AUTOMOBILE EMISSION CONTROL -
THE TECHNICAL STATUS AND OUTLOOK AS OF
DECEMBER 1974
A Report to the Administrator
Environmental Protection Agency
Prepared by
Emission Control Technology Division
Mobile Source Pollution Control Program
January 1975
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AUTOMOBILE EMISSION CONTROL -
THE TECHNICAL STATUS AND OUTLOOK AS OF
DECEMBER 1974
A Report to the Administrator
Environmental Protection Agency
Prepared by T- ._, .
Emission Control Technology Division
Mobile Source Pollution Control Program
January 1975
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CONTENTS
1. INTRODUCTION , , 1-1
20 CONCLUSIONS . 2-1
2.1 Conclusions „.„.„.... 2-1
2.2 Discussion of Conclusions „ • • • 2-2
3. EMISSION CONTROL, TECHNOLOGY, AND FUEL ECONOMY . . ' 3-1
3.1 General Factors that Influence Fuel Economy ...... 3-1
3.2 Effect of Emission Control Techniques .... 3-2
3.3 Effect of Emission Standards. . „ 3-2
3.4 Oxidation Catalyst Systems. 3-4
3.5 Advanced Oxidation Catalyst Systems 3-7
4. EMISSION CONTROL SYSTEM COSTS. . ..... 4-1
4.1 Sticker Price Increases in Perspective 4-1
4.2 Component Costs of Emission Hardware 4-2
4.3 Cost of Emission Control Systems 4-3
5. SULFATES AND OTHER UNREGULATED EMISSIONS 5-1
6. INDUSTRY STATUS 6-1
6.1 Industry Status - 1976 Model Year 6-1
6.2 Industry Status - 1977 Model Year 6-1
6.3 Industry Status - 1978 Model Year 6-4
7. INDIVIDUAL MANUFACTURERS REVIEWS ..... .... 7-1
7.1 Domestic Manufacturers 7-1
7.1.1 American Motors (AMC) 7-1
7.1.2 Chrysler 7-6
7.1.3 Ford 7-15
7.1.4 General Motors (GM) . 7-25
7.2 Non-Automobile Manufacturer Status. .......... 7-34
7.2.1 Gould. ...'..........„.. o .... 7-34
7.2.2 Dresser. . 7-41
7.2.3 Yamaha ..... 7-46
7.2.4 Questor 7-48
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7.3 Foreign Manufacturers . . 7-52
7.3.1 Alfa Romeo 7-52
7.3.2 BMW 7-58
7.3.3 British Leyland 7-60
7.3.4 Daimler-Benz 7-64
7.3.5 Fiat 7-71
7.3.6 Honda 7-75
7.3.7 Izuzu . . . 7-78
7.3.8 Mitsubishi 7-71
7.3.9. Nissan 7-85
7.3.10 Peugeot . . . 7-90
7.3.11 Renault 7-95
7.3.12 Rolls-Royce ..... 7-98
/ • J • J. J Oclct D«*«««»o**»»*«»«««o*oooo/ ~-LU^T
7.3.14 Toyo Kogyo 7-108
7.3.15 Toyota 7-112
7.3.16 Volkswagen 7-115
7.3.17 Volvo 7-118
8. APPENDIXES.
Appendix A A-l
Appendix B B-l
Appendix C C-l
ii
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SECTION 1
INTRODUCTION
This report is a summary of the current technical status and outlook
in the automobile emission control field. This report has been prepared
for the Administrator of the U,S« Environmental Protection Agency (EPA)
for two primary reasons:
1. To inform the Administrator of the current status in the emission
control technology area.
2. To highlight the important technical issues that may arise during
suspension hearings that EPA will hold if automobile manufacturers
apply for a one-year suspension of the 1977 HC and CO standards.
This report contains a summary and evaluation of the development programs
of 25 automobile manufacturers and other organizations involved in the
development of automobile emission control technology.
The time frame under consideration in this report is from the present
until the 1978 model year. Special emphasis is given to the model
years 1977 and 1978 since the emission standards for those years are
different, and more stringent, than the current, model year 1975, emission
standards. Although systems and concepts are currently under development
that have a potential for introduction later than the above mentioned
time frame they are not given major emphasis in this report. These
longer term concepts will be included in next year's and subsequent
reports. It should be noted that Congressional changes will result
in the relocation of the longer term engine development programs to
the Energy Research and Development Agency.
Most of the information in this report came from manufacturers' responses
to a request from EPA. Most of the responses were received during the
month of December 1974, so the information pertains to the period of
time immediately prior to December 1974. This specification of the time
to which the data relate is important in an area like emission control
technology, in which rapid progress is being made. 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.
Other data used in the preparation of this report were: a) 1975 certifica-
tion results, b) 1976 Part I applications for certification, c) the
technical literature, and d) the November 1974 report of the committee
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on Motor Vehicle Emissions*, National Academy of Sciences, called the
1974 NAS report in this report.
This report is the fourth in a series of reports on the same subject.
The earlier reports were:
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.
These are References 2, 3, and 4 respectively.
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 grams per mile hydrocarbons,
15.0 grams per mile carbon monoxide and 3,1 grams per mile oxides of
nitrogen are abbreviated 1.5 HC, 15.0 CO, 3.1 NOx with the understnading
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.
The current emissions standards are thus:
1975/6 Federal; 1.5 HC, 15.0 CO, 3.1 NOx
1975/6 California; 0.9 HC, 9.0 CO, 2.0 NOx
1977 50-State; 0.41 HC, 3.4 CO, 2.0 NOx
1978 50-State; 0.41 HC, 3.4 CO, 0.4 NOx
* Reference 1 - Report by the Committee on Motor Vehicle Emissions,
Commission on Sociotechnical Systems, National Research Council,
National Academy of Sciences, Washington, D.C., November 1974.
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SECTION 2
CONCLUSIONS
2.1 Conclusions
The conclusions listed below apply at the time this report was being
prepared, December 1974. In a technical area like emission control
technology where the rate of progress is so rapid, new developments
may require modifications of conclusions that were made earlier.
The EPA report team concludes:
1. Control of HC emissions is currently the most critical area in the
field of emission control, due to its relationship to air quality and
fuel economy.,
2. There is no inherent relationship between exhaust emission standards
and fuel economy.
3. Delaying or relaxing emission standards cannot guarantee that gains
in fuel economy will be made.
A. What the ultimate or final emission standards are going to be is
more important than the length of any delay or temporary relaxation of
the emission standards.
5. It is technically feasible to achieve any of the currently legislated
emission standards.
60 Achieving the 1977 or 1978 emission standards with fuel economy equal
to or better than current (model year 1975) vehicles is possible.
7. In the time frame considered by this report, the conventional engine
is the only powerplant that can be considered for widespread application
in automobiles.
8. Emission control technology has evolved to such a state that it is
possible to meet the 0.9 HC, 9.0 CO, 2.0 NOx levels with lead tolerant
systems.
9. The cost of systems that could be used to meet the 1977 standards
of 0.41 HC, 3.4 CO, 2,0 NOx could be such that no additional cost
penalty over current (1975) systems is incurred. However, lead time
considerations are such that the more cost-effective technology may not
be able to be applied to all vehicles by the 1977 Model Year.
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10. Activity in the area of unregulated pollutant emissions, especially
in the area of sulfate control technology development, is not commensurate
with the degree of the problem.
11. The development of systems targeted toward the 0.41 HG, 3.4 CO,
2.0 NOx standards is moving ahead slower than considered necessary for
successful certification with fuel economy equal to or better than
current cars.
2.2 Discussions of Conclusions
1. There are four major reasons why HC control is the most important
technical problem in the emission control area.
a. The potential need for more HC control. The National Academy
of Sciences, in their report on Air Quality and Automotive
Emission Control*, stated:
"At least in the Los Angeles
area, the Federal statutory
hydrocarbon emission standard
of 0.41 grams per mile may not
be sufficiently stringent to
ensure compliance with the
national ambient air quality
standard for oxidant. However,
present analyses are inadequate
to justify changes in the
Federal motor vehicle emission
standard for hydrocarbon at
this time,,"
Therefore HC control more stringent than the current 0.41 level
cannot be ruled out, at least in some areas, ort an air quality
basis.
bo The untreated HC emissions from conventional engines are strongly
dependent on spark timing, as is fuel economy. Relatively more
HC control will be required at spark timing calibrations that
are optimum for fuel economy.
c. HC emissions from automobiles come from other sources than the
exhaust. The most important source, other than the exhaust, is
evaporative HC emissions. The 1974 NAS report and the analysis
* Reference 5 - Air Quality and Automotive Emission Control - A report by
the Coordinating Committee on the Air Quality Studies, National Academy
of Sciences and National Academy of Engineering, prepared for the
Committee on Public Works, United States Senate pursuant to So Res 135,
approved August 2, 1973, Volume 1, Summary Report, September 1974 „
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by Heywood* both indicate that the actual evaporative emissions
from in-use vehicles, based on EPA data, are greater than the
current exhaust HC standard of 1.5 grams per mile. More work
in the effective control of evaporative HC emissions and refueling
losses is required. The change to the SHED-type technique, currently
underway within EPA, should be accelerated, even if it means
reordering present priorities, in the opinion of the report team.
d. The current EPA investigation of non-methane hydrocarbon (NMHC)
exhaust emission standards for vehicles may have other more
important ramifications than just making the vehicle emission
standards consistent with the ambient air quality standards.
The catalyst systems now being developed to meet low HC standards
tend to have a higher percentage of methane in the exhaust than
do the systems for which the current 0.41 gpm HC standard was
derived. Therefore, if the standards were changed to a non-
methane basis, the systems now under development could more
easily meet the non-methane standard cooresponding to 0.41 HC.
It may be possible to meet a non-methane standard without
resorting to more sophisticated HC control techniques, although
little data exists in this area. The potential exists, with a
NMHC standard, to use some of the cushion that such a standard
might have to improve fuel economy, but it must be pointed
out that the use of the extra cushion that a NMHC standard might
provide lies with the manufacturer.
2. The relationships between the exhaust emissions from a vehicle and
the fuel economy it delivers are not simple. In this conclusion, the
report team is in agreement with the 1974 NAS report.** The most important
consideration involves the entire vehicle system that is used to achieve
the exhaust emissions and fuel economy. The subject of emission and
fuel economy interrelationships is discussed in more detail in Section 3
of this report.
3. There is no assurance that relaxation of emission standards will
result in fuel economy gains. EPA does not have the authority to
require that fuel economy gains be made. Additionally, at a given
emission standard it is possible that several systems could be used
to comply. These systems may have different fuel economy capabilities,
and EPA cannot require that any certain system be used. The fuel
economy performance of future vehicles will be a result of actions
taken by automobile manufacturers, the same situation that has existed
in the past and exists today.
* Reference 6 - Chapter Four of The Automobile and the Regulation of Its
Impact on the Environment a report of the Legislative Drafting Research
Fund of Columbia University under NSF grant NSF-GI-29965, June 30, 1974.
** 1974 NAS report (reference 1) page 31.
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4. The long-term emission standards are more important than a temporary
delay or relaxation of the emission standards. There are two major
reasons for this.
a. Manufacturers must make near-term plans that are compatible
with long-term plans. In the opinion of the report team, the
automobile manufacturers cannot make firm plans for the near-
term that will be compatible with long-term plans without
knowledge of what the long-term emission standards will be»
No manufacturer will risk shifting development and production
toward systems that he feels will not be able to meet future
standards. The long lead times for changeover and the desire
to use tooling for as long as possible influence this attitude.
The report team feels that if the industry was given the mora-
torium that they apparently desire, without the knowledge of
what the emission standards will be after the moratorium, it
would hinder instead of help development programs for future
emission control systems. The industry, in all fairness, must
know the long-term requirements that they will have to meet, and
know them as early as possible. It is not exaggeration to say
that these long-term targets could encompass the time frame up
to arid including the 1990's.
b. The long-term requirements must be communicated to the industry
in such a way that the industry really believes that the re-
quirements will be enforced. If the industry does not believe
that the requirements will be enforced they will not make the
required development and investment committments, in the opinion
of the report team. An example of this is the current 0.4 NOx
• standard for model year 1978. Based on our review of the develop-
ment programs targeted toward this requirement, the report team
feels that the manufacturers do not believe this standard will
ever be enforced.
Of course the long-term targets must be what is required for
air quality. If a long-term requirement were set, and systems
were developed toward that target, and subsequently more stringent
levels were found necessary then the achievement of the new goal
might be delayed because the systems that were developed to meet
the previous targets might have no chance to meet the lower
target.
5. In this conclusion concerning the capability to meet future emission
standards, the report team is in basic agreement with the conclusions
of the NAS in the 1974 NAS report*. The specific standards for the
various model years are discussed more fully in Section 6.
* Reference 1, pages 1 and 2.
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6. In general, the emission control systems that are required to meet
future standards, while retaining improved fuel economy, are somewhat
more costly, more sophisticated, or less well developed than are current
systems. In general,the first cost increment paid for such improvements
for fuel economy are less than the increments attributable to meeting
the emission standards themselves.* These first cost increments are due
to the development cost, and the investment cost, both of which are in-
fluenced by the lead time available for introduction of the improvements.
Because of the lead time available for near-term introduction of the fuel
economy improvements, some first cost increases are likely. Use of
different types of technology may reduce or eliminate the first cost
increases, but this requires the correct combination of development
effort, investment, and lead time. An example of this is the system
that is now under study by GM that incorporates a lean engine operation
in conjunction with an oxidation catalyst. This system could be cheaper
than conventional oxidation catalyst systems, since the air pump, EGR
and EFE are eliminated.
7. New engine types can only be phased into production gradually, and
then only after extensive development and testing programs. The 1974
NAS report** estimates that Diesel engined and CVCC engined automobiles
could only account for 12 and 27 percent of domestic production, respectively,
by 1980. The market share in 1977 and 1978 would be considerably less,
and manufacturers might be pressed to meet the 1977 introduction dates
estimated by NAS for these engine types, in the opinion of the report
team.
8. The capability to certify at the California 1975 standards with a non-
catalyst system has already been demonstrated by Saab. Other systems
now under development, for example the Dresser carburetor, also show
that the 0.9 HC, 9.0 CO, 2.0 NOx levels can be met with no catalysts.
There are several implications inherent to this technical capability
statement. First, if systems are built and sold that do not require
lead-free fuel, the consumer will lose the maintenance advantages that
accrue with lead-free fuel use. Second, at any emission level below
the 0.9 HC, 9.0 CO, 2.0 NOx levels, lead tolerant systems will probably
have inferior fuel economy to lead intolerant systems**.*. At this level
the fuel economy may be about equal, comparing the Dresser results to
catalyst systems, for example. Thirdly, if the standards are maintained
* Reference 7, Potential for Motor Vehicle Fuel .Economy Improvement -
Report to the Congress October 24, 1974, prepared by the U.S. Department
of Transportation and the U.S. Environmental Protection Agency.
** Reference 1, page 114.
*** In This conclusion the report team is in agreement with the 1974
NAS report.
2-5
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at the 0.9 HC, 9.0 CO, 2.Q NOx level, EPA's requirements for lead-free
fuel cannot be supported on the basis that the only systems that can
meet such levels are catalytic ones that require lead-free fuel. The
report team estimates that by 1979, systems that do not require catalysts
at the 0.9 HC, 9.0 CO, 2.0 NOx level could be in full production.
9o Systems like ones that employ a Dresser carburetor and an oxidation
catalyst, or the lean engine calibration plus oxidation catalyst approach
now under investigation by GM may be attractive from the cost stand-
point. This is because the air injection system, EGR, and quick warm-up
devices can possibly be eliminated, which would tend to lower system
cost compared to 1975. On the other hand, system improvements like
improved oxidation catalysts and enlarged exhaust manifolds may tend
to add some cost. The overall cost result is difficult to estimate since
such advanced systems are in the early stages of development, but the
potential for lower or equal cost is there. Since the systems are in
an early stage of development, the report team estimates that it will
be difficult for all manufacturers to incorporate improved systems by
1977 on all models, especially those manufacturers who are not aggressively
developing such systems now.
10. Many substances are emitted from vehicles for which there exists no
emission standard. Among these substances are particulates (including
lead and sulfates), aldehydes, and polycyclic organic matter (POM).
In the area of particulate emissions for example, before any meaningful
characterization of the particulate emissions from vehicles is done,
those who characterize the particulates should know what are the most
important health related parameters for particulate emissions*. This
is important since the characterization work and the attendant procedures
could be much different if particulates were important on just a total
mass basis, or on the basis of a size distribution,or the basis of a
specific particulate material, or on the basis of some combination of
total mass, size distribution and specific material. In the area of
particulate emissions, the relative lack of adequate health effects
data makes interpretation of the existing data difficult. This is
especially important for the investigation and characterization of
alternate engine concepts such as the Diesel.
The unregulated pollutant given the most emphasis in the past year or so
has been sulfate. Characterization work has progressed, but relatively
little in the area of control technology development, aside from a small
EPA effort, has been done. The report team concludes that the manufacturers
are waiting to see if EPA thinks sulfate emissions from automobiles will
be a health hazard. If EPA does consider sulfate emissions a problem,
and does not act to lower fuel sulfur levels, then the industry will start
working on control technology, in the opinion of the report team.
* In recognizing this lack of basic information about the health related
aspects of particulates, we are in agreement with the NAS, reference 3,
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11. Development is moving ahead slowly, in the opinion of the report
team, because of self-imposed industry constraints.
The determination of the reasonableness of the various self-imposed
constraints (e.g. first cost, development cost, performance, etc.)
will have to be made by the Administrator. '
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SECTION 3
EMISSION CONTROL TECHNOLOGY AND FUEL ECONOMY
The subject of automobile fuel economy has received an increasing level
of attention lately as U.S. dependence on foreign crude is increasing.
Many factors influence the fuel economy an automobile will deliver,
including calibrations and modifications made to meet exhaust emission
standards. It is the intent, in this section, to explain the relation-
ship between emissions and fuel economy so that the inadequacy of the
cliches about emissions and economy can be fully understood.
3.1 General Factors that Influence Fuel Economy
To establish the proper perspective it should be understood that the
design and calibration of an emission control system are only two of
the many factors which influence automobile fuel economy. The multitude
of factors can be subdivided into operational and design factors,,
Operational Factors
The manner in which a vehicle is used has a significant effect on the
fuel economy of that vehicle. Among these operational factors are vehicle
speed, length of trip, engine temperature at the beginning of a trip,
ambient temperature, wind velocity, type of road surface, type of terrain,
altitude, the manner in which the vehicle is driven (smoothness of driving
and acceleration/braking habits), state of tune of the engine, tire
inflation pressure, and others.
Design Factors
The design and optimization of the entire engine/vehicle system also
has a significant effect on fuel economy of a given vehicle. These
engine/vehicle design factors include vehicle weight, engine type,
engine design, emission control system design and calibration, horse-
power, compression ratio, vehicle size and shape, transmission type
and design, axle ratio, tire design and construction technique, and
convenience devices such as air conditioning, power steering and others.
Ranking of Factors
It is extremely difficult to quantify the effect any individual factor
will have on fuel economy without knowing the values of all the other
factors. The fuel economy effect of a change in vehicle shape, for
example, depends on the way the vehicle is driven. Streamlining has
little or no effect during slow speed, stop and go driving but it can
have a substantial effect during high speed highway driving.
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Holding operational factors constant, the EPA certification tests
for 1975 showed differences in design factors accounted for up to 300%
differences in urban cycle fuel economy.
Holding design factors constant, EPA data show the difference between
typical city-type driving and highway type driving results in a 50%
difference in fuel economy. The addition of other operational variables
such as ambient temperature, can result in substantially greater differences,,
3.2 Effect of Emission Control Techniques
Although the cliche that "Emission control reduces fuel economy" is very
popular and often very true, it is a generalized statement that is
invalid when considering certain control approaches. Acceptance of
such a cliche as an indisputable fact could lead to erroneous conclusions
about the capability to simultaneously achieve improvements in emissions
and economy.
Some of the specific emission control related factors that affect both
the emissions and fuel economy of current engines are air/fuel ratio
and air/fuel ratio control, spark timing and spark timing control, degree
of exhaust gas recirculation (EGR) and methods of EGR control, choke
time, calibration and quick warm-up device control, intake air temperature
control, choice of exhaust gas aftertreatment type, and system optimiza-
tion. Table 3.2.1 gives the general effects these factors have on fuel
economy and exhaust emissions. The varied effect of different emission
control techniques such as the ones listed in Table 3.2.1 indicate
that it is not enough to know the directional effect of a system change
on exhaust emissions to deduce the directional change in fuel economy.
Some of the most effective control techniques, such as catalytic con-
verters, have no effect on fuel economy. The use of such devices allows
the "decoupling", as NAS put it*, of emission control and fuel economy.
Aftertreatment devices such as catalysts and thermal reactors only
affect fuel economy to the extent that engine calibration changes are
made to optimize their effectiveness. With lean thermal reactors or
catalysts, low emission levels can be achieved using engine calibrations
for optimum fuel economy.
3.3 Effect of Emission Standards
The net effect on fuel economy of a given emission standard depends on
the combination of control techniques used to achieve compliance.. Analysis
of EPA certification data has clearly shown that the fuel economy per-
formance of nominally identical cars (e.g. same weight, engine size,
axle ratio, etc.) can be significantly different while the emissions are
nearly the same. The difference in fuel economy is the result of the
difference in the usage of fuel efficient control technology. At a fixed
emission level fuel economy is a function of the usage of fuel efficient
control technology.
* Reference !„
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Table 3=2.1
Impact of Various Emission Control
Techniques on Fuel Economy
Technique
lo Retarded Spark Timing
2C Rich air/fuel ratio
3. Lean air/fuel ratio
4. Port EGR
5. Proportional EGR
6. Quick Heat Intake Manifold
w/fast choke
7. Heated intake air
8. Air injection
9. Oxidation catalyst
10. Reduction catalyst
11. Thermal reactor
12. Reduced compression ratio
Pollutants Controlled
HC, NOx
NOx
HC, CO, NOx
NOx
NOx
HC, CO
HC, CO
HC, CO
HC, CO
NOx
HC, CO
HC, NOx
Fuel Economy
Effect
Negative
Negative
Positive
Negative
None or Positive
Positive
Positive
Almost none.
None
None
None
Negative
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Erroneous conclusions about emission control and fuel economy can result
from ignoring differences in the control technology available and looking
at the effect of different levels of emission control using a particular
control system. With a fixed emission control system fuel economy is a
function of the degree of emission control required. When alternative
control approaches are not considered, changes in emission level can
only be achieved by altering basic engine calibrations such as spark
timing. Since minimum emissions and maximum fuel economy are usually
not simultaneously achieved, lower emission levels with a given system
result in degraded fuel economy.
Besides looking at emission control system/emission level/fuel economy
relationships with the control system held constant or the emission
levels held constant, it is also possible to consider the fuel economy
level held constant. With a fixed level of fuel economy the degree of
emission control achievable depends on the type of control technology
used. For example, the change in emission level from uncontrolled to
the 1975 Federal Interim levels (1.5, 15, 3.1) has been accomplished
at a fixed fuel economy level by selection of lean engine calibrations
and catalytic exhaust treatment systems.
The three underlined statements above are three different ways of looking
at control system/emission level/fuel economy relationships. Each
statement is a two-dimensional analysis of a three dimensional problem,
however. Unless one fully understands the three dimensional aspects
of the tradeoffs involved, it is possible to be misled about the expected
impact of a particular emission standard. Since there is no fixed
relationship between fuel economy and emission standards, it is impossible
to guarantee a change in fuel economy by a change in emission standards.
Appendix B contains further discussion of this topic.
3.4 Oxidation Catalyst (PC) Systems
The basic oxidation catalyst system used on 1975 model cars is capable
of providing about a 60% reduction in hydrocarbons and a 70% reduction
in carbon monoxide at 50,000 miles. If a manufacturer nominally
calibrates to 70% of the HC and CO standard and 80% of the NOx standard
to achieve a high probability of passing then his high-mileage goal
when certifying to the 1975 Federal standards would be:
HC = 1.5 x .7 = 1.05
CO = 15. x .7 = 10.5
NOx = 3.1 x .8 = 2.5
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with catalyst efficiency of 60%/70% for the HC and CO the "raw" or
"untreated" emission levels he must target for are:
HC = 1.05 T (1-.6) = 2.63
CO = 10.5 T (I-,.?) = 35.0
NOx = 2.5 T (1-0) = 2.5
If these emission levels can be achieved without resorting to emission
control techniques which detrimentally effect fuel economy, then it
is possible for the manufacturer to market an oxidation catalyst equipped
vehicle that complies with the 1975 Federal standards yet has excellent
fuel economy. Note that the untreated emission levels shown above are
higher than were required to meet the much less stringent 1974 emission
standards without catalysts. With the same safety factors the nominal
emission levels needed to meet the 1974 standards were:
HC = 2.8 x .7 = 1.96
CO = 28. x .7 = 19.6
NOx = 3.1 x .8 = 2.5
The addition of the catalytic control system on 1975 models resulted
in 50% reductions in tailpipe HC and CO levels but allowed 35% and 75%
increases in the "raw" emissions of HC and CO respectively. The catalyst
system gave manufacturers the flexibility to re-optimize the basic engine
for fuel economy by shifting some of the emission control burden to an
aftertreatment device. The unleaded fuel required for use with oxidation
catalysts necessitated the use of low compression ratios (which were
phased in beginning in 1971) in order that the engine would be satisfied
on the generally available 91 RON lead free fuel. While the use of
low compression ratio in itself can be expected to degrade fuel economy
by approximately 5% compared to a "regular fuel" engine, the unleaded
fuel causes less emission deterioration at high mileage which provides
additional flexibility in determining engine calibrations.
The combined effect of using catalysts and lead free fuel on the 1975
models has resulted in a level of fuel economy for many cars which is
equal to or higher than the fuel economy achieved by pre-1968 models
which were not emission controlled. As shown in Figure 3.4.1, the average
1976 model is now slightly better than the average 1967 model. The
emission control approaches which caused the nominal 12% economy losses
in 1974 have been less extensively used in 1975, because they were not
needed with oxidation catalyst systems.
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15
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FIXED MODEL MIX SALES WEIGHTED
FUEL ECONOMY VS MODEL YEAR
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UNCONTROLLED ECONOMY LEVEL
I
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1967 1968 1969 1970 1971 1972 1973 1974 1975
MODEL YEAR
Figure 3.4.1
3-6
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The hard data now available prove emission standards as stringent as
the 1975 Federal Interim standards can be achieved with fuel economy
equal to or better than the fuel economy of 1967 model cars. This is
not to say emission controls have no effect on fuel economy. The industry
now has the technology in hand to do somewhat better than the fuel economy
of their 1975 models since some engine efficiency compromises (e.g. low
compression ratio, some spark retard, etc.) are still made to meet the
1975 Federal standards. Obviously some manufacturers are making more
compromises than others (notably Ford, BMW, Toyota and Volvo) due to the
use of inadequate or inefficient aftertreatment systems. The reason
that a fuel economy loss is no longer apparent for the new car fleet
as a whole is that some of the technology developed to reduce emissions
(BOgo quick heat intake manifolds, high energy ignition, etc.) actually
tended to improve the fuel economy potential of the car0 Had such
technologies been adapted to uncontrolled automobiles, fuel economy
superior to that achieved by the 1975 model catalyst car could have
been realized. It is unlikely, in the opinion of the report team, that
the costs of developing such technologies would have been accepted by
the auto industry without the incentive provided by the emission standards.
3.5 Advanced Oxidation Catalyst (AOC) Systems
The level of fuel economy associated with emission standards more stringent
than the 1975 Federal Interim standards depends on the types of control
systems developed and used by the industry to meet the standards. As
shown in table 3.5.1, a reduction in emission standards from the 1975
49-state values of 1.5, 15., 3.1 to the 1975 California values of .9,
9o, 2.0 resulted in about a six percent drop in fuel economy, on the
average, using a fixed model mix for both the 49-state and California
fleets of each manufacturer. Note, however, that not all manufacturer
suffered losses in meeting the more stringent levels. Manufacturers
who used a more sophisticated approach on their California cars experienced
smaller losses or even improvements in economy on their California cars.
Ford, for example, used full catalytic treatment on their California
models but not on their 49-state cars. Saab used a more sophisticated
EGR system and air injection on their California cars. Volkswagen used
catalytic aftertreatment to a greater extent in California.
3-7
-------
Table 3o5.1
"49-State" vs. "California" Cars
Manuf .
General Motors
Ford
Chrysler
American
Motors
Volkswagen
Toyota
Nissan
Volvo
Peugeot
Audi
Saab
49-State
Economy
14.53
10.90
15.56
17.18
21.32
19.07
21.56
16.13
19.20
21.06
20.70
California
Economy
13.17
10.93
14.22
14.67
22.23
18.08
21.33
16.27
18.69
20.94
21.60
Percent
Change
-9.4%
+.3%
-806%
-14.6%
+4.3%
-5.2%
-1.1%
+.9%
-2.7%
-.6%
+4.4%
arithmetric average -2.9%
sales weighted average -5.7%
To achieve compliance with standards that are lower than the 1975 Federal
and California standards, manufacturers have two approaches open to them:
1. Recalibration of 1975 systems for lower emissions.
2. Use of improved emission control systems for lower emissions
without adversely affecting engine calibrations needed for good economy.
Some of the emission control techniques that could be used when taking
the second approach include:
1. Improved "Quick-heat" intake systems (SEFE)
2. Start catalysts
3. Proportional EGR (PEGR)
4. Modulated air injection (MAIR)
5. Improved thermal treatment of exhaust gas
6. Sonic carburetion
3-8
-------
7. Electronic spark control
8. Improved catalysts
9. Cold storage of HC emissions
10c On-board fuel distillation
'Each of these techniques has been reduced to hardware and successfully
emission tested„ The available test data indicate that when one or
more of these advanced control techniques are integrated into the basic
1975 model oxidation catalyst system, it is possible to achieve lower
emissions without adversely affecting fuel economy,,
Improved Quick-Heat Intake Systems
Quick-heat intake systems reduce cold start enrichment requirements by
transferring exhaust gas heat to the intake manifold during warm-up.
On several 1975 models a form of quick-heat system is used which consists
of a vacuum activated valve installed at the exhaust manifold outlet on
one side of a V-8 engine. During cold start the valve is closed and
exhaust gases are forced through the exhaust crossover passages in the
intake manifold to the opposite exhaust manifold., As the exhaust passes
through the intake manifold passages, heat is transferred to the "fresh"
intake charge through the walls of the exhaust crossover„
A more sophisticated application of the Quick-heat technique is the
Super Early Fuel Evaporation (SEFE) system which was designed by GM.
As shown in figure 3.5.1, the SEFE system is plumbed so that both
banks of exhaust gas are diverted to the intake manifold on cold starts,
A special plate, designed to promote efficient heat transfer, separates
the exhaust passage from the fresh mixture..
Start Catalysts
A "start" catalyst or "warm-up" catalyst is a low thermal inertia oxidation
catalyst which is used upstream of the main catalyst in a catalyst control
system. The performance criteria for the start catalyst are similar to
those for the main catalyst but rapid light-off is given a much higher
weighting and durability and resistance to "breakthrough" can be much
less important. A drawback to the catalytic control approach has been
that efficient pollutant control does not occur until the catalyst bed
has reached about 400°F. In order to achieve this temperature rapidly,
it is desirable to mount the catalyst very near the engine's exhaust
ports, keep the thermal inertia of the catalyst low, and keep the volume
of the catalyst low. Durability, resistance to "breakthrough" (inadequate
catalyst volume to convert high exhaust volumes), high warmed-up conversion
efficiency and other such considerations, however, make it. impractical
to select a catalyst and catalyst location solely because of its light-off
characteristics. The logical way to avoid the compromising of warm-up
3-9
-------
performance is to use two catalysts, one for warm-up and one for stabilized
conditions. The optimum start catalyst plumbing arrangement would be
one that completely removes the exhaust gas from the start catalyst
once the main catalyst has reached its light-off temperature. In this
way the start catalyst is not subjected to the deteriorating influence
of the exhaust stream any more than is absolutely necessary. Figure 3.5.2
shows a possible plumbing arrangement for a s'tart catalyst system.
Other designs which remove the exhaust stream from the start catalyst
have been developed by GM. Ford and Chrysler have experimented with
start catalysts that are left on stream all of the time. Table 3.5.2
shows the reduction in emissions achieved by Chrysler with their
start catalyst system which diverts 100% of the exhaust gas to the
start catalyst during warm-up but only 50% during stabilized conditions.
Table 3.5.2
Effect of Start Catalyst on Composite Emissions
Chrysler Data - 400 CID, C-Body
1.
2.
Two test average
without start catalyst
Three test average
with start catalyst
Emission ration, 2/1
HC
.37
.20
.54
CO
2.7
1.4
.51
NOx
1.35
1.35
1.0
Ford has experimented with small radial flow monoliths, close coupled
.to the exhaust manifolds, which approximately had double the HC and CO
conversion efficiency during the cold portion of the emission test.
Ford did not report data on a system employing both the small start
catalyst and the main catalyst.
Proportional EGR
EGR systems that are capable of delivering an optimum schedule of
recirculated exhaust gases are necessary if the adverse impacts that
less sophisticated systems have had in the past are to be eliminated.
While there is no EGR system yet in production that has been shown
to provide optimum scheduling, several systems such as the GM back-
pressure modulated system, appear to be better than others. No system
currently in use, as far as the report team could determine, takes
3-10
-------
advantage of the increased EGR tolerance which conventional engines
are known to have at higher loads. The report team concludes that
more development work in the EGR area is required since few manufacturers
have been able to provide the EGR rate versus load information which
EPA has specifically requested to be included in annual status reports
for the last two years.
Modulated Air Injection
It has long been recognized that an optimum air injection rate exists
for every operating condition of the engine. An inadequate exhaust 02
level results in less than optimum tailpipe emission levels whether a
catalyst is used or not. Excessive 02 levels tencj to quench reactions
in the exhaust manifold and catalyst. In general, it is desirable to
maintain an air injection rate that keeps the percentage of oxygen in
the exhaust stream constant. Most current AIR systems increase air flow
as engine speed increases but decrease flow as engine load increases.
Relatively simple modulating valves, already mass produced, are capable
of making a conventional AIR system deliver air in proportion to engine
load.
Preliminary tests at Ford demonstrated that 13-27% reductions in HC
emissions can be achieved by modulating air injection.
Sonic Carburetion
The theoretical capability of lean mixtures to simultaneously reduce
HC, CO and NOx emissions is well known. Achieving a consistent, well
vaporized or atomized mixture of air and fuel during transient operation
is, however, difficult. The fact that conventional carburetors can be
used to deliver extremely lean (18:1-19:1) air/fuel ratios on an over-
all basis does not mean the theoretical benefits of lean mixtures will
actually be achieved. However, a sonic mixing device, developed by Dresser
Industries, has demonstrated the capability to achieve the mixture
uniformity necessary to realize the theoretical advantages of lean
mixtures.
Dresser equipped vehicles tested by EPA and others have demonstrated
that the level of "untreated" emissions necessary to achieve the 1977
Federal Standards (.41, 3.4, 2.0) with a catalytic aftertreatment
system can be achieved with excellent fuel economy. In order to achieve
the 1977 standards the pre-catalyst emission levels need to be:
HC = .41 t (1-.6) = 1.03
CO = 3.4 T (1-.7) = 11.33
NOx = 2.0 * (1-0) = 2.0
3-11
-------
Levels lower than these have been demonstrated by Dresser on several
vehicles. EPA knows of no instances where Dresser has been unable to
achieve these levels when high volume exhaust manifolds are used to
promote the thermal oxidation of HC and CO in the exhaust. Even without
catalysts Dresser test vehicles have approached or equaled the 1977
standards when some spark retard is used to r,educe HC. The use of a
catalyst will, in the opinion of the report team, allow Dresser equipped
vehicles to simultaneously achieve fuel economy that is superior to the
economy achieved by typical vehicles in any previous model years, including
uncontrolled. Typical non-catalyst emission levels for Dresser equipped
vehicles are shown in table 3.5.3.
A more extensive discussion of the Dresser system can be found in
Section 7.2 of this report.
Cold Storage of HC Emissions
The cold storage concept is only effective on HC emissions. Since,
however, HC emissions are to be the critical pollutant when trying to
achieve the 1977 standards with high fuel economy, it may be a useful
addition to future emission control systems. The idea of the cold storage
system is to trap hydrocarbon emissions in a charcoal adsorber during
cold start and warm up operation. This is similar in concept to the
technique currently used to control evaporative emissions but on a larger
scale. During the first few minutes of engine operation the exhaust
gas is directed through a bed of activated charcoal after it passes
through the catalyst. The size of the bed required is approximately
equal to the size of the catalytic converter. When the catalyst reaches
light off temperature, the air pump is used to purge the hydrocarbons
stored .in the adsorber into the catalyst where they are very efficiently
oxidized. A schematic of the cold storage system is shown in Figure 3.5.3.
Both Daimler-Benz (Mercedes) and General Motors have experience with the
cold storage approach and both have reported data which shows the system
to be highly effective. As early as 1971 GM reported 30% reductions in
HC emissions with the use of this system. Work was stopped on the system
because it "requires such complicated pipes and valves — it is too
impractical for production consideration at the present state-of-the-art".
GM reactivated cold storage work when it appeared that high HC emissions
would keep their rotary engine from certifying in 1975. This fact gave
some indication to the report that the cold storage system may not be
as impractical as previously indicated, since it was resorted to when
the desire to certify a particular engine was high.
Figure 3.5.4, provided by Daimler-Benz, shows an engine's HC
emission rate with and without the use of a cold storage system. With
this system, cold start HC emissions are essentially eliminated. This
reduces the need to employ alternate HC control methods which may have
a detrimental effect on fuel economy. When used inconjunction with
catalyst systems, cold storage systems have been shown to cause HC
reductions between 30% and 80%. Data on a rotary engine test car are
shown in table 3.5.4.
3-12
-------
Table 3.5.3
Vehicle
Ford 351 CID
w/Dresser carb
and large exhaust
manifold.
Dresser Test Results
No Catalysts
Inertia
Weight
4500
'75 FTP Emissions FTP
HC CO NOx MPG
.41 4.7 1.30 11.3
Typical
Uncontrolled
Car of
Same
Weight,
MPG
1202
Chevrolet 350 CID
w/Dresser carb and
std. manifolds 4500
Chevrolet 350 CID
w/Dresser carb
and std. manifolds 4000
Capri 2600 cc
w/Dresser carb
and large exhaust
manifolds 3000
.88 4.7 1.70 12.9
1.18 6.0 1.16
.37 3.9 1.29
13.4
17.0
12.2
13.2
16.1
Levels needed to
certify at .41,
3.4, 2.0 with
catalysts
1.03 11.3
2.0
3-13
-------
Table 3.5.4
Effect of Cold Storage
1972 FTP
(1977 Standards would be .46, 4.7, 2.0
on the above procedure)
HC CO NOx
GM test car without
cold storage 1.03 2.2 1.5
With cold storage
for first two
minutes .21 2.2 1.5
3-14
-------
Electronic Spark Control
Conventional spark modulation systems change the timing by measuring
only:
1. engine speed
2. manifold vacuum
Some late model emission controlled cars also provide a simple on-off
control over the vacuum advance mechanisms as a function of:
1. transmission gear selection
2. engine speed
3. vehicle speed
4. engine temperature
Some models also employ spark delay valves which dampen the application
of advance provided by the intake manifold vacuum..
Despite the additional spark modulation which has been used in recent
years, much more needs to be done in the spark modulation area if fuel
economy is to be optimized at a given emission level„ Step changes
in spark advance which are now made on many vehicles, need to be
replaced with smooth and continuous modulation that is a function of
many additional variables including:
1. inlet air temperature
2. humidity
3. barometer
4. throttle position
More sophisticated spark control systems appear to be under intensive
investigation by Chrysler and others. The potential for fuel economy
improvements in the 5% range appear feasible with this type of system.
On-Board Fuel Distillation
Many of the emissions which are generated during the cold start portion
of the emission test are the result of the rich air/fuel ratios necessary
to achieve a combustible mixture of atomized and vaporized gasoline and
air with cold engines. Devices discussed earlier, such as Super EFE,
are effective at shortening the period of time that rich mixtures are
required by rapidly providing heat to the intake manifold. Other devices,
such as the Dresser sonic carburetor, reduce or eliminate the need for
mixture enrichment by improving the mixture preparation to the point
that little or no enrichment is required even with a cold engine.
If a more volatile fuel than gasoline could be used during warm-up
operation then adequate mixtures could be achieved with conventional
engines. Gaseous fuels such as CNG and LPG have been shown to reduce
3-15
-------
cold start enrichment requirements and cold start emissions but LPG
and CNG are not feasible replacements for gasoline because of supply
and handling problems. However, a means of obtaining a supply of
volatile fuel from gasoline to be used only during cold starts, has
been developed and several manufacturers reported the effect of such an
approach on exhaust emissions.
A volatile supply of fuel for use during cold starts can be obtained
by distillation of regular gasoline. By using heat to separate the more
and less volatile fractions it is possible to divide the fuel supply
once it is taken into the main fuel tank of the vehicle, A system developed
by Mobil Oil uses electrical resistance to distill off the ligher
fractions of gasoline and save them for use during cold start only.
After vehicle shut down the fuel in carburetor's float bowl is pumped
back to the main tank and the float bowls are re-filled with LEF (low
emissions fuel) from- the separate holding tank. With LEF used for start up,
enrichment is not required and HC and CO levels can be significantly
reduced. After the engine becomes sufficiently warm to use heavier
fuel, the LEF tank is turned off and the main fuel tank supplies the
carburetor and provides enough fuel to the LEF generator to replenish
the LEF tank. LEF replenishment can be accomplished in about five minutes
under normal conditions.
Data reported by Rolls Royce showed reductions of 44% and 28% for CO
and HC respectively when the LEF system was used on a non-catalyst
car. Since the LEF system reduces emissions during the time period prior
to catalyst light-off, the emissions reductions would be expected to be
larger with a catalyst system where the cold start emissions are a larger
fraction of the total emissions, Saab did test the LEF system on a catalyst
car and showed the results in table 3.5.5.
Table 3.5.5
Effect of On-Board Fuel Distillation
1977 Saab Prototypes
HC CO
Without LEF system .25 1.29
with LEF system .12 ,70
% reduction with LEF 52% 46%
3-16
-------
Saab indicated that they have no plans to use the LEF system in production
because they admit they can meet the statutory 1977 standards without
it. Other manufacturers who claim they cannot meet the standards seem
to be less interested in on-board fuel distillation.
GM has not recently reported any work in the dn-board fuel distillation
area but they were one of the early leaders, achieving 50% HC reductions
and 75% CO reductions during the cold phase of the test several years
ago. A schematic on the system tested by GM is shown in figure 3.5.5.
Improved Thermal Treatment of Exhaust Gas
Intelligent design of exhaust ports and exhaust manifolds can result in
significant reductions in CO and particularly HC emissions compared to
conventional, uncontrolled engine designs. If the exhaust gases can be
held at high temperature for a period of time, oxidation reactions continue
to occur. Several means of holding the exhaust gas at a higher temperature
for a longer period of time are available:
1. exhaust port liners
2. high volume exhaust manifolds
3. insulated exhaust manifolds
4. exhaust manifold baffling
Chrysler data shows HC reductions of up to 70% with the use of port
liners and Ford data shows HC reductions of 22% are possible on some
of Ford's engines when higher exhaust manifold volumes are used.
Improved Catalysts
The difficulty associated with the 1977 emission levels of .41 HC, 3.4 CO,
2.0 NOx is inversely related to the efficiency of oxidation catalysts
available to the manufacturer. The more of the emission control burden
that can be shifted off onto the aftertreatment system, the easier it
becomes for any standard to be achieved and the easier it becomes to
optimize for fuel economy. The improvement in catalyst performance that
has been realized in the past five years has been significant and their
is no reason to expect that the catalysts used on the 1975 models
represent the ultimate in performance. Ford reported that they expect
substantial improvements in catalysts efficiency due to the use of larger
catalyst volumes on 1977 models.
3-17
-------
Summary
The sub-systems discussed above are just examples of the possible control
approaches that can be used to produce low emissions- and high fuel economy
simultaneously. Some of these systems are complicated compared to typical
1975 systems but they are not all required to' achieve the 1977 standards
with good fuel economy. Some of these subsystems (e.g. Dresser carburetor)
may turn out to be simpler and less expensive than the components they
replace. Provided the necessity to meet stringent emission levels in
the future is accepted by a manufacturer, the report team predicts the cost
and complexity associated with any emission standard will continue
to decrease with time.
3-13
-------
Exhaust path
during cold
start
V— "->•"*( -\ \
(( ^-"^X >>>
Vx -^>r^ ••. • \^ I'l
Exhaust path when warm
Figure 3.5.1
-Super EFE
3-19
-------
FIGURE 3.5.2
START CATALYST SYSTEM
3- 20
-------
3-WAY
AIR VALVE
2-WAY
AIR
PUMP
HC ADSORBER
Figure 3.5.3 - Cold Storage System
C,H
,^^ j
\IC emissions with catalyst \n
but without cold storage a
HC emissions with catalyst
and cold storage
Time (minutes)
PURGE AIR INLET
CHECK VALVE
Figure 3.5.4 - HC Emission Rate with and without Cold Storage
3-21
-------
ON BOARD STILL SYSTEM
STILL
JL*
•/=
SHUTTLE VALVE
HI
•-oj-
1 HI ||
'IHt
FLOAT BOWL
DRAIN & FILL
] /SYSTEM
FUEL PUMPS
FUEL TANK
1972 EPA EMISSIONS
GRAMS/MILE
HC
CO
NO,
0.56
5.3
1.1
FIGURE 3.5.5
3-22
-------
SECTION 4
EMISSION CONTROL SYSTEM COSTS
This section has been added to address the cost of emission control
systems in greater detail than in previous years. The discussion in
this section has been limited to the conventional engine. The cost
of promising alternatives to the conventional engine are covered in the
EPA/DOT 120 day study report*. The alternative engines generally
have higher first cost for a given emission level than those engines
discussed here.
4.1 Sticker Price Increases in Perspective
There are many costs associated with controlling emissions from auto-
mobiles including:
1. First cost (sticker price increase)
2. Operating cost (e.g. fuel economy)
3. Maintenance cost
4. Investment cost
5. Reduced cost of plant, animal, and human health damage due
to the improved air quality possible with various emission
control systems.
This section addreses only first cost in any detail. This section,
therefore, contains inadequate information for a cost/benefit analysis
of any emission standards. A fixed emission level system with higher
first cost can produce lower total cost to the customer due to the
reduced maintenance and improved fuel economy which may be possible
with its use.
In the case of the 1975 Federal Interim standards, the report team
estimates GM could have met the standards for $80 less first cost per
car than they actually did, by eliminating the catalyst and calibrating
for lower engine-out emissions. A decision to do this would have cost
the customer about $500 more over 50,000 miles of vehicle life for
increased fuel costs.
* Reference 7
4-1
-------
Investment costs associated with the production of various emission
control systems were not specifically studied by the report team, and
little data was supplied on this issue in the manufacturers' status
reports. No evidence was uncovered which is at odds with the NAS conclusion
that, "...the somewhat higher level of capital expenditures (required
to meet '77 and '78 standards) should be no problem".
In this section the sticker price of emission control hardware will be
shown on both an individual component and a system basis. It should
be pointed out that the reader needs to be cautious in estimating any
reductions in sticker price which might occur because of the removal
of any emission control hardware which is already installed on vehicles
or is planned for use in the near future. Sticker prices include
amortization of the costs of research, development, and tooling. Many
of these costs have already been incurred for the systems necessary
to achieve current and future emission standards and the customer will
pay them whether or not the control hardware is ever installed in
production. Another factor is that of the profit made on emission
control hardware (despite claims that might lead one to believe there
is no profit in what the customer must pay for emission control).
Unless a lower profit is made on each car sold without some emission
controls, the estimated sticker prices of control hardware will not
be eliminated just because the hardware is not sold to the customer.
An important consideration in evaluating the first cost associated
a particular emission standard is that a learning process can be expected
to take place. In section 4.3 the report team will estimate the impact
this learning process can be expected to have in the future.
All stick prices given in this section are in terms of January, 1975
dollars and in addition to value added the costs include amortization
of research, development and tooling, dealer margin and profit.
4.2 Component Costs of Emission Hardware
One major factor in the costs of emission control componentry is the
source of the hardware. Manufacturers who build their own hardware
can be at a distinct advantage over other manufacturers who purchase
hardware from supplies. GM, for example, sells their air pump to many
other manufacturers, including Ford, Chrysler, and AMC. Another
important factor is the level of profit taken on emission control hard-
ware. The most important factors affecting the cost of emission control
componentry, however, may be the efficiency of the basic design used
and production volume. All four of these factors are undoubtedly contributing
to the differences in manufacturers estimated component costs which are
shown in table 4.2.1. The only significant discrepancy between the
estimates of NAS and the report team for nominal component costs concerns
the cost of electronic fuel injection.
4-2
-------
Table 4.2.1
Emission Control Component Costs
(Jan 75 Dollars)
Component
NAS Estimates
73 74
Range of Most
Manufacturers
Estimates
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
PCV valve
Evap Control
Transmission Controlled
Spark (TCS)
Anti-Dieseling Solouoid
Intake air heater
OSAC spark control
Hardened valve seats
Port EGR
Air system
PEGR
QHI manifold
Electric choke
HEI
Timing & other control
modulation valves
OX catalyst
NOx catalyst
Misc. mods thru '74
EFI
0_ Sensor
3-way catalysts
Thermal Reactor
Improved Exhaust System
QA and other tests
Ox Pellet cat chg.
Mono cat chg.
EFE
Start catalyst
$3.50
$17.00
$4.50
$6.00
$4.50
$1.00
$2.00
$11.50
$52.50
$36.50
$6.00
$6.00
$11.50
$3.50
$66.50
$45.00
$19.50
$53.00
-
-
-
-
-
-
-
-
-
3.
12.
-
-
-
-
-
15.
35.
23.
-
-
-
-
80 Pellet
61 Mono
86 Pellet
78 Mono
-
120
A
97
-
-
-
-
-
-
-
2
5
7
2
5
14
25
35 .
4
27
2
36
75
30
250
20
175
70
30
5
29
10
3
- 18
- 34
6
- 12
6
2
61
-
-
9
- 116
- 33
- 300
- 178
- 70
- 556
- 130
- 220
- 140
40
- 39
77
- 178
- 15
Report Team
Estimate
3
15
5
6
5
5
2
20
40
40
10
6
30
5
80 Pellet
50 Big Monolith
60 Each
20
250
20
100
100
30
10
70
150
15
50
4.3
Cost of Emission Control Systems
The system cost associated with any particular emission standard depends
on the individual components used to make up the system. There is some
difficulty in estimating costs for a particular standard because of
the several combinations of individual components capable of achieving
compliance.
4-3
-------
Table 4.3.1 shows the values of "typical" systems according to several
sources. No very significant differences exist between NAS and the
report team. The high "manufacturers' estimates" are generally from
European manufacturers with low production volume.
Table 4.3.1
Typical First Cost of Emission Control System
(Jan 75 Dollars)
NAS Range of most
73 74 Manufacturers! Report Team
Report Report Estimates Estimates
1974 Federal
(3.0, 28, 3.1) $139 84 50 - 120 100
1975 Federal
(1.5, 15, 3.1) - 159 100 - 450 200
1975 California
(.9, 9., 2.0) - 205 170 - 455 "240
1977 Federal
(.41, 3.4, 2.0) - 233 315 - 700 250 - 350
1978 Federal
(.41, 3.4, 0.4) $452 378 315 - 950 450
The "typical" systems which were used to construct the report teams
estimates were:
1974 Federal - PCV, Evap control, TSC, Anti-dieseling valve,
Intake air heater, Port EGR, some use of AIR, modulation valves,
misc. modifications.
1975 Federal - PCV, Evap control, Intake air heater, Port EGR,
modulation valves, misc. modifications, oxidation catalysts,
improved exhaust system materials.
1975 California - '75 Federal plus AIR
1977 Federal - '75 California plus TCS (low fuel economy) or
'75 California plus PEGR, EFE, and start catalysts (high fuel
economy).
1978 Federal - '77 Federal plus air switching and NOx catalysts.
4-4
-------
Table 4.3.2 considers other systems in addition to the "typical"
systems from table 4.3.1. In addition to the cost of meeting the
various standards during the year they become applicable the report
team has also estimated the "essential" cost of meeting the same
standards after a period for cost optimization. At the 1974 Federal
emission standards most cars could have gotten by with about an $80
expenditure over uncontrolled cars. To meet the standards with better
economy, however, it would have been necessary to increase system
cost somewhat, for example, by using partial thermal reactors to
eliminate the need for spark retard to control HC emissions. Given
sufficient lead time to develop new technology and to amortize costs,
it is the opinion of the report team that lean carburetion systems
such as Dresser's could allow achievement of the '74 standards with only
a $20 cost and excellent fuel economy.
At the 1975 Federal levels most cars could have certified with the use
of unleaded fuel and more spark retard than was used on the 1974 models.
Such a system would have cost about $120. To achieve good economy at
the 1975 Federal levels it is desirable to use an oxidation catalyst
system (probably without AIR) with its $200 first cost. Eventually
Dresser type induction systems should be capable of achieving these
standards without air pumps, EGR, or other devices. To maintain
optimized fuel economy at these levels, it may be necessary to use high
volume exhaust manifolds which would have a minimal cost increase over
conventional manifolds.
Table 4.3.2,
First Cost of Emission Control Systems
1st Year "Eventual"
Best Minimum Best Minimum
Applicable Standard Economy Cost Economy Cost
1974 Federal
3.0, 28., 3.1 150 80 20 20
1975 Federal
1.5, 15., 3.1 200 120 40 20
1975 California
.9, 9., 2.0 250 200 90 20
1977 Federal
.41, 3.4, 2.0 340 250 150 90
1978 Federal
.41, 3.4, 0.4 450 350 ? 300
4-5
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At the 1975 California levels the oxidation catalysts or lean thermal
reactor system would :»e necessary at a cost of about $200. The addition
of AIR and proportional EGR to the catalyst system should allow the
.9, 9, 2.0 levels to be met with excellent fuel economy. In the longer
term the Dresser-type of induction system should meet these levels with
only spark retard. Eliminating spark retard for improved economy, the
standards could still be met with the use of partial thermal reactors
for a total system cost of about $90.
To achieve the 1977 Federal emission standards (.4!, 3.4, 2.0) the
AIR/catalyst system with spark retard will be needed for most cars.
Avoidance of fuel penalties will probably necessitate the use of improved
quick-heat intake systems and start catalysts with a total system cost
of about $350. Dresser-type systems with partial thermal reactors and
spark retard could eventually achieve these standards ($90 cost) but
the use of Dresser with an oxidation catalyst system and high volume
exhaust manifolds makes the standards feasible with no fuel economy
loss and a $150 first cost.
At the 1978 Federal Standards, dual catalysts will be required both
in 1978 and in the longer term (assuming conventional engine technology).
Such a system will cost $350 and will probably require some spark retard.
The addition of technology sufficient to eliminate the need for spark
retard is estimated at about a $100 cost penalty.
The system choices discussed above are the report team's estimate of
what can occur given the incentive on the part of the industry to meet
future standards with low first cost or high fuel economy. As discussed
earlier in this report, however, the system choices are made after
considering many different aspects of automobile marketing strategy.
Under the current regulatory/economic/consumer demand situation, there
is no guarantee that systems with the potential for combined low
emissions, low cost, and high fuel economy will be developed and mass
produced.
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SECTION 5
UNREGULATED EMISSIONS
Unregulated emissions include sulfates, hydrogen sulfide, platinum,
palladium, polycyclic organic matter (POMs, a type of hydrocarbon),
aldehydes, reactive organic compounds, and particulate emissions. Since
almost all of the information submitted to EPA was on sulfates, most
of this chapter discusses sulfates with mention of the other unregulated
emissions being limited to a summary.
Hydrogen sulfide can be emitted from catalyst vehicles when they operate
under rich conditions. Hydrogen sulfide has a characteristic "rotten
egg" odor at levels far below those associated with adverse health effects.
Scattered reports have been received of hydrogen sulfide odors from
in-use 1975 catalyst vehicles. EPA is still assessing the magnitude
of this problem and what action can be taken to correct it. Preliminary
indications are that the H~S - emitting vehicles have improperly
adjusted or defective emission control hardware which results in
overly rich conditions into the catalyst.
There have been many attempts to quantify noble metal emissions
including platinum and palladium from catalyst equipped vehicles. To
date, noble metal emissions have been measured in only a few very isolated
cases. Work to measure these emissions and to determine the health
effects of noble metals is continuing.
Regarding aldehydes, reactive organic compounds, and POMs, some work
has been done in the past year indicating that emissions of these compounds
greatly decrease with the use of catalysts. Apparently, the catalyst
preferentially oxidizes the more reactive hydrocarbon compounds in
preference to less reactive ones. In fact, methane, a totally unreactive
hydrocarbon, now comprises a greater percentage (approximately 15 percent)
of exhaust hydrocarbons compared with pre-catalyst vehicles (which have
about 10 percent methane in the exhaust). Since methane is not included in
the ambient air quality standard, EPA is considering amending the
automotive hydrocarbon standard to exclude methane. The decrease of
these reactive emissions with the use of catalysts is a positive health
benefit.
Total particulate emissions of catalyst car burning unleaded fuel are
substantially lower than pre-catalyst cars which burned leaded fuel.
The lower particulate emissions are due to the lack of lead compounds
in the exhaust. Tests to date on oxidation catalyst vehicles have not
shown any serious problem due to catalyst attrition products (i.e. small
5-1
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particles of the catalyst itself) increasing particulate emissions.
Some reduction catalysts which would be required to meet a 0.4 gpm NOx
standard, have shown catalyst attrition. This phenomenon has occurred
with the Gould reduction catalyst which emitted nickel compounds in
preliminary EPA tests. The seriousness of this problem is not known
yet for the Gould catalyst,but will be evaluated in future programs.
At any rate, catalyst attrition products have not been found to be a
problem with oxidation catalysts.
However, it has been found that catalyst cars have increased particulate,
emissions, compared with non-catalyst cars burning unleaded fuel. This
increase is due to formation of sulfur trioxide over the catalyst with
subsequent combination of the SCL with water to form condensed sulfuric
acid. The SO. is formed by oxidation of SO. which is formed in the
engine from combustion of the fuel sulfur. The sulfuric acid or
sulfate, as it will be referred to, is considered a particulate and is
emitted only from catalyst cars. Sulfates from catalyst cars account
for less than 1 percent of the total sulfates in any AQCR with the
remaining 99 percent coming from photochemical oxidation of SO- emitted
from stationary sources. However, EPA is greatly concerned about
automotive sulfate emissions since they can result in high localized
sulfate levels along freeways and other places. Most of the work done
in the past year on unregulated emissions has been on sulfates.
The first major conclusion that can be made from this work is that
non-catalyst cars emit only trace quantities of sulfates with almost all
of the fuel sulfur being emitted as SO . This finding is in contrast to
some early work reported last year showing non-catalyst cars to emit
substantial quantities of sulfate.
Extensive work has been done in the past year to determine emission
factors for both pelleted and monolith catalyst cars. The first finding
is that pelleted catalyst vehicles emit less sulfate under the FTP than
monolith catalyst vehicles. This lower emission rate is due to a storage
reaction of sulfates and the alumina. This interaction occurs at low
catalyst temperatures (which occur at lower speeds) and is reversible
at higher catalyst temperatures where sulfates are released. Since
monolith catalysts have only small quantities of alumina compared with
pelleted catalysts, the storage phenomenon is much less pronounced for
monolith catalysts. The sulfates stored on the pelleted catalyst under
low speed conditions are later released in the transition from low to
high speed driving, and makes measurement of sulfate emissions from under
low speed conditions very difficult. After the transition period from
low to high speed driving, pelleted and monolith catalyst vehicles emit
essentially the same quantities of sulfate at higher speeds (60 mph).
Typical emission factors are given in the following table:
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Best Estimate Sulfate Emission Factors*
(mg/mi)
Pelleted Monolith
Catalyst Catalyst
Urban Driving (FTP) 10-15 30
Highway Cruise (60 mph) 50-60 50-60
Urban-to-highway Cruise Transition 100-300 50-60
*mg/mi assuming 0.03 percent by weight sulfur fuel (the current
national average). Also, assumes utilization of air injection.
Values for vehicles without air injection would be lower.
These numbers are best engineering judgements based on the data
discussed in this chapter. It is thought that, in accounting for the
storage phenomenon, pelleted and monolith catalysts have essentially
identical sulfate emissions over their lifetime. In certain areas such
as Southern California with fuel above the 0.03 percent national average
sulfur content, sulfate emissions would be higher than those shown above.
Also,these estimates are based on full size 1975 cars and do not consider
the improved fuel economy of smaller cars which would lower sulfate
emissions. Any future improvements in fuel economy over that of 1975
cars will result in lower sulfate emissions.
Various parameters on catalyst cars such as air injection rate, noble
metal loading, residence time, and catalyst temperature can be
optimized for maximum control of both sulfates and regulated gaseous
emissions (HC and CO). Preliminary work done by GM and Exxon (under an
EPA contract) suggests that control of air injection rate may be the most
promising of these areas. While limiting the air injection rate decreases
sulfates significantly, HC and CO emissions are increased. Work Is
continuing in this area.
Chemical traps installed after the catalyst also have the potential of
controlling sulfates. The automobile companies are doing almost no work
examining vehicle sulfate traps. Most of the work being done on sulfate
traps is through an EPA contract with Exxon. A calcium oxide trap has
been tested for 25,000 miles and removed over 90 percent of the sulfate.
By then, however, a serious back pressure had developed across the trap.
While work is continuing in this area, not enough data are available to
determine if this is a feasible control technique.
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EPA Is examining whether fuel desulfurization is technically and
economically feasible. Results on this work to date show the
following:
1. Gasoline desulfurization is technically feasible. A $2
to $4 billion capital investment will be required to lower
unleaded gasoline from 0.03% to sulfur levels of 0.006 - 0.01%.
This cost is equivalent to about 10/gallon.
2. About 3-5 years would be needed for equipment installation.
An additional potential cost implication in the fuel desulfurization
issue is the fact that sulfur-free fuel may allow the use of base
metal catalysts. These catalyst types are much cheaper than the noble
metal ones used now and are not currently used because they suffered .,
from sulfur poisoning in early development tests.
Sulfate emissions have been measured for a limited number of
advanced catalyst systems and alternate engines. While definitive
sulfate emission factors have not been obtained yet, it is our judgement
that sulfate emissions from systems with a reduction and oxidation
catalyst will be no higher than those from oxidation catalysts.
Preliminary in-house EPA work shows very low sulfate emissions from a
three-way catalyst designed for simultaneous HC, CO, and NOx control.
These low sulfate emissions are probably the result of close oxygen
control required for operation of the catalyst. Finally, EPA work
shows low sulfate emissions from advanced alternative engines including
the stratified charge and LDV Diesel. However, if the higher sulfur
content of Diesel fuel is considered, the Diesel can possibly emit
sulfates at rates approaching the catalyst vehicle.
5-4
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SECTION 6
INDUSTRY STATUS
6.1 Industry Status - 1976 Model Year
Since the standards are the same for model year 1976 as they are for
model year 1975, more emission control is not required. Therefore, all
new systems do not have to be developed and certified, as was the case
for the model year 1975. Most manufacturers will carry over their systems
from 1975 to 1976. The process of carry over is the use of the certifi-
cation from one model year for the next model year, which is permitted if
the standards and test procedures are the same, as is the case for model
year 1975 and 1976.
This does not mean that there will be no activity in the emission
control area, however. It appears that the practice of making running
changes to vehicles covered by existing certificates will increase
greatly. Manufacturers appear to prefer this course of action, since in
most cases they do not have to run durability cars if a running change is
approved. The report team estimates that running changes will be the
primary area of activity in the emission control certification effort
for model year 1976 for most manufacturers, and that EPA will have to
increase its efforts in this area to ensure that the effectiveness of the
certification procedures are not compromised.
In summary, the report team expects that model year 1976 will be one
that will involve a process of refinement of the current year 1975
systems.
6.2
6.2.1
Industry Status - 1977 Model Year
Systems to be Used -
1977 Model Year
There are two basic approaches that the manufacturers can take toward
meeting the 1977 standards of 0.41 HC, 3.4 CO, 2.0 NOx. The first
approach is the use of recalibrated systems like those used in 1975 to
meet the 1975 California standards of 0.9 HC, 9.0 CO, 2.0 NOx. The
additional HC and CO control required could be achieved for example, by
increased spark retard for HC control; and leaner overall carburetion
calibrations, shorter choke times, and increased air injection rates; for
CO control. While certainly a low-cost approach (for the manufacturer)
the approach of recalibrating a 1975 California package is expected by
the report team to result in a fuel economy penalty compared to the 1975
California package because we estimate that the increased spark retard
will offset any improvements due to the extra enleanment.
6-1
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The second approach is to employ improved oxidation catalyst systems,
based on the 1975 California package. HC is going to be the major
problem, although improved control of both HC and CO are needed to
meet the 0.41 HC, 3.4 CO, 2.0 NOx standards, compared to the 1975
California standards. HC is going to be the major problem for two
reasons: (a) current oxidation catalysts have lower high mileage
conversion efficiencies for HC than for CO. (b) The technique of
the use of spark retard for HC control is now considered much less
desirable than it once was, due to the current increased importance
being placed on fuel economy as a design goal. Indeed, today
the desire is to advance the spark toward the optimum, as much as
possible.
The report team uses the term AOC (for Advanced Oxidation Catalyst)
to describe the systems that employ more advanced emission control
that could be employed to meet the 0.41 HC, 3.4 CO, 2.0 NOx standards
without exhibiting some of the unattractive characteristics of a
recalibrated 1975 California package.
There are three basic areas in which improved control can be obtained.
These areas are:
1. Improvements to the air/fuel mixture process, mixture
distribution, transient fuel metering control, and the
warm-up mixture requirements. These are improvements
to the air/fuel mixture before combustion takes place
in the engine.
2. Improvements to the design of the combustion chamber,
the in-cylinder air/fuel motion and the ignition
system. These are improvements to the combustion
process in the engine.
3. Improvements to the systems that treat the exhaust
after combustion takes place in the engine.
A more detailed description of the types of system that could achieve
the desired results was provided in Section 3.
Most manufacturers are aware of the capabilities of more advanced
control technology, and some are actively working on improved systems.
However, most manufacturers, in the opinion of the report team, are
working on improved oxidation catalyst systems at a relatively low
level currently. One possible reason for this could be the current
reduced level of employment in the industry in general and possibly
in the emission control development area also, although we have no
data on current employment levels in this area. Another reason could
be that the industry is waiting to see what will happen during the
upcoming EPA Suspension Hearings, and also awaiting to see how their
proposals to the Congress and the Administration for a moratorium on
future standards are received.
6-2
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Not all of the system Improvements discussed in Section 3 will be
required on all 1977 models. The choice of which systems will be
used will depend on the specific engine family - emission control
system - vehicle combination and its performance with respect to
the 0.41 HC, 3.4 CO, 2.0 NOX level. More Importantly, the use of
advanced systems for model year 1977 will depend greatly on the
emphasis that any given manufacturer places on Improving or main-
taining his fuel economy performance demonstrated in 1975.
The report team estimates that the improvements generally to be in
use for 1977 will include improved catalysts, improved air injection
systems and better quick warm-up devices. However, this is dependent
on the assumption that the manufacturers now think that they will have
to meet 0.41 HC, 3.4 CO, 2.0 NOX in 1977, an assumption considered
questionable by the report team, since most manufacturers have adopted
a "wait and see" attitude.
6.2.2 Durability Testing Programs - 1977 Model Year
Two kinds of durability efforts are planned or underway currently that
could be interpreted as influencing the model year 1977 systems. The
first type of durability testing is an attempt by manufacturers who
used the crutch of catalyst replacement to pass certification in 1975.
These manufacturers will be trying to go 50,000 miles for 1976, with
improved catalysts and/or more confidence in the durability perform-
ance of their systems. The data from such testing could be used as
development data for model year 1977. The second type of durability
testing contemplated is early model year 1977 durability testing.
This is planned by some domestic manufacturers for very early in
calendar year 1975. While this early durability testing may give
more time for the manufacturers to make more extensive running changes
before model year 1977, the report team considers it likely that the
early certification durability attempts are too early to incorporate
much in the way of improved technology. A manufacturer may be reluctant
to try to certify a more sophisticated package if he is successful at
gettiing through certification durability with a simpler system, even
if he sacrifices fuel economy potential, in the opinion of the report
team.
In general, extensive fleets of development durability vehicles with
advanced systems are not now on the road, reflecting the same "wait
and see" attitude discussed above in the discussion of Systems to be
Used.
6.2.3 Progress and Problem Areas - 1977 Model Year
Progress has been made in the industry in general since a year ago,
primarily in the area of oxidation catalyst system testing and develop-
ment. Investigation of the engine calibration flexibility inherent
6-3
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with the catalyst approach has been a subject of increased activity.
Advanced systems have been tested with a low level of effort with some
encouraging low mileage results.
A problem area is the lack of extensive development and durability
testing mentioned above. The major problem at the 1977 level, in the
opinion of the report team, is system selection for 1977. The manufacturers
must be considering the answers to many difficult questions at this
point in time. Answers to questions such as: Am I going to have to
meet the standards? Is one system cheaper than the others? Do the more
expensive systems have greater fuel economy potential? By how much? Will
people buy the more expensive vehicle if it has better fuel economy? All
must be resolved by a manufacturer before he can commit to a firm
development/testing/certification effort for model year 1977.
6.3 Industry Status - 1978 Model Year
6.3.1 Systems to be Used - 1978 Model Year
Two basic types of systems are generally under consideration for model
year 1978. They are the dual catalyst system and the 3-way catalyst
system. The dual catalyst system, which uses separate catalysts for
NOx and HC/CO control has been under development longer than has the
3-way catalyst which uses a single bed to simultaneously control HC,
CO, and NOx- The major problem with the dual catalyst system is
expected by the report team to be HC, not NOx since the calibration
technique tends to increase the engine-out HC emissions, and more
sophisticated HC control techniques will have to be used. It must
be pointed out that no such development work was reported by the
manufacturers.
The second type of system under consideration for NOx levels below
2.0, the 3-way catalyst system, has recieved increased development
and testing in the last year or so. In fact it now appears to be the
only system under active development at low NOx levels. Many manu-
facturers are using the typical 3-way approach, a single bed catalyst
with feedback control of engine air/fuel ratio but there are some
variations being investigated by some manufacturers. The first varia-
tion is the system named 3-way + OX Cat by the report team. This
system employs a 3-way catalyst calibrated to bias the conversion to
favor NOx removal (although HC and CO are still converted) and uses
an oxidation catalyst downstream to convert any excess HC and CO. This
system is much like a dual catalyst system. The second variation on
the 3-way approach is in the way the correct air/fuel ratio mixture is
provided to the catalyst. Most 3-way systems use an oxygen sensor in
the exhaust stream to feed back a signal that is used to control the
fuel injection or carburetor metering to achieve the correct engine
out air/fuel ratio for efficient 3-way catalyst operation. Since the
expense of a fuel injection system is a square pill for much of the
industry to swallow, some manufacturers are investigating the use of
6-4
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feedback-controlled air injection to provide the correct air/fuel
mixture to the catalyst. This is considered a promising development
by the report team since it may be possible to achieve good 3-way
conversion at lower cost.
Most manufacturers that are developing the 3-way catalyst approach
have been able to attain the 0.41 HC, 3.4 CO, 0.4 NOx levels at low
mileage on developmental vehicles.
Low-mileage and optimization testing of dual catalyst systems have
not received much attention in the past year or so, a reflection of
the generally low level of effort in the area of systems targeted
toward 0.41 HC, 3.4 CO, 0.4 NOx. This is somewhat disappointing
because the developments reported by Gould* in the last year or so
represent the most significant advance to date in the NOx catalyst
area, in the opinion of the report team. This promising system, which
uses an oxygen removal catalyst (an oxygen getter) upstream of the
NOx catalyst to improve its durability performance, has shown good
low mileage activity, typically 75 to 80 percent net NOx conversion.
This type of system, used in conjunction with the engine calibration
techniques discussed by Gumbleton** could result in a dual catalyst
system with good fuel economy and low NOx emissions, since the
catalyst efficiency is high and the engine calibrations yield good
fuel economy with low (1.1 to 1.3 NOx) engine-out emissions.
6.3.2 Durability Testing Programs - Model Year 1978
Durability testing of systems targeted toward the 0.41 HC, 3.4 CO, 0.4
NOx level has virtually ceased for dual catalyst systems. Many
manufacturers have run no cars in the past year or have run just one
or two. The most promising dual catalyst durability results have been
reported by Gould with their latest system, with 50,000 equivalent
miles on a dynamometer and 25,000 of AMA durability, both tests showing
good net NOx conversion efficiency. With the assumption that the NOx
conversion efficiency can be maintained at 75 percent at 50,000 miles,
(Gould's tests show over 80 percent at 25,000 miles and relatively
low degradation in efficiency) an estimate of the capability of such a
system at 50,000 miles, calibrated for low engine-out NOx can be made.
With 75 percent efficiency and a 1.2 NOx input, the resulting emissions
* "Durability Experience with Metallic NOx Catalysts", SAE Paper
741081 by R. J. Fedor et.al. presented at the Automobile Engineering
Meeting, Toronto, Canada, October 21-25, 1974.
** "Optimizing Engine Parameters with Exhaust Gas Recirculation",
SAE Paper 740104 by James J. Gumbleton, et.al. presented at the
Automotive Engineering Congress, Detroit, Michigan, February 25-March 1,
1974.
6-5
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would be 0.3 NOx, a level enough below the 0.4 standard to give reason-
able chances to certify. Of course as mentioned above, HC may be a
problem and the capability of such a system will not be known until
such a system is built tip and tested. However, it does appear now
that meeting 0.4 NOx is now not an unreasonable proposition.
Durability testing with 3-way catalyst systems has been more extensive,
but the results to date generally have not been encouraging. One of
the durability problems with 3-way systems is that the percent loss in
efficiency in both HC/CO and NOx. Separately, efficiencies may remain
high but at different air/fuel ratios, the high HC/CO conversion at
lean air/fuel ratio and the high NOx conversion at a slightly rich
air/fuel ratio. The feedback control system continues to hold the input
air/fuel ratio between the peak efficiency points, so at high mileage
the conversion efficiency for both HC/CO and NOx is poor. The report
team considers this 3-way approach to be less attractive than the dual
catalyst approach at the 0.4 NOx level, because of the durability
problems, and the compromise between oxidation and reduction perform-
ance which is made.
6.3.3 Progress and Problem Areas - 1978 Model Year
The major progress toward meeting 0.4 NOx in the past year has been
achieved by Gould with their dual catalyst system. No automobile
manufacturer has done as well, in the opinion of the report team.
Progress has been made in the 3-way catalyst area also. Improved
catalysts are now being developed and tested. This area of improved
3-way catalysts must progress much more than it has to date to have a
chance at meeting 0.4 NOx, in the opinion of the report team. While
currently the best 3-way system might have a chance in a light weight
vehicle, for vehicles more typical of heavy domestic automobiles the
efficiencies are just not good enough at high mileage. Actually,
the report team feels that the 3-way catalyst development work is not
targeted at a 0.4 NOx target at all, but most manufacturers are
developing these systems for a NOx standard which they are guessing
will be about 1.0 NOx.
As pointed out in last year's report, the report team's analysis of
the development programs actually targeted toward to 0.4 NOx leads us
to conclude that manufacturers must believe that they will not have to
meet 0.4 NOx in 1978, if ever. Development and durability programs
are at such a low level of effort that it is doubtful that the manu-
facturers can get going in time to meet the levels still required
for 1978, even though the report team feels that the 0.41 HC, 3.4 CO,
0.4 NOx levels can be met, from a technical standpoint.
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SECTION 7
INDIVIDUAL MANUFACTURER'S REVIEWS
7.1.1 American Motors
7.1.1.1 Systems to be Used
Systems to be Used - 1976 Model Year
The 1976 American Motors Corporation (AMC) systems will be basically
the same as those of 1975. Exhaust backpressure modulated EGR and electric
assist chokes will be used on all models in 1976. Transmission-controlled
spark delay valves will be completely eliminated. Six cylinder models
will have a new stainless steel "hot spot" in the inlet manifold and
a new combustion chamber to improve detonation control and allow more
spark advance. All catalysts used by AMC are 160 CID, pellet-type
catalysts from AC Spark Plug. Pellets are spherical and are loaded
with about .05 troy ounces of noble metal in the proportion of 71%
platinum and 29% palladium. The 360-4V and 401-4V dual exhaust equipped
vehicles utilize one catalyst on eacfc side of their exhaust systems.
Systems durability data indicate that 1975 FTP fuel economy of the
232 six cylinder models may be significantly improved over the comparable
1975 models; however eight cylinder models demonstrated insignificant
changes in fuel economy. This is primarily due to spark advance
improvements on the six cylinder which were made possible by the
improved combustion chamber.
Systems to be Used - 1977 Model Year
The 1977 AMC system will include AIR, backpressure EGR, transmission
controlled spark (TCS) and the pellet type oxidation catalyst. Also
monolithic "start" catalysts near the exhaust manifold will be used
on all models. Six cylinder models will use one "start" catalyst and
eight cylinder models will use one on each bank. The new combustion
chamber design will be continued on the six cylinder models and
introduced on eight cylinder models. New pellet catalysts are being
prepared for AMC evaluation by AC Spark Plug.
AMC is investigating the use of a segmented monolithic main catalyst
for 1977. Several thin catalyst "biscuits" are separated by airspaces
to promote turbulent exhaust gas flow through the converter. Initial
test results indicated a HC deterioration problem.
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Fuel economy estimates presented by AMC indicated a 13% decrease in
fuel economy over 1976 models. The report team could not varify this
fuel penalty as AMC vehicles achieved the 1977 levels in only a few
instances. Some of those used methanol in the fuel.
Systems to be Used - 1978 Model Year
The AMC system for the .41 HC, 3.4 CO, .4 NOx level is stated to be
a dual catalyst system with backpressure EGR, switching AIR, TCS, and
the improved combustion chamber. The use of the stainless steel "hot
spot" will be extended to include eight cylinder models in addition to
the six cylinder models. Six cylinder models will use one reduction
catalyst and eight cylinder models will use two. The Gould GEM 68
reduction catalyst with an oxygen "Getter" is being prepared for testing.
AMC is developing a rich thermal reactor with Vortex Research and
Development. Initial results of .48 HC, 10.2 CO, 2.62 NOx did not
meet 1975 California levels. Catalysts, EGR, TCS, and the "hot spot"
intake manifold were not used. This is the only so-called 1978 system
tested by AMC in 1974.
According to AMC, fuel economy is reduced about 25% from 1975 Federal
models, however, no data were submitted to substantiate this figure.
Other Systems
The AMC status report mentioned the assessment of rich thermal reactors
for the AMC rotary engine program. No further details or data were
submitted on rotary engines.
No data was presented on advanced AIR or fuel metering systems. Electronic
control systems have hot been utilized except for electronic ignition.
No evidence of 3-way catalyst testing was reported. No improvements
have been noted for the AMC bimetallic actuated heat riser. In the
opinion of the report team, the inexperience of AMC with advanced
emission control systems, especially advanced fuel metering systems,
will cause unnecessary problems for AMC at 1978 emission levels.
Table AMC-1
1976 AMC Control Systems
AIR Number of Oxida-
Engine Drive Ratio EGR tion Catalysts
232 — x
232 1 x
258 — x
258 1 x
258 1 x 1
304 1.25 x 1
360-2 1.25 x 1
360-4 1.25 x 2
401-4 1.25 x 2
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7.1.1.2 Durability Testing Programs
Durability Testing Program - 1976 Model Year
AMC conducted durability testing on twelve vehicles at the 1976 49-state
and California emission levels. The objective of this effort was to
evaluate modifications designed to improve fuel economy and driveability
while maintaining compliance with the 1975/1976 standards.
Durability Testing Program - 1977 Model Year
At the .41 HC, 3.4 CO, 2.0 NOx level, AMC conducted durability testing
on five cars. The cars were equipped with upgraded 1976 California
systems, which for the most part amounted to recalibration of ignition,
carburetion and air injection rates along with the addition of a low
thermal mass monolithic converter between the exhaust manifold and
the conventional underfloor pelletted converter. None of the five '
cars complied with .41 HC, 3.4 CO, 2.0 NOx level. One car accumulated
50,000 miles and the remainder were at approximately 25,000 miles.
Durability Testing Program - 1978 Model Year
No durability testing was reported by AMC for NOx levels below 2.0
gm/mi.
7.1.1.3 Progress and Problem Areas
Progress and Problem Areas - 1976 Model Year
AMC has made progress in the area of system selection for 1976. The
1976 systems will generally be improved over the 1975 systems, especially
for the 6-cylinder models, AMC's biggest sellers. Improvements to the
EGR systems, (proportional), spark modulation systems (TCS eliminated),
induction system (new hot spot manifolds and electric assist chokes),
and a revised combustion chamber allowing more spark advance will all
tend to improve the entire control system over the 1975 package. A
problem for AMC for 1976 is that the V-8 engines will apparently
not get all of the improvements that the six cylinder engine gets,
probably because the V-8's are not as important a part of AMC's sales
picture as are the sixes, in the opinion of the report team.
Progress and Problems - 1977 Model Year
Because AMC's underfloor converters take a relatively long time to
light off, they are developing a system that employes an additional
low thermal inertia oxidation catalyst upstream of the main catalyst.
This configuration has many of the properties of a "start catalyst"
system. The term "start catalyst" as used by the report team, refers
to a catalyst which is used to improve cold-start HC and CO emissions,
but is hot capable of doing the whole HC/CO cleanup job. The catalyst
may or may not remain on-stream all of the time.
7-3
-------
Table AMC-2
1975 FTP Fuel Economy of Various AMC Models
Engine
232-1
302-4
360-2
Trans
M3
A3
A3
IW
3500
4500
4500
1974
—
12.3
10.8
1975
Federal
18.0
13.0
12.6
% Change
from 1974
—
+6
+17
1975
Calif.
13.8
12.7
11.8
% Change
from 1974
—
+3
+9
1976
20.9
13.2
12.4
% Change
from 1974
—
+7
+15
% Change
from 1975 Fed»
+16
+2
-2
-------
AMC's major problem at the 0.41 HC, 3.4 CO, 2.0 NOx level is the lack
of a definitive durability testing program. The major durability test
reported was one that, besides emission control system deterioration,
included several other tests in addition. The test involved operation
on Ohio interstate highways (not AMA) for mileage accumulation, the
evaluation of medium and low ash oils, an investigation of the effects
of a 10 percent methano1 fuel in additional to commercial unleaded Sohio
Cetrol fuel, evaluation of a carburetor detergent versus dispersant
plus solvent oil, and the evaluation of two different air injection
configurations. This development durability test should yield much
information to AMC, but it really does not indicate AMC's capability to
certify at 0..41 HC, 3.4 CO, 2.0 NOx, because so many of the test conditions
are different than the ones used for official certification. The report
team considers it likely that AMC will use this test to generate know-
ledge that will be useful in building up a 1977 pre-certification
fleet in the future.
Progress and Problems - 1978 Model Year
AMC has had a low level of effort on systems targeted toward the 0.4 NOx
level for a few years now, so AMC's indication that they were going to
evaluate a Gould GEM 68 catalyst system with oxygen getter was a hopeful
sign. Apparently, AMC has waited for a system that they feel has some
potential for success at the 0.4 NOx level. The Gould system is the best
one around at this point in time in the opinion of the report team. AMC
reported no data from this system, because it has not been tested yet. The
report team considers AMC's interest in this advanced dual catalyst
system to be encouraging since many other manufacturers seem to be
unaware of this system and its potential.
AMC's major problems at the 0.4 NOx level is lack of testing. No data
on any 0.4 NOx target vehicles was reported.
7-5
-------
7.1.2. Chrysler
7.1,2.1. Systems to be Used
Systems to be Used - 1976 Model Year
Chrysler Corporation will be recertifying virtually their entire line
in 1976 in an effort to improve fuel economy and reduce costs over the
1975 models.
Chrysler systems for 1976 are described in table Chrysler-1.
Table Chrysler-1
1976 Chrysler Control Systems
System Includes
Family
1 FD-225-1-35
1 FD-225-1-55
1 FD-318-2-35
1 FD-318-2-P
1 FD-318-2-55
1 FD-360-2-55
2 FA-360-4-P
1 FD-400-2-55
2 FB-400-4-P
1 FC-440-4ST-5L
2 FB-440-4HP-75
1 CD-225-1-P5S
1 CD-225-1-A55
1 CD-318-2-P5S
1 CD-360-4-P55
1 CD-400-4-P55
1 CD-440-4ST-P5L
2 CD-440-4HP-P75**
Venturi
Vacuum
Ported Amplified
EGR EGR
x
X
X
AIR Aspirator
x
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Oxidation
Catalyst*
.02 (All Pt)
.04 (All Pt)
.02 (All Pt)
.04 (All Pt)
.04 (All Pt)
.04 (All Pt)
.06 (All Pt)
.08 (70 Pt/30 Pd)
.04 (All Pt)
.04 (All Pt)
.04 (All Pt)
.04 (All Pt)
.04 (All Pt)
.06 (All Pt)
.08 (70 Pt/30 Pd)
* troy ounces of noble metal
** includes catalyst protection device
7-6
-------
The 49-State systems (families with identification codes starting with F)
are of two major components and consist of either EGR and AIR or EGR
and oxidation catalysts. The older ported EGR is still used on the
49-State 318 catalyst vehicles, and the improved venturi vacuum amplified
EGR is used on all others.
All California systems (code starts with C) consist of AIR (or an
aspirator), EGR, and oxidation catalysts. The aspirator used on one
of the California 225 CID engines is used to replace AIR. The aspirator
principle is to induce air into the exhaust manifold through a one way
valve during periods of low exhaust manifold^pressure created by the
pulsating engine exhaust. In Chrysler testing it has not been as
effective as air injection for HC and CO oxidation or fuel economy
optimization.
All Chrysler catalysts are made by Universal Oil Products (UOP) and
are monoliths. Catalyst loadings are stated in Table Chrysler-1.
The catalyst protection device on the California 440 engine relocates
the throttle stop positioner to provide more intake air flow during
decelerations which begin at engine speeds above 2200 rpm.
All 1976 systems also include orifice spark advance control (OSAC),
coolant controlled EGR (CCEGR), and electrically assisted chokes. The
OSAC is a spark delay valve. CCEGR prevents EGR system operation
while the engine is cold, and the electrically assisted chokes provide
more consistent choke operation. Other minor systems that are frequently
used are heated intake air, thermostatic ignition distributor vacuum
control (TIDC), an EGR timer, and coolant controlled idle enrichment
(CCIE). TIDC increases the vacuum spark advance when the coolant
temperature goes above 225°F. This is to reduce the engine's heat
rejection and prevent cooling system boil over. The EGR timer provides
35 seconds of engine operation without EGR after all engine starts.
CCIE supplements the choke and provides more accurate cold idle fuel
management.
The initial cost of 1976 Chrysler vehicles is expected to be an average
of nineteen dollars cheaper than the 1975 models. Fuel economy of the
1975 models is compared to 1974 models in table Chrysler-8. Though no
comparative data was presented, Chrysler estimated that fuel economy
of the 1976 models will be improved 0-10% over 1975 for an overall 3%
improvement. Catalyst replacement cost at 50,000 miles is expected
to be about $95.
7-7
-------
Systems to be Used - 1977 Model Year
The first choice Chrysler system to achieve the .41 HC, 3.4 CO, 2.0
NOx standard is the 1976 California system of AIR, venturi vacuum
amplified EGR, and oxidation catalysts plus a smaller, rapid light-off
"start catalyst" near the exhaust manifold. On V-8 engines there will
be a start catalyst on only one bank with a power heat valve on the
other bank to provide maximum exhaust flow through the start catalyst
during warm up. Six cylinder models will not need the valve system.
Other systems still being considered include dual start catalysts on
V-8 models, improved main catalysts to eliminate the start catalyst, a
lean burn-oxidation catalyst system with electronic spark advance on
the six cylinder and small V-8 models, and a dual catalyst system to
eliminate EGR and OSAC NOx controls. The report team feels that the
dual catalyst approach is unnecessary at the 2.0 NOx level and that
greater fuel economy benefits could be achieved with improved EGR, EFE,
and fuel metering systems.
Initial cost of the 1977 Chrysler vehicle is expected to increase $185
over 1975. Catalyst replacement cost at 50,000 miles is estimated at
$180 and includes replacement of both the start and main catalysts.
Chrysler estimates a 12% fuel economy loss for 1977 over the 1975
49-State systems. This fuel penalty estimate appears unlikely to
the report team as Chrysler data indicates 18-29% improvements in
fuel economy over similar 1974 models and improved or equivalent
fuel economy over 1975 for all complete or incomplete systems achiev-
ing the 1977 levels as shown in table Chrysler-8.
Table Chrysler-2
i?
Low Mileage 1977 System Results
Engine System HC CO NOx FE
225-A3 lean burn, ox. cat.
electronic spark advance .33 2.0 2.1 16.6
318 NOx cat. retard .32 2.9 1.1 12.1
318 NOx cat. .46 3.3 1.6 13.0
225-M3 1977 1st Choice .26 1.9 1.54 18.1
400-4-A3 1977 1st Choice .20 1.4 1.26 11.9
360 NOx Cat. .66 4.37 1.52 11.93
318 B body 76 C4 .34 3.20 1.91 12.41
318 B body 76 CA .33 3.26 1.75 12.73
Above at 15,000 miles .32 1.80 1.74 13.17
440"C body .26 2.60 1.75 9.44
Above at 10,000 miles .38 1.29 1.61 9.70
360-4 76 CA+100-0 Ox. Cat. .18 2.0 1.85
7-8
-------
The following table indicates the results obtained with a start
catalyst.
Table Chrysler-3
Start Catalyst Evaluation
Vehicle 1 - Chrysler Newport, 400-4V, A3, venturi vacuum amplified
EGR, AIR, Chrysler oxidation catalyst, dual Chrysler start catalysts.
HC_ CO NOx Fuel Economy
Without Start Catalyst .42 2.21 1.26 11.6
With Start Catalysts .20 1.20 1.28 12.3
(3 tests) .23 1.68 1.19 11.8
.17 1,29 1,32 11,6
Ratio:
With Start Catalysts
Without Start Catalysts .47 .62 1.00 10.2
Systems to be Used - 1978 Model Year
The Chrysler system for .41 HC, 3.4 CO, .4 NOx is a dual catalyst
system with switching AIR, EGR, OSAC, and spark retard. Both noble
metal and base metal NOx catalysts are still under consideration.
Also the Questor Reverter System with rich thermal reactors, heated
AIR, and NOx catalysts is slated to begin durability testing on a
single car.
Chrysler 1975 FTP testing has verified the capability of these systems
as in tables Chrysler-4 and Chrysler-5; however, the Chrysler testing
has been limited to only a few cars without optimum AIR, EFE, fuel
metering, or EGR (no EGR in some cases). Chrysler development in
most of these areas has not progressed much in the past year. This
will handicap Chrysler durability efforts at this control level by
placing greater burdens on the Chrysler catalysts. Furthermore fuel
economy cannot be optimized using the control systems tested by
Chrysler at the 1978 levels.
No cost estimates were submitted for the 1978 model year systems.
7-9
-------
Table Chrysler-4
360-2V, A3, 5000 Ib. Dual Catalyst Vehicle
HC CO NOx Fuel Economy
.40 2.85 .21 11.8
.35 2.55 .28 11.3
.26 1.68 .38 11,8
.25 2.56 .38 11.2
.26 2.6 .36 11.2
.25 1.36 .30 10.8
Table Chrysler-5
360-2V, A3 Questor Vehicle
IW HC CO NOx Fuel Economy
4500 ,39 3,14 .34 10.1
4500 .20 2.18 .38 11.0
5000 ,31 2.84 .32 9.4
5000 .15 1.94 .33 9.7
Other Systems
Development is continuing on standard venturi, small venturi, variable
venturi, altitude and temperature compensated, and concentric - staged
dual carburetors for improved emissions control system performance
for 1976 and 1977 Federal standards as well as for 1978, according
to Chrysler.
The Bendix electronic fuel injection system is to be installed on two
Chrysler vehicles soon in an attempt to improve fuel management for
1978. A Chrysler electronic fuel injection system also is being developed.
This system in conjunction with a Chrysler induction system produces
sonic mixture velocities and has extended the lean misfire point to
.052 F/A (greater than 12 A/F) according to Chrysler. Initial results
show 2.0 HC, 15.0 CO, and 2.3 NOx with this system on a 440 CID Imperial.
This system is eventually intended for use with oxidation and 3-Way
catalysts. The report team assumes that the 3-way catalytic approach
will not use the lean A/F ratio which is under investigation in the
current program. Also, the report team feels that this system with
an oxidation catalyst could prove to be a promising system for 1977
if development work could be hastened.
7-10
-------
Early fuel evaporation (EFE) systems are under active development at
Chrysler. The 1975 FTP results of these are presented in tables
Chrysler-6 and Chrysler-7. The electric hot spot (EHS) provides electrical
heating below the carburetor to a grid in the manifold during warm
up. Marked cold driveability improvements were noted with the EHS.
The 1977 levels were achieved by the aluminum intake manifold equipped
system. System emissions without the aluminum manifold were not stated
by Chrysler. Initial tests on an electric fuel vaporizer have shown
50% CO reductions over the first two minutes of the 1975 FTP. Also
the engine ran very smoothly and required much less additional fuel
to operate than was anticipated according to Chrysler. A single plane
"hot well manifold" has been developed with an improved hot spot for
faster warm up. Initial tests indicate a 20% improvement in distribution
with this manifold.
An improved EGR system is to be developed to increase the EGR rate at
low vacuum and keep the percent diluent more constant. This should be
similar to proportional EGR systems that others have had for some time
now. Also, an electronic EGR system is being prepared for testing. The
super-proportional "Goodwille" EGR system which provides increased EGR
rates during acceleration was not mentioned by Chrysler. Other notable
systems for which little or no new data were presented were the modulated
AIR system, the TCCS V-8, or the prechamber stratified charge 225.
Table Chrysler-6
Electric Hot Spot Evaluation
Vehicle 1- 1974 360 CID Fury, no catalyst, no AIR, two-plane intake
HC CO NOx Fuel Economy
With EHS 1.28 14.75 1.82 10.07
Without EHS 2.01 15.61 1.80 10.03
Vehicle 2- 360 CID Fury with lean carburetion (.056-.061 F/A), EGR,
no AIR, no catalyst, single-plane intake
HC CO NOx Fuel Economy
With EHS 1.48 14.1 5.2 11.62
Without EHS 1.68 17.7 4.45 11.73
Vehicle 3- 1973 360 CID Fury II with oxidation catalyst, AIR, EGR
two-plane intake
HC CO NOx Fuel Economy
With EHS .22 1.97 2.10 10.8
Without EHS .25 2.01 1.80 10,4
7-11
-------
Table Chrysler-7
Aluminum Intake Manifold Evaluation
Vehicle - 318 CID, Automatic, 4500 Ib. IW, with modified spark advance,
venturi vacuum amplified EGR, AIR, and a UOP catalyst.
HC
CO
NOx
.24
.33
.31
2.3
2.5
3.7
1.74
1.82
1.72
Fuel Economy
12.8
13.3
13.5
Engine Trans.
Table Chrysler-8
1975 FTP Fuel Economy of Chrysler Models
1974** 1975 1977 1978
Fuel Fuel % Change Fuel % Change Fuel % Change
IW Economy Economy From 1974 Economy From 1974 Economy From 1974
225
225
225
318
360-2
360-2
360-4
400-4
A3
M3
M3
A3
M3
A3
A3
A3
3500
3500
4000
4500
4500
5000
5000
5000
16.9
—
12.0
—
10.0
10.9
10.0
8.7
17.1
__
14". 5
10.7/13.0
12.9
11.4
—
10.9
1
__
21
—
29
5
—
25
„
18.1***
14.51/15.21
12.12
__
—
10.9l/11.0l
10. 6***/
11.9***
—
24
—
— —
—
10
29
_.
— —
— —
__ —
— —
9. 63/11. 4* -12/5
— —
—
1 1977 1st choice system w/o start cat.
2 base metal NOx catalyst + 10° retard
3 Questor system
4 Dual catalyst - No EGR
** .corrected from 1974 to 1975 FTP
*** 1977 1st choice system
7.1.2.2 Durability Testing Programs
Durability Testing Programs - 1977 Model Year
For the .41 HC, 3»4 CO, 2.0 NOx level, Chrysler has assembled a five car
fleet of 'C' body (full size) cars for durability testing, The cars
are equipped with 400 CID engines and several variations of their
"miniconverter" system which places the catalysts immediately behind
the exhaust manifolds. The variations in this fleet include different
catalyst sizes and loadings along with different exhaust heat valve
arrangements. No mileage or emissions data were reported.
7-12
-------
Durability Testing Programs - 1978 Model Year
At levels below 2.0 NOx Chrysler reported limited progress on their
evaluation of NOx catalysts. This effort involves three cars equipped
with the following NOx catalysts: noble metal on ceramic substrate;
an ICI catalyst on ceramic substrate; and a base metal on metallic
substrate. The best durability was achieved with the noble metal
catalyst which had a total of 20,000 miles when the test was terminated
due to engine problems. The deterioration of this catalyst was very
slight over this mileage. The ICI equipped car produced the lowest
emissions at the start but was significantly degraded after 10,000
miles. Chrysler has halted all durability testing pending further
developmental progress on systems at this emission level.
7,1.2.3 Progress and Problem Areas
Progress and Problems - 1976 Model Year
Chrysler has made and is making progress toward reducing the cost and
improving the fuel economy of their 1976 models. The changes are extensive
enough, however, to require Chrysler to recertify most models for 1976i1
Chrysler has also gained valuable field experience with a 100-car fleet'
of catalyst-equipped vehicles. This field experience has been valuable
to Chrysler by identifying user problems such as warm-up driveability,
detonation, and odor. Because this test started in January, 1974,
Chrysler stated that they were able to remedy many problem areas in
their 1975 models.
Progress and Problems - 1977 Model Year
At the 0.41 HC, 3.4 CO, 2.0 NOx level, Chrysler has made much progress
in the development and evaluation of the subsystems that might be used
for a full-effort system. Testing of improved catalysts, miniconverters,
improved warm-up devices, improved EGR, improved exhaust manifolds and
improved air injection systems has all been carried out on a developmental
basis. The major problem for Chrysler at the 0.41 HC, 3.4 CO, 2.0 NOx
level is that the combination and optimization of the total 1977 package
does not yet seem to have been accomplished. This is not too surprising,
since the report team has observed that many manufacturers develop
the components of advanced systems separately and only put them all
together when it is very clear that they are going to have to meet the
standards that such full-effort systems require. Chrysler apparently
is not at this point yet.
An additional problem for Chrysler at the 0.41 HC, 3.4 CO, 2.0 NOx
level is the lack of durability testing of the entire 1977 package.
Some tests may be just beginning, however the systems may not include
all of the 1977 components, and the fleet apparently consists of only
7 vehicles.
7-13
-------
Progress and Problems - 1978 Model Year
Chrysler has made some progress in the areas of catalyst screening and
evaluation. NOx catalysts made by Chrysler and other catalyst manu-
facturers have been bench tested. A limited amount of vehicle low
mileage testing was reported by Chrysler but no extensive durability
results were reported. Chrysler has tested a Gould GEM-68 catalyst
system with oxygen getter, but the vehicle was not equipped with EGR.
Chrysler stated in their status report that the vehicle was going to
be durability tested in the future. The report team learned that the
system was destroyed by the combination of fuel run out and ignition
failure on several tests before the vehicle was to be durability tested.
See section 7.2.1.
Chrysler's problems at the 0«4 NOx level remain lack of system development
and durability testing of full-effort systems.
7-14
-------
7.1.3 Ford
7.1.3.1 Systems to be Used - 1976 Model Year
The 1976 Ford systems are described in table Ford-1. Both Engelhard
and Matthey-Bishop catalysts are used. Noble metal loadings are of
66 percent platinum and 34 percent palladium for Engelhard catalysts
and 93 percent platinum and 7 percent other noble metal for Matthey-
Bishop catalysts. Ford uses three different monolithic substrates in
nine different sizes including either oval or circular cross sections.
The "half pass" (only half of V-8 exhaust is catalytically treated)
catalyst system will be used on all engines larger than the 302 CID
except on the 351 CID Granadas and Monarchs. Catalyst protection is
achieved by venting the air pump to the atmosphere when the vehicle
floor temperature exceeds a predetermined value. Improved EGR systems
are discussed in the Ford application for certification; however, they
are not used in 1976. These include the RELIC or recirculating exhaust
gas JLpad ^induced £ontrol system for EGR reduction during prolonged
cruise conditions and an exhaust backpressure modulated EGR system.
Both are more proportional than current EGR systems and according to
Ford can provide up to 1 mpg improvement in fuel economy at the 2.0 NOx
level. Spark delay valves, heated intake air, and electric assit chokes
are some minor systems frequently used by Ford.
Changes in costs and economy for the 1976 models were not stated by
Ford. In the opinion of the report team there is not much chance of
improved fuel economy over the 1975 models unless the California AIR,
EGR, oxidation catalyst (full pass) systems are recalibrated to the
1.5 HC, 15.0 CO, 3.1 NOx level.
Systems to be Used - 1977 Model Year
The Ford emission control systems to achieve the .41 HC, 3.4 CO, 2.0 NOx
are not finalized; however, the current first choice system is AIR,
EGR, and oxidation catalyst. Larger, improved monolithic catalysts
will be used with the exhaust backpressure modulated EGR, high energy
ignition (HEI), and variable venturi (2700 series) carburetors on some
models. Remaining models will use conventional carburetors. Internal
engine changes will include reduced valve overlap for improved low
speed operation and combustion chamber modifications to improve fuel
economy and emissions. The Ford introduction of HEI lags behind others
in the industry, but should provide some improvements in emissions,
driveability, and fuel economy.
7-15
-------
Ford estimated that the initial retail cost of the 1977 vehicle will
average $150-$200 more than the 1975 vehicle due to increased cost of
the emission control systems. Also, Ford indicated that an unknown fuel
penalty would be realized in 1977. This could not be verified by the
report team due to the absence of fuel economy data in the Ford status
report. Ford later stated that "vehicle testing to date (of backpressure
EGR system) indicates a potential increase of up to 05 to 1.0 mpg".
Table Ford-1
1976 Ford Emission Control Systems
Engine
CID
140 (2,3 "A")
140 (2.3)
171 (2.8)
200 A
250
250 (1CEF)
302 "A"
302 (1CMF)
302 (2CMF)
351W "A"
351W (1CEF)
351W (1CET)
351M/400 (1CET)
460
AIR
Drive Ratio
.95)
.95)
.95)
(1.37)
(1.37)
(1.37)
(1.46)
(1.46)
(1.50)
(1.46)
(1.46)
(1.46)
(1.46)
(1.25)
EGR
Ported
Ported
Ported
WA
VVA
WA
WA
WA
Ported
Ported
Ported
Ported
Ported
Ported
Oxidation Catalyst
Loading (tray oz) Manufacturer
.06
.02
.11
.11
.04
.04
.11
.05
.05
.07
E
M-B
E
E
M-B
M-B
E
E
E
E
VVA = venturi vacuum amplified
E = Engelhard
M-B = Matthey-Bishop
"A" = Alternate engine
The 1977 emission levels have been achieved at low mileage with vehicles
using the 140, 171, 250, 302, 400, and 460 CID engine. Vehicles powered
by the 140 and 400 CID engine have demonstrated the 1977 levels at
50,000 miles. Seven Ford vehicles achieved the 1977 levels in 1975
certification. Included were vehicles powered by the 140 and 250 CID
engines and the 360 and 390 truck engines.
Systems to be Used - 1978 Model Year
The first choice Ford system for the .41 HC, 3.4 CO, 0.4 NOx level will
include a 3-way catalyst followed by a "clean up" oxidation catalyst
with secondary AIR between the two catalysts, the exhaust, backpressure
7-16
-------
modulated EGR system, and electronic fuel injection or sonic carburetion
with feedback control. Also some cylinder head and inlet manifold
modifications will be made. The sonic carburetor will probably be
a Ford model rather than the Dresserator as Ford has shown considerable
interest in duplicating Dresser's results with Ford hardware.
A 2.3 litre Pinto using Bosch L-Jetronic fuel injection with oxygen
sensor feedback, EGR, secondary AIR, a 3-way catalyst, and a clean-up
oxidation catalyst has achieved .14 HC, .70 CO, and 1.5 NOx at low
mileage over the 1975 FTP. Average driveability was rated at 5.0
as compared to the minimum 5.5 rating of acceptability Ford would
prefer. Also a 2.8 litre Capri has achieved .23 HC, 2.08 CO, and .30 NOx
at low mileage over the 1975 FTP while using two 3-way catalysts
(one in each bank), dual oxygen sensors, and EFI. Average driveability
was rated acceptable at 6.8.
The Gould NOx catalyst in a dual catalyst system is an alternate system.
Gould achieved .24 HC, 3.3 CO, .26 NOx, and 12.5 mpg with their system
on a 351W Galaxie at low mileage without the oxygen "Getter". Ford
could not duplicate these levels after receiving the vehicle. Further
testing is planned using the GEM 68 catalyst with the "Getter".
The Questor system is another alternate system. An early Questor
system achieved the 1978 levels on a 351 5000 Ib. inertia weight vehicle
at low mileage and then deteriorated rapidly. Similar results occurred
with an improved Questor system on a 2.3 litre Pinto. The Pinto will
receive system modifications and further testing.
Other Systems
Systems using start catalysts and exhaust HC storage canisters have
been studied and dropped. The start catalyst, despite much improved
warm up characteristics, were said to have poor durability. HC storage
canisters were said to have safety and purging problems.
Single cylinder tests will be conducted to optimize the "fast burn"
concept. Increased EGR tolerance is expected to provide lower NOx
emissions, lower octane requirements, and improved engine efficiency
with a HC emissions penalty due to lower exhaust temperatures. Modulated
AIR experiments are being conducted to optimize air flow rate.
Three different sonic carburetors are being studied. Two are Ford
models and the third is the Dresserator. A Dresserator equipped Galaxie
without catalysts, EGR, or AIR was tested by the California Air
Resources Board in May of 1973. The vehicle achieved .32 HC, 4.7 CO,
1.58 NOx, and 10.8 mpg on the 1972 FTP. On a 1975 FTP basis these
results would be .28 HC, 3.4 CO, and 1.6 NOx. Spark retard was utilized
to lower HC emissions below the .41 level. CO and NOx emissions were
7-17
-------
unaffected by retard. The fuel economy was 7 percent better than the
average 1973 vehicle of the same weight class. Driveability of this
vehicle was judged to be acceptable by EPA personnel. Data from Dresser
indicated that without spark retard, fuel economy can be improved by
20 percent while HC emissions double. With a catalytic control system,
the Dresser vehicles could have fuel economy better than uncontrolled
cars and achieve the .41 HC, 3.4 CO, 2.0 NOx levels. The Ford development
program has demonstrated the hot start results in table Ford-2 without
AIR, EGR, or catalysts.
Table Ford-2
Hot Start Sonic Carburetor Results
HC CO NOx MPG
Ford Hinged Jaw .42 4.99 1.45 9.9
Dresser Model II .74 5.47 1.38 11.2
Ford indicated that sonic carburetors could not be in significant
production until 1979. The report team believes that serious develop-
ment could provide a cost effective sonic carburetor-catalyst system
for 1977.
Ford is also studying both the prechamber and direct injection PROCO
stratified charge engines. An agreement was signed with Honda to jointly
develop CVCC engines for Ford. The Pinto and Torino emissions are not
typical CVCC results on the 1975 FTP, as can be seen from the Galaxie
results in table Ford-3.
Table Ford-3
Ford CVCC Results on the 1975 FTP
HC CO NOx MPG
Pinto 140 M 3000
Torino 400 5000
Galaxie 400 A 5000
2.86
.68
.21
.19
.29
.24
.18
.24
.22
.24
.15
.15
14.96
4.77
2.51
2.32
2.77
2.20
2.26
5.14
2.72
2.32
2.17
1.67
1.70
2.04
1.81
1.87
1.80
1.58
1.88
1.66
1.69
1.60
1.83
2.36
20.8
9.6
9.9
10.1
9.9
10.6
9.2
10.5
9.4
10.5
9.1
9.3
Average Galaxie Results .211 2.60 1.81 9.9
7-18
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CVCC System
No efforts were reported to recalibrate the Ford CVCC vehicles to the
0.4 NOx level which has been consistently achieved by Honda 119 CID
models. Ford claims the prechamber CVCC "program has been delayed as
result of uncertain future NOx standards. A viable production program
requires that these prechamber engines can be mass produced if NOx
emission standard is retained at the 2.0 gm/mi level for at least ten
years..." In the opinion of the report team, the program has been delayed
because of Ford's reluctance to demonstrate that the .4 NOx level
can be achieved while requesting an emissions standard moratorium.
Furthermore, the report team is doubtful that Ford CVCC introduction
would occur at the 2.0 NOx level. Conventional engines can obtain
the 2.0 NOx level at as good or better fuel economy than that demonstrated
by the 400 CID Ford CVCC's. The report team does not wish to criticize
the CVCC approach as we feel that with EGRoptimization and exhaust
aftertreatment, the CVCC approach may prove to be competitive at the
more stringent 1978 levels in both emissions and fuel economy. Ford
indicated that some EGR studies will be made in the future.
A dynamically scavenaged prechamber system which eliminated the additional
inlet valve has been dropped because of poor fuel economy. No supporting
data was provided. An "add-on" prechamber device is also being studied.
No data was provided for this system either.
American Bosch, Robert Bosch, and Nippon-Denso are preparing fuel
injection systems and cost estimates of their proposed systems for
mass production of the PROCO. Champion Spark Plug is doing similar
work with spark plugs for the PROCO. The 351 PROCO equipped Montego
continued durability testing in 1974 at NOx levels recalibrated to
about 2.0-3.0 NOx. The higher NOx calibrations failed to provide
significant changes in fuel economy. HC and CO emissions tended to
increase as the NOx levels were reduced, however. Similar conventional
Ford vehicles achieved about 11 mpg in 1975 certification. The 400 CID
Ford engine was also converted to PROCO in 1974. The first effort was
the "Super Economy" Mark IV. All systems were optimized for fuel economy
and 14.1 mpg was achieved over the 1975 FTP; however, driveability and
combustion harshness were unsatisfactory. Three other 400 CID PROCO
vehicles were tested for NOx levels of 1.5-2.0. Early results were
reported as in table Ford-5. Fuel economy of comparable 1975 conventional
Ford models was about 10 mpg.
7-19
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Table Ford-4
351 CID PROCO Results Without Catalysts
HC CO NOx • MPG
5.54 22.0 .383 14.3
1.32 18.2 1.01 14.0
1.82 25.9 1.48 13.5
1.38 15.6 1.90 14.6
1.15 15.6 3.22 14.2
Table Ford-5
400 CID PROCO Results Without Catalysts
HC CO NOx MPG
Montego
900 Inj. Spray Angle 1.41 18.0 1.16 12.6
Montego
60° Inj. Spray Angle 1.51 12.7 1.71 13.1
Torino
100° Inj. Spray Angle 2.10 8.06 1.50 14.4
7.1.3.2 Durability Testing Programs
Durability Testing Programs - Update of 450 Car California Fleet
This fleet consists of 450 Ford sedans equipped with 400 CID engines.
The cars are basic 1973 production with the addition of monolithic
oxidation catalysts along with a catalyst overtemperature protection
system and the Ford air injection (Thermactor) system for reducing
HC and CO. These vehicles have been assigned to three large fleet
operators. Ninety of the vehicles are serving as a control group and
are being emission tested periodically. The remaining 360 vehicles
and the control groups will be tested whenever there is a customer
complaint. Forty-three vehicles in the control group have now completed
24,000 miles. The average emissions level for these 43 vehicles has
remained below the .41 HC, 3.4 CO, 2.0 NOx level. Some preliminary
conclusions of Ford were that the oxidation catalysts experienced a
decreasing rate of deterioration and that CO and NOx emissions were
affected by the maintenance performed. Nineteen catalyst failures
were experienced. All of the failures involved partial melting of
the catalysts and were attributed by Ford to misfiring caused by
faulty ignition systems. The catalyst overtemp protection circuit
which dumps the Thermactor air supply was ineffective because sufficient
air was already in the exhaust to cause catalyst damage.
7-20
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In addition, a set of four vehicles is being tested to evaluate the
performance of catalysts and exhaust systems on rough road and general
durability schedules. The two rough road cars have gone their scheduled
8000 miles with no reported problems. The two general durability
cars have accumulated 48,000 and 49,450 miles respectively, with no
catalyst problems reported.
A Dearborn 20-car fleet is accumulating customer type mileage. Equipped
identically as the previously mentioned fleets except for the addition
of a breakerless ignition system, these cars are being operated by Ford
engineers with close attention being paid to performance, warm-up and
driveability characteristics. Seventeen cars are at or beyond 15,000
miles and one car has reached 45,000 miles. The emissions level of the
car at 45,000 miles was 0.70 HC, 4.26 CO and 1.60 NOx. Three catalyst
failures were experienced as the result of ignition system breakdown.
Durability Testing Programs - 1977 Model Year
At the .41 HC, 3.4 CO, 2.0 NOx level Ford has four durability/evaluation
efforts underway. The "1976 Catalyst Durability Fleet" initiated in
July 1973, consists of 12 vehicles representing a cross-section of the
Ford model line. This fleet was established to evaluate the effectiveness
of different catalyst volumes and suppliers in reaching the 50,000 mile
durability goal at the .41 HC, 3.4 CO, 2.0 NOx emission level. Nine
vehicles have reached the 50,000 mile mark and one vehicle is at 25,000
miles. The remaining two vehicles were eliminated at 35,000 and 45,000
miles, respectively, due to catalyst melting problems. The 12 vehicles
consisted of two each of six different models. ' Four of the six model
types averaged above the .41 HC, 3.4 CO, 2.0 NOx level at 50,000 miles.
The "1977 Catalyst Technology Fleet" is a second effort at the .41 HC,
3.4 CO, 2.0 NOx level. Thirty-five vehicles began accumulating mileage
in May 1974 with more advanced monolithic catalysts employing larger
volumes and cell densities. Mileage to date on the vehicles ranges up
to 30,000. The highest mileage emission data reported was for four
vehicles at the 25,000 mile level. At this point the vehicles were
well below .41 HC, 3.4 CO, 2.0 NOx level. As with the "1976 Catalyst
Durability Fleet", this fleet is receiving corrective maintenance based
on emission levels, which is not allowable in official EPA procedures.
Ford explains this maintenance practice as best fulfilling their goals
for engine/catalyst system development.
Ford is also operating a "Pelleted Catalyst Fleet" utilizing the CM
pellet catalyst in 16 vehicles. The objective of this fleet is to
provide performance and deterioration information that will enable Ford
to objectively evalutate monolithic versus pelleted catalysts. An
average of 40,000 miles has been accumulated. No failures were reported
but the emission data at the higher mileages shows the average levels
of all cars to be in excess of .41 HC, 3.4 CO, 2.0 NOx.
7-21
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The fourth Ford effort at the .41 HC, 3.4 CO, 2.0 NOx level is the
"Feed Gas PAS Fleet". The objective of this effort was to attain
predetermined feed gas (non-catalyst) emission levels on vehicle fleets
tested at sea level and at altitude. The selected levels represented
Ford's estimate of the degree of emission control needed up-stream
of the catalyst to meet the .41 HC, 3.4 CO, 2.0 NOx level at the tail-
pipe. The majority of the sea level fleet met the feel gas level goal
but the fleet at altitude was unsuccessful. The sea level and altitude
fleets consisted of eight and five cars respectively which represented
a cross section of Ford models. A total of 4000 miles was accumulated
on each car.
The Ford PROCO (Programmed Combustion) engine has undergone additional
durability testing. Equipped with oxidation catalysts and EGR the
351 CID PROCO engine was installed in a 1972 Montego. The system was
calibrated to meet the .41 HC, 3.4 CO, 2.0 NOx level. Since Ford's
1973 Status Report the car has accumulated 16,000 miles of additional
AMA Durability, completing 50,000 miles. Some emission system failures
were experienced but the engine and injection system were relatively
trouble free. The fuel economy ranged between 13-15 mpg.
Durability Testing Programs - 1978 Model Year
Ford reported progress on two vehicle durability tests of systems targeted
for NOx below 2.0 gm/mi. The first test involved a 20,000 mile test of
a Questor equipped 351W-2V Ford. The emission level at zero mileage was
0.04 HC, 2.0 CO, 0.39 NOx. The HC and NOx levels remained low
through 15,000 miles but the CO control deteriorated steadily, reaching
7.86 at 20,000 miles. The HC control deteriorated rapidly between 15,000
and 20,000 miles where it jumped from 0.41 to 5.07 gm/mi. Ford reported
that secondary air system malfunctions and low compression in one
cylinder accounted for much of the degradation.
The second Ford effort at NOx below 2.0 was a 2.3L Pinto equipped with
Questor's third generation system which includes their own integrated
reactor - reverter exhaust manifold. The zero mileage emissions were
comparable to the Ford described above, but the system control deteriorated
quickly due to an insufficient secondary air system. The test was
stopped at 360 miles and the vehicle was returned to Questor for modification.
7.1.3.3 Progress and Problem Areas
Progress and Problems - 1976 Model Year
Ford is apparently going to use model year 1976 as a refinement and
optimization period for their emission control systems. They will
certify to the same emission standards for 1976 as they did for 1975,
7-22
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therefore the systems could be the same, and they are, for the most
part. Ford's approach using the half-pass system will be continued
on most large engined-vehicles. Ford could have used 1976 as a year
to try and certify full catalytic control systems that might have allowed
them to catch up some to their competition in fuel economy, but the
report team feels that Ford does not want to accept the extra cost or
the possibility that they might certify too low and meet the 1977
standards (one.* of their trucks with full catalytic treatment did in
1975).
Progress and Problems - 1977 Model Year
Ford has made significant progress in system selection for 1977. All
models will use full catalytic treatment of the exhaust gas, along with
improved catalysts, backpressure EGR, and high energy ignition. Ford
is depending heavily on the improved catalyst technology being developed
for them by their suppliers and now being tested and evaluated by Ford.
This improved catalyst technology, which Ford expects to achieve improved
conversion efficiency at high mileage, results from improvements in
catalyst material and larger catalyst volume.
Ford is also investigating other areas which may have impact on systems
for the 0.41 HC, 3.4 CO, 2.0 NOx level. Among these radial flow monoliths,
2r02 - copper chromite base metal oxidation catalysts, and sonic carbure-
tion. It may be that these developmental areas are investigations for
future (post-1977) introduction, and Ford claims the sonic carburetor
can only be in production in 1979. Part of the length of time necessary
for the introduction of a sonic carburetor, in the opinion of the report
team, is Ford's evident desire to develop their own sonic carburetor
like Dresser's, and they may be repeating some of the work already done
by Dresser.
Ford is rather unique in that they are running developmental durability
fleets targeted toward 0.41 HC, 3.4 CO, 2.0 NOx. Most manufacturers
are not. These fleets are being used to screen and evaluate catalysts
for possible use in model year 1977. Ford did not supply detailed
descriptions of the vehicles being durability tested, so it is not
known if the systems included all of the components that Ford actually
plans to use in 1977. Because another fleet will be started after the
two fleets are finished the report team concludes that the durability
data submitted by Ford was on less than full effort systems. Even though,
the results for the vehicles with highest mileage were below the 0.41
HC, 3.4 CO, 2.0 NOx levels at 25,000 miles.
* The durability vehicle was above the 1977 level
7-23
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Progress and Problems - 1978 Model Year
Ford's "current choice" system, a three-way catalyst plus an additional
oxidation catalyst is indicative of the status of Ford's efforts to
meet the 0.41 HC, 3.4 CO, 0.4 NOx standards. In the judgement of the
report team systems like the 3-way + ox. cat. under consideration by
Ford are inferior to dual catalyst systems in their potential for
achieving the 0.4 NOx standard. The report team has concluded that
Ford, like other manufacturers, is developing this type of system in
anticipation of a NOx target higher than 0.4, and Ford also does not
now plan to have to meet 0.4 NOx.
Indications of Ford's attitude toward meeting 0.4 NOx were evident more
than one year ago, as pointed out in last years report, when Ford
redirected their alternate engine programs to a 1.5 NOx target. The
report team concludes that Ford's conventional engine effort is also
targeted toward a NOx level higher than 0.4, and that this decision is
also about a year old.
Ford's efforts with independent developers of systems with potential
for 0.4 NOx capacity has been minimal in the past year. Ford learned
of the Gould GEM 68-getter system in February 1974. Currently, almost
one year later, Ford reported no tests on such a vehicle. Ford has
tested a Questor system in the past year and typical of most automobile
manufacturers' relationships with independent developers, the vehicle
was tested, something was found to be wrong with it, and the vehicle
was returned to Questor to have them fix it.
Ford continues to work on their PROCO engine program. However, the
redirection away from 0.4 NOx has not permitted the evaluation of the
improved injection systems for HC reduction in conjunction with a system
targeted toward 0.4 NOx. This is considered by the report team to be
unfortunate, since the biggest problem with the PROCO at 0.41 HC,
3.4 CO, 0.4 NOx has always been HC, not NOx.
7-24
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7.1.4 General Motors
7.1.4.1 Systems to be Used - 1976 Model Year
The General Motors systems for 1976 will Be nearly identical to those
used in 1975 with a few revisions for improved fuel economy. The 1976
Federal system will include quick chokes, EGR, and oxidation catalysts
on virtually all models.
Table GM-1
1975 GM Control Systems for 49 States Models
AIR
Chev
Chev
Chev
Chev
Chev
Chev
Chev
Pont
Pont
Pont
Pont
Pont
Olds
Olds
Olds
Buic
Buic
Buic
Buic
Cadi
140
262
250
350-2
350-4
400-4
454-4
350-2
400-2
350-4
400-4
455-4
260
350-4
455-4
231
350-2
350-4
455-4
500-4
X
X
X
EGR
Ported
Ported
Ported
Ported
Ported
Ported
Ported
Ported
Ported
Ported
Ported
B.P.
B.P.
Ported
Ported
Ported
Ported
Ported
Ported
Ported
CAT
160
260
260
260
260
260
260
260
260
260
260
260
260
260
260
260
260
260
260
260
All catalysts are pellet type with either cylindrical or spherical
pellets. The 160 CID and 260 CID converter both contain about .05
troy ounces of noble metal. The noble metal is 71% platinum and 29%
palladium.
California 1976 models will be very similar to the 49 state models
with AIR added.
Systems to be Used - 1977 Model Year
GM has several catalytic control systems under consideration for the
.41 HC, 3.4 CO, 2.0 NOx level. One is an extension of the 1975 Federal
system to include previously developed systems such as AIR, proportional
7-25
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EGR, EFE, and intake manifolds with improved distribution. Another
catalytic system uses very lean carhuretion in conjunction with an
oxidation catalyst. EGR and AIR are eliminated. Also studies are to
begin to evaluate small manifold-mounted "start" catalysts for use
with the larger main catalyst. Previous experience with manifold-
mounted catalysts should prove valuable.
The report team feels that the very lean carburetion plus oxidation
catalyst system is potentially one of the more initial cost effective
systems we have seen demonstrated at the 1977 emissions level. The
Chevrolet 400-4 vehicles are shown in Table GM-2 and can be.compared
with the extended 1975 catalyst approach. The fuel economy of all
three prototypes is down from the 13-14 mpg of the comparable 1975
Federal vehicles. Other prototypes at 1977 levels also show fuel
economy losses from the 1975 models. Not all systems were complete;
however, this does indicate that the 260 CD) pellet catalyst may no
longer be capable of doing all the work. A catalytic system with
improved "light off" characteristics could help eliminate the fuel
economy losses. One GM vehicle did achieve the 1977 levels in 1975
certification.
Table GM-2
1977 Systems Comparison
HC CO NOx Fuel Economy
AIR, EFE, backpressure
EGR, ox. cat. .15 1.4 1.5 10.7
Lean burn, ox. cat. .17 .8 1.9 10.8
2 data points .24 1.2 1.8 10.6
Systems to be Used - 1978 Model Year
GM systems for the .41 HC, 3.4 CO, .4 NOx level use catalyst technology.
Proportional EGR and EFE are used with all systems. One is a dual
catalyst system with reduction catalysts mounted near the exhaust
manifolds and the oxidation catalyst in the underfloor location.
Slightly rich A/F mixtures provide the reducing atmosphere and secondary
AIR provides the oxidizing atmosphere. A 3-way catalyst system is also
being considered. An oxygen sensor will provide feedback control to
either an electronic fuel injection system or a carburetor for near
stoichiometric A/F control. Another system includes the 3-way catalyst
followed by secondary AIR and a "clean up" oxidation catalyst.
All three systems have demonstrated the 1976 levels at low mileage,
but durability has not been established for any of them. GM effort
at .41 HC, 3.4 CO, and .4 NOx in 1974 consisted of testing on one dual
catalyst vehicle, two 3-way catalyst vehicles, and one 3-way plus
"clean-up" catalyst vehicle. The Nippon-Denso NOx catalyst in the
dual catalyst system completed 24,000 miles below .4 NOx.
7-26
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The 3-way catalyst vehicles at the 1978 levels have shown the potential
for fuel economy equivalent to their excellent 1975 GM counterparts as
shown in table GM-5. Dual catalyst vehicles exhibited somewhat poorer
fuel economy due to their richer carburetion to create the reducing
atmosphere in the NOx catalyst.
Other Systems
Alternate engine development has received considerable attention at
GM. The prechamber stratified charge engine appears to be the most
likely to succeed, but all indications are that it would not appear
during the time frame of this report. GM is concerned that exhaust
aftertreatment devices will be needed at 1978 levels to reduce fuel
economy losses. Honda converted both the GM 140 and 350 CID engines
to stratified charge some time before GM did; however, no joint Honda-
GM development program was reported.
Table GM-3
Prechamber Stratified Charge Results
CID IW Control System HC CO NOx MPG
350* 5000 — .15 2.72 1.66 10.5
350 5000 — .9 4.5 1.7 10.3
350 5000 Thermal Reactor .26 3.0 1.5 9.8
350 5000 Catalyst .19 .9 1.5 10.2
350 4000 — 1.2 4.1 1.4 12.5
350 4000 EGR 2.8 8.1 .43 11.7
*Honda CVCC conversion, done by Honda.
A GM stratified charge Vega was assembled in early 1974, but no test
results were reported to EPA.
A dual shaft, regenerated gas turbine has been reported which has
achieved .12 HC, 2.14 CO, and .36 NOx over the 1975 FTP. This vehicle
was not fully described, but at least part of the engine control system
used was not contained in the vehicle. Practical in-vehicle installa-
tion of those components has not been achieved. Fuel economy of this
vehicle was not stated; however, fuel economy and cost were said to be
specific problems. Single shaft turbines are also being investigated.
In the opinion of the report team, gas turbines will not be competitive
in the automotive market until a materials breakthrough permits signi-
ficantly higher temperature turbine operation.
The Diesel powered Opel 2100D was mentioned as having 20% better fuel
economy than a similar gasoline version over a low speed cycle, but
according to GM it will not be Imported due to small demand and problems
7-27
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with the Diesel engine. These engine problems include combustion
noise, particulate emissions, exhaust odor, and cold starting,
according to GM. GM also noted the inability of the Diesel to certify
at the 1978 NOx level.
The rotary engine program has slowed considerably since GM postponed
its introduction. According to GM, "Our decision was based primarily
on the conclusion that we did not possess emission technology which
would permit us to meet the 1977 standards at reasonable fuel economy
levels". The report team concluded that when optimized for fuel
economy, GM's rotary is barely competitive with conventional engines.
Since emission controls beyond those which are fuel penalty-free are
needed to make GM's rotary meet even the 1975 Interim standards, the
engine is not competitive in fuel economy. Table GM-4 compares the
GM rotary fuel economy to that of other 1975 vehicles of similar
inertia weight and power to weight ratios. It should be noted that the
GM rotary-engined vehicle in table GM-4 does not meet the 1975 Interim
standards, while the other vehicles do.
Table GM-4
GM Rotary Fuel Economy Comparison
Fuel Economy
City Highway
GM Rotary 206 14.5 20.5
Buick 231 V-6 20.3 25.3
Volvo 164 16.5 26.5
Mustang II V-6 15,5 22.7
No further information was presented on the GM super EFE system which
forces all the vehicle exhaust through the intake manifold to aid in
cold start fuel evaporation. Also no new data was presented on the
cold start HC storage system.
7.1.4.2 Durability Testing Programs
Durability Testing - 1975/1976 Model Year
General Motors has acquired extensive field durability experience at
the 1975/1976 Federal and California emission levels through their
"COPO" fleet. This fleet consists of 205 Chevrolets and is split into
two emission design levels: • 146 cars at the 1.5 HC, 15 CO, 3.1 NOx
Federal level and 59 cars at the .9 HC, 9 CO, 2.0 NOx California level.
Each level is further divided into underfloor catalyst and manifold
catalyst vehicles. The manifold catalysts are mounted immediately
behind the exhaust manifolds.
7-28
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Table GM-5
Current Fuel Economy of Various Systems
vO
1975 % Change 1975
Mfr. Engine Trans. IW 1974 Federal from 1974 Calif.
Chev. 140-1 A3 3000 19.5 19.0 -3
Chev. 350-2 A3 5000 11.0 12.4 +13
Chev. 400-4 A3 4500 — 13.8
% Change % Change
from 1974 1977 from 1974 1978
20. 45
— — — 12.22
12. l3
10.33
9.6*
10. 76
10.81
10. 61
% Change
from 1974
+5
+11
+10
-6
-13
Olds 350-4 A3
4500
9.7
14.6
+51
12.6
30
11.0
+13
lean burn and ox. cat,
2 3-way cat.
3 3-way cat. + ox. cat.
dual cat.
5 3-way cat. + EFI
6 extended 1976 Calif, ox. cat.
7 Above without AIR
-------
GM reports that over 8,000,000 miles have Been logged by the COPO
fleet. The type of service is primarily taxicab and the reported
results were generally good. The average emission levels of reported
sample groups were within the design goals and system durability
appeared to be good. The California 2.0 NOx level came closest to
being exceeded with the average level at 50,000 miles being approxi-
mately 1.9 gm/mi. A total of 20 catalyst failures were experienced,
but seven of these occurred after 50,000 miles and four involved
monoliths. All catalyst failures resulted from overtemperature
conditions caused by engine misfiring. The misfiring was attributed
to overly lean carburetion and fouled spark plugs.
GM reported that occasional inadvertant fueling with low lead fuel,
0.5 gm/gallon, did not result in measurable catalyst deterioration.
GM also reported the results of an investigation of catalyst fouling
on lead and phosphorous. After 3,000 miles of operation on leaded
fuel, an underfloor catalyst car and a manifold catalyst car were
operated for 7,000 miles on unleaded fuel. The underfloor catalyst
regained nearly all of the lost efficiency but the manifold catalyst
did not recover. Following 6,000 miles of operation on high phosphorous
fuel, the catalyst efficiency of several cars was cut in half. Subse-
quent operation on clean fuel did not result in catalyst recovery. GM
reported that the catalyst durability of the AMA schedule car was
fairly typical of the taxi and highway groups.
Durability Testing - 1977 Model Year
A second filed durability test is being conducted by GM on 25 Olds-
mobiles operated in California under customers service conditions.
Thirteen of the cars were tailored to meet the .41 HC, 3.4 CO, 3.1
NOx level and the remaining twelve were targeted for the .41 HC,
3.4 CO, 2.0 NOx level. All of the cars were equipped with EGR, EFE
and HEI and, in addition the 2.0 NOx cars have air injection.
The thirteen cars in the first group have accumulated between 25,000
and 33,000 miles and the second group has accumulated between 17,000
and 21,000 miles. Both groups average emissions are below the design
goals but several vehicles have exceeded the goals on individual tests.
The average emissions for eleven cars of the first group at 24,000
miles were .24 HC, 2.54 CO, 1.90 NOx and the average for five cars
of the second group at 16,000 miles was .37 HC, 1.44 CO, 1.46 NOx.
It should be noted that maintenance was performed on the emission
systems prior to testing, a procedure not allowed in official EPA
certification testing.
The fuel economy results of the Oldsmoblle fleets are interesting
because the second group of cars with lower emissions had better fuel
economy. The average dynamometer fuel economies were 9.03 MPG for
group 1 and 10.05 for group 2. GM reported that the evaporative
7-30
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control systems strongly influenced the cold start emissions. The
average emissions were reduced from .21 HC, 3.16 CO, 1.93 NQx to .17
HC, 1.93 CO, 1.86 NOx by substituting an empty canister for the normal
canister prior to cold start.
GM reported low mileage emissions data on 41 proving ground cars which
GM stated represented the "current state-of-development" toward meeting
the .41 HC, 3.4 CO, 2.0 NOx requirement level. The data indicates that
hydrocarbon control is the area needing the most improvement. It is
difficult to assess the probability of these cars complying with the
requirement at high mileage because practically no data was given for
above 2000 miles.
Durability Testing Programs - 1978 Model Year
At the .41 HC, 3.4 CO, 0.4 NOx level, GM reported AMA durability data
on 14 dual catalyst systems. However 13 of these had completed testing
in 1972 and 1973. Only one additional dual catalyst system was tested
on the AMA schedule in 1974. The car tested in 1974 exceeded the HC
and CO allowable level at 8000 miles and exceeded the NOx level at
25,000 miles. GM reported additional dual catalyst durability testing
involving 18 cars in the COPO fleet. The emissions performance of
this group was very unsatisfactory. The average NOx level exceeded 0.4
at zero miles. At 8000 miles the average emissions of HC, CO and NOx
all exceeded the 1978 standard levels. GM reported durability test
data for two cars equipped with three-way catalysts. These cars
operated on the AMA schedule. Both cars experienced rapid catalyst--
deterioration.
7.1.4.3 Progress and Problem Areas
Progress and Problems - 1976 Model Year
GM plans to use basically the same systems for 1976 as they did in
1975, therefore the report team concludes that GM will have no major
problems in model year 1976.
Progress and Problems - 1977 Model Year
GM has made progress in the area of system development and optimization
for model year 1977. GM's major problem in meeting the 1977 standards
is HC control. Tests run by GM with T77 prototype vehicles equipped
with 50,000 mile catalysts from 1975 certification showed that HC
emissions were generally too high. The GM approaches toward improving
the HC control capability lie in two areas, improving the 1975 systems
and the lean burn plus ox. cat. approach.
7-31
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The improved 1975-type systems are much like the GM 1975 California
systems that had PEGR and air Injection, GM is evaluating Improved
catalysts to go with this system, along with the use of a start cata-
lyst. The warm-up converter was discussed very vaguely by GM and no
data on such systems was supplied. This is a good example of an
advanced control approach possibly being held In the wings until it
is needed. Ford stated that one of the problems they saw with their
GM pelleted catalyst fleet was the deterioration of light-off capability,
which a start catalyst would help. GM has developed other approaches
like fuel distillers, charcoal traps, and super EFE that were investi-
gated and then not used because they did not have to be, and possibly
because they tended to be more costly.
GM's second approach for 1977 could have few if any of these extra-cost
hurdles to overcome, in the opinion of the report team. The lean burn
plus ox-cat approach does not use EFE, EGR or an air pump, therefore
this system can have significant cost reduction potential, In the
opinion of the report team. This system also may have HC problems
since GM's lean burn technology does not appear to have the HC control
capability that the best lean burn systems have (DresserTs, for
example). The GM lean burn approach, coupled with improved catalysts
and/or start catalysts has the potential to meet the 0.41 HC, 3.4 CO,
2.0 NOx levels at lower cost than current systems, in the opinion of
the report team.
Not much in the way of durability testing of advanced 1977 systems was
reported by GM, another problem area. Based on GM's status report,
the report team concludes that GM is waiting to see what happens in
the suspension hearing before they gear up to test such Improved systems
extensively, although it appears that the lean burn plus ox-cat approach
will be continued anyway because of its cost potential.
The most far-reaching problem at the 0.41 HC, 3.4 CO, 2.0 NOx level
for GM has been the inability to develop a control system that gives
the HC control needed for the rotary engine. Despite using systems
that may be considered too complicated or expensive for the conven-
tional engine, GM could not get the HC as low as necessary with a
catalyst system, and they did not want to use the thermal reactor
approach. The report team concludes that GM won't be able to certify
their catalyst-equipped rotary at 0.41 HC although thermal reactor
technology as demonstrated by Toyo Kogyo can do It. For GM to be
able to use the catalyst approach they will have to improve the basic
engine as Toyo Kogyo is doing, possibly by going stratified charge.
If the standards are 0.9 HC, GM may have a slight chance with their
rotary, although with approximately a 10 HC engine-out level, it is
going to take some doing, (a catalyst efficiency on HC of over 90
percent at 50,000 miles is implied).
7-32
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Progress and Problems - 1978 Model Year
GM has had a low level of effort at the 0,41 HC, 3.4 CO, 0.4 NQx level
for about a year now, evidenced by the fact that they ran only one NOx
catalyst car last year. GM, like other manufacturers appears to be
developing 3-way Cor 3-way plus ox-cat} systems in preference to dual
catalyst systems, with a higher NOx target than 0.4 NOx. The major
problem with the 3-way catalysts is conversion efficiency at extended
mileage.
The most promising low NOx results reported by GM were those from the
GM CVCC-type engine with EGR, 2.8 HC, 8.1 CO, 0.43 NOx, with no oxida-
tion or reduction catalyst. GM did not report any results with this
system with an oxidation catalyst. If the efficiencies of the GM
tests with a catalyst, but without EGR, are used report team estimates
that the GM CVCC-type engine with an oxidation catalyst and EGR would
have low mileage levels of 0.59 HC, 1,62 CO, 0.43 NOx, quite an accomplish-
ment for a 4,000 Ib. vehicle with no catalytic control of NOx.
GM also appears to have made progress in another area related to emissions,
but not specifically mentioned by GM as emission control technology. This
is in the area of vehicle weight. Past GM development vehicles targeted
toward 1977 and 1978 standards have ranged over the current GM inertia
weight range, with most of the test vehicles being in the 5,000 and 5,500
Ib. inertia weight classes. However, this year's status report showed
most of the larger vehicles being tested at 4,000 and 4,500 Ib. inertia
weight, indicating to the report team that GMrs full size cars may be
significantly lighter in, the 1977-1978 time frame. This lighter weight
is in the direction of improving both emission control capability and
fuel economy. The report team hopes that the inference of lighter
weight full-size GM cars in the future that we drew from their status
report is correct.
7-33
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7.2 Independent Developers
The automotive industry has historically relied on a vast number of
suppliers for all kinds of components from fasteners to frames, vee-
belts to valve springs and wheels to windshields. While most
manufacturers build their own engines, many of the components used
in and on the engines are purchased from suppliers. These engine
related components can include; pistons, piston rings, bearings,
bolts, valves, spark plugs, carburetors, etc. When emission
control devices became necessary the industry often looked to their
suppliers not only for the actual production of the hardware but
the design expertise as well. The best example of an emission
control device that has been designed and developed outside the
industry is the catalytic converter. Some domestic manufacturers
have developed considerable capability in this area but the suppliers
generally have more capability in the catalyst area than the
automakers themselves.
Much of the emission control hardware developed by suppliers has
been reported on by the automakers in their annual status reports
but several suppliers have done a sufficient amount of work
independent of any auto manufacturer to warrant separate coverage
in this section of the report. The four most significant non-
auto manufacturer developers in the past year have been:
1. Gould, Inc.
2. Dresser Industries
3. Yamaha
4. Questor Automotive Products.
The position the suppliers take on the feasibility of meeting the
statutory emission standards for 1977 and 1978 is somewhat different
than the position taken by most automobile manufacturers, especially
the domestic manufacturers. The suppliers have a vested interest
in the maintenance of the standards as they hope to sell the technology
and hardware necessary to achieve compliance. The automakers, on
the other hand, cannot "sell" the low emission characteristics of
their cars to the average new car buyer. To an automaker the standards
represent a cost that has little benefit, in our opinion. The emission
control development approach taken by the suppliers has generally
been more aggressive than that taken by the automakers.
7.2.1 Gould
Gould, Inc., a multi-divisional organization with head-
quarters in Chicago, has been involved in the development of metallic
NOx catalysts for several years. Gould's interest in catalyst
development was precipitated by materials requests made of
7-34
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Gould's "Clevite" bearing division by Ford and Chrysler. The auto
industry was familiar with Gould as an OEM supplier of components.
Other Gould products include; copper foil (for circuit boards), dry
cell batteries, small electric motors, torpedoes, powdered metal
products, rubber suspension components, air filters and oil filters.
The metallic reduction catalysts developed by Gould were discussed
at great length during the 1976 Suspension Hearings. The Gould
catalysts are designated as "GEM!1 (Gould Emission Material) followed
by a number (e.g., GEM 45, GEM 67, GEM 68) to designate specific
versions of the catalyst. Gould's catalyst, a monel based metallic
catalyst deposited on a metallic wire mesh, demonstrated very high
efficiency on several test vehicles (most built by Gould) but the
durability aspects were questionable. Several automobile manu-
facturers reported catastrophic catalyst failures at low mileage.
Even the best data, accumulated by Gould, showed rapidly decreasing
efficiency beginning at around 20,000 miles. It was the report
team's judgement at that time ('76 Hearings) that the lack of
sophisticated fuel metering systems and air metering systems on the
prototype vehicles was responsible for much of the poor durability
performance.
Gould has also theorized that the durability problems were due
to poor metering and they felt the amount of catalyst deterioration
was proportional to the frequency of lean excursions (too much
air entering the engine per unit of fuel).
Since the time of the 1976 Hearings, Gould has continued to invest
in NOx catalyst development. Recent efforts have been devoted
to finding a way to solve the poor metering induced problems
without actually improving fuel metering. Instead of relying on
outside sources to develop a fuel metering system that would keep
oxygen spikes (as occur on lean excursions) from reaching the NOx
catalyst, Gould has developed a triple bed catalyst system to solve
the problem. In front of the usual two beds (NOx catalyst and
oxidation catalyst) is a small oxidation catalyst that functions
as an oxygen remover. With this system installed lean excursions
no longer affect the NOx catalyst because the 0- remover, or
"Getter", eliminates the oxygen before it reaches the NOx catalyst.
A schematic of the Gould Getter system is shown in Figure 7.2.1.1.
During the federal emission test, 4 percent oxygen spikes which
normally occur on shifts and decelerations are almost completely
eliminated by the first bed of the new three bed system. This
performance was demonstrated to a member of the report team in
Gould's Cleveland laboratory.
7-35
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GOULD GETTER SYSTEM
• DISTRIBUTOR
- 1970 HI-PERFORMANCE
- 10° RETARD FOR INITIAL 45 SEC.
OF COLD START OPERATION
CARBURETOR
SLIGHTLY RICH (~I.5%CO)
9O-I20 SEC. ELECTRIC CHOKE WITH
1800 RPM (N)COLD START IDLE
SPEED
EXHAUST GAS
RECIRCULATION
« HC/CO OXIDATION
CATALYST
(PTX H-B)
• NOX REDUCTION
CATALYST
(GEM 68)
OXYGEN REMOVAL CATALYST
(I/2PTXJI-B)
AIR PUMP
\
12V SOLENOID
FOR PORT AIR
CONTROL
AIR INJECTION SCHEME
COLD START
I2O SECOND PORT INJECTION
2-3% RESIDUAL 02 AT CATALYST
HOT START
45 SECOND PORT INJECTION
CONTINUOUS SECONDARY
INJECTION TO OXIDATION CATALYST
-------
Getter System Durability
Extended durability testing of the new Getter system has been run on
four vehicles and one engine dynamometer setup. The engine dyno
test did not really test the capability of the getter to protect
the GEM catalyst from oxygen spikes as transient operation was not
included. The test did show, however, that when the latest Gould
catalyst, GEM 68, is not subjected to oxygen spikes it can retain
high, stable efficiency for 50,000 miles worth of exhaust gas.
Table 7.2.1.1 contains a summary of the dyno test.
Table 7.2.1.1
Steady State Conversion Efficiency
"50,000 Mile" Engine Dyno Test
GEM 68 with 02 Getter
"Mileage" Percent NOx Conversion (NET)
0 79.0
20,000 72.6
30,000 79.8
40,000 78.8
50,000 77.7
At the conclusion of the test Gould reported the substrate of the
catalyst had lost some ductility but no crumbling was evident*
Whether or not physical integrity would have been maintained had
the catalyst been subject to the vibration and shocks occurring
in an "over the road" test was not, however, determined by this 't
particular test. Gould also reported the microstructure of the
catalyst indicated 'some surface generation but not to the extent
leading to an exfoliation failure.
One vehicle test had reached 50,000 miles. The results are shown
in Table 7.2.1.2.
Table 7.2.1.2 i
50,000 Vehicle Durability
Datsun 610 with GEM 68, getter, PTX OXCAT
Mileage HC CO NOx
0 (1 test) .43 3.5 .47
5,000 (4 tests) .52 3.7 .44
15,000 (4 tests) .51 2.6 .37
25,000 (9 tests) .72 2.1 .40
35,000 (3 tests) .70 4.6 .41
42,000 (2 tests) .93 6.5 .70
50,000 (2 tests) .79 4.5 .95
7-37
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NOx values remained low until the testing at 42,000 miles. Inspection
of the catalyst revealed the rear support plate for the catalyst had
broken and allowed the rolled coil of metal mesh to telescope
rearward. The catalyst was pushed back together and a new backplate
was installed but activity remained low. Gould theorized that the
poor efficiency resulted from a non-uniform exhaust gas flow
distribution through the catalyst bed as the result of high
localized exhaust gas velocities eroding the catalyst surface
when it was in the "telescoped" condition after the backplate
failure. The backplate failure that caused this condition is
readily solvable, in the opinion of the report team.
Three larger vehicles have reached 25,000 miles of durability and
their high mileage results are shown in Table 7.2.1.3.
Table 7.2.1.3
25,000 Durability Results
Gould Getter System Test Cars
75 FTP 1975
Vehicle HC CO NOx MPG Counterpart
4500 In. 351 CID with .47 2.5 J33 12.3 11
EGR (3 test avg.)
4500 In. Chevrolet 350 CID .42 3.4 .38 13.7 '13
with EGR ( 4 test avg.)
4500 In. Chevrolet 350 CID .76 4.7 .27 12.9 13
with EGR (2 test avg.)
These are impressive results in light of the fact that no advanced
HC control techniques were employed and EGR systems were simple
non-proportional units. Fuel economy was essentially equal to
the 1975 versions of the same cars despite the sub - .4 NOx per-
formance. NOx conversion efficiency of the GEM catalysts has been
relatively stable on all three cars"since low mileage testing.
Other Testing Programs
Gould is involved in a program with the state of New York involving
the in-service testing of three Staten Island Police cars equipped
with their system. These vehicles are still at low mileage and will
be periodically tested by the N.Y. City lab as they accumulate
mileage.
7-38
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Gould has dealt with many automobile manufacturers including; GM,
Ford, Chrysler, AMC, Mercedes, Toyota, Toyo Kogyo and Nissan. At
the writing of this report the level of effort on Gould's system
by each of these manufacturers is low, and has been low since
EPA's public announcement that 0.4 NOx might be unnecessary.
Gould's in-house durability programs have always shown substantially
better performance than any programs involving an automobile
manufacturer. Testing at the automakers has often resulted in
catastrophic catalyst failures due to total ignition failures.and
some unexplained events. In the summer of 1974, for example, Gould
delivered a vehicle to Chrysler for testing which had met the
1976 levels at Gould's laboratory in Cleveland. Table 7.2.1.4
is a listing of the events which occurred with the vehicle
(car #178):
1. Car delivered to Chrysler by Gould.
2. Chrysler experiences misfire en route to proving
ground for emission testing.
3. Chrysler mechanic experiences total ignition failure
at speed while looking for problems with car.
4. Catalysts returned to Gould for checking. X-Ray
analysis and steady state efficiency tests are okay.
5. Chrysler re-installs catalyst on test car, runs out
of gas on emission test due to fuel weight system foul up.
6. Chrysler takes car to proving ground. Experiences two
ignition failures and runs out of gas in first 12 hours of testing.
7. Car is sent back to Chrysler engineering, runs out of gas
again on emission test.
8. Damaged catalysts are returned to Gould.
Gould has consistently demonstrated superior capability at optimizing
for low emissions with vehicles using their NOx catalyst despite the
fact that their experience with automotive systems optimization is
minimal compared to that of the auto industry.
EPA has been involved in confirmatory emission tests and particulate
emission tests of Gould vehicles over the past year. Preliminary
particulate test results indicate there is some nickel emissions
from high mileage catalysts but the type of nickel compound emitted
and the emission rate has not been firmly determined and more work is
underway. There is some evidence that the Gould vehicles have a large
(40-50%) fraction of methane in their HC emissions. This might be
expected from the steam reforming that could occur across the NOx
catalyst bed. If further tests validate preliminary data, it would ;
mean that the total HC emissions from Gould vehicles are less
harmful than from 'oxidation catalysts only' vehicles. If this is
7-39
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the case a non-methane HC standard would be particularly beneficial
for vehicles using the Gould system.
Progress and Problem Areas
In the last 12 months, Gould, Inc. has made more progress toward
the demonstration of 0.4 NOx than all domestic car manufacturers
combined, in the opinion of the report team. Besides demonstrating
superior NOx catalyst efficiency Gould has shown the potential for
achieving low NOx levels and good fuel economy simultaneously.
Gould's major problem is lack of industry support in the system
optimization area where Gould lacks expertise. Advanced control
hardware such as proportional EGR, EFE, etc. has not generally been
used during manufacturers tests of Gould's catalyst and such hard-
ware has not been made available to Gould for their own testing.
Particulate emissions from the NOx catalyst are a potential problem
that needs further quantification.
Indications are that if sub-1.0 NOx levels are not required, at
least in California, by the 1978 and 1979 model year, Gould will
go out of the catalyst business.
7-40
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7.2.2 Dresser
Dresser Industries, like Gould, 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 development of a sonic carburetor known as the
"Dresserator". Dresser felt the potential for the carburetion 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 to achieve fine fuel atomization over a wide
range of operating conditions by maintaining a choked flow condition
in the carburetor throat and metering fuel upstream of the throat
so that is must pass through 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 variability problems with coventional carburetors. The wall
wetting that occurs with conventional carburetors is less of a problem
for the Dresserator. With the quality of mixture supplied by the
Dresserator the theoretical benefits of lean (18-19:1 A/F) operation
can be achieved in practice.
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 where the ratio of manifold
to ambient pressure is less than .528. The Dresser carburetor, how-
ever, maintains sonic conditions over most of the engines 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 7.2.2.1
is a schematic of the Dresserator geometry. Movement of a slider
between two fixed jaws accomplishes the throat area changes necessary
as the engines 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 7.2.2.2 is a prototype Dresserator completely
assembled.
Emission Performance
Dresser equipped vehicles tested by EPA and others have demonstrated
that the level of "untreated" emissions necessary to achieve the 1977
Federal Standards (.41, 3.4, 2.0) with a catalytic aftertreatment
system can be achieved with excellent fuel economy. In order to
7-41
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achieve the 1977 levels the pre-catalyst emission levels need
to be: *•'.-
HC = .41 * (1-.6) = 1.03
CO = 3.4 T (1-.7) = 11.33
NOx - 2.0 T (1-0) = 2.0
Levels lower than these have been demonstrated by Dresser on several
vehicles. The report team knows of no instances where Dresser has
been unable to achieve these levels when high volume exhaust man-
ifolds are used to promote the thermal oxidation of HC and CO in
the exhaust. Even without catalysts Dresser test vehicles have
approached or equaled the 1977 standards when some spark retard
is used to reduce HC. The use of catalysts will, in the opinion
of the report team, allow Dresser equipped vehicles to simultaneously
achieve fuel economy that is superior to the economy achieved by
typical vehicles in any previous model years, including uncontrolled.
Typical non-catalyst emission levels for Dresser equipped vehicles
are shown in Table 7.2.2.1.
Auto Manufacturer's Cooperation
Cooperative studies have been carried out with Ford, GM, and
Chrysler with Ford showing the most interest. Ford and Holley
Carburetor have signed licensing agreements so far. No
manufacturer is showing a level of effort that is indicative
of a commitment to mass produce the system.
Progress and Problem Areas
Dresser's progress in the last year has been in the area of design
refinement. Major emphasis has been placed on making the Dresserator
mass producable. No significant progress in the emissions or fuel
economy area appears to have been made in the last year but none
was really necessary to stay well ahead of the capability of other
induction systems. No significant efforts appear to have been made
to adapt the Dresser to non-lean burn approaches such as 3-way
or dual catalyst systems but Dresser, like most auto manufacturers,
sees little need for low NOx systems in light of EPA's position
on the need for stringent NOx control.
A problem has been that the demonstration of a Dresserator in
combination with other advanced emission control systems has not
been pursued by any manufacturer. A "Dresser with catalyst"
demonstration would take all of one week to accomplish but has not yet
been reported.
7-42
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Dresser's main problem appears to be the result of the radically
different design of their Dresserator. The report team saw no
evidence that the Dresserator is not at least as mass producible
as the conventional carburetor but the significant changes in
production facilities that are probably necessary to build the
Dresserator must be a square pill for the industry to swallow. If
the industry accepts the production facility renovation necessary
to build Dresserators, the report team estimates the 1977 statutory
standards can be achieved with better fuel economy than has ever
previously been achieved in production and at lower system costs
than for 1975 cars.
7-43
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Vehicle
Ford 351 CID
w/Dresser carb
and large exhaust
manifold.
Chevrolet 350 CID
w/Dresser carb and
std. manifolds
Chevrolet 350 CID
w/Dresser carb
and std. manifolds
Capri 2600 cc
w/Dresser carb
and large exhaust
manifolds
Table 7.2.1
Dresser Test Results
No Catalysts
Inertia
Weight
4500
4500
4000
'75 FTP Emissions
HC CO NOx
Typical
Uncontrolled
Car of
Same
FTP Weight,
MPG MPG
.41 4.7 1.30 11.3
.88 4.7 1.70 12.9
1.18 6.0 1.16 13.4
12.2
12.2
13.2
3000
.37 3.9 1.29 17.0
16.1
Levels needed to
certify at .41,
3.4, 2.0 with
catalysts
1.03 11.3
1.5
7-44
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Incoming Air
Figure 7.2.2.1
Fuel/Air Mixture
to Engine
Figure 7.2.2.2
7-45
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7.2.3 Yamaha
Predominantly known as a manufacturer of motorcyclesf Yamaha
has also been a builder of passenger car engines for Toyota. In
the past year Yamaha has independently developed a system of subtle
modifications designed to reduce emissions without adversely
affecting fuel economy.
The Yamaha Lean Combustion Engine System consists of carburetor,
intake manifold and cylinder head modifications designed to
facilitate low emissions with air/fuel ratios in the 17-18:1 range.
None of these modifications were considered radical by the report
team. Exhaust manifolds are air gap insulated to promote oxidation
reactions in the post-cylinder phase. EGR is also used.
In August of 1974 two Yamaha vehicles were shipped to the EPA
Ann Arbor Laboratory for evaluation. Test results are summarized
in Table 7.2.3.1.
Table 7.2.3.1
Yamaha Lean Combustion Engine System
No Catalysts
75 FTP
Inertia grams/mile
Vehicle Weight HC CO NQx City MPG Highway MPG
Corolla 2250 .36 3.80 1.18 16.0 28.7
Celica 2500 .34 2.95 2.95 14.5 23.6
Celica 4000 .46 6.87 2.32 14.7 19.4
Emission performance of these vehicles was exceptionally good but
fuel economy was lower than the stock (1974) versions of
the two cars. The stock 1974 Corolla had city economy of 19.7 mpg
in California configuration and 23.6 mpg in the 49-state configuration.
Much of the poor fuel economy performance was due to the fact that
Yamaha attempted to achieve the 1977 standards without catalytic •
aftertreatment and had to resort to spark retard to control
emissions. At that stage of development the system did not have
the capability to meet the 1977 levels with high fuel economy.
Since the EPA testing, Yamaha has continued to develop their
system and the latest data, shown in table 7.2.3.2; indicate
significant progress is being made.
7-46
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Table 7.2.3.2
Yamaha Lean Combustion Engine System
No Catalysts
75 FTP
grams/mile
Vehicle Weight HC CO NOx City MPG Highway MPG
Corolla 2250 .28 2.87 1.87 22.3 34.1
Even without catalysts the Yamaha system demonstrated the 1977
levels can be achieved with good fuel economy using modifications
that represent relatively minor changes to currently produced
hardware. The report team estimates this system can be mass
produced by 1977.
The Yamaha system is catalyst compatible and further fuel economy
optimization should be possible if a portion of the emission control
burden is shifted to a catalyst. The non-catalyst emission
performance of the system is so low that little or no noble metal
would be required to stay well below the 1977 standards even
with much larger cars.
While the report team does not consider the Yamaha developments to
be as significant as the Dresser system, the Yamaha system is a
low risk, low cost, approach with few lead time problems that appears
capable of achieving the 1977 standards on small cars without
catalysts and on larger cars with minimal catalytic treatment. The
Yamaha accomplishments are especially significant in light of
Yamaha's automotive background, and the short period of time they
have been investigating the system.
7-47
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7.2.4 Questor
Questor is another multi-divisional company with experience in
supplying componentry (exhaust systems) to the auto industry.
The emission control system being developed by Questor Inc., called the
"Reverter" System, is basically a rich thermal reactor, followed
by a metallic NOx catalyst, followed by another thermal reactor.
No oxidation catalyst is used, and the system is lead tolerant.
A schematic of the system appears in Figure 7.2.4.1.
Two years ago, the Reverter system was evaluated by the report
team as having at least as much, if not more, potential to
attaining the .41 HC, 3.4 CO, 0.4 NOx level as any system that
the automobile manufacturers were developing, but that the
manufacturers were apparently not interested in the system since
it was not compatible with their 1975 oxidation catalyst systems.
Two years ago Questor was actively working on improvements to
the Reverter system. One of the drawbacks to some of the early
generation Questor systems was their relatively poor fuel economy,
which resulted from the rich operation required to keep the
reactors and the catalyst hot enough to work efficiently. Typical
idle CO values for these early prototypes were 7 to 9 percent, with
a resulting fuel economy penalty of up to 20 percent compared
to current vehicles. Questor has worked to improve the fuel
economy of the system by using a third generation packaging con-
figuration that reduces the heat loss, and by running leaner. In
order to keep the NOx levels down, Questor worked with metal
suppliers to develop improved NOx catalysts that are more active.
Questor estimated that with the latest systems the .41 HC, 3.4 CO,
0.4 NOx levels could be met with no fuel economy penalty over
1974 vehicles.
rr ~' •'
The nost promising Results £• date ha't* b««n achieved on the 1800 cc
Datsun vehicle shown in Table 7.2.4.1.
Table 7.2.4.1
Questor Reverter System
2750 IW Datsun Vehicle
City
Configuration HC CO NOx MPG
Stock 1973 Vehicle 1.05 8.96 1.80 18.6
Questor System w/Inconel 601
NOx catalyst . .13 2.6 .37 17.6
Questor System w/601 and RA330
catalyst .15 2.5 .31 17.9
Questor System w/IN 1013
catalyst .13 2.6 .21 20.1
1978 Standards .41 3.4 .40
7-48
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Exhaust Valve
Exhaust Port
Limited Oxidation Zone
Piston
Air Injection
Air Injection
— Reduction Zone
Metallic Nox
Catalyst
Final Oxidation Zone
Figure 7.2.4.1
Questor Reverter System
7^49
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Temperature related durability problems have been noted with the
Questor system but inadequate effort was spent on solution prior
to a significant reduction in program scope that occurred after
EPA's public position on 0.4 NOx was aired in 1973. Air injection
management has also been identified as a major problem that is not
being pursued. As Questor stated in their latest submission to
EPA:
"Due to the uncertainty and the imminent possibility
of a relaxation of the 1978 emission standards,
particularly for the control of NOx, the intensity
of our efforts has diminished. We have not under-
taken the costly durability programs which we
Initially planned.
This program has been very expensive and financially
burdensome for us. I am sure you can appreciate
that we cannot continue to underwrite extensive
research activities when the commercialization
potential of our system is endangered by changes
in legislation and lack of commitment from our
potential customers."
The most significant durability attempt that was made prior to
the lowering of priority is summarized in Table 7.2.4.2.
Table 7.2.4.2
Questor Durability Test
5000 IW Pontiac, 400 CID
System Mileage HC CO
0
9,000
18,000
23,000
23,000
28,000
36,000
47,000
50,000
51,000
.09
.36
.40
.24
.17
.08
.16
.22
.29
.19
3.03
2.76
2.66
1.56
2.70
2.
3.
89
05
3.5
2.99
3.22
NOx
.37
.30
.38
.62
.46
.61
.41
.32
.28
.27
Comments
Oxidation of NOx catalyst
noted, new catalysts in-
stalled.
First test with new catalysts,
not ye€" broken in.
7-50
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Cooperative Programs
Questor has been Involved in cooperative testing programs with
each of the four domestic manufacturers. Some programs are still
continuing but on at a low level of effort.
A 3500 IW Pinto vehicle has recently been built for Ford and
low mileage tests showed .14 HC, 2.7 CO, .26 NOx with 15.4 mpg.
A vehicle has been recently built for Chrysler that achieved
low mileage results shown in Table 7.2.4.3.
Table 7.2.4.3
Questor Dodge 360 CID
HC CO NOx MPG
4500 inertia .39 3.14 .34 10.1
4500 inertia .20 2.18 .38 11.0
5000 inertia .31 2.84 .32 9.4
5000 inertia .15 • 1.94 .33 9.7
Houston Chemical, a division of PPG, is testing another 3500 IW
Pinto vehicle with a Questor system. Low mileage results have
been below the 1978 standards.
Progress and Problems
Questor has made significant progress since the demonstration
of the first generation systems several years ago. Fuel economy
has been significantly improved without affecting the emission
performance of the system.
Questor's major problem is that the support needed to further
optimize the system is unavailable to them. Often cooperative
programs with auto manufacturers are stalled when Questor is
unable to prove to a manufacturer that their system can meet
the 1978 levels on durability. Cars are often returned to Questor
for relatively simple problems which any competent manufacturer
should be able to quickly solve by himself. No manufacturer
has stepped in and developed the improved fuel metering and air
modulation systems needed to further optimize the emissions and
economy of the Questor system. The report team estimates the
Questor system is mass producible and certifiable at the 1978
statutory levels by model year 1978. Some fuel economy loss relative
to 1975 would, however, be anticipated since the improved control
approaches needed to further optimize the system may not be
available by 1978 even if aggressive development toward such a goal is
begun now. Further studies of unregulated emissions from the
Questor system need to be carried out if it ever becomes a
contender in the future.
7-51
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7.3 Foreign Manufacturers
7.3.1 Alfa Romeo (Alfa)
7.3.1.1 Systems to be used
Systems to be Used - 1976 Model Year
Alfa is working on the development of emission control systems for
two different engine types. The first type is the current DOHC in-
line four-cylinder engine currently used in Alfas sold in the US. The
second type is a horizontally opposed four-cylinder engine of the type
used in the Alfasud vehicle, not now imported into the U.S. These
two engines are abbreviated "in-line" and "flat", respectively,
in this report.
For model year 1976 Alfa plans to use basically the same control
technology for the in-line engine as is used for model year 1975.
For the Federal interim standards of 1.5 HC, 15.0 CO, 3.1 NOx the
system consists of Alfa's mechanical fuel injection plus inlet air
temperature control and air injection. For the California require-
ments of 0.9 HC, 9.0 CO, 2.0 NOx an oxidation catalyst is added.
The converter housing is a flat pancake type, and the catalyst
used is a pelleted one supplied by SNAM Progetti. The active material
is platinum, and the loading is approximately .07 troy ounces per
vehicle. Additional modifications include a new exhaust manifold
and slightly different valve timing. 'Alfa has also experimented with
insulated exhaust manifolds but does not now plan to use them
for model year 1976. The catalyst by-pass system previously under
development has been dropped and a converter overtemperature warning
light is now used instead.
The work on the flat engine, originally scheduled for 1977, has
been expanded to include a 1300 cc carbureted version. This package
might be used for model year 1976, in the opinion of the report
team. For the 1.5 HC, 15.0 CO, 3.1 NOx requirements apparently
engine modifications and air injection will be used. For the
California requirements a monolithic oxidation catalyst supplied
by Degussa, with Pt and Ru as active materials will be added. The
loading has not been finalized.
Systems to be Used - 1977 Model Year
To meet the 0.41 HC, 3.4 CO, 2.0 NOx requirements Alfa plans to
use an improved version of, the 1975 California package for the in-
line engine. The basic modifications include changes to:the inlet
7-52
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system and catalyst changes to obtain higher oxidation efficiency at
high mileage. The inlet system changes involve dropping the current
4 throttle (one for each cylinder) setup and replacing it with a
single throttle. The basic reason for this, according to Alfa, is
that it permits the injected fuel to be vaporized better since the
pressure that the fuel sees should be lower for a longer time with
the single throttle setup. Alfa thinks that engine out HC may be
reduced by 30 to 40 percent with this approach. The drawback to this
approach is that the distribution of the valve-overlap induced internal
EGR (favored by Alfa) becomes poorer. Alfa is contemplating less
valve overlap or adoption of the variable valve timing originally
scheduled for model year 1978. The catalyst changes planned for
1977 are the use of a larger volume catalyst (2.0vs. 1.4 litres)
and possibly some increase in noble metal loading. *
The control system for flat engine for 1977 has not been determined
yet. The first choice system is engine modifications, Bosch
L-Jetronic fuel injection with feedback control and an 3-way •.
catalyst. Backup systems are the system with air injection and
carburetors instead of fuel injection (no feedback) and the
system with the fuel injection but no feedback, and air injection.
All systems may use an improved oxidation catalyst now under testing.
Although called an oxidation catalyst by Alfa the low mileage results
from the L-Jetronic/feedback system indicate that the catalyst is per-
forming as a 3-way catalyst, at least at low mileage with NOx results
below 0.4 being common.
Systems to be Used - 1978 Model Year
For the 0.41 HC, 3.4 CO, 0.4 NOx levels, Alfa is investigating four
approaches for the in-line engine: a) increased internal EGR
obtained by use of variable valve timing, b) some combination of
external and internal EGR, c) a dual catalyst system, and d) a
3-way catalyst system.
Alfa is one of the few manufacturers to have considered variable valve
timing seriously. This concept is not a new one. Many such approaches
have been proposed in the past, but Alfa seems to be far along in
the development of such a device. In most engines, the valve timing
is chosen as a compromise between low speed - low load operation and
high speed - high load operation. Valve overlaps that give good
high speed power, for example, generally result in poor idle quality,
misfiring and poor driveability at low speeds and loads. The idea
of having the valve overlap vary in such a manner to provide the
overlap (and hence good idle quality and driveability) at low speeds
and loads and increase as speed and load increases is an attractive
one from both the specific power output of the engine and NOx
7-53
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emissions. Most NOx is made under loaded conditions, where the
increased overlap should provide for more NOx control. Alfa submitted
no CVS data on vehicles equipped with variable valve timing, but tests
with the conventional system with increased overlap gave NOx emission
levels below 1 gram per mile. (0.54 to 0.60 with 50 of overlap).
For 1978 for the flat engine, Alfa plans to use a 3-way catalyst
system as its first choice. Backup systems are similar to the 1977
backup systems but with the addition of EGR. The catalyst is a 90/10
Pt/Ru Degussa OM 722/14M on a Corning substrate in a Gillet can. The
total loading has not yet been decided. The EGR system is of the
external type, something which Alfa has avoided in the past since
they feel that internal EGR (via valve overlap) is preferable. The
system is in the early stages of development. Alfa also mentioned
the possibility of using timed air injection i.e., air injection
only on the exhaust stroke of each cylinder. No data was reported
on this potentially promising system. Low mileage results with the
3-way catalyst system on the flat engine have been below the 1978
levels at Bosch but not at Alfa, leading Alfa to feel that the
results are not attractive enough to begin durability testing.
The following table shows the fuel economy results on the 1975 FTP
reported by Alfa for various systems targeted toward various emission
standards. In the table N.R. means not reported by Alfa and N.A.
means not applicable.
Table AL-1
Systems and Fuel Economy
Engine Type
Emission Standard
Target
System
In-Line
Flat
In-Line
Flat
In-Line
Flat
Flat
Flat
In-Line
Flat
1
1
.5
.5
0.9
0
.
.
.
,
.
.
.9
41
41
41
41
41
41
HC,
HC,
HC,
HC,
HC,
HC,
HC,
HC,
HC,
HC,
15
15
9.
9.
3.
3.
3.
3.
3.
3.
•
•
0
0
4
4
4
4
4
4
0 CO,
0 CO,
CO,
CO,
CO,
CO,
CO,
CO,
CO,
CO,
2
2
2
2
2
2
0
0
3.
3.
.0
.0
.0
.0
.0
.0
.4
.4
1 NOx
1 NOx
NOx
NOx
NOx
NOx
NOx
NOx
NOx
NOx
Air Injection
AI + OX CAT
AI + OX CAT
AI + OX CAT
3-Way
F.I. + AI
F.I. + AI + OX
N.R.
3-Way
(AI)
CAT
Inertia Weight Fuel Economy
3000
3000
2250
3000
2250
2250
2250
3000
2250
19.4
N.A.
18.7
22
N.R.
23.3
21
18.8
N.R.
23
7-54
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The main observation one can draw from Table AL-1 is that the fuel
economy depends on the system used. The most complete data are for
the flat engine, which show no trend with decreasing emissions but a
trend with different systems at the same emission level (see the 0.41 HC,
3.4 CO, 2.0 NOx case). The flat engined vehicle apparently has the
capability to get between 21 to 23 mpg if the correct emission control
system is used for the level considered. For the purposes of com-
parison, Alfa reported that the European version of the Alfasud with
emissions much higher than the levels considered in Table AL-1
(3.05 HC, 3S.84 00, 2.23 NOx) delivers 20.4 mpg.
7.3.1.2 Durability Testing Programs
Durability Testing Programs - 1976 Model Year
Alfa is just finishing the 50,000 mile durability testing for 1975
model year certification. Alfa indicated that they are just starting
1975 certification for the 1975 California standards. Therefore, as
stated in last year's report, Alfa is behind most manufacturers in
their development/certification cycle.
Alfa reported development durability results on three vehicles.
Two tests were stopped because the vehicles wore out (they had too many
miles on them) and the third test was with a now obsolete catalyst.
The most successful test 0.73 HC, 3.9 CO, 1.97 NOx at 47,000 miles
indicates that Alfa may have the capability to meet the 1975/76
California requirements. This test was run with Snam catalyst
BP-N2. Alfa stated that there was a newer catalyst BP-N3 with better
light-off characteristics, but no durability results were reported
with this catalyst.
As was mentioned in last year's-report Alfa seems to be using
certification durability testing as the final development test
of their systems for the in-line engine.
Although Alfa apparently plans to market their flat engine in the
1300 cc carbureted, air injection, oxidation catalyst form for
1976 only the report team estimates that much of the development
work reported is serving two purposes: Model Year 1976 development and
back up for 1977 and 1978 model year systems.
The durability results reported by Alfa seem to be directed toward
determing whether 9 inches of catalyst (three, 4 inch diameter by
3 inches long pieces) with no catalyst change or 6 inches of catalyst
(2 pieces) with a catalyst change will be certified. Alfa's planned
mileage accumulation schedule has been cut back due to a reduction of
overtime, elimination of the night shift, and introduction of lower
speed limits in Italy. While most of the tests were of a develop-
mental nature, i.e., catalysts not the same as those currently
planned, and different engine calibrations were used, the report
team estimates that Alfa's changes for meeting the 0.9 HC, 9.0 CO, 2.0 NOx
level are good.
7-55
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Durability Testing Programs - 1977 Model Year
Alfa reported no AMA durability results obtained with systems for
the in-line engine specifically targeted for the 0.41 HC, 3.4 CO,
2.0 NOx standards. In the opinion of the report team, Alfa will
use the durability results from the official 1975 certification
process for California as development information for this
level of control.
For the flat engine Alfa did not report any durability results with
the first choice (3-way catalyst) system. Alfa feels that it is
certain that the oxygen sensors will be available for 1977 production
from Bosch, so the only durability results to date have been
run with the L-Jetronic fuel injection and oxidation catalyst. The
single test reported ran to 14,000 miles with 0.88 HC, 7.01 CO,
1.09 NOx. Alfa stated that some unexpected enrichment occurred
during this test, which may account for the high HC and CO levels.
In addition it was not reported whether or not the vehicle had
air injection or not. If no air injection was used the HC and
CO levels would also be expected to be high, in the opinion of the
report team.
Durability Testing Programs - 1978 Model Year
Alfa did not report any durability data on systems targeted toward
the 0.41 HC, 3.4 CO, 0.4 NOx standards with either the in-line
engine or the flat engine.
7.3.1.3 Progress and Problem Areas
Progress and Problems - 1976 Model Year
Alfa has made progress in the last year in the areas of system
selection and control technology development. Alfa appears to be in
good shape for the 75/76 levels of control, especially if their
1975 California certification durability is successful. Alfa s
major problem at these levels is that they are somewhat behind most
manufacturers in the development/certification process, but if
Alfa does not mind certifying late, this is not a serious problem.
Progress and Efforts - 1977 Model Year
Alfa has progressed since last year enough to have a reasonable
idea of what system will be required to meet the 0.41 HC, 3.4 CO,
2.0 NOx standards with the in-line engine. Although the
modifications planned to the 1975 California package to meet these
standards appear reasonable, durability testing is the final proof,
and not much has been done in this area.
7-56
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Progress has been made in the flat engine development in the area
of identifying possible backup systems to the first choice system.
Durability testing with flat engine systems targeted toward these
levels is less than adequate, in the opinion of the report team.
Progress and Efforts - 1978 Model Year
Not much was reported for the in-line engine at the 0.41 HC, 3.4 CO,
0.4 NOx level. In the opinion of the report team, Alfa's major
problem at this level with this engine is the reliance on the
variable \valve timing system to get the low NOx necessary to
certify at this level. Other approaches, for example, dual
catalyst or 3-way catalyst were almost just mentioned in passing
as being approaches that could be used. This reliance on the
variable valve timing and the lack of durability data are the
major problems for Alfa with the in-line engine at this level.
Alfa has made more progress with the flat engine at this level. Their
3-way catalyst system has shown some promise at low mileage.
However durability testing on this system is far from being adequate.
One problem common to Alfa's entire emission control program is
apparently a cut back in the level of effort. Alfa stated that
the reduction of overtime and the elimination of the night shift
had slowed their progress in the critical durability testing
area with all systems.
7-57
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7.3.2 BMW
7.3.2.1 Systems to be Used
Systems to be Used - 1976 and 1977 Model Year
The BMW system for 1976 and 1977 will be similar to that of 1975. The
system includes a rich thermal reactor, AIR, and EGR. Four cylinder
engines are carbureted and six cylinder engines have Bosch "L-Jetronic"
electronic fuel injection. The EGR system is "two stage" and provides
increased EGR during accelerations.
With respect to fuel economy BMW states, "For 1976 and 1977 models a
light improvement (up to 10%) can be expected. The omission of the
EGR system and spark retard should be possible in the case of a highly
sophisticated thermo reactor system". The change in sales-weighted
fuel economy from 1974 to 1975 was a minus 14.9% for BMW due to the
use of rich thermal reactors. No increase in maintenance cost is
expected. The 1977 levels have frequently been met by BMW experimental
vehicles and one BMW vehicle* achieved the 1977 levels in 1975 certifica-
tion. The remaining 1975 certification vehicles were very near the
1977 levels.
The 1977 second choice system includes the addition of oxidation catalysts
to the current system should the thermal reactor prove to be undesirable.
Systems to be Used - 1978 Model Year
For 1978 two systems are under consideration by BMW. One is a dual catalyst
system, and the other is a 3-way catalyst system with oxygen sensor feed-
back control to the AIR system.
Other Systems
Improved EGR is planned for 1977 or 1978 introduction. Presumably
this will be one of the well known proportional EGR systems. Also a
stratified charge engine was briefly mentioned. No data was reported
for the stratified charge engine.
7.3.2.2 Durability Testing Programs
BMW reported durability test results for 14 vehicles with emission levels
targeted at or below the .41 HC, 3.4 CO, 2.0 NOx level. BMW was generally
unsuccessful at meeting these intended levels with the principal problem
being high CO emissions. It is noteworthy that a 2002 model was below
the .41 HC, 3.4 CO, 2.0 NOx level in the official EPA certification
testing for 1975.
* The durability car was above the 1977 levels
7-58
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7.3.2.3 Progress and Problem Areas
Progress and Problems - 1976/1977 Model Year
BMW has made substantial progress with their thermal reactor program.
The durability of BMW's thermal reactor is apparently adequate to satisfy
BMW. The report team considers BMW's choice of a thermal reactor emission
control system to be a reflection of BMW's design philosophy. BMW
places much emphasis on the performance and driveability aspects of
their vehicles. In the opinion of the report team a thermal reactor
design such as used by BMW is probably easier to optimize for performance
and driveability, compared to other types of systems that could be
used. BMW's system choice is not without drawbacks, however. The
design and calibration of BMW's system is such that BMW has suffered
a fuel economy penalty for 1975, a year in which many manufacturers
achieved gains. Although BMW may have the potential to improve fuel
economy somewhat for 1976 via recalibration, the report team considers
it unlikely that fuel economy for BMW can be improved greatly over the
1975 values for 1977 due to the system that BMW has chosen to use.
Other problems for BMW at the 1977 levels are marginal CO performance
on thermal reactor-equipped vehicles, and continuing misery with the
durability performance of development vehicles equipped with catalysts.
Progress and Problems - 1978 Model Year
BMW has made progress in system identification and low mileage development
at the 0.41 HC, 3.4 CO, 0.4 NOx levels. The basic systems seem to be
3-way as the first choice and dual catalyst as a backup system. Problems
for BMW at this level include catalyst durability with both systems,
an apparent lack of testing of the more advanced NOx catalysts with
dual catalyst system, and a less than adequate durability program, in
the opinion of the report team.
BMW also is developing a prechamber stratified charge engine, but from
the reported state of development of this engine, the report team con-
siders it an unlikely candidate for model year 1978 production due to
inadequate lead time. Part to this lead time is due to the apparent
desire by BMW to develop their "own" engine. While this may be
attractive from the patent and/or royalty point of view, the report
team considers it likely that BMW may be redoing much development
work already done by Honda in the development of the CVCC engine.
7-59
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7.3.3 British Leyland (BL)
7.3.3.1 Systems to be Used
Systems to be Used - 1976 Model Year
The basic approaches contemplated by BL toward meeting the 1976 standards
are very much the same as the approaches used for 1975. Two general
types of improvements were mentioned by BL as possibilities for 1976:
improved and/or larger catalysts, and fuel injection for some models.
Most of BL's effort is going into the improved catalyst area for 1976.
They hope to be able to avoid the catalyst change at 25,000 miles which
most of their 1975 catalyst-equipped vehicles require. Improvements
in HC efficiency at high mileage might allow this to occur, and BL is
testing catalysts with improved HC efficiency, although the CO efficiency
of the particular catalyst BL is testing (a Johnson-Matthey type 12 C)
may have been degraded somewhat.
BL is also developing thermal reactors for many of their engines, and
feels that the thermal reactor under development by Jaguar could meet
the California requirements of 0.9 HC, 9.0 CO, 2.0 NOx.
In general model year 1976 will see refinements of already existing BL
catalyst systems. No information was reported on any changes to the
1975 non-catalyst systems by BL, so the report team assumes that they
will remain the same.
Systems to be Used - 1977 Model Year
For the 1977 requirements of 0.41 HC, 3.4 CO, 2.0 Nox, BL is relying
heavily on the improved catalyst development now underway for the
1976 model year, although BL feels that the improved catalyst alone
will not be enough to allow them to certify to the required levels.
Other developments were reported that might be used at this level.
The first, a 3-way catalyst system on a V-12 Jaguar gave 0.5 HC,
4.0 CO, 1.8 NOx at zero miles, the only test reported. BL stated
that based on this test they do not consider it feasible to meet the
1977 standards, a statement that the report team considers to be somewhat
premature in nature, since it is based on one single test at zero miles.
The second system was a Triumph 4 cylinder engined vehicle with EGR
and an oxidation catalyst and, presumably, fuel injection. No air
injection was used and the results reported by BL were 0.26 HC, 4.6 CO,
8.0 NOx at zero miles. Obviously, this system needs more development
if the NOx figure is correct.
The third system is a thermal reactor development, done by GKN for
Rover-Triumph. Low mileage results are, typically, 0.2 HC, 3.3 CO,
1.13 NOx.
7-60
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Another development reported was the attempt at investigating a quick-
heat system for the V-8 Rover, and a parameter test of air injection
and catalyst efficiency on the same engine. Improvements in system
warm-up were shown, but no improvement in lean limit operation was observed.
No CVS tests were reported, with the quick warm-up system. The para-
meter tests of different air injection configurations and different
catalysts were used as a system development tool. The results of the
air injection optimization were apparently not tested with a catalyst
system on the 1975 FTP, however.
Another development mentioned in passing by 8L was an exhaust manifold
with integral catalysts. The warm-up performance of such a config-
uration should be attractive, in the opinion of the report team, if
the durability performance is found to be adequate. No data were reported
for this system.
Systems to be Used - 1978 Model Year
The basic BL approach for the 0.41 HC, 3.4 CO, 0.4 NOx levels is a
dual catalyst system. Use of a 3-way approach is also contemplated,
especially since BL stated "most catalyst companies have virtually
stopped work on straight reduction catalysts".
Low mileage results have been below the 0.41 HC, 3.4 CO, 0.4 NOx
levels with dual catalyst systems.
Tests with a Rover equipped with a Bosch L^-Jetronic system and a
reduction catalyst used a 3-way catalyst with no feedback gave 0.15
HC, 3.04 CO, 0.22 NOx at low mileage.
• r *'
Other systems included by BL in the 1978 systems discussion appear to
be systems that might be used in the 1978 time frame, not necessarily
0.4 NOx systems.
BL reported continuing tests with the Shell Vapipe system, basically
a air/fuel vaporizing and preheating device that uses a heat pipe for
heat transfer. Steady state operation was said to be good, but the
only CVS test reported was 6.77 HC, 12.71 CO, 4.39 NOx, not especially
impressive. The heat pipe system takes a long time to warm up,
according to BL.
The stratified charge engine development continues at BL. One design,
a modified Diesel engine is of the 3-valve type. Initial results were
not so encouraging, which is.not surprising to the report team, con-
sidering that the basic engine structure was developed for a Diesel,
not a gasoline, engine. New configurations are now, or have been,
under development by BL in both the 3-valve carbureted version and
in a 2-valve, injection version, but no data on any stratified charge
engine was reported by BL.
7-61
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BL's position on fuel economy is that emission-controlled engines have
suffered and will suffer great losses in fuel economy to meet standards,
quoting data on steady state cruises to show the difference between
U.S. and European versions of some vehicles. However, BL also mentioned
that on the basis of the LA-4, the 1975 versions of the Jaguars got
better fuel economy than the 1974's even though the standards are lower
in 1975. This indicates to the report team that the system choice
is important for BL as it is for other manufacturers when fuel economy
is being discussed. BL feels that the 10 to 20 percent gain shown by
the Jaguar models (1975 compared to 1974) will be lost in future years.
7.3.3.2 Durability Testing Programs
Durability Testing Programs - 1976 and 1977 Model Years
BL's durability testing appears to the report team to be a combined
catalyst screening/development/durability test program for both the
1976 and 1977 model years. Some durability progress has been made
since last year but apparently only a few vehicles have been run with
the latest J-M 12C catalyst with improved HC efficiency.
Many of the durability vehicles for which data were reported by BL were
exactly the same ones as were reported in BL1s status report one year
ago with no more miles accumulated.
Some of the more interesting durability data were reported on the
Jaguar thermal reactor program. The continued development and testing
of thermal reactor systems on Jaguars and other BL vehicles leads the
report team to conclude that BL would drop catalysts if they were given
emission standards that thermal reactors could meet. Such standards
would apparently be 0.9 HC, 9.0 CO, 2.0 NOx.
Durability Testing Programs - 1978 Model Year
At first blush, BL's reported durability testing on model year 1978
vehicles seems impressive, with data reported on 8 systems with over
69,000 total accumulated miles. On closer inspection, however, the
report team found that the data reported for 7 of the 8 vehicles was
identical to that reported one year ago. In the last year BL has
run only one vehicle targeted toward 0.4 NOx a total of 4836 miles.
The report team concludes that BL, like most manufacturers, has abandoned
development and testing of systems targeted to meet the 0.41 HC, 3.4 CO,
0.4 NOx standards.
7-62
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7.3.3.3 Progress and Problem Areas
Progress and Problems - 1976/1977 Model Year
BL has made significant progress in the last year, primarily in
the evaluation of improved catalysts developed by Johnson-Matthey.
BL may be improving to the point where they can go 50,000 miles without
a catalyst change in 1976, thereby putting them in a position com-
parable to the position the domestic manufacturers were in prior
to the start of 1975 certification (summer 1974).
Problems for BL with respect to meeting the 1977 standards include
less than adequate capability to keep the HC and CO levels below 0.41
and 3.4 at high mileage and the relatively low development and testing
reported for systems employing advanced engine modifications (like
Rover's EFE system) in conjunction with the latest oxidation catalysts.
Progress and Problems 1978 Model Year
BL's major problems at this level are all related to lack of effort at
the 0.41 HC, 3.4 CO, 0.4 NOx levels. Durability testing of 0.4
NOx dual catalyst systems is virtually nonexistent, the latest NOx
catalyst systems like Gould's with the getter system were not mentioned,
and the level of effort in the 3-way area appears to be very low.
Part of BL's problems may be due to the currently poor financial picture
of many manufacturers, including BL, although this was not specifically
stated by BL. When things get tight, advanced R & D programs are
many times the first to go, and in the opinion of the report team
this may be occuring at BL.
7-63
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7.3.4 Daimler-Benz (Mercedes)
7.3.4.1 Systems to be Used
Systems to be Used - 1976 Model Year
The Daimler-Benz system for 1976 will include AIR, EGR, and oxidation
catalysts on their six cylinder,, eight cylinder, and four cylinder
California gasoline engines. The four cylinder 49-state gasoline
engine includes AIR, EGR, and a lean thermal reactor. The eight
cylinder also uses Bosch "K Jetronic" mechanical fuel injection.
Previous V-8's had used Bosch electronic injection. All oxidation
catalysts are mounted in the exhaust manifold. The Engelhard II B
catalysts contain .09, .15, and .18 troy ounces of platinum and
palladium in a 2:1 ratio in the 4, 6, and 8 cylinder models respectively.
EGR sophistication also changes for these respective engines from
vacuum controlled EGR to venturi vacuum amplified EGR to two stage
vacuum controlled EGR.
The 1976 D-B Diesel model will be identical to those sold in 1975.
The only controls are classified as engine modification and include
the reverse flow damping valves (RFDV) to eliminate secondary fuel
injection for simultaneous HC emissions and fuel economy improvement.
Initial cost increase estimates for the various D-B control systems
over the comparable 1975 European models are shown in table DB-1.
Maintenance costs are not expected to increase for 1976 except for
the cost of catalyst replacement which will be about $400 for the
four cylinder including parts and labor. High catalyst cost ($320)
is blamed on the small number of catalysts used by Daimler-Benz.
Fuel economy of all 1976 gasoline models is expected to be better
than in 1975 as shown in table DB-2.
Systems to be Used - 1977 Model Year
D-B systems to meet the 1977 standard of .41 HC, 3.4 CO, and 2.0 NOx
will be modifications of the 1976 catalyst systems. The four cylinder
gasoline engine will receive a new exhaust manifold and a catalyst
of the same size as previously used on the six cylinder. The six
cylinder will receive the "K-Jetronic" fuel injection system.and transistor
ignition. Catalyst loadings are not finalized and catalysts will be
supplied by Engelhard and/or Degussa. EGR and AIR systems will be
identical to those on 1976 models for all gasoline engines.
7-64
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Diesel engines will be identical to those of 1976 except that the pneumatic
governor of the four cylinder will be replaced by a mechanical governor
similar to that of the five cylinder. Also both will get altitude
compensation.
Initial cost estimates are again in table DB-1. Maintenance costs
are not expected to increase over 1975 except for catalyst replacement
costs which will be approximately $460 ($380 parts and $80 labor) for
the four cylinder. 'D-B expects losses in fuel economy only for the
four cylinder gasoline models of 12% over the 1975 49 states model.
This penalty does not appear likely to the report team as the 1975
California version of the four cylinder*certified well below the 1977
standard (.09 HC, 2.35 CO, 1.42 NOx) at only a 6% fuel economy penalty
over the 1975 49 states version. A total of five 1975 D-B certification
vehicles from four of five families (2 gasoline*and 2 Diesel) certified
below the 1977 level.
Systems to be Used - 1978 Model Year
Two systems are still under consideration by D-B to meet the 0.41 HC,
3.4 CO, 0.4 NOx standard. The first choice is a dual catalyst system
with AIR switching, and the second choice is a 3-way catalyst
system with an oxygen sensor. Reduction catalysts will replace oxidation
catalysts in the exhaust manifolds of the first choice system. The
oxidation catalyst will follow and probably be near the engine although
other locations are still being considered (near firewall, under floor).
The second choice system catalyst would be located similarly to the
oxidation catalyst in the dual catalyst system. EGR and possibly AIR
may be eliminated with the 3-way approach according to D-B.
Diesel models will not be certified at the 1978 levels as they cannot
reach the 0.4 NOx,according to D-B.
Initial cost increase estimates are shown in table DB-1. Maintenance
costs again will not increase except for catalyst replacement costs which
will be about $750 for the six cylinder model (assumed to be first
choice system). Fuel economy changes of -8 to +7 percent as in
table DB-2 are expected by D-B. Both systems have demonstrated the 1978
level on experimental vehicles at low mileage.
Other Systems
D-B has experimented with turbochargers on gasoline engines. They
report reductions in all three pollutant with improved fuel economy at
comparable power; however no marketing intention was disclosed. Also
a stratified charge engine was briefly discussed. No operational details
were disclosed, and development appears to be in early stages as no
CVS tests have been run.
* The durability car was above the 1977 levels
7-65
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A pressure wave supercharger for the Diesel called the "Comprex" system
manufactured by BBC was also discussed. Essentially, intake air is
compressed by a pressure wave created by exposing the intake air in a
tube to high pressure exhaust gas on one end of the tube. At the
proper time with respect to the pressure wave, the other end of the tube
is opened to the inlet system and the compressed air charge is released.
Then the tube is purged of exhaust gas by ambient air and the cycle
is repeated. Other tubes or cells are connected in a squirrel cage
arrangement and are belt driven by the crankshaft. CVS results were
not obtained with this system due to Comprex choking from back pressure
created by the CVS system. D-B did not express intentions to market
this item either. This system was of interest in that boost pressures
obtained were significantly higher than those of conventional turbo-
chargers .
7.3.4.2 Durability Testing Programs
Durability Testing Programs - 1977 Model Year
For the .41 HC, 3.4 CO, 2.0 NOx level, D-B has had consistent success
meeting the 2.0 NOx level. However, the D-B experience at complying
with the HC and CO requirements has been unsuccessful with the exception
of their Diesel models. The principle problem appears to be lack of
catalyst durability. This explains D-B's procedure of resorting to
a catalyst replacement. Durability testing data for 1974 does not
indicate a significant improvement in catalyst durability.
Durability Testing Programs - 1978 Model Year
No data were reported.
7.3.4.3 Progress and Problem Areas
Progress and Problems - 1976 Model Year
D-B has made progress in the last year or so in the area of oxidation
catalyst performance at the interim levels. The catalyst changes
expected by D-B for most models only were actually required on the 240
gasoline engine for California. Other models do not require a catalyst
change. Since the standards are the same for 1976, D-B could use carry-
over for all models, but because they are introducing K-Jetronic on the
276 cubic inch gasoline engine, they will have to certify this new
system.
7-66
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Progress and Problems - 1977 Model Year
D-B has been successful enough in their Diesel engine development that
their 1975 Diesel vehicles have already certified below the 1977 standards,
D-B intends to use carryover for 1976 and 1977 on these vehicles. D-B
is apparently not just sitting on their hands in the Diesel engine
development area, however. The D-B status report contains two areas
in which progress has been made. The first area is the development
work on boosted Diesel engines. D-B has experimented with both the
Comprex supercharger (developed by Brown-Boveri) and with exhaust gas
driven turbochargers. The Comprex development has resulted in a Diesel
engine with the same power output as a naturally-aspirated gasoline engine
of equal displacement. The report team considers this a significant
accomplishment, since the specific power output for Diesels has up until
now always been below that of gasoline engines. No CVS tests were
reported with this setup, due to CVS backpressure problems, according
to D-B. The turbocharger work has paralleled the Comprex development
and D-B has run CVS tests that show improvements in the HG, CO and
fuel economy, with no change in NOx, however, the actual results were
not reported. D-B considers the turbocharger to be superior to the
Comprex at this stage of development.
The second area in which progress has been made with Diesels is in the
development of a V-8 Diesel engine. D-B reported data that indicates
that a 276 cubic inch Diesel engine is currently under development.
Introduction of such an engine would give D-B essentially two lines
of vehicles, one gasoline, one Diesel. D-B'currently has a 2.4 litre
gasoline and Diesel vehicle, a 2.8 gasoline and 3.0 litre Diesel vehicles,
and a 4.5 litre gasoline-engined vehicle. D-B reported only four cold-
start CVS tests with the 450D all over the 1977 levels, but the report
team is confident that D-B can certify this type of vehicle at the 1977
standards with further work. The fuel economy of the 450D is about 20
miles per gallon on the 1975 FTP, compared to about 10 miles per gallon
for the gasoline-engined 450 1977 research vehicle.
Another area in which development has been continued at D-B is the
continued work on the 417 cubic inch gasoline engine. The 6.9 litre
V8 has reportedly been delayed due to the energy crisis, but D-B
apparently is considering it for introduction in 1976 or 1977. Low
mileage emissions have been below the 1977 levels, and the fuel economy
is in the 8 to 9 mpg range.
One interesting development was not discussed much by D-B. This involves
the use of a start catalyst. A vehicle with such a system was reported
to be under devleopment, and the specific emission results for that
vehicle indicated good control of HC and CO on D-B's largest engine,
the 6.9 litre V-8.
7-67
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TABLE DB-1
FIRST COST OP 76/77/78 EMISSION CONTROL SYSTEMS
^\^^ Model
Value ^*^
added ^N.
for ^v.
1975
(breakdown
see FiR. V Al)
1976
(estimate
over 1975)
1977
(estimate
over 1976)
1978
( estimate
over 1977)
total value added
Tor 1978 t>m. control
L4D
240 D
5O States
5
.
* 64*
L5D
3OO D
50 States
6
1 '
* 18'
will not meet
0.4 g/mile NOX
-
-
Lk
230 '
Cal . Fed.
J*5O
+ 316
- 83
4- 22
+ l$6l
+ 20°
+ 176
648
252
X
X
X
L
28O/C
5O States
4 O9
-
+ i4oj
+ 12j
+ 49^
8J
+ 193
+ 21?Z
+ 20b
+ 237
839
6
280 S
5O States
389
-
+ UoJ
+ 12^
+ ^
83
* 193
+ 217T
+ 208
+ 237
819
V
U50 SE/L
5O States
^22
- »i
r'l'
- 29
* 636
* 313I
+ 30°
+ 3*0
799
8
k 50 SL/C
50 States
i
^55
- 33l
+ 12o
- 83
- 29
+ 636
* 31 3«
+ 308
+ 3^3
832
O\
00
Explanation of Footnotes 1-8 please refer to Section V A 2, page 3
Cost in US $ , 1 $ = DM 2,60, cost basis July
-------
TABLE DB-2
1975 FTP FUEL ECONOMY COMPARISONS FOR DAIMLER-BENZ
1974
Model
240D
300D
230 Cal 14.2
230 Fed 14.2
280/C/S 14.2
450 SE/L 10.6
450 SL/C 10.3
1975**
Fuel
Economy
24.1
23.9
15.8
16.8
14.5
11.4
11.5
% Change
from 1974
+11%
+18%
+2%
+8%
+12%
1976*
Fuel
Economy
24
24
16
17
14
12
13
% Change
from 1974
+13%
+20%
-1%
+ 13%
+ 26%
1977*
Fuel
Economy
24
24
15
15
14
11
12
% Change
from 1974
+ 6%
+6%
-1%
+ 4%
+ 17%
1978*
Fuel
Economy
14
14
13
10
11
% Change
from 1974
-1%
-1%
-8%
-6%
+7%
* from D-B
** from certification (1974 fuel economy is corrected to 1975 test procedure)
-------
D-B's major problem for model year 1977 is maintaining high conversion
efficiency at mileage with their catalyst-equipped gasoline-engined
vehicles. To data D-B reported that they have not chosen a specific
catalyst as yet. This is D-B's major problem even though the California
2AO gasoline and six cylinder California gasoline data vehicles*certified
below the 1977 standards in 1975.
Progress and Problems - 1978 Model Year
D-B may have made progress in system testing at low mileage for the
0.41 HC, 3.4 CO, 0.4 NOx level. They, unlike most manufacturers, appear
to have tested the GEM 68 catalyst, but the D-B status report was
vague as to the existence of the oxygen getter upstream. Other D-B
systems including 3-way and other dual catalyst systems have also been
tested.
D-B's major problem at the 0.4 NOx level is lack of durability testing.
D-B has no vehicles on durability targeted toward 0.4 NOx. D-B also
claimed that all Diesels would be dropped for 1978 because 0.4 NOx cannot
be met with the Diesel, in D-B's opinion. This is D-B's official
position, but in the opinion of the report team, D-B has the capability
to achieve 0.41 HC, 3.4 CO, 0.4 NOx with a Diesel. Results lower than
the 1978 levels were reported previously by D-B, but D-B will only
continue the required development if they feel that 0.4 NOx will be
enforced, which apparently they do not.
D-B's opinions on the NOx level achieveable with a stratified charge
engine are somewhat out ,of date. They claimed that no stratified
charge engine could get 0.4 NOx because a NOx catalyst could not be
used, but the Texaco and the PROCO engine can get to 0.4 NOx with EGR
only, which is public knowledge. Also the CVCC data from Honda
showing levels below 0.4 NOx is well-known.
* The durability cars were above the 1977 levels
7-70
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7.3.5 Fiat
7.3.5.1 Systems to be Used
Systems to be Used - 1976 Model Year
The 1976 Fiat control systems are identical to their 1975 systems.
The 49-states systems include AIR, spark delay valves, decel modulation,
and ignition controlled idle fuel shut off on the 79 CID L-4; and
the previous system plus vacuum modulated EGR on the 107 CID L-4.
These are some of the most unsophisticated systems in use today and
compromise fuel economy for initial cost benefits in the opinion
of the report team. The California systems are identical to the 49-
states systems except that the use of the idle fuel shut off is
extended to prolonged decelerations (shut off after decel modulator
function is complete) and a UOP oxidation catalyst is added. The
pellet-type catalyst is loaded with .03 troy ounces of platinum.
The Fiat initial cost increase estimates were 12.5% and 17% of the
cost of the corresponding European versions for the 49-states and
California versions respectively. Catalyst replacement is scheduled
for 1975 at 25,000 miles, but replacement cost was not stated.
The 1975 Fiats are not certified as yet; however, Fiat -tests indicate
improved fuel consumption from 1974 to 1975 with more improvement
possible for 1976. Most models have increased inertia weight for
1975.
Table Fiat-1
if
/
Fiat Fuel Economy Comparisons
% Change
Model 1974 1975* From 1974
Federal 128 Sedan, 4dr. 18.2 18.8 +3
Federal Spider 1800 18.8 19.0 +1
Federal Coupe 1800 16.7 17.8 +11
Federal X 1/9 21.3 18.0 -15
* From Fiat
Systems to be Used - 1977 Model Year
The Fiat system to meet the .41 HC, 3.4 CO, 2.0 NOx standard was not
directly stated; however, it was implied that the 1976 California
system is the basic system for 1977. Fiat would like to eliminate
the use of EGR if possible. The report team believes that Fiat
7-71
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should develop more sophisticated EGR systems instead of trying to
eliminate EGR so that Fiat could more effectively optimize for fuel
economy.
Initial cost of emission control systems was estimated to be 20% of
the vehicle cost. Maintenance cost and fuel economy estimates were
not available at this control level. Although Fiat has achieved
the 1977 levels at low mileage, they have presented data which
Indicates a rather unique deviation from others in the auto industry
in that Fiat is still having problems with all three pollutants
at the 1977 levels.
Systems to be Used - 1978 Model Year
To meet the 0.41 HC, 3.4 CO, 0.4 NOx Fiat plans to use a dual catalyst
system with secondary AIR in conjunction with the basic 1976 California
system. Use of the pellet oxidation catalyst is to be continued,
and the reduction catalyst is to be a monolith.
Initial cost of these emission control systems was estimated to be
25% of the vehicle cost. Fiat has reported only a very few successes
at the 1978 level. These successful tests were reported in early 1972.
Thus it is the opinion of the report team that Fiat needs to devote
far more time to systems development and testing.
Other Systems' for the Post - 1978 Time, frame
Fiat has reported efforts, but no data in the areas of pre-chamber
stratified charge, Diesel, gas turbine, and Rankine cycle engines.
The stratified charge program is just beyond the single cylinder
stage. Five pre-chamber Diesel engine prototypes have been installed
in vehicles and parameter studies will be made. A dual shaft prototype
gas turbine has undergone stationary testing. It has dual ceramic
regenerators, variable power turbine geometry, and a clutch between
the power turbine and compressor shaft. A turbine engine component
development program is in progress. A second turbine is to be
vehicle tested later. The Rankine cycle engine project has been
deemphasized due to fuel economy considerations.
Two electric cars have been built. They are conventional Fiats with
10 KW alternating current motors. A hybrid bus using the electric
motor and gas turbine may be built in the more distant future.
7-72
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Also electronic and electro-mechanical fuel injection have been applied
to conventional gasoline engines. They are not described; however,
one electro-mechanical system was said to be controlled by a mini-
computer, and is currently in a vehicle under dyno testing. No emissions
data were submitted.
7.3.5.2 Durability Testing Programs
Durability Testing Programs - 1977 Model Year
At the .41 HC, 3.4 CO, 2.0 NOx level Fiat reported durability testing
results for 14 vehicles. None of the vehicles achieved this emission
level for a significant number of miles. Fiat is having more problems
with HC and CO than with NOx.
Durability Testing Programs - 1978 Model Year
Fiat reported one durability test for a vehicle targeted at .41 HC,
3.4 CO, 0.4 NOx. This vehicle did not meet the HC and CO limits
at any point but it did comply with the NOx limit for approximately
5000 miles. This vehicle was equipped with a variation of their
.41 HC, 3.4 CO, 2.0 NOx level installation with the addition of EGR
and a NOx catalyst.
7.3.5.3 Progress and Problem Areas
Progress and Problems - 1976 Model Year
At the time of the preparation of this report, Fiat had not yet finished
certification for model year 1975, although it appears that they will
be able to certify at the interim levels. One of Fiat's problems,
compared to most manufacturers, is that a catalyst change is required
at 25,000 miles. This indicates to the report that Fiat's capability
with catalysts lags many manufacturers. Fiat does, however, plan to
try to go 50,000 miles with no catalyst change for model year 1976,
by using a slightly larger catalyst and the experience gained in
1975 certification. Some improvements in fuel economy may be
possible for Fiat in 1976 if their design philosophy can be modified
somewhat from the current one which uses spark retard extensively.
Progress and Problems - 1977 Model Year
Fiat did not report much data on systems specifically targeted toward
0.41 HC, 3.4 CO, 2.0 NOx. The report team estimates that Fiat will
rely heavily on the experience gained during 1975 and 1976 certification
for development knowledge for model year 1977. The most significant
problem for Fiat is lack of adequate high mileage catalyst efficiency.
7-73
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Another problem for Fiat may be design emphasis. The report team
feels that Fiat is very keen on the design and use of emission control
system modulating devices. An example of this is the extensive program
reported by Fiat on the development of a catalyst bypass system. This
type of system was under development by several manufacturers, but
most have dropped it because the systems generally are complicated
and expensive and most manufacturers feel that the time response of
such systems is too slow to prevent many types of catalyst damage. In
the opinion of the report team, Fiat would be a lot better off if they
directed their efforts to the design and development of systems that
control emissions all of the time, making the necessary improvements
to the ignition and fuel metering systems that are required, rather
than designing systems that work just well enough to get by on the
test.
Progress and Problems - 1978 Model Year
Fiat has had problems just meeting the 0.41 HC, 3.4 CO, 0.4 NOx
levels even at low mileage. Other problems for Fiat are the lack of
development and testing of the most recent NOx catalyst systems.
The 1978 levels may also be difficult for Fiat to attain with the
alternate engines under development. Although Fiat claimed that
their Diesel engine was equivalent to existing divided chamber
engines, this would put it about 1.0-1.5 NOx and Fiat reported no
data on any NOx reduction program for the Diesel.
7-74
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7.3.6 Honda
7.3.6.1 Systems to be Used
Systems to be Used - 1976 Model Year
The 1976 Honda 49-State system will be the same as the 1975 49-State
system. That is a conventional 1.2 litre engine with AIR and calibration
changes added to the 1974 system. Initial cost will be about $70.00 over
1974 due to those changes. The 1976 California system was stated to be
identical to the 1975 California 1.5 litre (90.8 CID) CVCC (Compound
Vortex Controlled Combustion) stratified charge engine. At least
partial exhaust after-treatment is accomplished in the stainless steel
lined exhaust manifolds. Recalibrations may be made to improve fuel
economy. Initial cost increase will be about $160.00 over the 1974
conventional engine.
Despite successful certification of the conventional 1.2 litre (75.5 CID)
engine, it cannot be sold in California due to high CO emissions (over
9 gm/mile) of the corresponding durability vehicle which resulted in
line crossing. All emissions values in table HO-1 include deterioration.
Table HO-1
1975 Certification Comparison of the 1.5 Litre CVCC versus the 1.2
Litre Conventional Engine with AIR
CVCC Conventional Engine
Transmission Emissions Fuel Economy Emissions Fuel Economy
HC CO NOx City Highway HC CO NOx City Highway
2A .518 4.80 1.52 24 29 .663 6.77 1.85 25 31
2A .506 4.28 1.35 23 28 .557 5.23 1.96 24 29
4M .556 4.34 1.26 28 38 .812 6.67 1.40 28 40
Systems to be Used - 1977 Model Year
The 1977 Honda system will be the 1.5 litre CVCC engine developed for the
1975 statutory standards. Changes from the 1976 California CVCC include
calibration changes and a lower compression ratio. Average emissions from
a 38 vehicle sample are .23 HC, 2.24 CO, and 1.15 NOx. Average fuel
economy was 25.2 mpg over the city driving cycle. Also 33-34 mpg was
indicated by Honda over the highway driving cycle. The previous sample
vehicles all used the 4 speed, manual transmission. No increase in
initial or maintenance cost over the 1976 California CVCC is expected,
and the fuel penalty is 10% over the 1976 California CVCC according to
Honda.
7-75
-------
Systems to be Used - 1978 Model Year
In 1978 Honda plans to use a 2,0 litre CVCC with either leaner mixtures
and no EGR or EGR. EGR may be used in either the pre-chamber or in
the main chamber. Early evidence indicates that if EGR is used, it
should be introduced into the pre-chamber. No new data was presented
at the 1978 emissions level, thus that it is assumed that no further
attempts have been made to optimize fuel economy with EGR. In 1973
Honda indicated capability at this emissions level with twenty-two
tests on three vehicles which averaged .294 HC, 2.65 CO, and ,297 NOx
at 18.0 mpg and ten tests on another vehicle which averaged .325 HC,
2.976 CO, and 0.383 NOx at 19 mpg over the 1975 FTP.
7.3.6.2 Durability Testing Programs
Durability Testing Programs - 1977 Model Year
At .the .!41 HC, 3.4 CO, 2.0 NOx level, Honda has successfully completed
50,000 mile durability tests on two vehicles. These vehicles were
Civic models equipped with 90 CID CVCC engines. No significant failures
were reported and the emission levels remained below the goal.
Durability Testing Programs - 1978 Model Year
Honda did not report any testing during this past year for systems
targeted at the .41 HC, 3.4 CO, 0.4 NOx level. However, Honda
has previously demonstrated stable performance for the CVCC at this
level, and Honda has stated that no problems are foreseen in main-
taining the emission results at high mileage, with CVCC engines.
Typical DF's for CVCC vehicles are less than 1.1.
7.3.6.3 Progress and Problem Areas
Honda does not have any major problems meeting any future emission
level. The problems that exist for Honda at the 0.41 HC, 3.4 CO,
2.0 NOx level and the 0.41 HC, 3.4 CO, 0,4 NOx level are to minimize
the driveability and fuel economy penalties that have been associated
with meeting those levels with prototype vehicles.
Honda continues, therefore to work on Improvements to their lean reactor
for improved HC control which will allow more spark advance for better
fuel economy at the 0,41 HC, 3.4 CO, 2.0 NOx level, a level which they
have already been below with durability cars for 50,000 miles.
At the 0.4 NOx level, Honda continues to investigate EGR approaches.
One of the problems for Honda is that the EGR approach that gives
lowest fuel consumption penalty increases HC and CO greatly (possibly
beyond the cleanup capability of their reactor) and Honda does not
want to use catalysts.
7-76
-------
Honda's emphasis on fuel economy is heightened by their position as
fuel economy leader in the U.S. market. They were the best in 1974
and they tied for best in 1975. The report team is sure that Honda
will do all that is necessary to remain number one in fuel economy,
and that their capability to do so is excellent.
7-77
-------
7.3.7 . Isuzu Motors Ltd.
7.3.7 »1« Systems to be Used
Systems to be Used - 1976 Model Year
Isuzu is tlie maker of the Chevrolet "LUV" and a new small sedan line
for 1976 introduction. Their emission control system for the 49-states
includes AIR, ported EGR, heated intake air, and an electric assist
choke.
The EGR system will replace transmission controlled spark (TCS) as a
NOx control. The compression ratio has been increased and the wedge
combustion chamber has been replaced by a hemispherical chamber. The
1976 California model is nearly identical to the 49 state version
with an oxidation catalyst and catalyst protection system added. The
catalyst is the 160 CID pellet catalyst from AC Spark Plug. When the
catalyst temperature reaches 1350 F, secondary AIR is dumped to the
atmosphere. If the catalyst temperature reaches 1830 F an operator
warning light and buzzer are actuated.
Initial cost of all emissions related hardware on the 1976 Federal models
will be $146. The 1976 California system will cost about $219 more than
the Federal system. Precertification data indicate that fuel economy
will be improved about 7% for the Federal vehicles and 5% for the
California vehicles over 1974 models. Emissions of the California
version at low mileage were far below 1977 levels at 0.2 HC, 1.4 CO,
1.1 NOx.
Systems to be Used - 1977 Model Year
The final selection of systems for .41 HC, 3.4 CO, 2.0 NOx has not been
made. An oxidation catalyst will probably be used, and additional hard-
ware may include backpressure EGR, AIR, exhaust port liners, improved
intake and exhaust manifolds, and high energy ignition. The improved
intake manifold will provide improved distribution and possibly early
fuel evaporation (EFE). The air system may be modulated; however, the
system description was too inadequate for proper evaluation. In the
opinion of the report team, modulated AIR systems are promising components
at .41 HC, 3.4 CO levels.
Early durability vehicles appeared to be inadequate especially for HC
durability; however none of the systems had initial HC levels as low
as the .2 HC reported for the final calibration of the 1976 California
models. The report team hopes that EFE is adopted by Isuzu as further
HC and fuel economy benefits could be realized.
7-78
-------
The improved exhaust manifold was not described; however it may be related
to the renewed Isuzu interest in thermal reactors. Their thermal reactor
is called "quasi-stoichiometric" as it operates near stoichiometrlc A/F
ratios. Early results of this system were .42 HC, 6.03 CO, 1.56 NOx,
and 21.0 mpg. Supposedly this system is aimed at the 1976 California
levels of .9 HC, 9. CO, 2. NOx; however, the 1976 California system will
not include the thermal reactor. The fuel penalty of only 5% over the
1976 Federal model is respectable for a thermal reactor system in the
opinion of the report team. This system approaches the Peugeot thermal
reactor concept; however, Peugeot has demonstrated better emission
results-
The 1977 system is expected to cost $65 more than the 1976 California
catalyst vehicles. This cost increase is primarily for AIR system
modifications and high energy ignition. Fuel economy was stated to be
21.3 mpg, though no supporting data was provided.
Systems to be Used - 1978 Model Year
Two systems are being considered for use at the .41 HC, 3.4 CO,
0.4 NOx level. A dual catalyst system utilizes a monolithic reduction
catalyst and a beaded oxidation catalyst in conjunction with switching
AIR, EGR, and TCS. The reduction catalyst is used for oxidation during
warm up. The EGR system was ported, and the AIR system was not modulated;
however it is assumed that the modulated AIR and backpressure EGR systems
could be utilized. A 3-way catalyst system was described which used
EGR and closed loop electric fuel injection. The system components
were not 'further described. Decel fuel cut off has been achieved.
Reported data indicates that only the dual catalyst system at low
mileage has achieved the 1978 levels.
Initial cost of the dual catalyst system was estimated to be $197 over
the 1977 vehicle. The 3-way system was estimated to cost $774.more
than the 1977 system. Electronic fuel injection accounted for $557
of the $774. Fuel economy was stated for only one dual catalyst vehicle
test. It was 17.4 mpg at zero miles.
Other Systems
An agreement has been made with Honda for CVCC engine development. A
prototyp^fe'^Mks completed in July 1974. No data was submitted.
A 119 CID Diesel prototype with the Ricardo Comet combustion chamber
has been built. Reported early results were .59 HC, 1.45 CO, 1.53 NOx,
30 mpg at 2750 Ib. inertia weight.
7.3. .2. Durability Testing Programs
Durability Testing Programs - 1976 Model Year
Isuzu light duty trucks have accumulated 5,000 miles of official durability
testing. Approval has been granted to start durability testing of
7-79
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two other light duty automobiles. Official durability in 1975 and
catalyst durability tests at Isuzu indicate that no problems should
be encountered in either Federal or California certification.
Durability Testing Programs - 1977 and 1978 Model Years
Durability testing of early 1977 prototype systems using the 160 CID
pellet converter indicate that further system improvements are needed,
especially for HC control. No durability testing has been run at the
.41 HC, 3.4 CO, .4 NOx level. Problems with low mileage achievement
of the 1978 levels apparently have prohibited mileage accumulation.
7.3.7.3 Progress and Problem Areas
Progress and Problems - 1976 Model Year
Previous 1975 certification, low mileage data, and 1977 durability
indicate that no problems should be encountered by Isuzu in 1976
certification.
Progress and Problems - 1977 Model Year
The emission durability problem of early 1977 systems indicates that
either feedgas or catalyst improvements must be made. Catalyst im-
provements depend on the progress of related GM programs. Improvements
in feedgas levels should be realized with the use of EFE, modulated
AIR, or thermal reactors.
Progress and Problems - 1978 Model Year
Efforts at the .41 HC, 3.4 CO, .4 NOx level must be increased. Although
Isuzu did achieve these levels at low mileage in 1974 with dual catalyst
systems, those systems failed to be durable. The CVCC and 3-way catalyst
programs are progressing very slowly and should be more rapidly continued
in the opinion of the report team.
7-80
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Table IZ-1
1975 FTP Fuel Economy of Various Isuzu Models
1975 % Change 1975 % Change 1976 % Change 1976 % Change % Change % Change
1974* Federal from 1974 Calif, from 1974 Federal from 1974 Calif * from 1974 1977 from 1974 1978 from 1974
20.5 18.7 -9 21.1 +3 22 +7 21.5 +5 21.31 +4 17.42 -15
* corrected from 1974 to 1975 FTP
1 from Isuzu
2 from one dual catalyst vehicle
oo
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7.3.8 Mitsubishi
7.3.8.1 Systems to be Used
Systems to be Used - 1976 Model Year
The 1976 Mitsubishi (makers of Dodge "Colt1') system for the 49-States
will be AIR plus EGR as in 1975. The AIR system will be modulated by
manifold vacuum and air pump outlet pressure through an air control
valve. EGR is nonproportional. Mitsubishi stated that considerable
work has been done on a reed valve aspirator system to possibly replace
the AIR system in 1976. No vehicle data was presented which used the
aspirator system; however, data from other manufacturers with similar
systems indicate that aspirators are less effective than AIR systems
for emission control. The 1975 carburetor with improved heat resistance
and an automatic choke will again be used in 1976.
The 1976 California system will utilize increased EGR, modulated AIR,
and a lean thermal reactor as in 1975. EGR is again nonproportional,
and the aspirator has not been considered for use in California.
Initial cost increase to the consumer was said to be $229 for the
Federal system and $327 for the California system over 1974 models.
According to Mitsubishi, the fuel penalty of the 1976 models will be
5-7% for 49-state models and 5-9% for California models over 1974.
Maintenance costs are expected to increase by $28 and $31 for the
respective models over 1974. These are calculated for a 50,000 mile
maintenance interval.
Systems to be Used - 1977 Model Year
The Mitsubishi system for .41 HC, 3.4 CO, 2.0 NOx will include modulated
AIR, nonproportional EGR, a pelleted oxidation catalyst, altitude
compensated carburetion, and high energy ignition. A proportional EGR
system is being developed for improved fuel economy and driveability.
The report team hopes that Mitsubishi can have the proportional system
for 1977. The catalyst volume is said to be about 45 in3. Its protection
system will consist of a driver warning light which is activated by
a fuse near the catalyst. The carburetor will operate lean, have more
precise A/F metering, and have an improved automatic choke. This system
has demonstrated 1977 levels frequently at low mileage. Development
of the AIR, EGR,rich thermal reactor system for 1977 has been suspended.
Initial cost increase to the consumer is estimated to be $95-$120 over
1976 Federal systems. Fuel economy is equivalent to 1975 California
models according to Mitsubishi; however, very little actual data was
presented. Maintenance costs are to increase by $15 over 1976 models.
This increase is due to recommended tail pipe emissions testing.
Catalyst change cost at 50,000 miles will be $30-$50.
7-82
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Systems to be Used - 1978 Model Year
The 1978 Mitsubishi system will include dual catalysts, proportional
EGR, switching AIR, high energy ignition, and improved carburetion.
The noble metal NOx catalyst will be monolithic, and the oxidation
catalyst will be the pellet catalyst used in 1977. The catalyst
warning light will monitor both catalysts. The proportional EGR
system is not finalized; however, it is to be modulated by venturi
vacuum or amplified manifold vacuum. The AIR system is complicated.
During warm up, air is injected near the exhaust valves aiid allows the
NOx catalyst to be used as an oxidation catalyst. After light-off
of the oxidation catalyst, the air is switched to two locations in
the exhaust pipe. The first bleeds modulated air into the reduction
catalyst for CO/02 ratio control. The second provides modulated air
into the oxidation catalyst. The necessary air control valves are
not yet available according to Mitsubishi. The carburetor will be
similar to the altitude compensated model of 1977. Improvements over
the 1977 carburetor will include Improved A/F metering and a quicker
release choke. Intake manifold heating will be used for the first time.
Spark retard will be used only during warm up conditions. Tests of
apparently incomplete systems have yielded low mileage results as good
as .22 HC, .73 HC, .22 NOx. Development work is beginning on'an
electronic fuel injection system and an undescribed fluidic controlled
fuel system.
Initial cost of the Mitsubishi system for .41 HC, 3.4 CO, and .4 NOx
was estimated to be $77-$197 over the 1977 system. Maintenance costs
are not expected to increase over 1977. The only fuel economy data
that was presented again indicated that fuel economy will be equivalent
to the 1975 California models. Replacement cost of the oxidation
catalyst was $30-$35 as in 1977. And replacement cost of the NOx
catalyst was said to be $68-$184. All stated catalyst replacement
costs include labor charges.
Development of the triple catalyst system which yielded .20 HC, 2.85
CO, .25 NOx at low mileage has been suspended "due to its difficulty in
production feasibility". It included separate catalysts for NOx
reduction, ammonia decomposition, and HC-CO oxidation.
In the opinion of the report team, the lack of proportional EGR and
advanced fuel metering systems are unnecessarily hampering Mitsubishi
durability efforts at the 1978 levels.
7.3.8.2 Durability Testing Programs
Durability Testing Programs - 1976 Model Year
Since Mitsubishi easily achieved these emission levels in 1975 certi-
fication, no problems are expected in 1976. The 1975 Federal vehicles
were generally closer to the .9 HC, 9 CO, 2.0 NOx levels of California
than they were to the Federal levels. California vehicles frequently
had HC levels below .41 gm/mile.
7-83
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Durability Testing Programs - 1977^-1978 Model Year
The most successful of four 1974 durability vehicles at the 1977 levels
was vehicle number 203. This was a 97.5 CID Colt with a manual trans-
mission and a control system consisting of AIR, EGR, and an oxidation
catalyst. The emissions were .34 HC, 1.94 CO, 1.89 NOx at 38,000 miles
though NOx levels had exceeded the 1977 levels as early as zero miles.
The 1973 status report contained vehicle #201 which was similar to
#203 and achieved .28 HC, 2.13 CO and 1.82 NOx at 60,172 miles with
no catalyst change. Previous NOx emission levels- had usually exceeded
1977 levels. Vehicle #201 was equipped with AIR and an oxidation
catalyst. Vehicle #302 was also in the 1973 status report. It was
equipped with AIR and an oxidation catalyst. All emissions were below
the 1977 levels up to and including the 20,760 mile test point (.33 HC,
2.20 CO, 1.68 NOx at 20,760 miles). Vehicle #302 was not mentioned
in the 1974 status report.
Only one Mitsubishi vehicle has demonstrated the .4 NOx level at 5,000
miles (.40 HC, 3.53 CO, .40 NOx). Even this is impressive when it is
considered that improved AIR, EGR, and fuel metering systems are still
being developed.
7.3.8.3 Progress and Problem Areas
Progress and Problems - 1976 Model Year
The major problem for Mitsubishi in 1976 is fuel economy. A 5-9% fuel
penalty was reported over 1974 models; however, 1976 systems will remain
essentially unchanged. Proportional EGR and catalysts could have regained
much of that penalty, in the opinion of the report team.
Progress and Problems - 1977 Model Year
Mitsubishi is primarily concerned with catalyst durability in 197,7. HC
durability failures have been a problem for many pelleted catalyst users.
The report team feels that this problem can be eliminated in the case of
Mitsubishi with the use of improved cold start HC control techniques.
The switch to proportional EGR again would benefit Mitsubishi. The
decision to drop the rich thermal reactor system will prevent further
fuel economy problems.
Progress and Problems - 1978 Model Year
1978 Mitsubishi problems include poor NOx catalyst durability, poor
CO/02 ratio control into the NOx catalyst, and reduced passenger space
due to underf loor catalyst installation. CO/0,2 ratio control will be
improved with the electronic fuel injection system. Improved EGR should
reduce the burden of the NOx catalyst and help prolong its life. The
loss in passenger space should not be too significant.
7-84
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7.3.9 Nissan (Datsun)
7.3.9.1- Systems to be Used-'.
Systems to be Used - 1976 Model Year
The 1976 49-states Nissan control system is comparable to the 1975
system. It includes heat control, EGR, AIR, decel modulation, simplified
EFE, and spark control devices. The transmission controlled spark
(TCS) on manual transmission vehicles, spark delay valves (SDV) on
automatic transmission vehicles, and less than optimal EGR indicate
failure to optimize fully for fuel economy in the opinion of the report
team, even though the B-210 was one of the fuel economy leaders.
The 1976 California system is similar to the 49-states system with an
altitude compensated carburetor, an oxidation catalyst, and catalyst
overtemperature protection system added. The catalyst is an Engelhard
noble metal monolith with 0.06 troy ounces of noble metal loading in
a 2 to 1 platinum to palladium ratio. Initial cost was originally
estimated at $350 - 450 over 1973 and has not been updated. Table NI-1
indicates fuel economy changes from 1974 certification to 1975 certi-
fication. The only correction made was for conversion of 1974 fuel
economy to 1975 fuel economy due to differences in test procedures.
The tendencies of increased engine size and vehicle inertia weight
are ignored, thus exaggerating Nissan's losses and reducing their
gains in fuel economy.
Systems to be Used - 1977 Model Year
The 1977 Nissan system is similar to the 1976 California system. The
catalyst will be larger, and the distributor advance and EGR rate will
be recalibrated. Development work has started on proportional EGR
and HEI, but they may not be completed for 1977. Initial cost increases
are said to be $80 - 150 (over 1975 California) for a larger catalyst
only and $140 - 230 for the larger catalyst, HEI, and proportional EGR.
Nissan estimated an 11% fuel economy penalty from 1973 which was primarily
due to retard. The report team views this estimate as accurate if
EGR improvements are not available by 1977. A 1975 710 wagon* attained
the 1977 levels in 1975 certification.
Systems to be Used - 1978 Model Year
Nissan has four systems still under consideration for 1978. In
descending order of choice, these are a dual catalyst system, a 3-way
catalyst system, the Questor"Reverter system, and a rich-lean reactor
system. The 1978 levels have been achieved at low mileage by the first
three preferred systems.
* The durability car exceeded 1977 levels
7-85
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TABLE NI-1
1975 FTP FUEL ECONOMY COMPARISON FOR NISSAN
Model
Pickup
710
B210
610
260Z
*
**
***
****
Trans-
mission
M4
A3
M4
A3
M4
A3
M4
A3
M4
A3
1974** 1975 1975 California 1977 1978
Fuel % Change Fuel % Change Fuel % Change Fuel % Change
Economy from 1974 Economy from 1974 Economy from 1974 Economy from 1974
19.3 19.9* +3
21.3 19.6 -8
20.4 21.9 +8 19.9* -2
21.6 18.0 -17
24.5* 27.4 +12 27.3 +12
23.2 24.5 +6 23.2 0 »
21.0* 20.0 -5
20.7 20.1 -3 18.7**** +10 18.6*** -11%
16.3*
16.5
two test average
corrected from 1974 to 1975 FTP
17 test average from 8 vehicles w/mileage from 0-23,800 miles
40 test average from 10 vehicles w/mileaee from 0—25.800 miles - are .4 em/mile NOx tareet vehicles
-------
The dual catalyst system is similar to the 1977 system with the addition
of a reduction catalyst and an AIR switching control. During warm up
the air is injected in front of the reduction catalyst to use it as
an oxidation catalyst. When warm up is completed, the air is injected
after the reduction catalyst and before the oxidation catalyst. The
best estimate of fuel penalty is about 11% .
Bosch "L Jetronic" electronic fuel injection (EFI) with a feedback 02
sensor is used to control the A/F ratio with the 3-way catalyst.
A/F ratio must be held at 14.7 (+ 1%) according to Nissan. Expected
EFI capability is + 3%. EGR also assists in NOx control.
The Questor system includes AIR and two thermal reactors with a NOx
catalyst between the two thermal reactors, Secondary air is introduced
into both reactors.
The rich-lean reactor system has two induction systems. The first pro-
vides a very rich mixture to half the cylinders and the second provides
a very lean mixture to the remaining cylinders. All cylinders exhaust
into a thermal reactor. No data was presented for this system.
Other Systems Under Development
Nissan has a stratified charge engine under development similar to the
Honda CVCC in principle. It is called the NVCC engine. The following
low mileage results in table N-l have been reported*
TABLE N-l
THE NISSAN NVCC ENGINE
IW HC CO NOx F.E. CID
2500 .88-90 5.11-5.45 1.43-1.50 22.3-22.6 108
2750 .28-37 2.9 -3.5 1.15-1.20 17.2-17.6 119
Rotary and Diesel engines are also being studied at Nissan; however
neither appears likely to be introduced to the American market within
the time frame of this report. The Nissan Diesel, which is sold
in Japan, achieved .23 HC, 1.35 CO, and 1.36 NOx with 28 mpg in an
uncontrolled state in EPA tests.
Also an on-board fuel distillation system is being developed to eliminate
choke operation during cold starts. The system consists of an electrically
heated volatile fuel storage tank, additional fuel pumps and solenoids,
a coolant temperature sensor, and a modified carburetor. Early test
results show 25-30% reductions in CO without catalyst, and 70% reductions
in CO without catalysts using highly volatile fuel during warm up .
The Dresser carburetor will also be investigated by Nissan.
7-87
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7.3.9.2 Durability Testing Programs
Durability Testing Programs - 1977 Model Year
At the .41 HC, 3.4 CO, 2.0 NOx level, Nissan did not report any vehicle
durability testing progress since their previous status report.
Durability Testing Programs - 1978 Model Year
At the .41 HC, 3.4 CO, 0.4 NOx level, Nissan had conducted durability
testing on six vehicles over the past year. Four of these were equipped
with dual catalyst systems and two were equipped with three way catalyst
systems. In general both systems complied with the .41 HC, 3.4 CO,
0.4 NOx requirement at low mileage but system degradation caused
emissions to exceed this level on both systems when mileage approached
20,000. The total vehicle durability mileage accumulated on systems
of this level has dropped from 186,400 miles reported in the previous
reprot to 82,500 reported for the period covered by the current status
report.
7.3.9.3 Progress and Problems Areas
Progress and Problems - 1976. Model Year
Nissan indicated that they will attempt to make improvements in fuel
economy and driveability for 1976, using the same systems that they
used for 1975. However no data was reported that showed how they
were going to do it. Nissan also did not indicate if they were going
to try to go 50,000 miles without the catalyst maintenance that some
models required in 1975.
Progress and Problems - 1977 Model Year
Nissan stated that they had not made a great deal of progress since
last year and the report team would tend to agree. No more durability
results were reported and Nissan did not indicate that any complete
1977 systems had been tested yet. Nissan has, however, run catalyst
volume tests which give some idea of how much extra catalyst volume
would be required to make the 1975 California package get below 0.41
HC, 3.4 CO, 2.0 NOx.
Progress and Problems - 1978 Model Year
Nissan continues to evaluate several systems, including dual catalyst,
3-way catalyst and thermal reactor concepts. Tests run during the
last year have been unsatisfactory with dual catalyst systems. Nissan
reported a failure at 15,600 miles with the promising Gould GEM 68
7-88
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catalyst. However no data were reported. Nissan included copies of
letters between Nissan and Gould about the release of the data. Gould
apparently wanted some data so they could try to analyze the failure.
No data on the Questor system was reported, just the cover page of a
Questor report.
Nissan is also having problems with their 3-way systems including
A/F ratio control, shifting of the maximum 3-way efficiency A/F
value, quality control with 02 sensors, 02 sensor instability at low
temperature, and 02 sensor durability.
7-89
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7.3.10 Peugeot
7.3.10.1 Systems to be Used
Systems to be Used - 1976 Model Year
Peugeot has not stated what systems will be used on the 1976 gasoline
models thus 1975 systems will be reviewed. The 49-State gasoline
models are powered by a 120 CID inline four cylinder with AIR and a
rich thermal reactor for HC and CO control. The axial flow thermal
reactor is mounted after the exhaust manifold. The outer shell is
stainless steel and the inner shell is Inconel 600. Two single
barrel Solex carburetors provide fuel metering. Choke control is
manual, but has a coolant controlled device which deactivates the
choke should the driver fail to do so. California models are identical
except for the addition of the "Coppolair" device which is a decel
modulator.
Initial cost increases were stated to be $135 and $186 for the
respective Federal and California models over 1973 models. Recent
1975 certification results indicate no change in fuel economy for the
four speed wagon and an improvement in fuel economy of the automatic
sedan.
Peugeot will also offer the 504 Diesel models in all 50 States with a
129 CID engine. Advanced emission control systems are not needed,
but some fuel injection system modifications were made in 1975.
These include retarded injection timing, injectors with reduced lift
and increased delivery,' and the addition of non-return valves in the
fuel lines, all for improved HC control.
Systems to be Used - 1977 Model Year
Peugeot has two systems under consideration for use on 1977 gasoline
models. Both systems have achieved the 1977 levels at low mileage.
The first choice system for the 120 CID engine Includes AIR, EGR,
the "Coppolair" device, and an oxidation catalyst with an over-
temperature bypass system. A final catalyst selection has not been
made, and both monolithic and pellet type catalysts are still under
consideration. A catalyst change may be necessary at 25,000 miles.
The dual single barrel carburetors will be replaced by one single
barrel carburetor with altitude compensation. The Intake manifold
also has been revised for improved distribution. The second choice
system is identical to the first choice system except that a thermal
reactor replaces the catalyst and its related protection system. In
the opinion of the report team, Peugeot is one of the leaders in
thermal reactor technology. Their consistent achievement of the
.41 HC, 3.4 CO levels with thermal reactors Is considered an important
technological accomplishment.
7-90
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Initial cost increases over 1973 were stated to be $660 for the
first choice system and $490 for the second choice systems. Changes
in fuel economy are indicated in table PE—1.
In the opinion of the report team, durability HC problems of the first
choice system could be alleviated with more effort directed toward the
cold start portion of the FTP. Catalyst location is poor for rapid
warm up, and exhaust gas is not used for quick heating of the intake
manifold.
The 504 Diesel model may use oxidation catalysts at the .41 HC, 3.4
CO, 2.0 NOx level to reduce HC emissions. Peugeot has attained these
levels with only fuel injection revisions, but combustion noise levels,
which are of great importance at Peugeot, were considered unacceptable.
Fuel injection parameters are still being studied to find a non-
catalytic solution that is acceptable to Peugeot.
Systems to be Used - 1978 Model Year
Peugeot is considering three systems for use in 1978 on their four
cylinder gasoline models. The first choice system includes a reduction
catalyst, secondary AIR and oxidation catalyst, a catalyst protection
system, and proportional EGR. The noble metal reduction catalyst is
to be used as an oxidation catalyst during warm up because of its
proximity to the exhaust manifold (.8 meters). The AIR system will
include an exhaust temperature modulated bypass to further aid warm
up. The oxidation catalyst will be the same as the 1977 catalyst which
has not been selected. • A reduction catalyst selection has also not
been made. The second choice system is the same as the first choice
system, but includes a thermal reactor to assist in catalyst warm up
in the event that the NOx catalyst cannot be operated as an oxidation
catalyst. The third choice system includes proportional EGR, a
3-way catalyst, and catalyst protection systems. Peugeot states that
A/F ratio control within a 0.2 A/F ratio range is both necessary and
possible with oxygen sensor feedback control to a carburetor. Peugeot
"asked a specialized company to adapt on a 504 engine one of those
(air-fuel control) devices which can be piloted by the oxygen probe."
Initial cost of the first or second choice system is estimated to be
$910 over the 1973 model. The third choice system is estimated to be
$760 over 1973. Fuel consumption of the dual catalyst vehicles
averaged 18.25 mpg according to Peugeot, but 1978 emission levels
were not achieved.
7.3.10.2 Durability Testing Programs
Durability Testing Programs - Post 1976 Model Year
For gasoline engines targeted for the .41 HC, 3.4 CO, 2.0 NOx level,
Peugeot reported durability test data for eight vehicles. Five of
7-91
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Table PE-1
1975 FTP Fuel Economy of Peugeot Gasoline - Fueled Vehicles
1977 1977
Sedan
•vl
VO
N>
% Change % Change
1974* 1975 from 1974 Catalyst from 1974
A3 17.8 17.0 -4
M4 17.6 19.5 +11 17.6** 0
Thermal Reactor
18.7**
17 . 5**
% Change
from 1974
+5
-1
* corrected from 1974 to 1975 FTP
** from Peugeot
-------
these were equipped with the first choice system, i.e. AIR, EGR,
"Coppolair" and catalyst, and three with the second choice system
(thermal reactor instead of catalyst}.
The HC and CO control of the first choice system cars deteriorated
excessively and catalyst mechanical problems were also experienced.
The mechanical problems were a container failure and a mounting
failure. One vehicle has reached 50,000 miles and another vehicle
is at 31,000 miles and still running. Testing of the remaining
vehicles has stopped.
The three vehicles with second choice systems all experienced thermal
reactor failures at relatively low mileages. Peugeot described the
failures as a destruction of the inlet core. The highest mileage
achieved was 15,900. The emission performance of the system appeared
to be good. All three vehicles were under the .41 HC, 3.4 CO, 2.0
NOx level.
Peugeot did not report any durability test data for Diesel engines
at the .41 HC, 3.4 CO, 2.0 NOx level.
For gasoline engines at the .41 HC, 3.4 CO, 0.4 NOx level, Peugeot
reported test data on four vehicles. These tests were not full
system tests but were intended to evaluate the durability of only
the reduction catalysts. Peugeot noted the variation in NOx conversion
efficiency when a system was run alternately with dual catalysts and
then with the reduction catalyst only. This behavior is due to the
formation of ammonia in the reduction catalyst and subsequent conver-
sion of it to NOx in the oxidation catalyst. The observed effect is
a reduced conversion efficiency with the oxidation catalyst present.
Apparently, Peugeot did not understand this phenomenon and they
interrupted a valuable test to investigate it.
Peugeot's technique of running systems with only the reduction cata-
lyst yields misleading results because the ammonia is not converted
to NQx, over the oxidation catalyst. Thus it appears that three of the
four reported tests were of questionable use. The data from the fourth
test which used both catalysts showed insufficient control of HC, CO
and NOx.
Peugeot did not report any Diesel engine durability testing at the
.41 HC, 3.4 CO, 0.4 NOx level.
7.3.10.3 Progress and Problem Areas
Progress and Problems - 1976 Model Year
Peugeot should have no problems with their thermal reactor systems for
1976, since the standards are the same and Peugeot did not indicate
that they were going to make major changes in their gasoline engines.
Peugeot has made progress in the Diesel area for 1976.
7-93
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Progress and Problems - 1977 Model Year
More problems than progress exist for Peugeot at the 0.41 HC, 3,4 CO,
2.0 NOx level. Durability is a problem with Both catalytic converter
and thermal reactor equipped gasoline engines. Diesel development is
more favorable, but Peugeot considers the injection system modifications
that they have tried that met the 0.41 HC level too noisy. They have
experimented with a catalytic converter on the Diesel, which must be
a disappointment to them, especially since Daimler-Benz has already met
the 0.41 HC, 3.4 CO, 2.0 NOx levels in 1975 with their Diesels without
resorting to use of a catalyst.
Progress and Problems - 1978 Model Year
Peugeot is having durability problems at this level. Their effort has
been slowed somewhat by the misleading results generated on the NOx
catalyst only tests. Peugeot does not feel that the Diesel can make
0.4 NOx.
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7.3.11 Renault
7.3.11.1 Systems to be Used
Systems to be Used - 1976 Model Year
Three basic systems will be used by Renault to achieve the 1976 Federal
emission levels. The Renault 17 Gordini utilizes Bosch electronic
"L-Jetronic" fuel injection and AIR. The Renault 12, 15, and 17TL
will use AIR plus an oxidation catalyst or AIR, EGR, and an oxidation
catalyst. The AIR system is a typical manifold air injection system
with a constant 1.14 drive ratio. The EGR is a venturi vacuum modulated
system. All three systems use heated intake air, conventional bimetallic
chokes, and conventional breaker point distributors. The carbureted
versions may have altitude compensation. The fuel injected Gordini
has a higher compression ratio than the other models with the 100.5
CID engines, and it develops 24% more power. California systems will
be like the Federal systems except that the fuel injected Gordini will
not be sold in California.
The initial cost increase over comparable 1974 European models was
estimated at $300 for AIR/ox. cat. models, $375 for AIR/EGR/ox. cat.
models and $500 for the EFI/AIR models. Fuel economy of the similar
1975 models indicated that significant gains (up to 33%) in fuel
economy would be realized by Federal vehicles equipped with four speed
manual transmissions. Fuel economy of automatic transmission equipped
vehicles remained about the same as the 1974 vehicles.
Systems to be Used - 1977 Model Year
The Renault system for the .41 HC, 3.4 CO, 2.0 NOx levels ..will be AIR,
EGR, and oxidation catalysts. AIR, EGR, oxidation catalysts are similar
to those used in 1976. Electric assist chokes and electronic ignition
will be introduced in 1977. The use of EFI on the Gordini will be
continued. Carburetion may be altitude compensated, and a decel HC
control device may be installed to keep the throttle partially open
during deceleration. The EFI system controls decel HC in basically
the same fashion as inlet air is allowed to bypass the closed throttle.
The use of thermal reactors in 1977 has been ruled out due to poor
emission reductions and poor fuel economy. Also pellet catalysts
are being studied for possible use. Renault vehicles have frequently
achieved the 1977 levels at low mileage. A 1975 emission certification
data vehicle achieved .216 HC, .680 CO, 1.19 NOx at 4,000 miles without
deterioration. No emission data was provided in the Renault status
report that was completed after October of 1973.
7-95
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Initial cost of 1977 Renault systems is said to be similar to the com-
parable 1976 systems. Fuel economy and maintenance cost information
were not provided by Renault.
Systems to 'be Used - 1978 Model Year
Three approaches are being considered for use in 1978. Renault favors the
3-way catalyst approach which includes EFI with feedback through an oxygen
sensor to electronic fuel injection. AIR and EGR are not used. Carbureted and
mechanical fuel injected versions of the 3-way system are also being
studied. Another system is the dual catalyst, AIR, and EGR system. A
NOx catalyst is in or near the exhaust manifold and followed by an oxida-
tion catalyst further downstream. The AIR system switches to provide air
to the NOx catalyst during warm up and air to the oxidation catalyst during
warm operation. A more proportional EGR system may be employed. A strati-
fied charge approach is also being considered. Details of the engine were
not provided; however, only single cylinder work has been reported. With
regard to their stratified charge system Renault stated that 1) post combus-
tion devices will be needed for HC control, 2) the 3.4 CO level will be
easily attained, and 3) fuel economy is approximately equivalent to the
conventional engine. The Renault dual catalyst and 3-way catalyst systems
have both achieved the 1978 levels at low mileage. The 3-way results have
been most impressive and include .05 HC, 2.33 CO, .15 NOx and .15 HC, 1.79
CO, .16 NOx, at low mileage.
Fuel economy and cost data were not provided by Renault.
7.3J.L2 Durability Testing Programs
Durability Testing Programs - 1977-1978 Model Year
The current Renault status report does not show any vehicle durability
testing for the past two years. This appears to be a neglected area for
Renault in the opinion of the report team. Previous years test data shows
mixed results for the .41 HC, 3,4 CO, 2.0 NOx level. HC and CO control
were good but NOx control was insufficient. Preliminary 1975 model year
certification data indicates that two data vehicles* have achieved approxi-
mately .40 HC, .58 CO, 2.26 NOx and .29 HC, 1.04 CO, 1.19 NOx with deteriora-
tion. No durability data was reported by Renault for the .41 HC, 3.4 CO,
0.4 NOx level.
7.3.113 Progress and Problem Areas
Progress and Problems - 1976 Model Year
While Renault had not completed certification for model year 1975 at the
time of this report, preliminary data indicate no emission problems and fuel
economy improvements over previous years.
*
durability vehicles exceeded the 1977 levels,
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Progress and Problems - 1977 Model Year
As discussed in the systems description, preliminary 1975 model year
certification data indicates certain models* will be under the 1977
levels. This is encouraging, but Renault is still lacking proportional
EGR, modulated AIR, and early fuel evaporation (EFE) systems. Renault
also needs to expand their vehicle durability testing program.
Progress and Problems - 1978 Model Year
Along with the other potential users of the 3-way catalyst Renault must
improve oxygen sensor and 3-way catalyst durability. An early leader
in 3-way catalyst technology, Renault has, disappointingly, made little
recent progress.
The data car was above the 1977 levels.
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7.3.12 ROLLS-ROYCE (RR)
7.3.12.1 Systems to be Used
Systems to be Used - 1976 Model Year
RR's policy is to have one 50-state system to meet U.S. requirements
so in 1976 they will be making 0.9 HC, 9.0 CO, 2.0 NOx systems only.
The system is the same as the 1975 50-state system, electronic
ignition, EGR, air injection and a Johnson-Matthey/American Lava
catalyst. This package certified at 0.54 HC, 6.81 CO, 1.65 NOx for
1975. Since the fuel economy for the 1975 package was not out-
standing even for a 5500 pound IW vehicle (9.0 "city", 12.0 "highway")
RR plans to try running changes to the EGR and spark timing to up
the fuel economy for 1976. RR's fuel economy is improved in 1975
compared to 1974, however, by about 10 percent. Major changes that
would require full certification are not worth it, according to RR.
Systems to be Used - 1977 Model Year
To meet the 0.41 HC, 3.4 CO, 2.0 NOx standards, RR will employ the
following:
1. Larger Engine (444 CID vs. 412)
2. New Carburetor (SU HIF 7)
3. Proportional EGR
4. Improved Catalyst
The larger engine has reduced friction and an improved combustion
chamber, both of which tend to help the engine-out emissions, according
to RR. Operation at a lower BMEP for the same power (larger dis-
placement) helps NOx too, due to lower in-cylinder temperatures.
The new carburetor has lower friction bearings and viscosity com-
pensation. The PEGR system is a Rochester Products valve with an
Eaton transducer, which gives better fuel economy at the same NOx
level than does their current system.
The improved catalyst is the J-M type 12C, also mentioned by British
Leyland. Improved efficiency at high mileage is claimed for this
catalyst and RR's discussion would indicate that it is slightly
improved, but not enough to permit meeting 0.41 HC and 3.4 CO in
RR's opinion. This catalyst will be used in a larger size for 1977
with increased air injection rates. Lowest results to date are
0.12 HC, 2.58 CO reported by RR as zero mile results from their
1975 system. A backup system to the first choice system is also
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under development. This uses a dual exhaust system with a catalyst
in each exhaust manifold, instead of the current full flow underfloor
unit. This may permit both larger catalyst volumes and a better match
between light-off and durability.
Another control system mentioned by RR requires special mention. 'This
is a version of a distiller system developed by Mobil Oil and called
the LEF (for Low Emissions Fuel) system. The basic principle of
systems of this type is to distill a portion of the fuel of high
volatility. This fuel is stored in a separate tank and used only
to start the vehicle. Use of a volatile fuel for startup can reduce
or eliminate the choke, thereby substantially improving HC and CO
emissions during the critical period after the cold start before the
catalyst has reached light-off temperature.
RR reported tests run by Mobil of a non-catalyst Daimler-Benz 280 that
showed reductions in HC and CO of 35 and 52 percent respectively
when LEF was used for 100 seconds on the 1972 FTP.
Results reported by RR of a Daimler-Benz vehicle with an oxidation
catalyst showed slightly different results. The CO was dramatically
reduced, and the vehicle could start without a choke with excellent
driveability but HC emissions went up. Results without LEF were
0.19 HC, 1.65 CO, 2.39 NOx; with LEF 0.26 HC, 0.77 CO, 2.10 NOx
were typical results, with the lowest CO being on the test that showed
0.29 HC, 0.48 CO, 2.37 NOx. The overall test program showed HC up
20%, CO down 60%, NOx up 14%
RR results with LEF have been less promising, possibly since they
used LEF for 30 seconds only. Their non-catalyst results showed
the same trend that the Daimler-Benz results showed with a catalyst,
HC and NOx up and CO down.
RR does not feel that they need LEF to meet 0.41 HC, 3.4 CO, 2.0 NOx
so they do not plan to use it currently. However, RR feels that the
LEF system has potential for use in a) vehicles that may be marginal
on CO (as would be the case, they feel, with a CVCC engined RR
vehicle) or b) a dual catalyst system.
No fuel economy results were reported with any LEF system. There
may be a benefit from the no choke operation, but it must be
remembered that some energy has to be used to distill the volatile
fuel.
Systems to be Used - Model Year 1978
RR is considering four candidate systems for the 0.41 HC, 3.4 CO,
0.4 NOx levels. The first system uses a Solex 4 bbl carburetor,
EFE, PE6R, closed loop modulated air injection and a 3-way catalyst.
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The second system uses Bosch L-Jetronic fuel injection with feedback
control a 3-way catalyst and PEGR. The third system is a Honda .CVCC
type pre-chamber gasoline engine with PEGR and an oxidation catalyst
if necessary. The fourth system uses the current twin S.U. carburetors,
PEGR, and a dual catalyst system, with switched air injection.
The first system requires the closed loop controlled air injection
which is still under development by Solex. RR, therefore, is waiting
until Solex has some hardware that they can test.
The development of the second system received a severe setback when
Bosch told RR that an 8-cylinder L-Jetronic package was not going to be
available. This has caused RR to investigate whether or not the
K-Jetronic (which will be available in an 8-cylinder version) would
be an acceptable substitute. Current system configuration calls for
slightly rich operation of the three way catalyst with air injection
and a supplementary oxidation catalyst, thus making it a 3-way + OX cat
system. RR has just started work on this system, the first
objective being to get rid of the oxidation catalyst and air pump
if possible.
The CVCC system work has been stopped due to: 1) Inability to project
NOx levels below 1.0 gpm at 5500 pound IW, 2) Insufficient lead time
and 3) High heat rejection to the coolant from this type engine. RR,
however is continuing the testing on the Honda-sized engines and vehi-
cles in case the NOx standards are relaxed or someone else comes up with
a breakthrough.
The dual catalyst system is the only one under active development
now. NOx catalysts from Johnson-Matthey and ICI have been tried.
The best results were 0.74 HC, 3.9 CO, 0.52 NOx with an ICI catalyst.
RR, like other manufacturers, mentioned that they thought the catalyst
manufacturers had just about quit developing NOx catalysts.
According to RR, the catalyst manufacturers see no market and
think that the 0.4 NOx standards will be relaxed and are therefore
concentrating on 3-way catalyst development.
RR's position on 0.4 NOx is that they feel that it may not be .required.
They state that 1.0 gpm NOx is the lowest standard that can be
achieved with a 5500 pound vehicle and anything below 2.0 NOx will
result in a fuel economy penalty.
RR also included in their status report an internal RR report that
surveyed the field of near term engine possibilities including con-
ventional engines, stratified charge engines (PROCO, TCCS, CVCC) and
Diesel engines. The conclusions of the report were that RR should
develop the first three of the four systems now contemplated by RR
to meet 0.4 NOx. The PROCO, TCCS and Diesel engines are thought
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to be "expensive long term projects involving entirely new designs
of engine with installation problems whose only merit is improved fuel
economy".
The RR report contains RR's own estimates, based on existing data
extrapolated to RR's projected 5000 pound IW. The RR estimates show
the Diesel to be the clear fuel economy winner, but RR estimates that
the best a 5000 pound Diesel could do would be about 1.2 NOx and 15 mpg,
down from about 17 mpg at 2.0 NOx. PROCO and TCCS with EGR and oxidation
catalysts are estimated to be about 16 mph at 2.0 NOx, 14 mpg at 1.2 NOx
and 12 mpg at 0.4 NOx. No other engine types were estimated to be above
12 mpg by RR at any NOx level. Although the report team does not
necessarily agree with all of the RR estimates (being somewhat more
sanguine about the NOx potential of the Diesel, for example), the RR
summary chart is reproduced in this report as an example of one company's
careful thinking about advanced powerplants and as an illustration of
some of ithe potential differences among various engine types.
7.3.12.2 Durability Test Programs
The durability data reported by RR was sparse. Data were reported on
the 1975 certification testing which gave the certified values of
0.542 HC, 6.81 CO, 1.65 NOx with corresponding DF's of 2.44, 2.31 and
1.0 respectively. The other durability data mentioned were a 10,000
mile test with the improved J-ty 12C catalyst. RR indicated that the
catalyst efficiency was improved, but no test results were shown from
that 10,000 mile test.
7.3.12.3 Progress and Problem Areas
Progress and Problems - 1976 Model Year
Since the Emission Standards are the same, and RR does not plan to
recertify, RR does not have any major problems for 1976. The progress
that has been made by RR, reflected in their improved fuel economy and
reasonably low emissions for 1975/76, has enabled them to use much of
the effort that might be expended for 1976 certification toward 1977.
Progress and Problems - 1977 Model Year
RR seems to have made progress in system selection for 1977. The
improved oxidation catalyst under consideration by RR appears to have
the capability to be a successful 0.41 HC, 3.4 CO, 2.0 NOx system.
If the improvement shown by the 12C catalyst at zero miles is maintained
over the 50,000 mile durability test RR's chances are good. A serious
problem however, in the opinion of the report team, is that RR does not
seem to have much durability experience with their improved 1977 system.
This is the case for both the prime and backup systems. RR also reported
that they were worried about having to meet 1.5 NOx in California for
1977, since they only make 50-State vehicles.
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Progress and Problems - 1978 Model Year
RR seems to have covered the field with four possible systems for
use in 1978. These systems are much the same as those considered
promising by other manufacturers. However, development work on all
but the dual catalyst system has stopped. Supplier problems have
hurt the carbureted, modulated closed loop air injection, 3-way catalyst
system and the fuel injection with feedback, 3-way system. The CVCC
system cannot be produced in time for 1978 because development lead
time is too short. The lack of supplier support for the first two
systems is seen to be another problem for RR. Problems with the dual
catalyst system include inability to reach the 0.41 HC, 3.4 CO, 0.4 NOx
levels at low mileage, and apparently a total lack of durability testing.
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O
OJ
i
o
i
8
Area of confidence
Area of speculation
B.OOO Ib Inertia Weight Vehicles
Diesel Engine*
Stratified Charge Engines
Conventional S.I. Engines witr
E.G.R. & Oxidation Catalyst
Conventional S.I. Enginoswrth
E.G.R. & Reduction (or three way)
— Catalyst & Oxidation Catalyst
Advanced fuel metering
Advanced fuelmetenng
Closed loop fuel metering
Present fuel metering
Present fuel metering
Closed loop air injection
10
i-h
ft
O
3 hrj
§•€ •,
CD
O
tt>
0.6 .8 1.0 1.2 1.4 1.6 1.8 2.0
CVS/CH NOx Limit in Gm./Mile which system is designed to meet
Trends in Fuel Economy v ISJOx Limit for Various Engine Types
-------
7.3.13 Saab
7.3.13.1 Systems to be Used
Systems to be Used - 1976 Model Year
The 1976 Saab control systems are identical to their 1975 systems.
The 49 state system consists of Bosch K-Jetronic fuel injection
added to the basic engine. A non-proportional EGR system is added
to the package for automatic transmission vehicles. In addition to
the improved metering of the K-Jetronic, Saab has benefited from
careful attention to emission control design and a. relatively light-
weight vehicle line. This has resulted in an effective and efficient
system which Saab claims has improved performance, driveability
and fuel economy while reducing emissions.
The K-Jetronic fuel injection system is a continuously injecting
mechanical system. The rate of injection is regulated by an air
measuring valve which senses engine air flow.
The California vehicles will have proportional EGR and AIR in
addition to the K-Jetronic.
Table SA-1
Saab Fuel Economy Data - 49 State
(3000 Pound Inertia Weight)
Model Year Transmission MPG % Change from 1974
1974 Manual 17.8*
1974 Automatic 16.8*
197? Manual 20.8 +17%
1975 Automatic 17.8 +6%
1976 Manual 21.1** +193!
1976 Automatic 21.1** +26%
1977 Manual 18.5** + 4%
1977 Automatic 18.0** + 7%
1978 Manual 21.0** +18%
1978 Automatic ***
* Corrected from 1974 to 1975 FTP
** Data from Saab
*** Data not available
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The table below contains cost information reported by Saab.
Table SA-2
Saab Cost Information
MODEL YEAR
1975-76 1977 1978
Fed Gal 1st Choice Backup
Added cost to 32 81 204 176 309
manufacturer
Sticker price 47 120* 306 265 462
increase
* Omitted from Saab data. Calculated using average markup of
the other systems.
Systems to be Used - 1977 Model Year
Saab plans to use a monolithic oxidation catalyst in addition to its
1975-1976 California package to comply with .41 HC, 3.4 CO, 2.0 NOx
level. Saab previously reported that their first choice was a
pelleted catalyst due to unsatisfactory durability of monoliths.
Recent test experience has changed their opinion. Since the previous
durability problems of monolithic catalysts were experienced almost
exclusively with carbureted engines, it appears to the report team
that the adoption of'the K-Jetronic precipitated the switch to
monoliths.
Systems to be Used - 1978 Model Year
To meet the .41 HC, 3.4 CO, 0.4 NOx level Saab's first choice
system will be a 3-way catalyst with an oxygen sensor in addition
to the K-Jetronic fuel injection. Their backup system will be dual
catalysts combined with AIR and proportional EGR. Saab provided
the following test data on a 3-way system.
HC CO NOx
Fresh Catalyst 0.21 3.83 0.61
Aged 220 Hours 0.23 4.10 0.59
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Other Systems
Saab reported development progress on an on-board distillation system.
This systems allows the engine to be started and warmed up without
the use of cold start enrichment. This is accomplished
by supplying the engine with the highly volatile light ends of the
fuel for the first two minutes of operation. The system includes a
boiler/separator which extracts the light ends from the regular
fuel and then stores this light fuel in a special tank. Saab
furnished the following test data for a 1977 model year system
Saab 99:
Table SA-3
Saab On-Board Distillation Fuel System
HC CO
1977 system .25 1.79
1977 system and OBD .12 .70
Saab reported that this system was acquired through an agreement with
Mobil Oil Corporation. While the results are encouraging, Saab
reported that they do not plan to proceed further with this system
because they have confidence that their existing systems will be
sufficient to comply with the future standards.
Another promising cold start aid reported by Saab is electrical
heating of the K-Jetrbnic's fuel nozzles. Saab reported that work is
continuing with Bosch on this technique. No test data was furnished
by Saab. Another cold start technique utilizing the K-Jetronic is
acceleration - enrichment. This technique works similarly to a
carburetor's acceleration pump. Saab reports that this technique
allows the use of less overall cold enrichment. Apparently the
K-Jetronic unit is calibrated for lower baseline cold enrichment
and utilizes the acceleration - enrichment to provide enrichment
when it is most needed - during acceleration.
7.3.13.2 Durability Testing Programs
11 Durability Testing Programs - Post 1976 Model Year
At the .41 HC, 3.4 CO, 2.0 NOx level Saab reported durability testing
on six cars. Unfortunately, the reported test data contained little
high mileage emissions data. The test cars were equipped with AIR,
EGR and oxidation catalysts in addition to the K-Jetronic fuel injection.
The highest mileage reported was with one car at 32,878 miles with 0.30
HC, 1.44 CO, 1.'82 NOx. At the .41 HC, 3.4 CO, 0.4 NOx level, Saab
reported that durability testing was about to commence on one car.
This vehicle is equipped with a 3-way catalyst system including an
oxygen sensor for feedback.
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7.3.13.3 Progress and Problem Areas
Progress and Problems - 1976 Model Year
Saab will use the same systems for 1976 as they certified in 1975.
Saab's performance in 1975 was a real accomplishment, improving their
fuel economy and certifying to both the Federal and California standards
with no catalyst. Since Saab used Indolene 30 (leaded fuel) in
certification, their performance is a demonstration that the 0.9 HC,
9.0 CO, 2.0 NOx standards do not require the use of catalysts and
therefore lead-free fuel, at least for 3000 Ib. inertia weight vehicles.
Progress and Problems - 1977 Model Year
Saab has a minor problem in that they recently switched their catalyst
choice away from pellets to a monolith, so they don't have as much
experience with them as they might like, and their limited durability
results show it. Because of their impressive no-catalyst emission
levels Saab could almost get by with a hot rock as a catalyst, in the
opinion of the report team.
Saab's status report reflects their status at the 0.41 HC, 3.4 CO,
2.0 NOx level. For this year's report we asked manufacturers specifically
for information on advanced HC control techniques, since for most
manufacturers, HC is going to be the biggest problem at the 0.41 HC,
3.4 CO, 2.0 NOx level, Saab also reported working on advanced HC
control techniques such as the Mobil Oil LEF system, but even though
Saab's results showed HC and CO reductions of 52 and 46 percent,
respectively, Saab does not plan to use the device because they feel
their emissions are low enough already.
Progress and Problems - 1978 Model Year
Saab has durability problems with their 3-way system, and the limited
low mileage results reported were above the 0.41 HC, 3.4 CO, 0.4 NOx
levels. Saab favors the 3-way approach, and no data on their dual
catalyst systems was reported. Saab's reported progress with the 3-way
approach is somewhat slower than other manufacturers which surprises
the report team since Saab has always been one of the leaders in
emission control, despite their small size and low U.S. sales volume.
Saab should be a big fan of the 3-way approach, in the opinion of the
report team, because they, like the leaders in the 3-way field, have
already accepted the cost "penalty for fuel injection. Part of Saab's
less than outstanding results to date with the 3-way approach may be
that Bosch is doing a lot of the work for them, and the results may
be slow in coming from Bosch to Saab to EPA.
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7.3.14 Toyo Kogyo (Mazda)
7.3.14.1 Systems to be Used
Systems to be Used ~ 1976 Model Year
Toyo Kogyo will continue to market both rotary and reciprocating
engines in 1976, In response to the energy crisis TK has embarked
upon an extensive development effort to dramatically improve the
fuel economy of the rotary, while retaining acceptable emissions
The rich thermal reactor has been scrapped and TK will introduce
in 1976 a lean thermal reactor system called the "Lean Combustion.
System" (LCS), The LCS will include engine modifications, reactor
system improvements, secondary air system improvements, and changes
to the induction and ignition systems. TK estimates that fuel
economy will be improved by 40% compared to 1974 which would give
their 2750 pound vehicles about 15 miles per gallon on the city
test. TK plans to certify the same type system for both California
and the 49 states.
For 1976 model year reciprocating engined models, TK will use different
systems for the 77.6 cubic inch and the 96,8 cubic inch engines.
Both will use enlarged exhaust manifolds which TK refers to as
reaction manifolds. The 77.6 cubic inch engine will also be
equipped with proportional EGR and an oxidizing catalyst. The
96.8 cubic inch engine will have air injection along with the
reaction manifold.
TK reported that the 77.'6 cubic inch engined-vehicles for California
will use air injection, proportional EGR and an oxidation catalyst in
addition to the reaction exhaust manifold. Two systems are being
considered for the California 96.8 cubic inch engine. One system
is essentially the same as the smaller engine system. The alternate
system would employ a thermal reactor along with vacuum modulated
air injection. This alternate system appears to be identical to
the original 1975 system which was dropped following the establishment
of the interim standards. TK estimates that the fuel economy of the
1976 model year reciprocating engines will be equivalent to the
1974 figures.
Systems to be Used - 1977 Model Year
For their rotary engines at the .41 HC, 3,4 CO, 2.0 NOx level, TK
will augment their 1976 LCS package with the addition of proportional
EGR and high energy ignition. An alternate system for 1977 will
employ fuel infection to achieve a stratified charge. This system,
called the ROSCO (Rotary Stratified Combustion)), is based on the LCS
and will use a lean thermal reactor. This system utilizes the natural
swirl of the rotary engine in combination with a timed injection to
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create an effective charge stratification, This engine has a potential
for improved fuel economy and lower NOx, TK expressed some uncertainty
as to the introduction date of the ROSCO, as 1977 and 1978 were alternately
cited. TK estimates the fuel economy of both the LCS and ROSCO for the
1977 model year to be equivalent to 1976 rotary engines.
Three alternative systems were reported by TK for the 1977 model
year reciprocating engines. The first system is similar to the
1976 California catalyst system except for a change in the inlet
port configuration. The new arrangement will induce a swirl to
achieve improved combustion. The second alternative system will
employ a rich thermal reactor along with a modified secondary air
system which both modulates and heats the air. This system also has
proportional EGR. The third system for 1977 is a prechamber type
stratified charge engine using either an oxidizing catalyst or a
lean thermal reactor. TK did not provide fuel economy estimates for
these systems, but it was reported that their goal was equivalent
or better than 1974,
Systems to be Used - 1978 Model Year
TK reports that a new divided chamber rotary engine is under develop-
ment for the ,41 HC, 3.4 CO, 0.4 NOx level. Called the SCP (Stationary
Combustion Process), this engine utilizes lean carburetion to supply
the main (rotating) chamber and fuel injection for the separate (sta-
tionary) chamber. TK claims that this concept has a strong potential
for lower NOx, because of the charge stratification and self EGR in
the separated chamber.
Two systems were reported for 1978 model year reciprocating engines.
The first utilizes a dual catalyst along with modulated air injection
and proportional EGR. The second system would use the prechamber
stratified charge engine proposed for the 1977 model year along with
proportional EGR and an oxidation catalyst,
7.3.14.2 Durability Testing Programs
Durability Testing Programs - 1976 Model Year
Toyo Kogyo reported durability testing of nineteen 1976 model year rotary
engine cars. Fourteen of these were California systems and five were
49 State systems. Three of these cars had accumulated substantial
mileage and were safely under the compliance level. The remainder
were at low mileage (500-2000 miles), The average reported fuel
consumption for the 49 state.cars ranged from 15-17 MPG and for the
California cars ranged from 14 to 16 MPG. While the test procedure
for these fuel consumption figures was not spelled out it is assumed
to be the official urban test. If this is the case, TK has scored
a major improvement with the lean thermal reactor system.
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Durability Testing Programs - 1977 Model Year
At the .41 HC, 3.4 CO, 2.0 NOx level, TK reported durability testing
of three cars with rotary engines. Two had the augmented Lean
Combustion Systems (LCS-I1) and one was equipped with the ROSCO
system. The low mileage emission data showed compliance with the
1977 standard except for one of the LCS-II cars being above the NOx
level. The fuel economy was reported to be 16 to 17 MPG.
TK reported durability data for three cars equipped with reciprocating
engines. All three cars exceeded the 1977 standard at high mileage,
Durability Testing Programs - 1978 Model Year
At the ,41 HC, 3,4 CO, 0.4 NOx level, TK is testing three reciprocating
engine cars. Two were equipped with dual catalyst systems plus EGR.
No test data were supplied for the dual catalyst cars. The low mileage
results for the reciprocating stratified charge engined vehicle were
0.25 HC, 3.5 CO, 0.8 NOx.
TK reported only low mileage test data for two rotary engined vehicles
at the 1978 levels. The first vehicle had 0.33 HC, 1.73 CO, 0,38 NOx
with 16 mpg, and the second had 0.30 HC, 0.20 CO, 0,58 NOx and 17 mpg,
7.3.14.3 Progress and Problem Areas
Progress and Problems -• 1976 Model Year
TK has made significant progress toward the development of systems
targeted toward the 1976 interim standards. In constrast to most
other manufacturers, who are doing little or nothing extra for 1976
over 1975, TK is revamping their entire emission control development
effort. The design criteria have been changed, now fuel economy and
emissions are equally Important. Emission control was previously
the overriding design constraint. This has caused TK to embark on
perhaps the most extensive development program to improve both emis-
sions and fuel economy of any manufacturer. The lean system (LCS)
for 1976 rotary engines will have improved fuel economy over the 1974
systems, by approximately 40 percent while maintaining emission control
to the interim levels. Improvements will also be made with the recipro-
cating engine, and a smaller size engine may be introduced for 1976.
TK feels that the conventional engine with a catalyst is better than
a thermal reactor for fuel economy at the 0.9 HC level.
The report team considers TK's major problem for 1976 to be lead
time to introduce all of the improvements that are planned.
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Progress arid Problems " 1977 Model Year
For 1977 TK is showing some of the expertise in rotary engine develop-
ment that has enabled them to become the worldfs leader in rotary engines.
The technological base that enabled TK to turn the rotary engine from
a German curiosity into a viable high-volume production engine is being
turned toward meeting the 0.41 HC, 3,4 CO, 2,0 NOx levels with improved
fuel economy, TK's approach toward meeting their emission and fuel
economy goals is to improve the basic engine as much as possible. This
approach is somewhat different than GM's approach with the GM rotary
engine. GM has tried many sophisticated aftertreatment devices to
try to convert the excessive engine-out HC emissions of their engine
and has not been successful, TK's lean thermal reactor and the direct
cylinder stratified charge engine are the better technical approaches,
in the opinion of the report team.
More problems exist with the reciprocating engine than exist with the
rotary engine at the 0.41 HC, 3,4 CO, 2.0 NOx levels. TK is trying
to find a better catalyst currently for their 1977 package.
Progress and Problems - 1978 Model Year
TK has also made great progress toward meeting the 1978 standards
with the rotary engine. Their prechamber stratified charge rotary
has achieved 0.33 HC, 1.73 CO, 0.38 NOx at low mileage, equipped
with an oxidation catalyst, The fuel economy is also significantly
Improved (16 mpg) over the 1974 levels. However, this package has
not yet been durability tested.
TK is also considering a new prechamber reciprocating engine for 1978,
in addition to their dual catalyst system, although the development
is not as far along with the prechamber engine.
A problem for TK at the 0.41 HC, 3.4 CO, 0,4 NOx level may be also
common to other years' development programs, Consider the following:
completely new lean thermal reactor systems for 1976, improved lean
thermal reactors and/or a new direct cylinder fuel injected stratified
charge engine in 1977, and a new prechamber stratified charge engine
for 1978! This is just for the rotary engine, similar but somewhat
less radical changes (until 1978) were also planned for the reciprocating
engine.
The report team considers TK's planned efforts to be a .larger effort
than any other manufacturer, and a problem may be that TK's R&D,
tooling, and manufacturing capability might be strained to the limit.
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7.3.15 Toyota
7.3.15.1 Systems to be Used
Systems to be Used - 1976 Model Year
Toyota reports that their 1976 model year systems will be unchanged
from 1975 with the only exception being the addition of a catalyst or
thermal reactor to the light duty trucks for California to comply with
the tougher '76 standard there.
For the 49-State standards,Toyota will employ both catalyst and non-
catalyst systems. For their two smaller, 4 cylinder engines Toyota
will rely on engine modifications, EGR and air injection. The smallest
engine will not need EGR to meet the 3.1 gpm NOx standard when installed
in the 2500 Ib. inertia class Corolla. Their larger, six cylinder,
engine family will use AIR, EGR and an oxidation catalyst.
The California vehicles will all employ oxidation catalysts in addition
to their 49-State systems.
Systems to be Used - 1977 Model Year
For the .41 HC, 3.4 CO, 2.0 NOx level, Toyota's first choice system will
consist of engine modifications, AIR, proportional EGR, reactive exhaust
manifold and an oxidation catalyst. For a backup system, Toyota would
substitute a full-blown thermal reactor for the reactive manifold.
Fuel consumption for 1977 Toyotas is estimated to be equivalent to
1975 for the first choice system and approximately five percent less
for the second choice thermal reactor system. Toyota did not furnish
any cost data for these systems.
Systems to be Used - 1978 Model Year
At the .41 HC, 3.4 CO, 2.0 NOx level, Toyota's first choice system is
a 3-way catalyst in conjunction with Bosch L-Jetronic fuel injection
and proportional EGR. Toyota was previously pursuing a dual catalyst
system and might switch back if the 3-way does not work out. The
fuel economy of the 3-way system should be on the order of a five percent
less than achieved with 1974 systems.
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7.3.15.2 Durability Testing Program
Durability Testing Program - Post 1975 Model Year
Toyota has extensive experience with systems at and below the .41 HC,
3.4 CO, 2.0 NOx level. Toyota was originally working toward a self-
imposed goal of achieving a .41 HC, 3.4 CO, 1.5 NOx level by 1975.
For this reason they have an advantage on other manufacturers at this
time. Toyota reported 1974 durability test data for 14 vehicles
targeted to the .41 HC, 3.4 CO, 2.0 NOx level. Toyota demonstrated
consistent success in meeting this level particularly with their P-3
system which consists of engine modifications, air injection, EGR,
thermal reactor and a pelletted oxidation catalyst.
Toyota performed durability testing on 17 cars targeted for the
.41 HC, 3.4 CO, 0.4 NOx level. However, twelve of these were tested
prior to 1974 and, therefore, do not represent the latest technology.
None of the cars was able to achieve the 1978 standard level for more
than 4000 miles without catalyst replacement. Two of the five cars
tested this year had three-way catalyst systems which incorporated
the Bosch L-Jetronic fuel metering system.
7.3.15.3 Progress and Problem Areas
Progress and Problems - 1976 Model Year
Toyota plans to use 1976 as a year to improve fuel economy and
reliability and to reduce costs. Little detail was provided on how
they plan to do this.
Progress and Problems - 1977 Model Year
Toyota stated that there were problems with driveability, packaging,
maintenance (catalyst .change is contemplated), fuel economy and cost
with their 1977 catalytic emission control systems. In the opinion
of the report team, Toyota has a good idea of what will be required
to certify at 0.41 HC, 3.4 CO, 2.0 NOx since they had targeted for
more stringent standards (0.41 HC, 3.4 CO, 1.5 NOx) a long time ago
and have much experience at these levels. Much of Toyota's problems
at this level are cost related, in the opinion of the report team.
Toyota may not want to accept the additional cost inherent in their
1977 system, especially since they reported that the cost of the 1976
car (with no new systems and a cost reduction effort underway) would
increase due to inflation alone.
7-113
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No data was reported on the CVCC engine under development by Toyota
under an agreement with Honda, even though this engine was reported
to be under development for model year 1975 production for the Japanese
market. If this is true, it should be available on some models for
the U.S. market by 1977, in the opinion of the report team. Toyota
should have the capability to match what Honda has already demonstrated
can be done with this engine concept at the 0.41 HC, 3.4 CO, 2.0 NOx
level. Toyota has already achieved emissions below the required levels
with this concept.
Additionally, no data was specifically reported on the Yamaha concept
(see section 7.2.3 - Yamaha). This is somewhat surprising, since
Yamaha makes one of Toyota's engines for them and have modified it to
achieve emissions below the 0.41 HC, 3.4 CO, 2.0 NOx levels with m>
catalyst and good fuel economy, with a set of engine modifications that
appear to the report team to cost less than $50.
Progress and Problems - 1978 Model Year
Toyota has returned their dual catalyst system to the research stage
and like most manufacturers has stopped working on systems targeted
toward 0.4 NOx, in the opinion of the report team. Some 3-way work
is estimated by us to be actually targeted at a higher NOx level.
7-114
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7.3.16 Volkswagen
7.3.16.1 Systems to be Used
Systems to be Used - 1976 Model Year
Volkswagen appears to be in a state of flux at this time with
regard to 1976 systems. The 1975 systems are being reshuffled and
expanded with the result being that models will be available with
more than one system. For example, it appears that the Rabbit will
be available either carbureted as in 1975 or with the Bosch K-
Jetronic fuel injection. A logical explanation for this change
would be that the likely improvement in fuel economy resulting
from the addition of the K-Jetronic will enhance the sales appeal.
Indeed, there is some likelihood that a Rabbit, so-equipped, could
achieve that best overall fuel economy of all vehicles tested.
During 1975 model year certification, VW models* representing 51%
of the their estimated sales were certified at levels below
.41 HC, 3.4 CO, 2.0 NOx (the 1977 standard). All of these were
water-cooled engines with EGR, AIR and oxidation catalysts. The
catalysts were replaced at 30,000 miles. The cost of the catalyst
change was quoted by VW as $177.
Systems to be Used - 1977 Model Year
At the .41 HC, 3.4 CO, 2.0 NOx level, VW reports their first choice
system will be fuel injection, EGR and an oxidation catalyst. The
air-cooled engines will use L-Jetronic fuel injection and the
water-cooled engines will use K-Jetronic. L-Jetronic is an electronic,
timed injection system, whereas K-Jetronic is a mechanical, continuous
injection system. VW describes the catalyst as "improved/very hot
operating". No durability or efficiency data was provided for this
new catalyst. For water-cooled engines. VW indicated that another
first choice system would be AIR, EGR and an oxidation catalyst in
conjunction with carburetion instead of fuel injection. VW
estimated that -the first two systems would cost five percent more
than the 1975 model year systems and would yield equivalent fuel
consumption. VW estimated that the third system would be equal in
price to 1975 systems but would suffer a five percent fuel economy
penalty. The driveability of all three was predicted to be unchanged
from 1975. VW indicated that a catalyst change would be still required
for all three systems.
durability cars were above the 1977 levels.
7-115
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Systems to be Used - 1978 Model Year
For the .41 HC, 3.4 CO, 0.4 NOx level, VW reported that their first
choice system would be fuel injection, EGR and a 3-way catalyst with
oxygen sensor feedback. As with the 1977 model year systems, the
air-cooled engines will have the Bosch L-Jetronic unit and the water-
cooled engines will have the K-Jetronic unit. VW estimated that the
adoption of these systems will result in an 18% cost increase over
1975 models. VW also estimated that fuel economy would decrease by
5 to 8 percent and the driveability would be unchanged.
7.3.16.2 Durability Testing Programs
Volkswagen's current status report provided very little information
on durability testing. VW merely stated that the test fleet consisted
of 130 vehicles with 20 percent of these running AHA durability, 20
percent "experiments" vehicles and 60 percent in customer type service.
Durability and emission data were not reported and no breakdown was
made regarding the emission level design goals for the 130 test vehicles.
The 1975 model year certification results provide a measure of reassurance
that Volkswagen will be able to comply with the .41 HC, 3.4 CO, 2.0 NOx
level. Models representing 51 percent of VW1s projected sales, certified
at levels below .41 HC, 3.4 CO, 2.0 NOx. In the opinion of the report
team this resulted from VW's lack of durability testing prior to the
actual certification, which caused VW to overshoot the degree of emission
control. All of the models certifying at this low level had undergone
a catalyst replacement at 30,000 miles.,
7.3.16.3 Progress and Problem Areas
Progress and Problems - 1976 Model Year
Because VW plans to use basically the same systems for 1976 as are
used for 1975 no major problems are seen for VW at the 1976 interim
levels. Some manufacturers like VW, who relied on a catalyst change
to help them meet the standards, are going to try to recertify with
no catalyst change for 1976 as they gain confidence and experience
with the catalyst approach. However, VW apparently will continue
to rely on the customer paying the $177 for the catalyst change at
30,000 miles that their water-cooled engines now require.
Progress and Problems - 1977 Model Year
VW may go with improved catalysts and fuel injection on the 1977
package but little data was provided on the catalyst except that it
operated hotter. Since VW has already certified about half* of their
model line below the 0.41 HC, 3.4 CO, 2.0 NOx standards (with the
catalyst change) they only have to work on the other half if they
do not want to make any improvements.
the durability cars were above the 1977 levels.
7-116
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Progress and Problems - 1978 Model Year
VW apparently will use the 3-way approach to meet the 0.41 HC, 3.4 CO,
0.4 NOx requirements. Little data was provided especially on durability
testing of the 3-way package in its latest generation with VW's new
vehicles. VW, like other manufacturers apparently has not done much
testing at this level recently.
7-117
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7.3.17 Volvo
7.3.17.1 Systems to be Used
Systems to be Used - 1976 Model Year
The Volvo control system for 1976 will be essentially unchanged from
1975. The 49-State systems for manual transmission cars will consist
of breakerless ignition and AIR along with the Bosch K-Jetronic continuous
fuel injection. The 49-State automatic transmission vehicles will have
non-proportional EGR as well. The 1976 California cars will have Engel-
hard monolithic oxidation catalysts and proportional EGR in addition to
basic 49-State system.
The Bosch K-Jetronic system is a continuous injection, mechanical system
(as opposed to the L-Jetronic which is a timed injection, electronic
system). The rate of injection for the K-Jetronic is regulated by an
air valve which senses engine air flow.
The fuel consumption data in the following table was provided by Volvo.
Table VO-1
Volvo Estimated Fuel Consumption
Based on EPA 55% City 45%
Highway Driving*
% change
Model Year Transmission , MPG from 1974
1974 Fed
1974 Fed
1974 Cal
1974 Cal
1975 Fed
1975 Fed
1975 Cal
1975 Cal
1976 Fed
1976 Fed
1977
1977
1978**
1978**
1978***
1978***
M
A
M
A
M
A
M
A
M
A
M
A
M
A
M
A
20.0
21.5
21.7
22.1
20.5
19.5
20.5
20.2
20.1
19.0
20.0
18.9
18.0
17.0
20.4
19.3
__
^^
2%
-9%
. -5% >
-9%
.5%
-12%
0%
-12%
-10%
-21%
+2%
-10%
* Data from Volvo
** Dual bed catalyst and EGR
*** 3-way catalyst and EGR
7-118
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The estimated cost information shown in the following table was provided
by Volvo.
Table VO-2
Estimated Emissions System Cost
Model Year Cost
1975-1976 Federal $105
1975-1976 Calif. $290
1977 $508*
1978 $560*
* Includes $174 for catalyst replacement
Systems to be Used - 1977 Model Year
For the .41 HC, 3.4 CO, 2.0 NOx level, Volvo is planning on using breaker-
less ignition, AIR, proportional EGR and an Engelhard oxidation catalyst
in addition to the K-Jetronic fuel injection. Volvo reported that the
system will also be augmented by some combination of the following
techniques: fast off lean choke, retarded spark timing and catalyst
change. The fast off lean choke is incorporated into the K-Jetronic fuel
injection and includes an acceleration enrichment feature which helps
maintain good driveability during warm up.* The retarded spark and catalyst
change are last resort techniques due to their adverse effects upon
fuel economy and cost.
Systems to be Used - 1978 Model Year
At the .41 HC, 3.4 CO, 0.4 NOx level Volvo reports that their first
choice system will consist of breakerless ignition, proportional EGR
and a 3-way catalyst with oxygen sensor feedback to the K-Jetronic fuel
injection. Volvo, working in conjunction with Bosch and Englehard, has
made impressive progress in 3-way catalyst technology. High catalyst
conversion efficiencies are being maintained up to 1000 hours on bench
testing. Volvo's back up system for 1978 is a dual bed catalyst with .
EGR and AIR.
*
Volvo reported that the lean choke and acceleration enrichment resulted
in CO and HC emissions reductions of 60% and 35% respectively in CVS
testing.
7-119
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Other Systems
Bosch reported a 50% reduction In CO during cold start CVS testing
through the use of electrically heated fuel nozzles on the K-Jetronic.
This resulted from a further shortened choke period with the fast off
lean choke system. Unfortunately, Volvo reports that the associated
problems of vapor locking, fouling and clogging of the injectors due to
fuel cracking combined with the electrical drain C5 to 10 amp per
injector) have caused them to abandon this concept. In the opinion
of the report team the fuel cracking problem which results from ex-
cessively heating the fuel febove 200°C) could be surmounted by further
development effort. The electrical drain could be overcome by a larger
capacity battery. The potential benefits of heated fuel nozzles, in
the opinion of the report team, justify further development efforts,
if more HC and CO control is needed by Volvo in the future.
7.3.17.2 Durability Testing Program
Durability Testing Program - Post 1976 Model Year
At the .41 HC, 3.4 CO, 2.0 NOx level, Volvo reported durability test
data on 25 vehicles. Nineteen of these were their first choice f77
system, i.e. AIR, proportional EGR, oxidation catalyst, and Bosch
K-Jetronic fuel injection. The remaining six were 3-way catalyst
systems calibrated for this level. The first choice '77 system
demonstrated consistent success in maintaining this level. The 3-way
systems showed very low emissions at zero miles but deterioration of
conversion efficiency quickly resulted from drift of the "window".
The oxygen sensors were changed frequently to realign the air/fuel
ratio to the efficient conversion range. Four of the six 3-way
systems have accumulated 50,000 miles and the other two are at 30,000
miles. The best performing system used a Kali Chemie 516-59 3-way
catalyst.
Volvo did not report any vehicle data on systems calibrated for the
.41 HC, 3.4 CO, 0.4 NOx level. However, the previously described
3-way system testing is laying the groundwork for a 3-way system' for
this level. Volvo did report impressive progress on dynamometer
testing of 3-way systems at this level, with high conversion efficiencies
holding nearly constant for up to 800 hours. This would be equivalent
to 24,000 miles at an average speed of 30 mph. This system employed
an Engelhard advanced generation 3-way catalyst.
7.3.17.3 Progress and Problem Areas
Progress and Problems - 1976 Model ^Year
Volvo will probably have no problems In meeting the 1976 requirements
if they keep their systems the same as may be the case. Some work is
underway to try to eliminate the air pump for 1976, and if this is
successful, a cost savings is possible.
7-120
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Progress and Problems - 1977 Model Year
Volvo has made more progress in durability testing of 1977-type systems
than any other manufacturer. Volvo has had systems running on high-
speed durability and taxi service, in addition to AMA mileage accumula-
tion » The durability experience has been generally favorable with
both the '77 oxidation catalyst system and the 3-way systems targeted
for 1.5 to 2.0 NOx. The report team concludes that Volvo has demonstrated
the capability to run 50,000 miles below the 0.41 HC, 3»4 CO, 2.0 NOx
levels consistently.
A problem mentioned by Volvo was the inability to get improved catalysts
and substrates from the suppliers. This could be a problem since Volvo
wants to use a better catalyst to avoid spark retard. Whether or not
spark retard for HC control is going to be necessary or not depends
on the success of Volvo's lean choke and cold-start acceleration enrich-
ment development programs both of which look very promising. Volvo
has tested other advanced systems such as a partial thermal reactor
and electrically heated fuel injectors, but they prefer not to use those
approaches.
Progress and Problems - 1978 Model Year
Volvo has progressed during the last year to become the leader in 3-way
catalyst technology, the 3-way approach being Volvo's only real system
at the 0.41 HC, 3.4 CO, 0.4 NOx level. The experience with the 3-way
systems targeted toward -2.0 NOx (no EGR was used) show the capability
to achieve 0.41 HC, 3.4 CO, and approximately 1.0 NOx with no EGR.
Volvo says that EGR will cut the NOx about 50% but the fuel economy
and driveability advantages of the 3-way approach are lost. If the
NOx standard were 1.5 or 2.0 NOx Volvo would still go 3-way, because
they really like the approach.
The 02 sensor now has durability satisfactory to Volvo (more than
12,000 miles), and several promising 3-way catalysts have been tested.
Volvo's catalyst aging tests showed a new catalyst just labeled "proto-
type" catalyst that had better efficiencies for HC, CO and NOx than
any catalyst Volvo has tested to date but no car data were mentioned.
Another progress area for Volvo has been catalyst mechanical durability
which they now feel is adequate. Volvo is one of the few manufacturers
continuing to make a reasonable effort to meet 0.4 NOx, in the opinion
of the report team, and no manufacturer has a better chance with the
3-way approacho
7-121
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APPENDIX A
DISCUSSION OF THE METHODOLOGY
In the main body of this report the report team makes conclusions
about the capability of manufacturers to certify vehicles at
various emission standards. This appendix describes the methodology
used by the report team to arrive at those conclusions.
The subject of the appropriate methodology to use when estimates are
made of the capability of manufacturers to meet future emission
standards has been one that has received much attention in the past
few years. The major area of discussion has been the methodology
that the Administrator of EPA has used in making decisions concerning
technological feasibility. This determination is one of the four
determinations that he must make under the requirements of the
Clean Air Act, when he makes a decision to grant or deny an applicant's
application for suspension of the standards.
The EPA methodology used by the Administrator has evolved during
the past few years, from the methodology used in the first suspension
hearings to the one used in the latest suspension hearings. Much
of the evolution of the EPA methodology used in the suspension
hearings was due to suggestions made by the U.S. District Court of
Appeals (District of Columbia Circuit) in their decision in the
case International Harvester vs. Ruckelshaus. The latest EPA
methodology for analysis of data from applicants in suspension
hearings can be found.in Appendix B to the decision of the Administrator
on remand from the United States Court of Appeals for the District
of Columbia Circuit, April 11, 1973. The methodology used in this
report is a different methodology than that used by EPA in the above-
mentioned analysis of suspension hearings data. There are two
main reasons for this.
The first reason has to do with the nature of this report. This
report is a report to the Administrator of EPA on the current status
of emission control technology and the outlook for future development
and demonstration. This report is intended to have two main uses.
The first use is as a briefing-type document for the Administrator
and other EPA officals as to what the current status of advanced
emission control system development is. The second use is as a
document in which the important technical issues related to the
capability of the manufacturers to meet future standards is
discussed, and in which, the EPA technical staff's best judgements
on the important issues are transmitted to the Administrator. Thus,
the nature of the report is different than the technical appendixes
to the Administrator's decisions which have employed the other
methodology.
A-l
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The second reason has to do with the data available. Any methodology
for analysis of data is necessarily a function of the type, extent,
and quality of the data to be analyzed. Additionally the length
of time it takes to apply a methodology to data should be compared
to the time available for analysis. Most of the data supplied by
manufacturers in their 1974 Status Reports was of a nature that
essentially precluded the use of the suspension hearings-type
methodology. This is because the suspension hearings-type methodology
requires that extensive durability data on a wide variety of vehicles
be available. These vehicles should, ideally be targeted toward the
standards in question. This type of data was not generally available
in the manufacturer^ Status Reports.
The methodology used in this Report involved use of the following
sources of data.
1. The 1974 and 1973 Status Reports submitted by the manufacturers.
2. 1975 Certification Data.
3. The technical literature.
4. The November 1974 NAS report.
5. The results of the methodology previously used in the suspension
hearings.
The manufacturer's 1974 Status Reports were used to gauge the current
development status of the manufacturers, and by comparison to their
1973 Status Reports help determine the progress that had been made in the
year long interval.
The 1975 certification data were used 'to investigate the current
level of technology that the manufacturers have already demonstrated
in certification.
The technical literature was examined to keep abreast of the latest
published information in the area of emission control and fuel
economy.
The November 1974 NAS Report was studied as a source of data and
informed opinion in the area of emission control technology and as
an indication of technical issues considered important by the NAS.
The results of the suspension hearings-type methodology were used to
determine what emission levels at 50,000 miles could be expected to
result in a high probability of success in certification. These
values were taken as typically between 70 and 80 percent of the
standards, depending on the specific pollutant and emission control
system.
The report teams estimates of the ability of manufacturers' ability
to meet future standards is based on study and analysis of the above
data sources. The estimates represent the collective judgement of the
report team. Specific assumptions involved in arriving at the con-
clusions can be found in the body of this report.
A-2
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APPENDIX B
EMISSION CONTROL, TECHNOLOGY, AND FUEL ECONOMY
During the preparation of this report the report team experimented with
several ways to describe the relationships between fuel economy, emission
control and level of technology. As discussed in Section 3, the relation-
ship is fundamentally one of three variables, and just examining two
of them may be misleading.
The relationships are depicted schematically in the figures that follow
in this Appendix. The representations are 3-dimensional surfaces,
the variables being emission control, fuel economy, and control technology.
The variables on the figures are qualitative in nature. Increasing
emission control is indicated in the direction of the arrow on the
"emission control" axis, increasing fuel economy (relative to uncontrolled
vehicles) is indicated in the direction of the arrow on the "fuel
economy" axis, and increasing emission control system capability is
indicated in the direction of the arrow on the "control technology"
axis.
Figure B-l shows the general shape of the 3-dimensional surface. At
any given fixed value of one of the three variables, the relationship
between the other two can be seen by passing an imaginary plane through
the surface.
B-l
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ta
I
NJ
00
f<
(D
W
EMISSION CONTROL
-------
Figure B-2 shows the case for the 1973-4 Federal standards. The
intersection of the plane labeled "3,28,3.1" indicates the range of
control system/fuel economy combinations that could have been used.
The "*" indicates the location of a typical U.lS. car. The low level
of control system sophistication used (considerable reliance on spark
retard) resulted in a fuel penalty of about 15%, compared to uncontrolled
vehicles.
B-3
-------
•s
l-t
CD
01
N>
EMISSION CONTROL
-------
Figure B-3 shows the.case for the 1975 Federal Interim Standards.
Of the range of control system/fuel economy combinations possible,
the choice of more advanced control technology (catalysts) resulted
in a fuel economy benefit compared to 1974, despite the 50% reduction
in HC and CO emissions required by the standards.
Considering the star: on figure B-3, the fuel economy gain over 1974 is
seen to be a result of moving toward increased control technology,
which permitted optimization for fuel economy. Had 1974-type systems
been used, the resultant fuel economy would have been lower, at the
same level of control technology as was shown by the star on figure
B-2.
B-5
-------
w
i
OQ
(D
U>
l^T,
EMISSION .CONTROL
-------
Figure B-4 shows that at the 1975 "California" level the control
technology used was not sufficiently advanced to prevent a loss in
economy compared to the Federal interim standard cars. However,
exceptions exist. Saab, for example, did not drop lower on the
surface due to the use of sufficiently advanced technology.
B-7
-------
I
00
•s
i-i
tt>
W
u^
EMISSION CONTROL
-------
Figure B-5 shows the surface for the statutory 1977 standards. Current
industry claims are that a fuel penaly will be realized in meeting
this goal. As shown in the figure, this would be expected if the
control technology used is the same as that used for the California
standards. Whether or not a fuel penalty will be avoided or a gain
will be achieved depends on the emission control techniques selected.
The level of control technology necessary to achieve the .41, 3.4,
2.0 level with fuel economy as good or better than 1975 model cars may
be possible with several different control approaches.
'' The range of fuel economy values possible lies between the two stars
on figure B-5
B-9
-------
w
I
•3
i-i
n>
-------
Figure B-6 summarizes the previous figures. Looking at figure B-6
one can see the following trends:
- From 1974 to 1975 Federal we moved from a level of low technology
(engine calibration changes, engine mods) and low fuel economy
to more advanced technology (catalysts) and improved fuel economy.
- The 1975 California standards resulted in a slight fuel economy
loss and the use of slightly more advanced technology.
- The fuel economy associated with the 1977 standards will depend
on the system used to achieve compliance. No system change from
1975 California will cause a fuel economy loss.
The 1977 systems could be anywhere on the line connecting the two
stars labeled 77 with a question mark.
B-ll
-------
OQ
H
n>
-------
Figure B-7 shows where the three different "two dimentional" ways
of looking at emission tradeoffs come from. None of them tell the
whole story. The most popular way of looking at the tradeoffs is to
consider fuel economy vs. emission control with "all other things
equal". This is a simplistic viewpoint that ignores the realities of
available and developing control technologies. At any point in time
the use of control technology necessary to minimize the fuel economy
impact of stringent emission standards will generally result in
increased system complexity and costs.
There are three different two-dimensional graphs shown on figure B-7.
The one (labeled A) that shows fuel economy versus emissions is only
valid for a fixed system. Likewise the top 'graph (labeled B) is only
valid for a given fuel economy level, and the figure (labeled C) is
only appropriate at a given level of emission control.
B-13
-------
t
H-
OQ
c
1-1
(D
THE TRADE-OFFS ASSOCIATED".
WITH LOW EM155/OAJ5 DEPEMD
ON ONE'S POINT OF V/IEW
-------
It is important that the different ways to look at fuel economy, emission
control, and technology be understood. This enables one to resolve
different points of view on the complicated subject of fuel economy
and emissions, and also to keep from being misled.
B-15
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APPENDIX C
UNREGULATED EMISSIONS
C.I Introduction
Very little information on unregulated emissions was included in the
recent submissions to EPA; GM, Ford, Chrysler, and several foreign
manufacturers included some limited information on sulfates: supple-
mented by some SAE and other publications on the subject. The manu-
facturers submitted more extensive information on sulfates to EPA
earlier in the year in response to a March 8, 1974 Federal Register
request for such information. The companies have reported very little
new information since then.
This Appendix will summarize the information submitted with regard to
the work done to date on sulfates and discuss the current outlook for
control of sulfate emissions from catalyst vehicles. Almost no in-
formation was submitted on other unregulated emissions such as POMs,
reactive organics, aldehydes, catalyst attrition products, noble metal
emissions such as platinum and palladium, other sulfur compounds such
as hydrogen sulfide, and other miscellaneous compounds such as phosphine.
Therefore, these other emissions will not be discussed in this appendix
although they were mentioned in Section 5.
C.2 Measurement Methods for Automotive Sulfates
The two basic measurement procedures used for automotive sulfates are
the condensation method and the absorption method. The absorption
method was used by Chrysler and EPA in some early work. The condensa-
tion method is used by all other investigators including EPA and is
the preferred method to measure sulfates.
The condensation method involves diluting the entire vehicle exhaust
with great quantities of dilution air which cools the exhaust and allows
formation and condensation of sulfate. particles. The sulfate is
collected by filtering a small, stream of the diluted1 exhaust through a
nuclepore, millipore, glass fiber or other filter. The filter can
then be analyzed for sulfates by a number of standard methods.
The absorption method involves passing a small quantity of undiluted
exhaust through an impinger containing isopropyl alcohol. The sulfate
is absorbed in the isopropyl alcohol and can be analyzed directly.
Unfortunately, small quantities of sulfur dioxide can also be absorbed
in the isopropyl alcohol and are later converted to sulfate. This
method can give spuriously high sulfate readings and is not considered
by most investigators to be accurate.
C-l
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C.3 Sulfate Emissions From Non^atalys-t Cars
Until recently, the magnitude and form of sulfur oxide emissions from
automobiles has Been of relatively little interest compared with other
automotive emissions. However, after testing revealed high sulfate
emissions from catalyst-equipped cars, it became important to know
how much of this was a result of the catalyst, and now much sulfate
had been in the auto emissions all along.
Reporting on tests performed on non-catalyst cars, all investigators
except one have confirmed the belief that no appreciable amount of fuel
sulfur is converted to sulfate in a non-catalyst car.. Chrysler, using
the absorption measurement technique EPA has since found unreliable
for auto exhaust, found almost as much sulfate in non-catalyst exhaust
as in catalyst exhaust.
Other tests using the condensation method show only trace quantities
of sulfates from non-catalyst cars. Extensive tests have been run by
GM, Ford, Exxon, Ethyl, and EPA under various driving conditions for
1974 type cars. These tests show an approximate emission factor of
about 1 milligram per mile or less than 1% conversion of fuel sulfur
to sulfate. '
C.4 Sulfate Emissions from Catalyst-Equipped Cars
When preliminary tests revealed that catalyst-equipped cars emit a
significant amount of sulfate in their exhaust, more extensive testing
was done. Results from' this testing have so far indicated that there
are a wide variety of possible influences on sulfate emissions.
Some of the largest differences in emissions have been attributed to
the type of catalyst used. In most types of driving, pelleted catalysts
show very different behavior than monolith catalysts. A major factor in
causing this difference between pelleted and monolith catalysts appears
to be the existence of a "storage effect" whereby catalysts at certain
operating conditions (most notably cold-start and low-speed driving)
appear to be storing a portion of the sulfur compounds in the engine
exhaust. Many of the tests have shown that pelleted catalysts exhibit
a substantially larger storage effect than monolith catalysts, which
store very little, if any, sulfur compounds.when used with non air
injection equipped vehicles. When sulfur compounds are being stored
by the catalyst, low sulfate emission rates result. During other types
of driving, previously stored sulfur compounds may be released.
Because of this storage effect, the generation of repeatable and
meaningful sulfate emission data, particularly for cars with the
pelleted catalyst, becomes quite complicated. One approach might be
to make measurements only after stabilized conditions (determined by
no net gain or loss of sulfur compounds from the catalyst over the
test) have been reached. Unfortunately, the type and extent of pre-
C-2
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conditioning required to reach, such stabilized conditions are not
yet known. However, it is not clear that result? obtained after such
preconditioning would be truly representative of emissions from vehicles
in actual use, since a substantial part of the emissions in reality
might be from non-stabilized Vehicles.
C.4.1 The Storage Effect
In many of the tests performed on catalyst equipped cars, the total
sulfur emitted as SC>2 plus 803 in the exhaust was substantially less
than either the amount of sulfur in the fuel consumed by the engine
or the total sulfur measured in the exhaust before the catalyst.
Since in tests with non-catalyst cars the sulfur recovery was usually
over 90%, this is considered evidence of sulfur "storage" on the
catalyst. This storage phenomenon has been detected at times -under
many types of driving conditions, and appears to be related to both
the previous history of the catalyst and Its Immediate operating
conditions.
Storage of sulfur compounds on a catalyst is probably caused by a
chemical reaction of these compounds with the alumina support. To
date, it is believed that sulfate may be the primary compound stored
on catalysts even though S02 is theoretically capable of being stored
as sulflte. This is based on work done by Ford. Some recovery of
stored sulfur as SC>2 suggests that the latter phenomenon is also
occurIng.
0
Large quantities of sulfate can be stored on the pelleted catalysts
due to the large mass Cup to 8 Ibs.) and surface area of alumina present.
The monolith catalysts consist of a low mass cordierite.support covered
with an alumina washcoat. While the washcoat itself may adsorb sulfur
compounds, one would expect the amount adsorbed by the low mass washcoat
to be considerably less than that adsorbed by the much higher mass of
alumina in a pelleted catalyst.
Storage for Pelleted vs Monolith Catalysts
During cold-start FTP tests conducted by GM, both pelleted and monolith
catalysts stored sulfur. Storage for precious metal pelleted catalysts
with air injection (AIR) ranged from 25-90% of the fuel sulfur. Noble
metal monolith catalysts with AIR*demonstrated comparable storage of
40% to 80%, but only 10% without AIR.
In tests under 60 mph cruise conditions, Ford used fresh catalysts
with little or no preconditioning. They discovered practically no
storage for monolith catalysts when the data were averaged over a 2000
mile run. However, the results of the Individual tests conducted at
intervals during the 2000 miles would sometimes show storage of up to
15-20%, and at other times, net releases of sulfur. Since the total set
of results averaged to very nearly zero sulfur storage, the individual
C-3
-------
variations were taken to be a result of the measurement techniques.
In a similar tysst with a pelleted catalyst, 24% storage was exhibited
both at the beginning and end of a 1000 mile run, but the supporting
data are weak.
For GM's 60 mph tests, catalysts were used which had previously been
subjected to 20 or more consecutive FTPrs. In an initial 10 minute
test, sulfur recovery was always greater than 100%, going as high as
422%, indicating release of stored sulfur. The results for extended
60 mph cruise conditions were less consistent. The pelleted catalyst
without AIR showed large initial release, stabilizing to about 100%
recovery. The pelleted catalyst with AIR exhibited both release and
storage'; with no stabilization after 4 hours. A monolith catalyst
with AIR showed a short initial release, developing to a fairly stable
pattern of about 20% storage at the end of 4 hours. Therefore, sulfate
storage is greatest for a pelleted catalyst type under FTP conditions.
Time Required for Storage
In efforts to find out something about the storage capacities of
different catalysts operating under different conditions, several tests
observed the time or mileage required to reach a steady output of
sulfur. If the initial transient emissions caused by storage has
stopped and the sulfur in the exhaust equals the fuel sulfur intake,
then the catalyst must be in equilibrium. If the catalyst shows a
steady storage or release of sulfur, then stabilization has been reached,
but not equilibrium.
Overall, the submissions indicate that a stable rate of sulfur storage
(stabilization) was achieved after about 1000 miles of operation under
steady-state high speed operating conditions for both pelleted and mono-
lith catalysts which had a history of only little low speed driving.
However, only the monolith catalyst appeared to achieve equilibrium
(no further storage) within that period. Tests with catalysts with
histories of multiple FTPs failed to provide conclusive evidence of
either stabilization or equilibrium after a thousand miles or so of
operation under steady conditions.
This storage problem means that it will be very difficult to obtain
accurate emission factors for pelleted catalysts under the FTP.
Emission factors must be estimated based on engineering judgement.
C.4.2 Comparison of Pelleted and Monolith Sulfate Emission Factors
Much of the test data that has been given to EPA was the result of
attempts to determine differences in sulfate emissions between monolith
and pelleted catalysts. Such a difference might result in a lower life-
time sulfate output, or lower sulfate emissions under conditions which
have a high potential of air quality impact, such as urban "canyon"
driving conditions.
C-4
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The data indicate a high variability in absolute solfate emission
magnitudes among different driving conditions. Some of these varia-
tions are manifestations of the storage effect, while others suggest
relationships between sulfate emissions and catalyst operating
parameters.
Sulfur Emission Rates Without Storage Effects
Sulfate emissions under FTP driving tests are usually substantially
higher for monolith catalysts than for pelleted catalysts,.as detailed
in the next sub-section. However, these are usually at neither
stabilization nor equilibrium states. Such results reflect the greater
storage capacity of pelleted catalysts.
In tests which did reach stable sulfate emission rates, Exxon Research
and Engineering specially preconditioned both pelleted and monolith
catalysts at a certain fuel sulfur level, then ran them at 60 mph
cruise conditions at a different fuel sulfur level. For both catalyst
types, the initial transients caused by storage stopped after about
60 minutes, and the sulfate emission rates stabilized at nearly identical
levels.
Tests involving extended mileage accumulation on pelleted and monolith
catalysts were conducted by Chrysler. They ran a monolith catalyst over
50,000 miles, and a pelleted catalyst for 20,000 miles. The monolith
catalyst initially released 8.4% of the fuel sulfur as sulfate, but
after 2,000 miles maintained a steady rate of 10.4%. The pelleted
catalyst showed much larger initial variations during the first 1,000
miles, but recorded a 10.3% conversion at 20,000 miles, equivalent to
the monolith. No firm conclusions should be drawn from this because
Chrysler did not include in its submissions information regarding what
kind of driving conditions the catalysts were subjected to. However,
these tests indicate that monolith and pelleted catalysts may have
similar sulfate emissions after a short initial mileage period.
Thus, the limited data available indicate that when sulfur storage on
the catalyst is not a factor, pelleted and monolith catalysts convert
fuel sulfur to sulfate at comparable rates.
Sulfate Emissions Under Typical Driving Conditions
The relative sulfate emissions for pelleted and monolith catalysts
under typical driving conditions are of considerable interest. The
particular driving conditions examined are: extended urban-type
driving, extended highway type cruises, and the period of initial
transition from urban driving to highway driving.
C-5
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For a cold-start FTP, which.
-------
Table C-l
Average Sulfate Emissions
Driving Condition
60 mph cruise
ci
40 mph cruise
30 mph cruise
1972 FTP
Test Group
Ford
Exxon R&E
GM
Exxon R&E
Ethyl
GM
Ford
GM
Exxon R&E
GM
Catalyst
Monolith
Pelleted
Monolith
Pelleted
Monolith
Pelleted
Pelleted,
No AIR
Monolith
Pelleted
Monolith
Monolith
Pelleted
Monolith
Pelleted,
no AIR
Monolith
Monolith
Pelleted
Monolith,
no AIR
Pelleted ,
no AIR
Number of Tests
8
2
4
22
2-8
4-16
6-24
18
4
6
2-8
2
2-8
2-8
18
16-64
46-184
4-16
12-48
*In milligrams of H2SC«4 per mile, with 0.03% sulfur fuel (mg/mi/300 ppm)
**Results obtained by Exxon in later -work under an .EPA contract are considerably lower
than these emissions. These results are about 30 milligrams/mile.
Average Emission*
57
50
53**
60
48
48
44
47
16
63
76
74
62
66**
26
10
1
2
-------
Table C-l (cont.)
Average Sulfate Emissions
Driving Conditions
Test Group
Catalyst
Number of Tests Average Emissions*
1975 FTP
Ten Minutes at 60 mph
after extended FTP
running
10 mph cruise
Exxon R&E
GM
GM
Pelleted
13
16
Pelleted
Pelleted,
no AIR
Pelleted,
no AIR
6-24
2-8
2-8
83
13
0
o
oo
* In milligrams of H2S04 per mile, with 0.03% sulfur fuel (mg/mi/300 ppm) .
**Presumably, GM means that the amount of sulfate present was below their limit of detection.
-------
C.4.3 Best Estimate Sulfate Emission Factors
It has been demonstrated that the level of sulfate emissions depends
on the catalyst type, the driving conditions, and sulfur storage from
previous conditioning. To develop a set of emission factors for use
in air quality impact modeling, all of these considerations must be
taken into account.
For example, there must be separate emission factors for 60 mph cruise
conditions and initial 60 mph driving after extended low-speed or FTP
driving, because of the large storage effect to be expected in the
latter case. Also, separate emission factors are needed "for monolith
and pelleted catalysts. To develop an overall average emission factor
for any particular driving condition, the proportion of monolith catalysts
to pelleted catalysts must be estimated.
For the following best estimate emission factors, all of the sulfate
emissions were normalized to a fuel sulfur level of 0.03% (300 ppm S)
which is the current, national average. Implicit in this procedure is
the assumption that the sulfate emissions are linearly dependent on the
fuel sulfur level.
From all of the data, best estimate emission factors for several driving
conditions have been compiled and are presented in Table 2. Results of
the FTP, 30 mph, and 40 mph tests are grouped together for the urban
conditions category, low-to-moderate speeds. The 60 mph tests comprise
the highway conditions category, and the GM short 60 mph tests after
extended FTP conditioning and similar EPA tests make up the urban-to-
highway cruise transitiftn category.
For both pelleted and monolith catalysts, the emission factors assume
the use of air pumps. These emission factors are based on the fuel
economy achieved by 1975 cars in the 5000 Ib. inertia weight class
(i.e. the full size car). Any improvements in fuel economy in future
years would result in lower sulfate emissions since the amount of sulfate
formed is directly proportional to the total amount of gasoline burned.
These emission factors are also based on 0.03% sulfur level fuel, the
current national average. These emission factors would be higher for
areas such as Southern California with higher sulfur level fuels
(0.05% average).
C-9
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Table C-2
Best Estimate Sulfate Emission Factors*
Pelleted Monolith
Catalyst Catalyst
Urban driving 10 - 15 30
Highway cruise 50 - 60 50 - 60
Urban-to-highway cruise
transition, 100 - 300 50 - 60
* rag/mi assuming 300 ppm S fuel .
C.5. Sulfate Emissions from Advanced Emission Control Vehicles
No information was supplied on sulfate emissions from vehicles with
dual catalyst or three-way catalyst systems. Both of these systems
are used for NOx control as well as HC and CO control. These types of
control systems are not planned for production for the model year
75-77 years but would be required to meet model year 78 standards.
Very little data has been submitted to date on the subject of sulfate
emissions from alternative engines. The only records of alternative
engine tests were supplied by GM, which tested a Diesel, a rotary,
and a stratified charge engine.
The Diesel was a 1973 Opel with no special air pollution control equip-
ment. It showed sulfate emissions to be about the same on a mg/ml/ppm S
basis as a non-catalyst car, but this translates into relatively significant
sulfate emission rate when the high sulfur content of Diesel fuel is
taken into account. Using No. 1 distillate fuel containing 840 ppm
fuel sulfur the sulfate emissions were 6 mg/mi, less than catalyst
cars at FTP conditions. The sulfate emission for No. 2 distillate
(3900 ppm fuel sulfur) was 16 mg/mi.
Tests of the following four alternate engines showed sulfate emissions
similar to non-catalyst cars:
Honda CVCC
GM Experimental Stratified Charge
GM Rotary without catalysts
Toyo Kogyo Rotary with thermal reactors
C-10
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C.6. Control Through Vehicle Modifications
C.6.1 Engine/Catalyst Modifications
Only very limited information was included in the submission on how
vehicle or catalyst parameters affect sulfate emissions and how these
parameters can be altered to reduce sulfate emissions. Ideally, some
parameters such as catalyst formulation, catalyst temperature, air
injection rates or space velocity could be changed to reduce sulfates
to an acceptable level and yet maintain adequate control of HC and
CO emissions. However, most companies are only beginning programs
in this area and have no results to report.
Catalyst Formulation
Regarding catalyst formulation, GM reports some data showing base metal
catalysts to have low sulfate emissions while noble metal catalysts
have significantly higher sulfate emissions. While use of base metal
catalysts for control of HC and CO emissions was rejected by auto
manufacturers due to poor durability, this poor durability was due
in part to sulfur poisoning (possibly storage) at lower temperatures.
If fuel sulfur levels were reduced to where the base metal catalysts are
no longer subject to poisoning the base metal catalyst would have the
advantage of substantially lower materials cost. This assumes that there
are not other durability problems.
No work was reported on how various noble metal formulations affect
sulfate emissions. Possibly a Pt-Pd mixture gives different sulfate
emissions than Pt alone. This point is being examined by an EPA
contract with Exxon.
Catalyst Structure
GM states that the basic catalyst structure of monolith versus pelleted
is an important parameter in controlling sulfate emissions. According
to GM, a pelleted catalyst, due to its greater capacity to store sulfates,
would have lower sulfate emissions over the FTP when fresh than a monolith
catalyst. After the sulfate storage on the pelleted catalyst has
stabilized to some degree, sulfate emissions increase. However, all
tests have shown the pelleted catalyst to still have lower sulfate
emissions than the monolith over the FTP.
However, both catalysts have equivalent stabilized sulfate emissions
at 60 mph. Before determining that a pelleted catalyst has lower overall
sulfate emissions than a monolith catalyst, the fate of the stored sulfur
C-ll
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compounds must be determined. If all of these stored compounds are
later released as 863, the pelleted catalyst may have overall sulfate
emissions identical to those of a monolith catalyst. These points are
discussed in more detail in a prior section. It is our judgment at
this time that substantial sulfates are released from a pelleted catalyst
in the transition from low to high speed driving.
Catalyst Loading
The effect of noble metal loading on sulfate emissions was investigated
by GM using a laboratory apparatus and actual engine exhaust. S02
and 803 emissions were measured from catalysts with 0.1% and 1.0%
platinum at a constant temperature. The results are given in Table 3.
Table 3
Effect of Noble Metal Loading on Sulfate Formation
S03. PPm
Catalyst 1000°F 1100°F
0.1% Pt 7.0 5.7
1.0% Pt 8.2 6.1
These tests show that increased platinum loading results in slightly
higher sulfate formation. However, the effect is a small one,indicating
that higher noble metal" loading required for improved durability at
lower emission levels will probably not result in greatly increased
sulfate levels.
Catalyst Temperature
Theoretically, catalyst operating temperature is expected to have a
significant effect on sulfate formation. The thermodynamic equilibrium
constant for 802 oxidation is such that higher temperatures lead to
decreased sulfate formation. Also, the temperature and activation
energy required determine the kinetics for the reaction, i.e., the
rate at which the reaction occurs. With the sulfur system, the above
parameters are such that at lower temperatures the 802 oxidation
reaction would be very slow and at higher temperatures S02 would not
oxidize at all. Unfortunately, automotive catalysts operate most
of the time in the intermediate temperature range where 802 oxidizes
readily. Low temperature operation is not feasible because HC and CO
oxidation would also be very slow. High temperature operation results
in poor durability.
C-12
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GM did several experiments measuring S02 oxidation rates on pelleted
catalysts at various temperatures. The results, which give sulfur
emissions as a function of temperature, are difficult to interpret
because GM does not indicate previous operating conditions for the
catalyst and whether the catalyst has reached equilibrium regarding
sulfate storage at the time of the test. These tests indicated that
maximum sulfate emissions occur at 1200°F, and that beyond this tempera-
ture sulfate emissions decrease. These results do suggest that modifica-
tion of catalyst operating temperature should be studied for its potential
in controlling sulfate emissions.
One item of interest noted in these tests was that emissions of 802
and sulfates combined were less than the sulfur input to the catalyst
at lower temperatures but increased with increasing temperatures.
This is due to storage of sulfur componuds on the pelleted catalyst at
low temperatures and the release of the stored compunds at higher
temperatures. As the temperature increases, the percentage of total
sulfur compounds represented as sulfates decreases. Exxon is also
investigating this point in their EPA contract and will have results
shortly.
Air Injection Rate
Air injection rate is expected to affect sulfate formation in that
excess oxygen results in higher sulfate formation, with all other
conditions (e.g., catalyst temperature) being identical.
Initial work was done in this area by GM, who measured sulfate emissions
of catalyst cars with and without air pumps. As shown in Table 4,
substantial increases in sulfate emissions were found for both pelleted
and monolith catalysts when air injection was used.
Table C-4
Effect of Air Injection on Sulfate Emissions
During 1972 FTP
Catalyst Air Pump Fuel Sulfur Sulfates
Monolith (car C-32419) Off 0.03% less than 0.001 gm/mi
On 0.03% 0.02
Off 0.065% 0.003
On 0.065% 0.143
Pelleted (car ES83189) Off 0.026% 0.001
On 0.019% 0.004
C-13
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The preliminary tests indicate that, in some cases, the presence of
air injection causes a very large increase in sulfate formation. It
must also be noted that the results of GM's tests showed large varia-
tions from test to test and from vehicle to vehicle. These limited
data also showed lack of air injection to result in an approximate
twofold increase in HC and CO emissions. Clearly, much more work
is needed in this promising area.
GM did additional tests measuring the effect of two levels of oxygen
on sulfate formation at five different temperatures. These results,
given in Table C-5, show that a twofold increase in oxygen level
approximately doubles the amount of sulfate found, at least at lower
temperatures.
Table C-5
Effect of Oxygen Level on Sulfate Formation
S03 ppm
Catalyst %02 900°F 1000°F 1100°F 1200°F 1300°F
0.1% Pt
(A/F 15.4,
SV 28,000) 1% 5.0 4.5 - 7.2 6.5
0.1% Pt 2% 12.7 10.7 11.8
While these results show the effect of oxygen level on sulfate emissions,
they indicate on clear trend of catalyst temperature versus sulfates.
Earlier findings showed maximum sulfate formation at 1200°F. It is
not possible to resolve this discrepancy at this time. However,
these reuslts are promising in that they indicate a reduction of sulfates
at lower oxygen levels. Close control of air injection could effectively
inhibit much of the sulfate formation.
Some recent work at Exxon under an EPA contract also shows low air
injection rates result in low sulfate formation but higher CO emissions.
Space Velocity
Space velocity, in effect, determines the total time period in which
the exhaust gas is in contact with the catalyst. Space velocity is the
exhaust flow (ft3/hr) measured at standard temperature and pressure,
divided by the catalyst volume (ft3). The reciprocal of space velocity
C-14
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is contact time usually expressed in hours, that the exhaust gas is
exposed to the catalyst. Thus, a smaller catalyst bed results in a
larger space velocity number but .shorter contact time. A larger
catalyst bed generally results in longer contact times and thus more
effective HC and CO oxidation, and is less likely to suffer "break
through", i.e., exhaust gas passing through the catalyst bed without
reacting. However, a catalyst bed that is too large (i.e., a low
space velocity number) will have a very long warm-up period and high
cold-start emissions. A trade-off is made between these two factors to
define an optimum space velocity.
Sulfate emissions can also be affected by space velocity, with a low
space velocity resulting in higher sulfate emissions. It should be
possible to add sulfates as another variable in defining optimum space
velocity.
GM is the only company which reported tests to determine the effect
of space velocity on sulfate formation. These tests are summarized
in Table C-6 and were run at 1200°F with a pelleted catalyst.
Table C-6
Effect of Space Velocity on Sulfate Formation
Space Velocity Sulfate Formation
7,000 hr - 1 18%
28,000 hr - 1 14%
These tests results show greater sulfate emissions at lower space
velocity, which allows more time for sulfates to form in the catalyst.
This result suggests that, at least at 1200°F, sulfate formation is
limited by reaction kinetics (i.e., the reaction rates) rather than
thermodynamics. Even though the effect of space velocity is small,
it seems to be, nevertheless, one more variable to consider in designing
a catalyst for low sulfate emissions.
C.6.2 Sulfate Traps
If it is not possible to adequately control the formation of sulfates
in the catalysts, it may be possible to control sulfate emissions
by use of a sulfate trap after the catalyst. A sulfate trap is a device
which by chemical reaction or mechanical means removes sulfuric acid
particles and 803 from the exhaust gas downstream from the catalyst.
C-15
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Most of the feasible sulfate traps are chemical traps and involve
the reaction of acidic sulfate with a base. Sulfate trap devices,such
as limestone scrubbers, were developed to control sulfur dioxide emissions
from stationary sources. These traps have not been previously considered
for automotive use. Very few comments were received on sulfate traps
other than general comments from Ford and GM and some specific comments
from Atomics International.
Mechanical Traps
Mechanical traps of a centrifugal separator design have been developed
by DuPont, Ethyl, and PPG to remove lead particulates from automotive
exhaust. It is theoretically possible that sulfuric acid could be
removed by this type of trap ±f_ the sulfate particles were condensed
into particulates before the exhaust reaches the trap.
The Ford comments on mechanical traps stated that exhaust system tempera-
tures are too high to allow condensation of exhaust sulfates. EPA
measurements of temperatures along standard exhaust lines show this
statement to be true. Ford mentions that a heat exchanger could be
used to lower the temperature of the exhaust. However, this heat
exchanger would condense the water in the exhaust if a large temperature
drop occurred. If water did condense, and there is a large amount of
water in automotive exhaust, the water would not only present a large
storage problem, but much of the sulfuric acid could be lost by entrain-
ment. Ford feels it is virtually impossible to maintain the temperature
below the condensation point for sulfuric acid yet above the condensation
point of water over the wide range of driving conditions.
EPA can tentatively conclude on the basis of the Ford comments and
our own measurements of exhaust systems temperatures that the mechanical
trap is not a promising control technique.
Molten Carbonate Traps
Atomics International Division (AI) of Rockwell International commented
on the general issue of sulfate traps and stated that they had developed
and tested an exhaust scrubber device which has been effective in
removing particulates from automobile exhaust gases. This scrubber
works by passing the exhaust gas through a molten alkali metal carbonate
mixture consisting of equal parts by weight of lithium, sodium and
potassium carbonates. A calculation shows this salt mixture will require
changing every 15,000 to 20,000 miles.
However, a major problem with this type of trap is potential emission
of alkali carbonate itself by entrainment from the trap. Limited data
from Atomics International indicate an emission rate at 60-70 mph
corresponding to a 2.2% loss of the scrubbing salt over 15,000 miles.
Additional work is required to determine the magnitude of these problems.
C-16
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Exxon is examining sulfate traps under contract to EPA and feels the
molten carbonate trap has low potential compared with other possible
traps. They cite the above entrainment problem, mention that the trap
cannot work until the salt is molten, and feel that the molten salt
mixture is corrosive and hard to contain. Due to these probelms, Exxon
does not plan to test molten carbonate traps in their program.
Metal Oxide and Other Metal Carbonate Traps
Metal oxides, such as calcium, aluminum, zinc, magnesium and manganese
oxides are candidates for use in automotive sulfate traps. Metal car-
bonates such as calcium carbonate, can also be used. These substances
react chemically with the sulfuric acid to form inert sulfate salts.
A trap containing calcium carbonate functions similarly to one with
calcium oxide in that the solid compound (calcium carbonate or calcium
oxide) reacts with the sulfuric acid. A calcium carbonate trap is
different from the molten carbonate trap discussed earlier which used
molten salts at high temperatures. Metal oxide and calcium carbonate
scrubbers are used to control stationary sources 802 emissions. Ford,
GM, and Exxon commented on metal oxide sulfate traps.
Ford has done a paper study of metal oxide sulfate traps and feels
calcium oxide would be an effective trapping agent. However, Ford
calculates that 250 Ibs. (a cube of 20 inches on an edge) of calcium
oxide is required to control sulfate emissions over 50,000 miles.
Periodic replacement of the calcium oxide at specified mileage intervals
would decrease the size of the trap. Ford also commented that the high
C02 content of the exhaust converts calcium oxide to calcium carbonate
which is also an effective trapping agent. Ford has not done any
testing with a calcium oxide sulfate trap.
Ford feels that a sulfate trap containing alumina is more promising.
It would require 32 pounds of alumina over 50,000 miles. Alumina is
the same substance used for catalyst pellets and readily reacts with
sulfuric acid. However, Ford commented that attrition of the alumina
could occur. Any development program for sulfate traps must measure
for trap attrition products. Finally, Ford stated that a major design
problem with alumina and other compounds is a suitable trap design to
assure adequate contact between the alumina and the exhaust gas.
GM has designed and tested a 90 in3 vehicle sulfate trap containing
alumina. The sulfate trap was installed on a vehicle with a GM catalyst
and tested over the FTP. GM stated that the results of the testing over
the FTP were inconclusive due to low baseline emissions over the FTP
without the trap. Clearly, the trap must be tested under conditions,
such as 60 mph cruise, which result in high sulfate emissions. GM,
using slightly different assumptions than Ford, calculates that 10-20 Ibs.
of alumina are needed over 50,000 miles.
C-17
-------
Exxon commented that they have a laboratory program to test calcium
oxide traps. Furthermore, Exxon is under contract with EPA to test and
evaluate vehicle sulfate traps containing alumina, calcium oxide, or
other promising materials. One potential problem with metal oxide traps
is that the sulfate compound formed from reaction with the trapping media
with 80s is larger in volume than the metal oxide. The trap must be
designed to accommodate this expansion.
Almost all of the actual vehicle tests on sulfate traps have been done
under at EPA contract with Exxon. A 25,000 mile test was run on a CaO-
Si02 - N&20 trap which showed high removal of sulfate. However, due
to expansion of the trap material as sulfates were trapped, a high
pressure drop across the trap developed, making the vehicle almost
inoperable. Another test with this sorbent in a different geometry for
minimum pressure drop will be run. However, these results were very
encouraging in that they show this trap has the capacity to control sulfates
from 25,000 miles.
Despite the encouraging results it is not possible at this time to make
any conclusions about the effectiveness or cost of sulfate traps, and
more evaluation and testing is needed which will be done in the next
year.
C.6.3 Other Approaches Suggested
The only other sulfate control technology suggested was by Chrysler
Corporation, who recommended use of leaded fuel to reduce sulfate
emissions from catalyst vehicles. However, Chrysler used the Method 8
absorption procedure for measuring sulfates. As explained earlier in
this appendix, Method 8 can detect up to 25% of the SC>2 present as
sulfate. Therefore, the results of Chrysler's tests are highly question-
able.
Chrysler has run non-catalyst vehicles on unleaded and leaded fuels
and found lower sulfate emissions with leaded fuel. (Chrysler is one
of the few investigators to find significant levels of sulfate emissions
from non-catalyst vehicles.) Use of leaded fuel can result in the
formation of lead sulfate which is insoluble and not measured by the
adsorption method. Lead sulfate also is thought to have less harmful
health effects than soluble sulfates.
Chrysler feels that use of leaded gasoline in catalyst vehicles would
result in formation of lead sulfate and significantly decrease soluble
sulfate emissions. This conclusion is based on comparing sulfate
emission results from running non-catalyst vehicles on leaded and unleaded
fuel. However, sulfate emission tests were not run on catalyst vehicles .
with leaded fuel.
C-18
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A major question to be resolved is whether catalyst-equipped vehicles
can operate on leaded fuel without excessive catalyst deterioration.
All data so far indicate that catalyst vehicles cannot operate on leaded
fuel as it is currently made, containing both ethylene dibromide and
ethylene dichloride scavengers. Chrysler feels that ethylene dibromide
alone is a catalyst poison and that catalyst-equipped vehicles can
perhaps operate satisfactorily on fuel containing lead alone or lead
and ethylene dichloride. Both GM and Ford feel that lead alone irreversibly
poisons catalysts. This issue has not yet been resolved. If it is found
that catalysts can use fuel with lead alone with ehtylene dichloride,
and if the engine will operate satisfactorily on such a fuel, further
testing to determine if use of leaded fuel would decrease sulfate
emissions would be desirable. At this point in time, it is our judgment
that use of leaded fuel to lower sulfate emissions does not seem to be
a viable option.
C-19
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