make conclusions
about the absolute level of performance of the various catalysts difficult.
However, the results may be of some use in assessing the relative per-
formance of the various catalysts. The results are shown on Table
Volvo-10.
The results shown in Table Volvo-10 are somewhat difficult to interpret.
The results are shown for two sets of two apparently identical catalysts.
The two TWO16 catalysts and the two Degussa catalysts are the same
catalysts shown in Table Volvo-9. The differences in performance could
be due to catalyst-to-catalyst variability, or to differences in feed-
back control system calibration, or to differences in oxygen sensors.
Several different code number sensors were used. Volvo did not discuss
the reasons for the differences in performance. If there is a reason
due to calibration differences between the two TWC-16 catalysts, the
first calibration would appear to be the most effective of the tested
systems, yielding extrapolated 1000 hr catalyst efficiencies of over 80
per cent for all three pollutants.
Oxygen Sensor Durability
Current Volvo-suggested oxygen sensor maintenance (a change of the
sensor) is scheduled for 15,000 mile intervals. In an attempt to
investigate the impact of longer sensor change intervals, Volvo has
conducted a program to run various sensors for extended mileages. Based
on the results of the testing to date, Volvo states that "the prospects
for increased oxygen sensor life are excellent." Some of Volvo's tests
to 30,000 and 50,000 miles have shown good results, but until further
production and field experience has been generated with this new tech-
nology Bosch, the oxygen sensor supplier, is not prepared to recommend
an increase in the interval.
7-449
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Table Volvo-10
Catalyst
TWC-9B
TWC-16
TWC-16
OM 721
OM 721
Efficiency at
Zero Hours, per cent
HC CO NOx
Durability Performance
of Various 3-Way Catalysts
Efficiency at
Extended Hours, per cent
HC CO NOx
86 99
97
95
93
97
95
99
100
98
70
99
81
84
99
75 91
86
76
86
92
89
73
80
88
80
92
78
78
70
Comments
Full 1000 hours. Two sensor changes. NOx
efficiency dropped to 61% at 600 hrs, a sensor
change point, after which NOx efficiency
improved. A leaner setting at 1050 hours
yielded efficiencies of 84, 99, and 75 per cent,
Results reported to 800 hours. Stable
performance, with no sensor changes indicated.
Full 1000 hours. Two sensor changes reported.
HC and CO performance steadily decreasing.
NOx efficiency as low as 66% at 400 hours.
Test stopped at 500 hours due to poor
conversion. No sensor changes reported.
Full 1000 hours. All efficiencies steadily
decreasing. No sensor changes reported.
-------
Current sensors can exceed 30,000 miles without mechanical problems, but
exhaust deposits (unspecified) cause the signal to drift slightly,
according to Volvo. Volvo did not specify what direction (rich or lean)
the sensor shifted toward, but an examination of the Volvo results
indicates that the sensors tend to shift rich.
Volvo reported results from the durability testing of 27 sensors. These
sensors were tested on seven different vehicles. The sensors were
tested for mileages ranging from 185 miles to 53,155 miles. Two sensors
failed and three cracked.
Of the other sensors four are still running, and the others have been
replaced or the test has stopped. Six sensors were labeled "rich" after
the testing. Trends with mileage were not clear. Of the eleven sensors
that had accumulated in excess of 30,000 miles, four were "ok", one was
"rich", two had cracked, three are still running, and one had failed.
The sensor tested for the longest period, 53,155 miles, was "ok".
Vehicle Durability Testing
Volvo is running test fleets of 3-way catalyst vehicles. The fleets are
of two types, in-use and developmental.
U.S. Test Fleet
About one year ago, Volvo started a fleet of 25 3-way catalyst equipped
vehicles on an in-use durability test. The vehicles are being driven
primarily by Volvo employees, to simulate actual in-use driving. Volvo
plans to run the sensors on these vehicles beyond 15,000 miles, except
when a definite sensor problem shows up. The results to date from this
testing are shown in Table Volvo-11.
7-451
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Table Volvo-11
Emissions Results from
25-Car In-Use Fleet*
Test Mileage
0
10,000
20,000
Number of
Vehicles at
This Mileage
25
18
7
Average Emissions
HC CO NOx
0.21
0.31
0.34
2.71
3.50
3.92
0.13
0.42
0.63
* Volvo Status Report, page 58.
Volvo did not report the individual vehicle test results or any infor-
mation about sensor changes. Compared to the average in-use emissions
of all the 1975 model year vehicles tested in EPA's emission factor
program at the 10,000 mile point (1.38 HC, 23.7 CO, 2.47 NOx), the
results are seen to be much better. Reductions of 78% for HC, 85% for
CO, and 83% for NOx are implied. Volvo pointed out that the emissions
at 20,000 miles were close to or above the statutory levels. According
to Volvo, this confirms Volvo's assertion that real life emissions and
deterioration factors exceed those obtained during certification testing.
The actual 20,000 mile test results from Volvo's durability car with 3-
way catalyst system were 0.26 HC, 3.45 CO, 0.37 NOx. The results
predicted from the DF least squares line for 20,000 miles are 0.25 HC,
3.71 CO, 0.39 NOx. Using the DF line results, Volvo's in-use experience
suggests offsets (in-use compared to certification) of +26% for HC, +5%
for CO, and +38% for NOx, at 20,000 miles. The differences may be due
in part to the differences in maintenance. The Volvo certification
vehicle had its oxygen sensor changed at 15,000 miles, whereas some of
the in-use fleet may not have received a sensor replacement.
7-452
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Developmental Test Fleets
Volvo reported developmental durability results on fifteen vehicles
equipped with 3-way catalyst emission control systems. Of these fifteen,
ten were equipped with the B21 engine and five were equipped with the
B27 engine. The vehicle test results are shown on Table Volvo-12.
There are four types of durability schedules indicated on Table Volvo-
12: EPA, Road, Tire, and Taxi. EPA is assumed to be the official AMA
test used for EPA certification. Road is assumed to mean general in-use
service. Tire is assumed to be a rapid mileage accumulation test,
originally designed to test tires. Taxi is assumed to be taxicab use.
Volvo did not report the test on which the fuel economy was measured.
Fuel content was not specifically stated.
Volvo also reported test results from nine vehicles equipped with a
B21 engine that were durability tested with catalysts of different Pt/Rh
ratios. Two catalysts (F and G) at the 19/1 Pt/Rh ratio were tested.
These catalysts differed in processing, according to Volvo. No details
were provided. The third catalyst (H) has a 5/1 Pt/Rh ratio catalyst.
Volvo ran vehicles on three test cycles: EPA, taxi, and tire. The
vehicles were not specifically identified, so it cannot be said if these
vehicles are in Table Volvo-12 or not. The 19/1 F and G catalysts could
be TWC-9B and TWC-9D, and the 5/1 catalyst could be TWC-16. Table
Volvo-13 lists the results at 50,000 miles and the computed DFs. The
fuel used was stated to be 0.02 to 0.03 grams per gallon lead, more
typical of the 1975 certification fuel than the lower lead levels found
in use and in the current test fuel.
7-453
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Vehicles with B21 Engines
Vehicle
Identification
JJP 448
GCZ 769
DOD 889
ANM 502
JPA 393
DPF 536
BUG 530
HLH 550
DPF 536
JJB 941
JJB 561
HJL 545
JGY 272
HWD 059
Type of
Test
Taxi
Taxi
Tire
Tire
Taxi
Tire
Road
Taxi
Tire
EPA
Vehicles with B27 Engines
HJL 545 Tire
EPA
Tire
EPA
EPA
Table Volvo-12
Volvo Durability Vehicles*
Catalyst
516/TWC-16
516/TWC-16
516/1WC-16
516/TWC-16
516/TWC-21
516/TWC-9B
516/TWC-9B
516/TWC-9B
514.5/TWC-9D
514.5/TWC-9D
Degussa TWC
516/TWC-16
516/TWC-16
516/TWC-16
516/TWC-16
Mileage
30,000
HC
0.22
0.69
CO
4.04
6.20
NOx
0.12
0.36
MPG
0
62,640
70,684
80,940
0.12
0.31
0.24
0.45
2.75
3.70
3.05
5.09
0.09
0.22
0.34
0.62
16.2
16.3
15.7
16.8
16.8
50,137
62,180
77,216
24,394
45,071
0.32
0.48
0.45
0.30
0.33
3.74
4.62
6.79
3.18
5.26
1.29
0.78
1.24
0.57
1.31
17.1
16.2
16.9
17.7
16.7
15.2
10,000
25,000
45,000
50,000
0.27
0.30
0.64
0.41
5.58
3.46
5.40
4.49
1.32
0.38
0.36
1.10
15.1
15.1
15.1
14.8
* Volvo Status Report, page 29, page 60.
-------
Table Volvo-13
50,000 Mile Results
and Deterioration Factors*
Catalyst
Test
EPA
EPA
EPA
Taxi
Taxi
Taxi
Tire
Tire
Tire
jPt/Rh)
F
G
H
F
G
H
G
H
H
(19/1)
(19/1)
(5/1)
(19/1)
(19/1
(5/1)
(19/1)
(5/1)
(5/1)
50,000 Mile Emissions
HC
0.
0.
0.
1.
0.
0.
0.
0.
0.
52
39
23
37
45
18
32
21
38
CO
2.56
3.22
5.04
10.9
6.42
2.26
3.74
3.45
3.42
NOx
1.
1.
0.
1.
1.
0.
1.
0.
0.
81
89
51
98
10
69
30
26
28
Deterioration
HC
1.
2.
1.
5.
0.
0.
1.
0.
1.
76
10
60
51
84
72
79
72
50
CO
1.19
1.20
1.65
3.95
0.67
0.68
1.05
0.74
1.39
Factors
NOx
4.27
4.70
2.56
1.65
2.41
3.56
4.06
6.50
1.93
* Volvo Status Report, page 4.
The results shown on Table Volvo-13 must be interpreted in light of the
fuel lead level. As far as catalyst poisoning goes, Engelhard stated
that there was more poison effect on a catalyst at 5,000 miles with the
1975 type fuel than there was on a 25,000 mile catalyst using the 1977
type fuel. It may be stretching a point to conclude that the Volvo
50,000 mile results shown in Table Volvo-13 are equivalent to 250,000
miles of operation, because thermal aging effects are not accounted for,
but it is probably appropriate to conclude that the 50,000 mile results
would be significantly better than those shown if lower lead levels were
used. Table Volvo-13 also can be interpreted to support the superiority
of the 5/1 catalyst, especially for HC and NOx control at 50,000 miles.
An examination of the Volvo data for which there were both base engine
and tailpipe emissions reported can be used to compare the TWC-16 and
the TWC-9B (5/1 Pt/Rh ratio and 19/1 Pt/Rh ratio catalysts, respectively),
High mileage (50,000 or greater) efficiencies for HC, CO, and NOx are
shown for the two catalysts in Table Volvo-14.
7-455
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Table Volvo-14
High Mileage 1975 FTP Cold Start
Conversion Efficiencies of Two Pt/Rh Ratio Catalysts
Catalyst
TWC-9B (19/1)
TWC-9B (19/1)
average
HC
78%
64%
71%
CO
82%
57%
70%
NOx
65%
71%
TWC-16 (5/1)
TWC-16 (5/1)
TWC-16 (5/1)
average
83%
74%
79%
82%
80%
79%
80%
75%
91%
92%
86%
The low and high mileage base engine levels are shown in Table Volvo-15.
All the vehicles used the B21 engine.
Table Volvo-15
Base Engine Values
Mileage
Low
Low
Low
Low
Low
Average
High
High
High
High
High
Average
Vehicles
GZC 769
HLH 550
DOD 889
DPF 536
ANM 502
-
GZC 769
HLH 550
DOD 889
DPF 536
ANM 502
-
HC
1.55
1.34
1.28
1.43
1.54
1.43
0.96
1.22
1.27
1.45
1.46
1.27
CO
18.1
13.4
18.5
17.9
18.1
17.2
12.69
14.03
17.46
20.79
16.64
16.32
NOx
3.51
3.02
2.89
3.29
3.65
3.27
2.81
3.28
2.83
3.67
3.63
3.24
The base engine emissions did not change greatly during mileage accumulation.
7-456
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Volvo's durability program is an example of an experimental program
apparently designed to get information quickly on a variety of subjects.
Compromises have apparently been made in terms of of determining pre-
cisely what the performance of the advanced systems will be on official
EPA durability. The cycles run in most cases were not AMA durability,
possibly because of time constraints (a tire test could be expected to
put more miles on a vehicle in a given amount of time, compared to AMA
schedule) or desire to get experience on a different duty cycle (the
Taxi test vehicles). Additionally, many sensor changes were made,
possibly in an attempt to evaluate different sensors and sensor durability.
Finally, the lead level in the fuel actually used for the vehicles
reported was not precisely specified by Volvo. Some vehicles were
apparently run on 0.02 to 0.03 gpg fuel, and the catalyst efficiency
slave vehicle was apparently run on sterile fuel. In last year's
status report, Volvo reported that in January 1975, the fuel was changed
from 0.02-0.026 gpg to 2 to 5 ppm. It is assumed that all vehicle test
data reported by Volvo in this year's report were run on the lower lead
content fuel, except for the results shown on Table Volvo-13.
Because of the above differences between the durability test program
that Volvo ran and the official certification test that is used to
determine compliance with the standards, the results have to be interpreted
carefully.
7.3.17.4 Progress and Problems
Volvo has maintained their position of being one of the leaders in the
3-way catalyst development field. They are the first manufacturer to
have introduced such a system into commercial use, for the 1977 model
7-457
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year on the California vehicles equipped with the B21 engine. Volvo
also plans to try to introduce the 3-way catalyst system for the B27
application for California for the 1978 model year.
Volvo is also the manufacturer that has come the closest to certifying a
vehicle at the statutory emission standards. Their performance with the
B21 California application has been the best reported to date.
Volvo's biggest emission control problem is with CO at the 3.4 gm/mi
level. Volvo feels that driveability compromises may have to be made to
control CO to the 3.4 CO level. Generally, there has been no difficulty
in attaining the CO control needed for the 9 CO level. Another major
area of difficulty for Volvo has been the adaptation of the 3-way catalyst
system to the B27 engine, due to both the engine's basic emission levels
and its configuration. Regarding CO control, Volvo did not report
further work on either the quick chokes with cold-start acceleration
enrichment approach or the heated injector approach which were previously
reported to EPA.
Because of their concentration on non-EGR systems, Volvo may have
slipped behind other manufacturers in the EGR area. Other manufacturers
are exploring the use of electronically controlled EGR systems, for
example. Below NOx levels of 1.0, Volvo feels that they would need to
incorporate EGR into their system.
No emission results were reported for vehicles lighter in weight than
current models. Volvo's current sales-weighted composite fuel economy
is about 20 mpg, which is probably less than the requirements for the
1981-1984 time period. It is known that Volvo has a lighter weight
vehicle in Europe, due to their takeover of DAF, but no emission results
were reported for such a vehicle. It may be that the development time
to adapt that vehicle to meet the U.S. standards is significantly less
than three years.
7-458
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APPENDIX 1
-------
ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON. D.C. 20460
Dear
As part of its continuing overview of the industry's efforts, and
to implement sections 202(b)(4) and 202(b)(5) of the Clean Air Act, as
amended, the Environmental Protection Agency needs current information
on efforts by automobile manufacturers to meet the 1978 and 1979 and
subsequent model year light duty motor vehicle emission standards.
Accordingly, pursuant to section 307(a)(1) of the Clean Air Act, you are
requested to provide information regarding your development status and
progress toward meeting these standards. This information is similar to
and will update the information which your company has provided in the
past in response to similar requests.
The desired information, which is described in the enclosed out-
line, is divided into five main areas: a) information describing the
design of your emission control systems, b) information describing your
test and development programs, c) emission data covering both regulated
and non-regulated pollutants, d) fuel economy, and e) cost informa-
tion. Additionally, any specific questions that may be relevant only to
your company are attached to the enclosed outline.
In previous years some submissions have been incomplete with respect
to information regarding programs and systems identified as primarily
concerned with fuel economy. I understand that the rationale behind
this was that these systems were related only to fuel economy and had no
significance for emissions. This rationale implies that emissions and
fuel economy are unrelated, which conflicts with previous statements
made by the industry that fuel economy and emissions are related. On
this basis, I request that your submission include complete coverage of
all fuel economy related programs and developments. This will allow my
staff to analyze this information, and determine the degree to which
emissions are affected.
Al-1
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-2-
The Agency is becoming increasingly aware of the important role
that driveability plays in the emissions performance of vehicles in
customer use. It is suspected that unfavorable driveability character-
istics may increase the likelihood that a vehicle will be maladjusted in
an attempt to improve driveability. It is requested, therefore, that
your submission provide complete information on the driveability char-
acteristics of current and developmental emission control systems. The
Agency should also be provided with a complete account of all systems
that are intended to improve or influence driveability.
The information provided by your company should, in general, follow
the enclosed outline. You may limit the information supplied in re-
sponse to this request to that information which has not previously been
supplied to EPA. However, if portions of the desired information have
already been supplied to EPA and you wish not to resubmit these materials,
please indicate the appropriate documents by specific reference.
Three copies of your response should be submitted to EPA no later
than December 15, 1976. Responses should be addressed to:
Director, Emission Control Technology Division
Attention: Status Report Team
Motor Vehicle Emission Laboratory
2565 Plymouth Road
Ann Arbor, Michigan 48105, USA
We realize that much of the information requested on the 1978 model
year systems may be included in your company's 1978 Part I certification
application. That document, however, is needed by the Certification
Branch, and cannot be made as available to the Status Report Team as is
necessary for the purpose of this report. Therefore, if you choose to
reference the Part I in your submission, include two copies of that
document with your response to this letter, in addition to the other
information requested in the outline.
Questions concerning the data requested should be addressed to Mr.
John DeKany, Director of the Emission Control Technology Division, whose
group has primary responsibility within EPA for acquiring, analyzing,
and reporting data on the status of technology for automotive emission
control. Also, staff from that Division may contact you for additional
information or explanations, and such requests should be considered by
you to be an integral part of the request for data made by this letter.
Your cooperation in ensuring that the Environmental Protection
Agency receives clear, detailed, and understandable information describ-
ing the efforts of your company in the design, development and testing
of 1978, 1979 and subsequent model year emission control systems will
Al-2
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-3-
contribute materially to assuring a sound decision making process
related to the implementation of the Clean Air Act.
Sincerely yours,
Roger Strelow
Assistant Administrator
for Air and Waste Management
Al-3
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OUTLINE FOR EMISSION CONTROL STATUS REPORT
The following outline should be followed in submitting the requested
information. Any information not identified in the outline or the
discussion of the outline that you feel is necessary for an accurate and
complete description of the emission control technical effort of your
company may also be included.
Since the legislated emission standards for 1978 are .41 HC, 3.4 CO, 0.4
NOx, this scenario should be fully discussed. Because of Congressional
interest in modifying the emission standards for future model years, the
House-Senate Conference Committee Report scenario should also be discussed.
The Conference Committee Report reflects the most current Congressional
considerations for near-term modification of the Clean Air Act. Each
emission standard of the Conference Committee Report, which is as follows,
should be discussed separately:
Model Year HC CO NOx
1978 1.5 15 2.0
1979, 1980 .41 3.4 2.0
1981 .41 3.4 1.0
I. Emission Control Systems
A. Identification and description of the entire emission control
system
B. Discussion of system optimization
C. Description of system operation
II. Development and Testing Program
A. Description of test program and organization
B. Test program basis and rationale
C. Test vehicle description
D. Test program status
III. Experimental Data
A. Vehicle data
B. Non-vehicle data
IV. Fuel Economy
A. On the 1975 test procedure ("city" cycle) and on the EPA
non-metropolitan ("highway") cycle
B. Fuel economy on other cycles
V. Cost Information
A. First cost
B. Operating cost
VI. Confidentiality of Trade Secret Information
Al-4
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Discussion of Outline
I. EMISSION CONTROL SYSTEMS
The Agency needs information on all systems that either directly or
indirectly influence emission control. As explained in the accompany-
ing letter, systems that affect fuel economy and driveability may
significantly influence emission control. Accordingly you are requested
to provide the information discussed below for all systems and com-
ponents that have been or are now being developed for the purpose of
improving emissions, fuel economy or driveability.
A. Identification and Description of the Engine Emission Control
System
This should include both a generic and specific description of
each system (first choice and all backup systems) under con-
sideration for the model years under discussion. If any feature
of the emission control system differs between model lines it
should be treated as a different system. An example might be
the emission control system for a ZOOOlb. IW vehicle as contrasted
to the emission control system for a 5000 Ib. IW vehicle. An
example of a generic model year 1977 emission control system is
engine modification, EGR, and an oxidation catalyst. The de-.
tailed description should include enough information about the
system to distinguish it from other systems in the same generic
category. The description should be accompanied by engineering
drawings and pictures when appropriate to more fully identify
and describe the system or subsystem. At least the following
topics should be discussed and fully identified.
1. Engine type - reciprocating 4-stroke, rotary, etc.
2. Engine modifications - compression ratio, combustion
chamber shape, valve timing, bore/stroke ratio, spark
plug location, etc.
3. Intake system - detailed description of carburetor(s),
fuel injection system, choke and choke control, intake
manifold and intake port.
4. Exhaust port and manifold description.
5. Ignition system - spark advance as a function of all spark
control parameters.
6. EGR system - flow rate as a function of engine speed and
load, type of control, take-off location, introduction location,
type of cooling (if cooled).
Al-5
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-2-
7. Air injection - type of pump, supplier, flow rate vs.
engine speed and load, modulation and switching control,
location and type of air injection nozzles.
8. Thermal reactor - type (lean/rich), configuration,
materials, internal flow geometry.
9. Catalysts - type (reducing, oxidizing, three-way), active
material (general) class, loading and total weight of each
catalyst material and the total in troy ounces per vehicle,
substrate structure type (monolith/pellet), substrate com-
position, washcoat composition, total surface area of the
washcoat, surface area per displacement of the washcoat,
catalyst location, shape and size, geometry, manufacturer
and manufacturer's identification number, nominal space
velocity and space velocity range.
10. Evaporative emission control system - general descrip-
tion including degree of use of air cleaner/horn as storage
volume, type of storage material, volume of storage mater-
ials, purge and fill tube routing, purge rate, purge controls,
and location and design of purge vapor inlet to the air
cleaner/carburetor/exhaust system.
B. Discussion of System Optimization
1. This should include a discussion of the design constraints
within which each system was optimized for emissions. Examples
of such constraints are fuel economy, safety, cost, drive-
ability, packaging, maintenance, and performance. Quantita-
tive values should be identified for all of the constraints
for which your company has determined such quantitative values.
Others should be discussed in the manner in which they were
set down for the design engineer.
2. This should provide a discussion of all designs that were
not successful in surviving the optimization studies that
your company performed, giving the criteria by which they
failed.
3. Of the systems that are under consideration for the
model year being discussed, identify and explain the trade-
offs that have been made within the emission control system.
Trade-offs to be considered are first costs, operating costs,
fuel economy, emission levels, driveability, performance, and
durability. The rationale considered in evaluating these trade-
offs shall be described and explained. Quantify any examples
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by including design calculations or engineering reports.
An example might be catalyst location, where one emission
control related trade-off could be the trade-off between
a location close to the exhaust port for fast light off
vs. a more remote location that might provide a longer
catalyst life. Another trade-off might be the inter-
action between increased mechanical octane (to permit
operation on 91 RON fuel at higher compression ratio,
for improved fuel economy) and the desire to reduce
engine-out HC emissions.
4. The Agency considers that there are two primary areas
in which the design and/or operation of the emission control
system might influence vehicle safety. These areas refer
to fuel system/evaporative emission control design and/or
operation and catalyst temperature. To assist the Agency
to understand the emissions/safety interrelationships, please
answer the following questions.
a. At what stage in the research, design, development
and testing phase are the safety aspects of emission
control systems and/or devices considered?
b. What sort of testing and analysis is performed to
evaluate the designs for their likely safety-related
performance? Please give specific examples.
c. List and discuss all changes made to the exhaust and
evaporative emission control systems developed by your
company that were made because of safety considerations.
Include both changes made during the development process
and changes made after the systems were in production.
5. The discussion of system optimization should also include
discussion of evaporative emission control, with special
emphasis on the interactions between the evaporative and exhaust
emission control system. The Agency knows that there can be
interactions between the evaporative and exhaust emission
control systems, and considers the subject area to be a more
important one for the future, especially at low HC and CO
levels with more effective evaporative emission control
systems. More effective evaporative emission control systems
may be required for the 1978 EPA 6 gram SHED standard.
Therefore, you are requested to discuss the optimization of
the entire emission control system, including the evaporative
emission control system. The discussion shall include listing
of all test results, including all SHED tests run on your
vehicles with developmental emission control systems.
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6. Discuss any trade-offs or emission control system modi-
fications that may have been made to improve sulfuric acid
or hydrogen cyanide emissions.
C. Description of System Operation
1. The sequence of operations of the entire emission control
system during the 1975 Federal Test Procedure should be
discussed in detail, with special attention given to those
parameters which vary during the cycle, for example, spark
timing, the choke position, air injection (if modulated or
switched), EGR flow rate, and evaporative system purge.
As backup information to the general description of how the
emission control system works during the emission test, please
provide the following quantitative information as a function
of time during the 1975 CVS-CH test, starting with "key-on".
a. engine exhaust flow rate in SCFM
b. engine air flow rate in SCFM
c. spark timing-vacuum and centrifugal separately,
plus total spark timing or simply total spark timing
if an electronic system is used.
d. exhaust gas recirculation rate as a percentage of
fresh inlet air flow.
e. air injection flow rate into the exhaust manifold
or pipe*.
f. nominal engine air/fuel ratio, as determined upstream
of any aftertreatment device, for example a catalyst or
thermal reactor.
g. exhaust gas temperature before and after any after-
treatment device.
h. catalyst temperature (if a catalyst is used). The
information may be presented graphically, for example,
superimposed on the speed vs. time trace of the emission
test, or in tabular form, on a second-by-second basis.
i. exhaust gas 02 level before and after any after-
treatment device.
j. evaporative system condition and purge rate.
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The above information is requested for each engine family/
emission control system. If more than one control system
behaves the same during the test, that may be noted and not
detailed. However, control systems with markedly different
characteristics; i.e., proportional vs. non-proportional
EGR or different carburetor metering principles, should not
be deleted.
2. The way in which the system operates under the following
other conditions should be discussed; the emissions under
such conditions should be quantified in III-A below.
a. Operation in low (less than 60 degrees F) or high
(greater than 86 degrees F) temperature ambient conditions.
b. Operation under conditions of speed and/or load
which do not occur during the 1975 Federal Test Procedure.
c. Operation at low barometric pressure, for example,
at elevations significantly higher than sea level.
II. DEVELOPMENT AND TESTING PROGRAM
A. Description of Test Programs
1. This should include a general description of the type of
laboratory or bench scale testing carried out on emission control
subsystems or components.
2. This should include a description of any catalyst screening
tests and the basis for selecting/rejecting catalysts.
3, This should include a discussion of any tests made for
optimization purposes described in I-B above, a general des-
cription of the variables that were changed, the range over
which they were varied, and the inferences drawn from the
system of optimization tests.
B. Test Program Basis and Rationale
1. This should include general discussion of the use of
vehicles for component testing and trade-offs studies,
especially as it affects system optimization. Distinction should
be made between vehicles used for component testing vs.
complete system tests.
2. This should include a complete description of all vehicle
emission test programs for the model year under discussion,
including the number and type of vehicles, the reasons for
choosing the vehicle mix, the mileage accumulation schedule
for each vehicle and the number of emission tests at each
mileage point.
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C. Test Vehicle Description
This should include an identification of the vehicle; car line,
test weight, transmission type, axle ratio and an identification
of the emission control system as outlined in I-A.
D. Test Program Status
This should include a discussion of the current status of each
emission durability vehicle and a comparison of its status with
respect to the original planning. Significant problem areas, if
they exist, should be identified.
III. EXPERIMENTAL DATA
^
A. Vehicle Data
1. Include 1975 FTP data on all durability fleet vehicles
described in II-B above.
2. Include a description of the reasons for any vehicle not
completing the full scheduled durability mileage.
3. Include a discussion of the driveability and performance
of the test vehicle, again with quantitative data and with
quantitative comparisons to current model year vehicles.
Please include the driveability rating procedure used by your
company if this has not previously been supplied.
B. Non-Vehicle Data
1. This should include the results from any catalyst screening
tests, with a description of test methodology, and must include
the test results from the catalysts that were selected for the
durability vehicles.
2. Include any other non-vehicle data considered important,
such as engine dynamometer studies of the effect of fuel
contaminants on catalyst durability.
C. Unregulated Pollutant Emissions
All data developed by your company on the emissions of sulfuric
acid, hydrogen cyanide, platinum, other particulates, and other
unregulated pollutants emitted from
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future emission control systems, and from current vehicles, should
be presented. This includes all data from bench, engine dyna-
mometer and vehicle tests.
A full description of the measurement methods (driving schedule,
sampling ami analytical techniques) used to obtain the above in-
formation should be provided.
IV. FUEL ECONOMY
A. On the 1975 Test Procedure
Provide the weighted 1975 fuel economy for all tests run on advanced
emission control systems. Use the following formulae for fuel
economy and fuel consumption:
2423
fuel economy in miles per gallon = .866 HC+..429 CO+ .272 C02
Where HC, CO and CO are the weighted exhaust constituents in grams
per mile for the entire 1975 test, with the same .43/.S7 cold start/
hot start weighting as applied to .the HC and CO values for the 1975
test also applied to the C02 values.
fuel consumption in litres per 100 kilometres = 235.2
mpg
B. On the EPA Non-metropolitan Driving Cycle
Provide the fuel economy and fuel consumption data for all tests
run using the EPA Non-metropolitan ("Highway") Driving Cycle. Use
the formulae in IV-A, above except that the HC, CO and C02 values
in grams per mile are, of course, not weighted.
C. Fuel Economy on Other Cycles
If you possess fuel economy data using a different procedure, you
may also submit that data. The test procedures should be refer-
enced or specified in detail, if that information has not been
previously submitted to EPA.
V. COST INFORMATION
A. First Cost
1. The cost breakdown should be in the same form as that used
by the National Academy of Sciences Committee on Motor Vehicle
Emissions in Table 5-2 of their February 15, 1973 report to the EPA.
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This should also be specific as to what fraction of the
various product lines will require specific devices.
B. Operating Costs
This should include expected extra costs to the customer over the
vehicle lifetime (assume 50,000 miles) due to:
1. Fuel and lubricant cost, specifying the miles per gallon
fuel economy assumed for each engine family and a comparison
to 1973 model year vehicles of the same class.
2. Maintenance cost other than catalyst replacement. Such
estimate should break out parts of labor cost separately,
providing the ratios of parts cost for OEM vs. replacement
cost. The estimate should also indicate the expected level
of required maintenance on each major emission control com-
ponent which results in such costs.
3. Catalyst replacement cost. This estimate should separate
labor and material costs and should give the estimated life of
the catalyst. Material costs should break out catalyst and
container costs.
VI. CONFIDENTIALITY OF TRADE SECRET INFORMATION
A. Information submitted in response to the request which accompan-
ied this outline will be deemed to have been obtained pursuant to
section 307(a)(1) of the Clean Air Act.
B. This means that only information which"...would divulge trade
secrets or secret processes" will be kept in confidence. (Even
this information will not be kept confidential in two situations:
(1) when the information is emission data, or (2) if and when the
information becomes relevant to any proceeding under the Act. See,
in particular, paragraph D.) In order to assure that such information
will be kept confidential prior to any such proceeding, you must
1) put the information on separate pages in the report that are
clearly marked "CONFIDENTIAL" and are easily detached from the
report and 2) in a separate section of the report labeled "CONFIDENTIAL
INFORMATION" identify the number of each page on which confiden-
tial data appear and provide in that section the information to
substantiate your claim for confidentiality. If such claims for
confidentiality and supporting information are not provided at the
time of submission of your response to this inquiry, all claims
of confidentiality will be deemed to have been waived.
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C. If the Administrator determines that a satisfactory showing
has not been made that the information would disclose trade secrets
or secret processes, you will be notified by certified mail. No
sooner than 30 days following the mailing of such notice, any in-
formation with respect to which trade secret status has not been
established will be placed in a public docket. Any information
as to which the Administrator determines that a satisfactory
showing has been made will be held confidential in the period
prior to commencement of any suspension proceeding.
D. As in the case of the previous suspension proceeding, if any
trade secret information becomes pertinent to the issues raised in a
new proceeding on an application for suspension^ it may be disclosed
by the Administrator. In order to retain confidential treatment
of such information you must show to the satisfaction of the Admin-
istrator, that non-disclosure of such information is justified by
"...exceptional considerations",* as that phrase was defined in the
course of the previous suspension proceeding. The showing that
must be made is that the information is of such slight probative
value in resolving the issue being considered by comparison to the
harm likely to result from disclosure that public release of the
information is not justified. If the Administrator determines that
a satisfactory showing has not been made, you will be notified by
certified mail. No sooner than 10 days following the mailing of
such notice and telephone notice to a representative of your General
Counsel's office, such information will be placed in a public docket.
Any information as to which the Administrator determines that a
satisfactory showing has been made will-be held confidential and will
not be considered by the Administrator in deciding whether to grant
or deny a pending application for suspension.
* December 3, 1974 39 FR 233 P. 41899
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Table Al-1
Date of Receipt of Status Reports
from the Various Manufacturers
(Requested Dates: December 15, 1976 for
all manufacturers except MECA members
which were due January 3, 1977)
Date
December 10, 1976
December 14, 1976
December 15, 1976
December 16, 1976
December 17, 1976
December 20, 1976
December 21, 1976
December 27, 1976
December 29, 1976
December 30, 1976
January 3, 1977
January 10, 1977
Reports Received from
Mitsubishi
Chrysler
Holley
Bendix
GM
Questor
Ford
Toyota
Ethyl
Rolls Royce
Nissan
Honda
AMC
AMC
Ford
Mitsubishi
Toyo Kogyo
Citroen
Toyota
Volvo
Fiat
VW
Peugeot
Renault
Walker*
Comments
Early, incomplete
status report
Early
On time
1 day late
Incomplete Status Report
Incomplete Status Report
Two days late
Five days late
Part I only
Six days late
Status Report completed
Cal. information for
Status Report
Twelve days late
Status Report received
Fourteen days late
Fifteen days late
Nineteen days late
Seven days late
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January 12, 1977
January 18, 1977
January 20, 1977
January 21, 1977
January 24, 1977
February 4, 1977
February 8, 1977
February 22, 1977
February 28, 1977
* MECA Member
Engelhard
Matthey Bishop*
Dresser
Bosch
Saab
BMW
Fuji
Mercedes-Benz
British Leyland
U.O.P.*
Gould
Twenty-eight days late
Fifteen days late
Thirty-six days late
Thirty-seven days late
Forty days late
Fifty-one days late
Fifty-five days late
Sixty-nine days late
Fifty-six days late
Never received
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