Automobile Emission
Control - The State of
the Art as of
December 1972
a report to
the Administrator,
Environmental Protection Agency
prepared by
Division of Emission Control Technology,
Mobile Source Pollution Control Program,
Office of Air and Water Programs,
Environmental Protection Agency
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AUTOMOBILE EMISSION CONTROL
THE STATE OF THE ART
AS OF DECEMBER 1972
A Report to the Administrator,
Environmental Protection Agency
Prepared by
Division of Emission Control Technology
Mobile Source Pollution Control Program
February 1973
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CONTENTS
1. ABSTRACT . 1-1
2. SUMMARY AND CONCLUSIONS .......... 2-1
2.1 Summary . 2-1
2.2 Conclusions . . 2-4
2.3 Discussion of Conclusions 2-7
3. INDUSTRY STATUS - 1975 DEVELOPMENT ..... 3-1
3.1 Systems to be Used for Model Year 1975
and the Constraints Influencing
Their Design . 3-1
3.2 Durability Testing Programs 3-8
3.3 Catalyst Screening Programs . 3-10
3.4 Lead Time for 1975 Production and an
Identification of the Critical Items. . 3-10
3.5 Significant Problem Areas 3-13
3.6 Summary Discussion - Model Year 1975. . 3-16
4.- INDUSTRY STATUS - 1976 DEVELOPMENT 4-1
4.1 Systems to be Used for Model Year 1976
and the Constraints Influencing
Their Design 4-1
4.2 Durability Testing Programs 4-4
4.3 Catalyst Screening Programs 4-4
4.4 Lead Time for 1976 Production and an
Identification of the Critical Items. . 4-5
4.5 Significant Problem Areas . 4-6
4.6 Summary Discussion - Model Year 1976. . , 4-8
5. NON-AUTOMOBILE MANUFACTURER DEVELOPMENT
STATUS . 5-1
5.1 Catalyst Manufacturers 5-1
5.2 Other Manufacturers . 5-3
5.3 Summary Discussion . 5-8
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CONTENTS (Continued)
6. INDIVIDUAL MANUFACTURERS REVIEWS . 6-1
6.1 Domestic Manufacturers 6-1
6.1.1 American Motors 6-1
6.1.2 Chrysler ....... 6-8
6.1.3 Ford . 6-24
6.1.4 General Motors .......... 6-45
6.1.5 International Harvester 6-64
6.2 Foreign Manufacturers . . 6-70
6.2.1 Alfa Romeo 6-70
6.2.2 BMW 6-75
6.2.3 British Ley land 6-80
6.2.4 Daimler-Benz (Mercedes) 6-86
6.2.5 Fuji Heavy Industries (Subaru) . . 6-95
6.2.6 Honda . 6-101
6.2.7 Mitsubishi . 6-109
6.2.8 Nissan (Datsun) 6-118
6.2.9 Renault 6-127
6.2.10 Saab ....... 6-133
6.2.11 Toyo Kogyo (Mazda) 6-141
6.2.12 Toyota 6-153
6.2.13 Volkswagen 6-160
6.2.14 Volvo 6-165
6.2.15 Peugeot . . 6-174
7. APPENDIX 7-1
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SECTION 1
ABSTRACT
This report contains a summary and evaluation of information
and data reported individually to EPA by 20 different auto-
mobile manufacturers and other organizations involved in
the development of emission control technology.
This report describes the state of the art in automobile
emission control technology as of the time frame in which
the report was written and the data reported. Most of the
information used to prepare this report came from status re-
ports submitted to EPA by the 20 manufacturers in response to
a letter sent to them from EPA on September 8, 1972. Most
of the status reports were received in the time period of
November-December 1972. Therefore, most of the data is char-
acteristic of the state of the art at/or before December 1972.
This report covers the emission control systems planned for
use in model year 1975 and 1976, results of the durability
testing reported to date, the significant technical problem
areas, and the development status of the industry with respect
to model years 1975 and 1976.
This report is a companion document to a similar report —'
prepared last year by the Division of Emission Control Tech-
nology. This report is somewhat different in scope than the
earlier report, being essentially a description of the current
state of the art and the progress made in the last year, while
last year's report had, in addition to information similar to
that included in this report, a description and explanation
of various types of emission control devices. If the reader
I/ Automobile Emission Control^-A Technology Assessment as of
December 1971
1-1
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of this report is unfamiliar with either the terminology
used or the emission control devices discussed in this
report, he is referred to Sections 2.2, 2.3, 4 and 5 of
last year's report.
This report contains conclusions about the ability of
manufacturers to certify vehicles in model years 1975 and
1976.
1-2
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SECTION 2
SUMMARY AND CONCLUSIONS
The purpose of this report is to summarize and discuss the
state of the art in automobile emission control technology.
The approach used in preparing this report was to obtain
information from manufacturers concerning the status of
their development programs; review and analyze the reported
information; and, based on the review of the data, assess
and report the state of the art in emission control technol-
ogy. Discussion of the state of the art is reported on an
industry-wide basis and on an individual manufacturer basis.
A copy of the letter requesting the data from the manufacturers
can be found in the Appendix. Twenty (20) manufacturers
responded to the request for information.
2.1 Summary Estimate of Manufacturers' Ability to Meet the
1975 and 1976 Standards
The current state of the art of emission control technology is
such that a wide range of both technical approach and technical
achievement exists among the 20 manufacturers discussed in this
report.
The technical approaches reported by the 20 manufacturers have
been grouped into two classes, catalytic systems and non-catalytic
systems. The manufacturers who are developing catalytic systems
have been further subdivided into classes based on EPA judgment
of their relative accomplishments as of the time the information
was received. These subdivisions represent above average, average,
and below average demonstrations of the technology necessary to
certify vehicles for model year 1975 and 1976. The non-catalytic
systems have not been subdivided and are judged to be equal
demonstrations of technical accomplishment.
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For model year 1975 the classes are:
75-1 Non-Catalytic Approach.
Three manufacturers are in this class: Honda, with their CVCC
engine, Toyo Kogyo with their rotary engine + thermal reactor
and Daimler-Benz with their Diesel engine. None of these
emission control systems use a catalyst or require unleaded
gasoline. All have demonstrated emission levels below 1975
requirements, Honda and Toyo Kogyo having reported satisfactory
50,000-mile durability data. The manufacturers in this class
are predicted to be able to certify the above-mentioned approaches
for model year .1975. These manufacturers currently comprise
less than 1% of the U. S. market. There is little information
upon which to base predictions of their market share in 1975,
but it will probably remain small.
75-2.1 Catalytic System Approach - Above Average Development
Status
Three manufacturers were judged to be in this class, GM,
Chrysler and Ford. These manufacturers have demonstrated
emission control achievements with the "typical" 1975-type
control system (engine mods, air injection, EGR and oxidation
catalysts) that is superior to other manufacturers developing
the same generic system. All of these systems require unleaded
fuel. These manufacturers, in the judgment of the report team,
will probably be able to certify for model year 1975. The
manufacturers in this group currently comprise about 85% of the
U. S. market. Their share of the U. S. market in 1975 is
assumed to be very nearly the same. Their market share depends
on the performance of the manufacturers in the next two classes,
and what fraction of their model lines the three manufacturers
are able to successfully certify for model year 1975.
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75-2.2 Catalytic System Approach - Average Development Status
This class of manufacturers is the largest in number, 11
manufacturers being included. This class is also the most
variable in technical achievement, with some manufacturers
ranking close to class 2 and some ranking nearly in class 3.
In alphabetical order, these manufacturers are AMC, BMW,
Daimler-Benz (gasoline), Fuji, Mitsubishi, Nissan, Peugeot,
Toyota, Saab, Volkswagen and Volvo. The ability of these
manufacturers to certify for model year 1975, in the opinion
of the report team, remains in question. Currently, these
manufacturers constitute approximately 13% of the U. S.
market. The market share of this class in 1975 will depend
on the ability of the individual manufacturers to certify.
75-2.3 Catalytic System Approach - Below Average Development
Status
There are three manufacturers in this class, Alfa Romeo, British
Leyland (BLMC) and International Harvester. Their ability to
certify for model year 1975 is considered unlikely. Currently
these manufacturers constitute less than 2% of the U. S. market.
What their market percentage will be in 1975 is not known as
their projected ability to certify is presently highly uncertain.
For model year 1976 the classes are:
76-1 Non-Catalytic Approach
There are three manufacturers in this class, Honda, Toyo Kogyo
and DaimlerrBenz (Diesel). All three have demonstrated control
below or very close to the 1976 levels without use of any
catalyst but no durability data has yet been reported. Con-
sidering the poor performance of NO catalysts reported to date,
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this alone puts these manufacturers in a somewhat more favor-
able position than the other two classes. These manufacturers
may be able to certify for model year 1976. Their share of the
market is discussed under class 75-1.
76-2.1 Catalytic System Approach - Average Development Status
This class is representative of the current industry-wide
capability. These manufacturers are developing systems that
use catalysts to control HC, CO and NOX. All of the manufacturers
in classes 75-2.1 and 75-2.2 plus BLMC fall into this category. These
sixteen manufacturers currently have 98% of the U. S. market.
The ability of this class to certify for model year 1976 is
judged questionable.
76-2.2 Catalytic System Approach - Below Average Development
Status
This class includes Alfa Romeo and International Harvester.
The same comments used for this class for 1975 apply for 1976
as well.
2.2 Conclusions on the Status of Technology for Meeting the
1975 and 1976 Standards
Implicit in the conclusions listed below are three assumptions:
1. Unleaded fuel averaging less than .05 grams per
gallon (gpg) lead content will be available for model
year 1975-76 vehicles.
2. The certification procedure for model year 1975
would remain the same as it is currently, with the
following exceptions. In addition to catalyst replace-
ment and EGR maintenance being allowed, the manufacturers
will be required to run certification on fuel of a
minimum of .03 gpg lead content, assumed to be represen-
tative of the average lead content in the field.
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3. Vehicles owned and operated by the public will
continue to receive the same maintenance, both in
frequency and quality, as is the case today. This
means that vehicle owners will continue to obtain
vehicle maintenance that affects emission performance
only when something is noticeably wrong with the
vehicles and when the vehicles are maintained the
owner will only be concerned about the things that
are noticeably wrong. No assumptions about the
possible success of state inspection plans in changing
the habits of the average motorist were made, since
those programs are as yet undeveloped.
The conclusions listed below apply at the time that this report
was written. In an area such as emission control technology
where such rapid progress is continually being made, the time
frame in which conclusions are made must be kept in mind. New
developments may be reported that would require the conclusions
listed below to be modified. For example, the significant
achievements obtained by Honda were announced during the
preparation of this report. Very little was known about the
concept prior to Honda's disclosure.
The EPA report team concludes:
1. If EPA does not adopt averaging of the emissions from
vehicles for assembly line testing and warranty/recall
purposes, then only one manufacturer (Honda) would be
predicted to even have a chance to comply with all the
emission requirements for model year 1975.
2. If EPA adopts the averaging of emissions from vehicles
in a given engine family to determine compliance with the
assembly line test and warranty/recall provisions of the
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Clean Air Act, then manufacturers currently representing
at least 85% of the current U. S. market will probably
be able to certify vehicles that comply with all require-
ments related to meeting the 1975 standards.
3. The state of the axt with respect to the dual catalyst
emission control systems favored by most manufacturers
being developed in an attempt to meet the 1976 standards,
is not as advanced as was the development of 1975-type
emission control systems last year at this time.
4. The major industry-wide technical problem with 1976
emission control system development is the same now as
it was one year ago, the absence of an acceptable NO
A,
catalyst.
5. Three non-catalytic systems have demonstrated the
emission control required to meet the 1975 standards.
Two non-catalytic systems (Honda CVCC and Toyo Kogyo
rotary) have demonstrated 50,000-mile durability at or
below the 1975 emission requirements. The emission
performance of these two systems has been verified by
tests at the EPA laboratory in Ann Arbor. The three
non-catalytic systems have potential to meet the 1976
standards. Some catalytic systems are expected to
meet the 1975 standards. The dual catalyst approach
favored by most manufacturers appears, at this point
in time, to have less potential for meeting the 1976
standards than do the non-catalytic systems.
6. The catalytic emission control system that has so
far achieved the 1976 emission levels for the greatest
number of miles is not a typical dual catalyst system
and is being developed and demonstrated by a supplier
to the automobile industry.
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7. The on-the-road emissions from 1975 vehicles may
be somewhat higher than the standards against which
prototype vehicles are certified, because of limited
assurance, at this point in time, that vehicles will
be maintained and operated as carefully as may be
necessary to have them continue to meet the standards.
This issue will become far more important as regards
1976 systems, since the HC and CO emissions from a
1976 system may even exceed the HC and CO emissions
from uncontrolled vehicles, if catalytic control of
emissions fails in service.
2.3 Discussion of Conclusions
Conclusions 1 and 2 reflect the difference that the averaging
of emissions makes. It is recognized that there are important
legal and policy implications in the ultimate EPA position on
averaging, but those issues are beyond the scope of this re-
port. Conclusions 1 and 2 indicate only what the assumptions
of allowing or not allowing averaging mean with respect to
the technical capability of the industry to comply.
Conclusions 3, 4, 5, and 6 indicate that significant improve-
ments in the area of NO catalyst technology are still required
Ji
if the dual catalyst approach favored at this point in time by
most manufacturers is to be successful.
There are three main reasons for conclusion 7. First, the
current EPA durability mileage accumulation schedule is
probably not as rigorous a test for catalytic emission control
systems as it is for non-catalytic emission control systems.
Since catalytic systems are thus not subjected to the same
degree of stress in certification testing that they may be
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in actual service, especially with, respect to heavy loads
and concurrent high exhaust temperatures, it must be assumed
that the performance of catalysts on the road may not be as
good. Second, there is less than complete assurance at this
point in time that vehicle owners will be effectively required
to perform all the maintenance that may be needed to keep
1975 emission control systems operating properly. Third, the
actual average lifetime of automobiles is about 85,000 miles,
as contrasted to the 50,000-mile "useful" life of the current
regulations. There are no current Federal regulations for
control of emissions from automobiles beyond 50,000 miles.
2-8
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SECTION 3
INDUSTRY STATUS - 1975 DEVELOPMENT
3.1 Systems to be Used for Model Year 1975 Compliance and
the Constraints Influencing Their Design
Systems to be Used
The predominant emission control system planned for use in
model year 1975 by the automobile manufacturers is the
system employing engine modifications, exhaust gas recir-
culation, air injection, and an oxidation catalyst.
The engine modifications planned for use in model year
1975, compared to an uncontrolled vehicle, involve modi-
fications to permit operation with lead-free fuel, intake
and carburetor system modifications, spark timing and con-
trol modifications, and combustion chamber and exhaust
port modifications.
The modifications to permit operation on lead-free fuel
are, primarily, lowering the compression ratio to allow
use of 91-octane fuel which is assumed to be the principal
octane level with unleaded fuel, and the introduction of
hardened valve seats to prevent valve seal recession.
Many manufacturers have already incorporated these engine
modifications, and virtually all manufacturers will have
instituted these change by model year 1974.
The intake system and carburetion modifications involve
three basic changes: quick release chokes, improved carbure-
tors, and quick heat manifolds.
The purpose of quick release chokes is to provide just enough
choking to get the engine started. This tends to minimize
the CO emissions during the cold start portion of the emission
test when most of the CO and HC are formed. Conventional
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chokes are not satisfactory because they are too erratic
in operation and they maintain choking action for too long
a period of time after the engine is started.
The carburetor improvements scheduled for model year 1975
are in the area of fuel metering. The air/fuel ratio must
be controlled more precisely than current practice and some
manufacturers are planning to employ altitude-compensated
carburetors, which automatically adjust the mixture depending
on the barometric pressure.
The quick heat or "stove" manifolds provide two advantages.
They provide better fuel evaporation during the cold start
portion of the emissions test, thus helping to minimize CO
emissions, and they also tend to improve cold engine drive-
ability by providing a better mixture to the cylinders
quicker than conventional systems.
The advanced induction and carburetion systems are not yet in
production. Because of the long lead times necessary for the
casting of intake manifolds, current prototype durability
fleets of the manufacturers are not all equipped with quick
heat manifolds. The advanced carburetors are also just
becoming available in a production-like form. Many manu-
facturers are currently testing modified current production
carburetors.
The spark timing and control modifications in many cases
involve use of electronic ignition systems. These systems
provide better and more reliable ignition. Some manufacturers
are already mass producing these systems. The spark timing
and advance will be similar to current (1973) model year cali-
brations.
The combustion chamber and exhaust port modifications, compared
to an uncontrolled vehicle, are made to optimize the surface-
s-volume ratio and to conserve exhaust heat, respectively.
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Manufacturers have already made the combustion chamber changes,
but the exhaust port changes, for example, shorter exhaust
ports or exhaust ports with liners, are not generally in pro-
duction now.
The exhaust gas recirculation systems planned for use in 1975
are for the most part, similar to those in use on current (1973)
models. Some manufacturers are developing more sophisticated
systems that match engine air flow requirements in a proportional
manner, but since these type systems may not be necessary to
meet the 1975 Federal NO standard of 3.1 grams per mile they
X
may not be used nationwide.
The air injection systems for 1975 are similar to the existing
systems but may differ in application. Since the catalytic
converters may need more air than can be provided by conven-
tional pumps, designers have two options: drive the existing
pumps faster or use pumps with greater displacement. Since
most development vehicles use current pumps with a greater
drive ratio and have had durability problems,the trend at
this time is to favor larger pumps.
The oxidation catalyst is the component of the 1975 emission
control system that is the most different from current (1973)
emission control systems. The most favored type of oxidation
catalyst for use in 1975 systems is the precious metal mono-
lith. Precious metal refers to the type of active material
(the actual catalyst). These metals include the chemical ele-
ments of the platinum group: Platinum, palladium, osmium,
iridium, rhodium and ruthenium. Most catalyst active materials
for automobile application mainly contain varying proportions
of platinum and palladium as active materials. The term "mono-
lith" refers to the structure of the substrate upon which the
washcoat and active material are placed. Monolithic structures
are one piece, with passages through which the exhaust passes.
They differ from the bead type, which are a large number of
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separate beads or pellets around which the exhaust gas flows.
Some manufacturers are still considering bead catalysts with
base (non-precious) metals as active materials, but most manu-
facturers now consider the precious metal monolith as a more
optimum choice.
There is another kind of catalyst being considered for applica-
tion in 1975. This type of catalyst is known as "promoted base
metal." Typically, this is a base metal pellet catalyst con-
taining a very small amount of precious metal to promote the
catalytic reaction. These types of catalysts may offer some
advantages over other types of catalysts. They may be more
efficient than base metal catalysts, and they may be cheaper
than precious metal catalysts. General Motors is the manufac-
turer doing the most extensive development and testing work
in this area.
The above-mentioned components and subsystems constitute what
will be referred to in this report as a typical 1975-type
emission control system.
Some manufacturers are not planning to use typical 1975-type
emission control systems on all their vehicles. These systems
are discussed in section 6 in the individual manufacturers'
reviews. The manufacturers are Honda, Daimler-Benz (Mercedes),
and Toyo Kogyo.
The costs for 1975 emission control systems, and the fuel economy
penalties associated with their use vary greatly. Cost estimates
from the manufacturers range from a low of $100 to a high of $1500,
compared to a 1973 vehicle. The fuel economy penalty anticipated
by the manufacturers ranges from none to a 45% increase. Discus-
sion of the manufacturers"cost and fuel economy estimates can be
found in the individual manufacturer's reviews. Part of the
reason for the wide spread in the anticipated fuel economy
penalty reported may be the lack of a standardized industry-
wide procedure for measuring and reporting fuel economy.
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Constraints Influencing the Design of 1975 Emission
Control Systems
Acceptable emission performance is not the only requirement
that the modern automobile must meet. Federal safety require-
ments and other requirements imposed by the manufacturers
themselves must also be met by the vehicle designers. It is
beyond the scope of this report to discuss all of the constraints
involved in the design of the modern automobile. For example,
there are constraints placed on the vehicle designer for the
purposes of making the ultimate vehicle more attractive to the
potential buyer. These constraints should not be considered
unimportant, however, since the safest and cleanest automobile
would be of no use if the buying public rejected them in pre-
ference to older, presumably less safe and less clean vehicles.
The constraints that are within the scope of this report are
the constraints that affect the design of the emission control
system.
The major 1975 design constraints are: Cost, performance,
driveability, packaging, fuel economy, compatibility with
1976 requirements, applicability to all models, and lead time.
When emission performance and system durability affect the
above-mentioned parameters greatly, compromises have to be
made.
The automobile industry is extremely cost conscious. The
types of costs that are considered most important are the
projected manufacturing costs and retail price. The projected
manufacturing costs are pertinent to this discussion. Auto-
mobile manufacturers have staffs whose sole job is to estimate
production costs for items. These cost estimates are quite
detailed, involving estimating costs down to fractions of a
cent per part. Considering the total number of parts produced
yearly, (pistons, for example, are produced in quantities of
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greater than 50 million annually), the need for accurate
cost predictions is clear. Cost information of this type
is considered highly confidential by the industry.
No manufacturer has indicated to EPA that an absolute cost
ceiling has been placed on the 1975-type emission control
system. However, cost is certainly one major constraint on
the acceptability of any given design. Non-precious metal
catalysts have received much attention for this reason.
Vehicle performance and driveability are other parameters
than can impose constraints on the emission control system.
For example, the desire to maintain vehicle acceleration
and driveability at or near current levels can cause compro-
mises in such emission control system areas as EGR flow rate,
carburetor calibration, spark advance, and catalyst design
(backpressure), among others.
Packaging is a constraint that currently primarily affects
the design of the catalytic converter. Because of the desire
of most manufacturers to make as few changes as possible to
the existing vehicles, the design of the catalytic converter
has been constrained to a great degree by the space available.
This has influenced the choice of the catalyst material, and
the size, shape and positioning of the catalyst relative to
the exhaust manifolds.
Fuel economy is a design constraint that affects the EGR system
design, the spark advance and timing selection, the choice of
the air pump and catalytic converter design. Most manufacturers
appear to have accepted as inevitable the small losses due to
the air pump and the increased exhaust backpressure due to the
catalyst but are still working to minimize the losses due to
the EGR and spark retard.
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Compatability with the requirements for both 1975 and 1976
is another constraint. Systems which have promise to meet
the 1975 standards, but which, in the opinion of the manu-
facturers, have little or no chance to meet the 1976 NO
H
requirement, have been abandoned, or not fully investigated.
It makes little sense to the manufacturers to have a "one
year" system. Such an approach would be very expensive and
disruptive to the normal design, development and production
cycle.
Another more recent constraint on the design of emission con-
trol systems is related to EPA's recent policy decisions regard-
ing defeat devices and emission control system modulating devices,
Since the information supplied by the manufacturers on the status
of their "1975/76 developments was submitted before the public
hearings on emission control system modulating devices, l-ittle
specific information regarding these types of devices was
included. It is the opinion of the report team, however, that
the manufacturers are now'carefully reviewing their 1975/76
designs in the light of the EPA policy on defeat devices,
especially catalyst bypass systems.
Manufacturers are extremely interested in systems that can be
applied across their current model line. They are reluctant
to develop systems that have limited application, especially
if the systems cannot be used on some of their current models.
Lead time is also another constraint. Better systems, if they
cannot be produced in time to meet the statutory deadline, have
received little or reduced emphasis. One of the results of
this time constraint is that the manufacturers have not seriously
considered unconventional propulsion systems for model year 1975,
except for the rotary engine.
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How and why a given manufacturer gives more or less weight to
each of these constraints results in a design philosophy for
the emission control system. Which contraints are considered
most important, which less important, and how much emission
control capability is sacrificed because of these constraints
varies from manufacturer to manufacturer. No manufacturer
has provided quantitative information concerning how these
tradeoffs are made, the reasons for making them, and how much
emission control may have been sacrificed.
3.2 Durability Testing Programs
Durability of 1975-type emission control systems was identified
as a major problem area over a year ago. The ability of emis-
sion control systems, especially the catalysts, to remain effec-
tive for the required 50,000-mile AMA durability schedule
remains a major problem area for some manufacturers. For this
reason, the experimental test programs that the manufacturers
are conducting to assess the durability of their 1975 prototype
vehicles are extremely important.
Generally, manufacturers have to undertake two types of dura-
bility testing. The first type is the AMA-type 50,000-mile
schedule. This is the schedule that is used by EPA to calcu-
late the deterioration factor from the manufacturer's durabi-
lity fleet vehicles. This deterioration factor (DF) is then
applied to the 4,000-mile emissions from the manufacturer's
emission data fleet. Since the manufacturers must comply with
the EPA requirements to be able to sell vehicles, the perform-
ance of the emission control systems on AMA durability has to
be known. For this reason, many manufacturers conduct "mock
certification" AMA durability runs prior to the official certi-
fication runs to be sure that their vehicles will be able to
comply.
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The second type of durability testing done by the manufacturers
is the usual product acceptance testing. Automobile manufac-
turers have spent much time and money in trying to develop
test procedures that will duplicate the wide range of usage
that automobiles encounter once they are sold. In an attempt
to duplicate the use (and abuse) to which customer-operated
vehicles are subjected, the manufacturers perform many tests
at high speeds and loads, under arctic and tropical temperature
conditions, over many different road conditions, and under many
different types of driver treatment. This type of testing has
historically been performed to ensure customer acceptability
and to uncover durability problems which might result in un-
acceptable warranty costs.
The warranty and recall provisions of the Clean Air Act have
caused this type of testing to take on added importance. The
manufacturers are concerned about the costs and negative
publicity that might result from recall programs that may
result from failures in the field. Recalls for emission con-
trol system failures may be even more expensive than the past
recalls for safety-related items have been, since the causes may not be
as evident and the labor, parts, and testing costs may be
high.
The type of durability testing given the most emphasis in this
report is the AMA durability. There is much more data avail-
able on this type of durability schedule, and data from the
other types of durability schedules may not be directly com-
parable among manufacturers.
There is a wide spread in the scope and type of durability test
programs on 1975 prototype vehicles that have been reported to
EPA. While some manufacturers have not reported that any ve-
hicles are currently being durability tested, other manufacturers
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have reported that extensive fleets of vehicles are running.
Manufacturers also vary in the rate at which mileage is accu-
mulated, some finishing the 50,000 miles in a period of time
close to the minimum, others taking much longer.
The number and type of vehicles in any given manufacturer's
durability fleet appear to be in most cases a result of cost
constraints and prototype parts availability, rather than
the result of a thorough and comprehensive analysis of what
is actually needed to demonstrate the ability or inability
of a system to certify for model year 1975.
3.3 Catalyst Screening Programs
The screening of oxidation catalysts for possible use in
model year 1975 is not as active now as it was a year ago.
The major reason is lead time. For a new catalyst to suc-
cessfully pass the laboratory activity and aging tests, the
dynamometer durability tests and the 50,000-mile vehicle tests,
the amount of required time is sufficiently long to make it
doubtful, at this point in time, that even the so-called
"magic bullet" (a catalyst with no problems) could get through
the testing process in time for use in model year 1975 with
job one starting at the usual time.
Some manufacturers, however, may still be screening catalysts
and/or substrates of their own preparation, because of the cost
savings to them if either catalysts or substrates are made in-
house. Since some manufacturers are also becoming more profi-
cient in the catalyst/substrate art,they are seriously consi-
dering being their own source of catalyst or substrate.
3.4 Lead Time for 1975 Production and an Identification of
the Critical Items
The lead time information in this report came primarily from
two sources. The first source is a study done for EPA by the
3-10
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Aerospace Corporation.- This study is an independent analy-
sis of the lead time issue with information concerning lead
time being obtained from catalyst suppliers, substrate sup-
pliers, parts suppliers, machinery suppliers, and tool sup-
pliers. The major domestic automobile manufacturers also
supplied information. The study was primarily limited to
domestic manufacturers and suppliers. The .other source of
information concerning lead time was the responses sent to
EPA by foreign and domestic manufacturers on .the status of
their 1975 development.
The period of time encompassing the last two months of 1972
appears to be a watershed period with respect to lead time.
If certain commitments have not been made by about the first
of the year (1973) then it will be very difficult for the
manufacturers who have not made commitments to be able to
meet the usual "job one" date (July-August) in 1974, for
the 1975 models.
The main lead time problem for model year 1975 is the problem
of creating an entirely new supplier industry for the automo-
bile industry. This new supplier industry complex is the
industry that will have to produce the needed components
for the catalytic converters to be used by most of the
automobile manufacturers. This group of suppliers can be
subdivided into four functional groups. Some suppliers may
perform more than one function.
The first group is the raw material producers. The most
important raw material producers are those that produce
precious metals, especially platinum and palladium. To
2/ Assessment of Domestic Automotive Industry Production
Lead Time for 1975/76 Model YearsThe Aerospace Corpora-
tion, 15 December, 1972.
3-11
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meet the demand for the precious metals which are the active
materials in the type of oxidation catalyst most likely to
be used for model year 1975, the production of the platinum
mines will have to be increased.
The second group is the catalyst substrate producers. These
producers are going to be making an entirely new product, in
very large quantities. The substrate manufacturers will most
likely have to construct new manufacturing facilities, or
extensively modify existing facilities.
The third group is the catalyst producers. These producers
will also need new facilities to coat the substrates with a
high surface area washcoat and then to apply the actual active
catalyst materials.
The fourth group is the catalyst container producers. After
the catalyst substrate has been washcoated and activated, it
must be installed in a container that is inserted into the
exhaust pipe. This group will also have to install new faci-
lities to produce the required components.
It appears, at this point in time, that the single most import-
ant item affecting the lead time issue is the ability of the
catalyst substrate manufacturers to produce substrate at the
needed volume in time. This is based on lead time information
furnished to EPA by the potential substrate suppliers. Since
at least two of the major vehicle manufacturers are consider-
ing the production of their own substrate, the lead time for
substrates may not be as critical as it now appears, but there
is little information available on the plans and ability of
the vehicle manufacturers with respect to substrate produc-
tion in-house.
There are other emission control related components that may
involve lead time problems, such as new carburetors and mani-
3-12
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folds, but these problems are not considered as severe as
the problems with the catalytic converters.
All of the lead time information submitted to EPA has been
based on the conventional new model start-up time of July-
August 1974. There is a period of approximately 4 months
that could be used to extend the lead time available to the
manufacturers. No manufacturer has indicated to EPA that
they will definitely follow such an approach.
In summary then, on a production lead time basis, the auto-
mobile companies appear to have taken or have plans to take
action to ensure the availability of all elements of the
1975 emission control system and to ensure the integration
of these components into the vehicle. If those plans are
carried out, they should be able to produce 1975 vehicles
starting at the usual time.
3.5 Significant Problem Areas
For 1975 system development, there are three interrelated
major problem areas: Durability testing, catalyst failures,
and lead time.
Durability Testing
In general, the durability testing currently being conducted
by the manufacturers is non-optimum as some or all of the
following deficiencies can be found in most programs.
1. Insufficient numbers of vehicle are currently under test.
More vehicles with the same emission control system should be
accumulating mileage to allow sound decisions to be made on
what to produce for model year 1975. Also, a full range of
the manufacturers vehicle mix should now be on test, especi-
ally if there are major differences in the emission control
system among models.
3-13
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2. Mileage accumulation is too slow. Because of the common
practice of developing emission control systems while mileage
is being accumulated, the rate of mileage accumulation for
many manufacturers is slow. For example, some manufacturers
have taken over one year to run 50,000 miles while the mini-
mum time for development testing can be about 4 1/2 to 5
months. (Certification testing has been done in a period
of time as short as 3 1/2 months on an all-out 24 hour per
day, 7 days a week basis.) Therefore, the important dura-
bility data is not being generated as fast as it could be,
which is especially important when the lead time problems
are considered.
3. Non-optimum systems are being tested. Many manufac-
turers are accumulating mileage on systems that are not com-
pletely representative of full 1975-type systems. It is
common to have durability vehicles running without some of
the advanced components that the manufacturers have developed
and are planning to use for model year 1975. Advanced
carburetors and intake manifolds are the most common miss-
ing components. The latest model or generation of catalysts
is also frequently missing.
Premature Catalyst Failures
Premature catalyst failures are the second significant prob-
lem area. The problem is compounded by the fact that the
reasons for the failures are, in many cases, not known.
The durability mileage schedules call for periodic testing,
usually in 4,000-mile increments. If a catalyst failure is
diagnosed at one of these checkpoints, it is usually diffi-
cult to pinpoint exactly when and why failure occurred.
The inability to explain failures (and conversely, the in-
ability to explain success) is a serious problem especially
since commitments to production will depend on the outcome
of the tests.
3-14
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The reason for many of the failures may be catalyst
over-temperature. The usual results are failure of the
substrate due to melting and/or cracking. Since cracking,
for example, is not always followed by an immediate rise
in emissions, diagnosis of the cause of catalyst failure
is difficult. The judgment Of the report team is that
many failures are caused by an excess of combustible mater-
ials (either fuel (HC) or CO) entering the catalyst. This
condition can be caused by many conditions, but the most
likely cause is some form of failure to ignite the air/fuel
mixture in the cylinder.
Poisoning of the catalyst by trace contaminants (lead,
phosphorous and sulfur) is also a problem, but quantita-
tive data on the exact effects from extensive vehicle tests
is lacking. Control of lead contaminants to the proposed
EPA certification level of .03 grams per gallon may not
be as great a problem as was claimed earlier by some manu-
facturers.
Lead Time
Lead time is the third major problem area. Because of the some-
what less than ideal situation with respect to durability testing,
the manufacturers are holding off their commitments to the last
possible instant. Whether or not they are waiting too long is
a controversial matter, but their potential suppliers have
indicated that if decisions and firm commitments are not made
at about the time of this report (November-December 1972),
the "drop dead" dates may be passed.
One possible contributing factor to the need for the manu-
facturers to make decisions at the latest possible time may
not be entirely within their control. One of the reasons
why the decisions are being held up is the lack of durability
3-15
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testing on the advanced "second generation" catalysts. It
appears that the supply of such catalysts to the manufacturers
may have been slow in being made available and the quantities
were limited. Therefore, the vital results from the durability
testing have not been available to the decision makers in the
industry as soon as both they and their potential suppliers
would like.
3.6 Summary Discussion Model Year 1975
In summary, there is little doubt that Honda with their CVCC
engine, Toyo Kogyo with their rotary engine and Daimler-Benz
with their Diesel engine will be able to meet the 1975 stan-
dards .
A number of other manufacturers appear capable of meeting
the 1975 standards with catalytic systems, although the
durability of the catalytic systems appears to be poorer
than the durability of the non-catalytic systems that can
meet the 1975 standards. Catalyst durability is still a
major problem for some manufacturers.
3-16
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SECTION 4
INDUSTRY STATUS - 1976 DEVELOPMENT
4.1 Systems to be Used for 1976 Compliance and the Constraints
Influencing Their Design
Systems to be Used
The typical 1976 emission control system includes all the compo-
nents of the 1975 emission control system plus a' reduction catalyst
for NO control, switching controls for the air injection
J^
system, and possibly a more sophisticated EGR system.
The principal difference in the 1976 system is the addition
of another catalyst. This catalyst, called a reduction or
NO catalyst, is placed in the exhaust flow between the engine
J^
and the HC/CO catalyst. The NO catalyst must operate in an
X
atmosphere that provides enough CO to reduce the NO. To
achieve this CO level, the carburetion is adjusted to provide
a mixture richer than in the 1975 systems.
Many catalysts have been considered for use as NO catalysts
a
in the 1976 systems, but now there are two general types under
serious consideration. The two types use platinum and/or other
precious metals or some sort of nickel-containing alloy, such
as stainless steel, as active material.
As is the case with the HC/CO catalyst, various substrates
could be used for NO catalysts. At this point in time, the
J^
preferred substrate type appears to be the monolithic substrate.
1976 systems will also have provisions for controlling the
location of the air injection. A valve and extra air injection
lines will be needed. The purpose of this switching function
4-1
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is to enable the NO catalyst to operate as a HC/CO catalyst
Jt
during the initial cold start period. During this period,
air is injected upstream of the NO catalyst making it act
X
as an HC/CO catalyst. When both the NO catalyst and the
X
HC/CO catalyst are hot enough to begin converting, the air
is injected between the NO catalyst and the HC/CO catalyst.
J*
The EGR systems in 1976 may be different from those used in
1975. Because of the need to reach the 0.4 gram per mile NO
X
level, all additional control to below the levels achieved
by the 1975-type EGR systems is highly desirable. Getting
substantially lower NO emissions with EGR may require the
Ji
use of a proportional EGR system. Current (1973) and most
planned 1975 EGR systems do a poor job of matching EGR flow
to the requirements of the engine. Systems that offer
proportional flow characteristics are under development.
Whether they will be used may be interrelated with the NO
X
catalyst status at the time at which decisions must be made.
There is another type of emission control system under develop-
ment for possible application for model year 1976. This type
of system uses a single catalyst to control HC, CO and NO .
^•• j±
It is known that some catalysts can efficiently convert HC,
CO and NO simultaneously. The catalysts that use precious
X
metals are an example. This feature has been used by Universal
Oil Products (UOP) in the "Tri-component catalyst" (tri-
component referring to the three gaseous emissions HC, CO and
NO ). The major drawback to the use of a single catalyst for
Ji
control of HC, CO and NO is the requirement for very tight
•&
control of the exhaust oxygen level into the catalyst. If
the air/fuel ratio is too rich, the catalyst loses control of
4-2
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HC and CO and acts like a NO catalyst in a dual catalyst
Ji
system. If the air/fuel ratio is too lean, the catalyst
loses control of NO and acts like an HC/CO catalyst.
It is doubtful whether carburetors or fuel injection alone
at the present state of the art can control the air/fuel
ratio accurately enough to make the concept of a single
catalyst work. However, the reason for the widespread
interest in this type of system is due to an additional
type of control which has been under development for the
past year or so. This system is a feed-back loop that senses
the exhaust gas oxygen level, and feeds back a signal that
controls the air/fuel ratio of the engine. Most of the
development on this system has been done by Bosch, in con-
junction with various European automobile manufacturers,
and by Bendix in this country.
The cost and fuel economy penalty predictions by the manu-
facturers show the same wide range for 1976 systems as for
1975 systems, the cost ranging from a low of $115 to a high
of $1900 and the fuel economy penalty ranging from a 3% to a 50%
increase, compared to 1973 vehicles.
Constraints Influencing the Design of 1976 Emission
Control Systems
The constraints influencing the design of the 1976 emission
control systems are much the same as the ones influencing
the design of the 1975 systems. There are, however, some
differences. Because of the different (richer) air/fuel
requirements of the NO catalyst, the carburetion has to be
H
even more closely controlled than the 1975 systems. The engine
must be run rich, but not too rich, because the HC/CO baseline
4-3
-------
levels will be too high., and not too lean because then the
NO catalyst will not reduce the NO under lean operation.
X
Because having a NO catalyst upstream of the HC/CO catalyst
X
delays the light-off of the HC/CO catalyst, the NO catalyst
X
must work as an HC/CO catalyst during the cold start. This
requires switching the air injection location.
4.2 Durability Testing Program
The durability testing programs currently being conducted by
the industry on 1976 prototype systems are limited. The
manufacturers claim that the present state of the art in NO
J^
catalyst durability has not advanced to the level at which
extensive durability programs are warranted. For this reason,
the number of vehicles currently undergoing durability testing
with 1976 systems on them is quite small, compared to the
number of 1975 prototypes currently being tested.
No vehicle has been reported to EPA that has successfully
completed the 50,000-mile durability test at or below the
1976 emission requirements. Compared with the durability
testing reported by the manufacturers on 1975 systems at
this point in time last year, the 1976 durability testing
is not as extensive.
4.3 Catalyst Screening?Programs
The manufacturers are currently conducting extensive catalyst
screening programs in an attempt to find the optimum NO
Ji
catalyst for use in the 1976 systems. Thousands of tests have
been performed on many different catalysts. Each manufacturer
has a unique set of screening tests, but generally, they involve
three types of tests: laboratory bench activity and aging
tests, single or multicylinder engine activity tests, and
vehicle tests.
4-4
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The laboratory bench activity and aging tests are usually
the first tests performed. The catalyst is checked for NO
2C
conversion efficiency, both as a function of temperature and
CO, and for ammonia (NH-j) formation. The conversion efficiency
of the NO catalyst, when used as an HC/CO catalyst, is another
" • * . *
parameter that is measured.
The engine tests are usually performed on only the more pro-
mising catalysts. Activity, NH- formation, and some durability
testing are important here.
Once a candidate catalyst has passed the first two screening
tests, it is usually put on a vehicle and the entire system
is optimized for low emissions. Depending on the results
of these vehicle tests, the catalyst may or may not enter a
durability testing program.
4.4 Lead Time for 1976 Production and an Identification of
the Critical Items
Currently, lead time is not a major constraint for the pro-
duction of 1976 emission control systems. The manufacturers
have designed the 1976 systems to have a minimum number of
changes from the 1975 systems.
The most critical item from the lead time standpoint is the
reduction catalyst. Because there are so many unknowns
about the eventual catalyst system to be used for the 1976
model year, very little can be done with respect to detailed
contractual commitments for NO catalysts at this point in
*»
time.
If the commitments for the 1975 systems are made in time
to ensure the existence of the catalytic converter supplier
industry, the manufacturers will have approximately 12 months
4-5
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(until December 1973"January 19741 in which, to screen,
develop, and test NO catalysts. After that point in
J^
time, lead time for 1976 systems will become a critical
issue.
4.5 Significant Problem Areas
The most significant problems currently being encountered
by the manufacturers in their 1976 development programs all
are related to the NO catalyst. The major problems are
X
the general state of NO catalyst development, catalyst dura-
X
bility and efficiency, ammonia formation, and ruthenium oxidation.
NOX Catalyst Development Status
When the Clean Air Act was passed, automobile and catalyst
manufacturers already had some background in oxidizing
catalysts. The development of HC/CO catalysts for California
in the 1960's and the very extensive experience of the catalyst
manufacturers in the use of oxidizing catalysts in other
applications had already established a basis from which the
catalyst technology for oxidation catalysts could start and
be adapted to the legal requirements for 1975. This was not
the case with NO catalysts. No automobile-related development
X
work was done on NO catalysts in the California program in
Ji
the 1960's and the use of NO reduction catalysts in other
X
non-automobile applications was not as extensive as the use
of oxidation catalysts. Therefore, the baseline for the
application of NO catalysts was much less advanced than the
.A.
baseline technology level for oxidation catalysts. The
demonstrated emission control technology at this point in
time reflects this difference.
Catalyst Durability and Efficiency and Ammonia Formation
Catalyst durability is another 1976 development problem. NO
ji
catalysts must generally be run at a higher temperature than
4-6
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HC/CO catalysts. This makes over-temperature excursions more
critical, and many NO catalysts have been destroyed due to
X
over-temperature. Because the operating temperature is higher,
the severity of the thermal shock problem is also greater,
both for "upshock" and "downshock" (heating up and cooling
off the catalyst).
Catalyst efficiency is also a problem. Initially, manufac-
turers attempted to have the NO catalyst do the entire NO
X X
clean up job without EGR. This requires very high efficiencies.
The problem is that some NO catalysts do show very high test
X
efficiencies (greater than 95%) and almost no NO comes through
j£
them, but not all of the NO is reduced to nitrogen and oxygen.
X
Some NO catalysts are also very efficient in producing
Ji
ammonia (NH.,) from NO and the hydrogen (H~) present in the
exhaust. Although ammonia is not currently regulated as a
pollutant (it is_ objectionable and noxious) , ammonia emissions
are not the only problem. The oxidation catalyst is very
effective in oxidizing the NH, back to NO . Thus, the net
O X
efficiency of a catalyst pair is important and a catalyst
with lower gross efficiency and less NH3 formation may be
superior to one with higher gross efficiency and greater NEU
formation.
Ruthenium Oxidation
Another catalyst-related problem area is a consequence of
trying to find a NO catalyst that does not produce much
X
ammonia. If ruthenium (Ru), one of the precious metal group,
is added to a catalyst formula containing platinum, for
example, the resulting catalyst produces little NH.,. However,
the use of ruthenium as a catalytic material results in two
4-7
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problems: first, ruthenium is reported to be even more
scarce than platinum; and second, ruthenium forms a volatile
oxide. When the NO catalyst is operated as an HC/CO
X '• • -
catalyst during the cold start, some of the ruthenium is
oxidized and is lost. These two problems have caused some
manufacturers to continue to try to find or develop other
NO catalysts with low NH-. formation characteristics.
ji O
Other Problem Areas
Other current problems in the development of 1976 systems
are due to the richer air/fuel ratios needed for the NO
X
catalyst. These problems are increased HC/CO loading to
the oxidation catalyst and fuel economy.
The richer air/fuel ratios used in the 1976 systems can cause
greater input HC/CO emissions to the oxidation catalyst. This
implies that the overall HC/CO conversion efficiency of the 1976
dual catalyst system will have to be higher than the overall
conversion efficiency of the 1975 system. Since maintaining
high conversion efficiency at extended mileage is currently
a problem with 1975 systems, it is likely to be an even more
serious problem with 1976 systems.
Richer air/fuel ratios can mean poorer fuel economy. Many
manufacturers have reported that they think that the 1976
model year vehicles will have poorer fuel economy than current
(1973) systems. There is, however, little comparable data to
quantify the extent of this projected loss.
4.6 Summary Discussion - Model Year 1976
No manufacturer has yet demonstrated the capability to meet
the 1976 standards for 50,000 miles.
The three non-catalytic systems (Honda CVCC engine; Toyo
Kogyo rotary engine; and Daimler-Benz Diesel engine) that
4-8
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have demonstrated the capability to meet the 1975 standards
are all judged by the report team to have significant
potential for meeting the 1976 standards.
The catalytic systems being developed for 1975 may, with
the addition of a better reduction catalyst, evolve into
successful 1976 systems. However, the performance to date
of dual catalyst systems is such as to suggest, in the
opinion of the report team, that the potential for success
for such dual catalyst systems is less than the potential
for success of the non-catalytic systems.
4-9
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SECTION 5
NON-AUTOMOBILE MANUFACTURER DEVELOPMENT STATUS
5.1 Catalyst Manufacturers
Of the large number of catalyst manufacturers that are
potential suppliers to the automobile industry, three manu-
facturers have reported that they have built and tested
emission control systems on vehicles. The three manufacturers
are Engelhard, Universal Oil Products (UOP) and Matthey-
Bishop (a subsidiary of Johnson-Matthey).
5.1.1 Engelhard
Engelhard has built and tested several vehicles. The most
important vehicle for the purposes of this report is a Ford
Torino Station wagon, which was reported by Engelhard to
have completed more than 50,000 miles of durability testing
without a catalyst change. The vehicle was equipped with
the Engelhard Type IIB catalyst (an improved "second genera-
tion" catalyst), air injection and EGR. Since there is very
little durability.data from the automobile manufacturers on this
type of catalyst, the emission performance of this vehicle/
catalyst combination is important.
What actually was demonstrated by the Engelhard durability
results is difficult to determine. The fuel used was lead
sterile, and thus significantly lower than the lead level
that is expected to be used for model year 1975 certifica-
tion. The mileage accumulation schedule was not strictly
AMA, and the engine was replaced at 8,000 miles.
5-1
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The Engelhard vehicle has been tested at the EPA laboratory
at 58,000 miles. The test results were:
HC CO NO
.38 1.42 1.62
.45 1.61 1.50
Average .42 1.52 1.56
The EPA emission tests show that the Engelhard vehicle has
excellent CO control and somewhat less satisfactory HC con-
trol, when compared" to the 1975 standards. Both HC and CO
control are very good for a system in which the catalysts
have been exposed to exhaust gas for nearly 60,000 miles
of vehicle operation.
No catalyst failures were reported in the mileage accumulation
for this vehicle. Compared to reports of frequent catalyst
failure from the manufacturers, this test was much more suc-
cessful. The reasons for this are not known, but the fact
that the mileage accumulation was less rigorous than the
more stringent durability tests that the manufacturers
perform (in addition to AMA durability) , and the character-
istics of the fuel and lubricant used by Engelhard, may have
had a significant influence on the favorable result.
5.1.2 Matthey-Bishop
Matthey-Bishop is another catalyst manufacturer that has
reported results on vehicle tests. Matthey-Bishop has reported
results on two vehicles, one with a 1975-type emission con-
trol system, the other with a 1976-type emission control
system. The vehicle with the 1975-type emission control
system is the vehicle that received much attention during
5-2
-------
the Suspension hearings in the Spring of 1972. At that
time, the vehicle had accumulated approximately 24,000
miles and was under the emission levels required for 1975.
Additional information obtained since then indicates that
there were some substrate and baseline emission problems
with the 1975 control system vehicle after 24,000 miles.
These problems caused Matthey-Bishop to reconsider whether
they should do vehicle testing of 1975-76 prototypes or
to continue to do research and development work on catalysts.
Matthey-Bishop has chosen the latter course, and their
vehicle durability program is currently inactive.
5.1.3 Universal Oil Products (UOP)
UOP has reported successful completion of two 50,000-
mile durability tests with catalyst systems. These results
are considered significant, since the tests were run with
conventional lubricating oil and fuel of .02 gpg lead con-
tent. On catalyst PZ 217, the 50,000-mile results were:
HC .15 gpm CO 1.2 gpm
On catalyst PZ 236 the results at 50,000 miles were:
HC .22 gpm CO 1.45 gpm
The results are considered good, especially for PZ 236 since
the precious metal loading was .018 troy ounces, compared to
the .07 troy ounces for PZ 217.
5.2 Other Manufacturers Development Status
Many non-automobile and non-catalyst companies have developed,
or are developing, 1975-76 emission control systems. Of the
many companies, four are the most significant: DuPont, Esso,
Ethyl and Questor.
5-3
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5.2.1 DuPont
DuPont has long been active in emission control development.
They have been especially interested in emission control sys-
tems that are lead tolerant. Much of the recent development
work has been with a rich thermal reactor and a sophisticated
EGR system. The EGR system is a proportional one, controlled
by exhaust gas back pressure with the exhaust gas introduced
above the throttle plate.
Typical results with this type system on a full-size vehicle
are:
HC CO N0v
X
Approx. .15 Approx. 6.0 Approx. .5 - .6
The above results indicate typical rich thermal reactor per-
formance.- good HC control, but CO and NO emissions above
J^
the 1976 levels.
DuPont also reported some results on a smaller vehicle with
the same type of control system. In this case, the vehicle
was a Ford Pinto currently on durability testing at 36,000
miles. The results were reported to be:
HC CO N0v
X
.25 4.5 .6
Again, the characteristic performance of the rich thermal
reactor is evident.
DuPont is continuing to develop their emission control
system further. They also are developing particulate
trapping systems for vehicles.
5-4
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5.2.2 Esso
Esso has developed two distinct emission control systems
aimed at achieving 1976 emission levels. The two systems
are the Rapid Action Manifold (RAM) rich thermal reactor
system and a dual catalyst system.
The RAM system has demonstrated good emission performance
for a rich thermal reactor. Two tests at EPA gave the
following results:
HC
.11
.10
.11
CO
4.76
3.19
3.98
NOV
X
0.67
0.67
0.67
Average
The CO control for the RAM is good, one of the two tests
achieving 1975-76 CO levels. The NO , however, is above
J\
the 1976 level.
Esso reported that they have been able to achieve the 1976
emission levels at low mileage, as have many manufacturers
using dual catalyst systems. Esso's development is important
because they reported that up to 20,000 miles of durability
on a chassis dynamometer the emission levels were below the
1976 levels. At 30,000 miles the emissions were above the
1976 levels on CO and NO . This durability performance is
Jt
superior to that reported to date by the automobile manufacturers.
Esso attributes the loss of NO control to a loss of active sur-
it
face area of the catalyst. The fuel used in this test was lead
sterile which may have influenced the favorable results. Esso
reported that they are not yet ready to put vehicles on the
road for mileage accumulation, since they are still developing
the NO catalyst.
5-5
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5.2.3 Ethyl
Ethyl, like DuPont, has been extremely interested in emission
control devices that are lead tolerant. Ethyl has been in-
volved for several years in the development of thermal reactor
systems for automobiles. The system receiving the most
attention has been the Ethyl Lean Reactor system, a lean ther-
mal reactor, EGR, and special three venturi carburetor system.
Emissions from this system have consistently been above the
1975-76 standards. Typical results in 1971 were:
HC CO N0v
X
.52 6.2 1.37
More recent tests with a quick heat manifold, proportional
EGR system, and a 17.5 to 1 air/fuel ratio setting for the
carburetor yielded on an 8 test average basis:
HC CO NO
.27 3.6 2.3
Ethyl is continuing development on their system with approxi-
mately 5 cars in their development fleet. They have not
reported any NO levels below the requirements for 1976, and
X
since their system operates at a lean air/fuel ratio the use
of a NOX reduction catalyst is precluded.
5.2.4 Questor
Unlike DuPont, Esso and Ethyl, Questor is not as well known
as an independent developer of emission control systems.
Questor Automotive Products is a diversified automotive parts
supplier, making, among other things, exhaust systems and pis-
ton rings. Questor has been working for a few years on the
5-6
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emission control system that they call the "Reverter."
Basically, the Reverter system is a rich thermal^reactor
followed by a metallic NO catalyst, followed by another
a
thermal reactor. In order to maintain high reactor and
catalyst temperatures, the system is carbureted very rich,
typically 9-10% CO in the exhaust. No EGR or spark retard
control is used with the system.
The Reverter system can operate on leaded fuel. Current
prototypes, therefore, have compression ratios that corres-
pond to this characteristic (9.2 to 1) .
The high temperature promotes good HC and CO oxidation in the
thermal reactors and also keeps the NO catalyst operating at
J^
a point where its efficiency is high. The high temperature
operation of the NO catalyst may also be beyond the tempera-
J+
ture range in which ammonia (NH_) is formed. Also, the rea-
son why the system does not appear to be strongly affected by
the lead in the gasoline (at least at low mileage) is the
fact that most of the lead is in the vapor phase at the higher
temperatures of the Reverter system and does not deposit out
on the catalyst and clog or poison it.
The high temperature of operation of the Reverter system is
also responsible for its disadvantages. To keep the tempera-
ture high, the engine is run rich to provide the fuel (HC and
CO) necessary to keep the temperature in the system high.
This causes a loss in fuel economy. The high temperatures
also require use of more expensive materials in the construc-
tion of the Reverter system, compared to conventional exhaust
systems. The high temperatures also may cause problems
related to excessive under-hood temperatures.
The Questor Reverter system has been tested by American Motors,
Chrysler, Ford and General Motors. Although not every test was
below 1976 levels, the Reverter system has demonstrated impres-
5-7
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sive emission control when tested by all four of the automo-
bile manufacturers.
The Reverter system has also been tested at EPA. The emis-
sion levels were also below the levels required for 1976.
All the tests, both at the manufacturers and at EPA, have
been on low mileage (less than 8,000 miles) prototypes.
All four of the automobile manufacturers have expressed
reservations about the Reverter system. In general, the
aspects that the industry considers negative are the fuel
economy penalty and the unproven durability. Of the four
automobile manufacturers, only General Motors currently
has a joint development program with Questor.
Another factor besides fuel economy and durability is that
at the present time, it would be almost impossible to employ
a Reverter system for model year 1975, due to lead time con-
straints. This means that the typical 1975 system now planned
for use would be good for only one year. The manufacturers
do not like to contemplate writing off the costs for a 1975
system in such a short time.
5.3 Summary Discussion Non-Automobile Manufacturer Develop-
ment Status
The Questor Reverter system has not demonstrated durability
success or failure. No vehicles have yet been run to 50,000
miles, although durability testing on the AMA durability
schedule is now underway. Until such tests are completed,
the feasibility or infeasibility of the Reverter system will
not be demonstrated. However, it is the judgment °f the re-
port team that the Questor Reverter emission control system
is at least as effective as the 1976 emission control systems
currently under development by the automobile manufacturers.
5-8
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In fact, the Reverter system may be superior to many 1976
dual catalyst systems, having completed 19,000 miles of
durability testing at the time this report was written and
remaining under the 1976 levels. Information from the
vehicle manufacturers did not indicate that any results
superior to the Questor results have yet been achieved.
As regards all of the other systems discussed in this section,
it is the judgment of the report team that the potential
of those systems for meeting the 1976 standards is much less
than the potential of the Questor Reverter system.
5-9
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SECTION 6
INDIVIDUAL MANUFACTURERS REVIEWS
6.1 DOMESTIC MANUFACTURERS
6.1.1 AMERICAN MOTORS (AMC)
6.1.1.1 1975 Development Status
Systems to be Used - '75
The AMC system for 1975 is planned to be a typical 1975 system
employing engine modifications, air injection, exhaust gas
recirculation and an oxidation catalyst. The engine modifi-
cations may include a quick heat intake manifold and breaker-
less ignition. AMC has done extensive development work in
the engine modification area, primarily in combustion chamber
design. They have worked extensively with both GM (AC) and
Engelhard, and at this time, appear to favor the AC underfloor
pellet catalyst. Since at the time of the writing of this
report, GM had not finalized the catalyst active material type
and loading, it is not too surprising that AMC has not done so
either.
Although AMC mentioned development work on the breakerless
ignition and quick heat intake manifold, little data was
reported on those subsystems. In fact, it is not clear
whether or not AMC has ever tested a complete 1975 system
including the breakerless ignition, quick heat intake mani-
fold and the rest of the system (including a good catalyst).
AMC reported little information about design constraints
that would permit some logical development pattern to be
inferred from the information they did present. It can
only be conjectured, for example, how the results on the
GM catalysts that AMC has achieved can be construed to be
better than the results with the platinum monolith catalysts.
Possibly AMC is aware of the current encouraging results
obtained by GM on their latest promoted base metal catalysts.
6-1
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AMC shows a good example of the development problem faced
by a relatively small manufacturer. Because of limitations
caused by their small size AMC has not been able to do all
of the in-house development work that they would probably
like to. As a result, they have had to depend on outside
suppliers for most of their components.
The American Motors status report indicated that 1975 AMC
vehicles will have 9% poorer fuel economy than 1970 vehicles.
This is about an additional 5% loss from 1973 vehicles.
More development work may reduce this penalty since AMC
works closely with GM which is not experiencing a penalty
from 1973 to 1975 systems.
AMC estimated that the retail price increase required to
meet the 1975 standards will be about $275 ('72 dollars)
compared to 1970 vehicles. Catalyst replacement, if required,
for a V-8 powered vehicle is estimated by AMC to cost $76.
If catalyst replacement is not required, the maintenance
cost of the 1975 vehicle may be less than '70-'74 vehicles,
especially if a breakerless ignition is used.
Durability Program - '75
The American Motors vehicle durability program is designed to
assess the degree of the various problem areas associated
with preliminary system designs.
Three vehicles with 1975 prototype systems have been run
to 50,000 miles by AMC:
DOO-24 3000 pound, 232 CID
D20-6D 3500 pound, 304 CID
D17-11 3000 pound, 258 CID
A fourth vehicle, D28-25D, suffered converter over-temperature
and a resulting vehicle fire. With the exception of this
last car, AMC considers their durability program to be on
6-2
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schedule. Several other vehicles are at relatively
low mileage points. Currently only two of AMC's three
engine families have been represented in the durability
program. Vehicles using the third engine family have
been prepared for low mileage testing. Thus, it appears
that ultimately all of AMC's current engines will be
represented.
The basic thrust of the AMC program is one of catalytic
system evaluation. As such, the vehicles which have com-
pleted 50,000 miles of testing have not been equipped with
full 1975 emission control concepts. Specifically lacking
are quick heat intake manifolds and advanced carburetion.
Testing has been performed in accordance with standard
Federal procedures with the exception of maintenance. On
vehicle D17-11, a cylinder head change was required at
about 28,000 miles. It appears, however, from the data
that this type of maintenance did not significantly affect
the overall deterioration factor calculation. Fuel used
had a lead content of less than .02 grams per gallon.
Listed below are the HC and CO deterioration factors re-
ported for the three vehicles which have completed 50,000
miles of operation:
Vehicle HC DF CO DF
DOO-24 1.96 2.66
D20-6D 2.03 2.11
D17-11 3.77 less than 1.0
At this point, AMC has demonstrated relatively severe
deterioration of their systems under test. Low mileage
data does not seem to be representative of a full effort
on a complete 1975-type system.
6-3
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Catalyst Screening Program - '75
The catalyst screening work used by AMC is done by GM
and is described under the GM section.
Progress and Problem Areas - '75
Progress
AMC has made progress in the last year on catalyst system
selection and component development.
In the area of catalyst system selection, AMC apparently
now considers the AC division of GM to be one of their
potential suppliers of both catalysts and containers.
Their description of the system that they are concentrating
their development on indicates that it is the same as the
AC underfloor system. The catalyst choice, however, has
not yet been made.
AMC also reported that they have done some development work
on quick heat intake manifolds.
Problem Areas
AMC reported that their major problem area was that "...none
of the systems tested to date has shown the ability to meet
the 50,000-mile durability requirements of the certification
test procedure." Lead time and an unexplainable vehicle fire
were also reported as problem areas.
While the 1975 levels have been achieved with the GM underfloor-
type system, AMC has not been able to demonstrate 1975 emission
levels with their own catalyst system located inside the
standard muffler and installed in the normal rear muffler
location.
6-4
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Conclusions - '75
The report team concludes that AMC's chances of certifying
for 1975 are questionable. They have been grouped into
class 75-2.2, Catalytic System Approach - Average Develop- -
ment Status. Data available on six-cylinder vehicles with
noble metal monolith catalysts indicated that certification
of part of AMC's product line is possible. Data on V-8
powered vehicles and vehicles using pelleted catalysts was
less encouraging. Insufficient data on systems employing
the advanced engine mod concepts being developed by AMC
makes a more definite conclusions impossible at this time.
AMC's chances of certification are highly dependent on GM's
ability to supply them with acceptable catalysts and on AMC's
ability to adapt the GM catalysts to AMC vehicles.
6.1.1.2 1976 Development Status
Systems to be Used - '76
The two systems planned for use by AMC appear to be virtually
identical to those under consideration and development by
GM for 1976. AMC, therefore, in the opinion of the report
team, appears to be focusing most of their effort on adapting
the GM-type system to their vehicles, rather than designing
and developing one of their own.
Of the development tests reported, not one (of the total of
9 reported) met the 1976 levels. The only system that AMC
has ever reported testing that met the 1976 levels was
covered in their 1971 status report. That was the Questor
Reverter system. No development work or testing has been
reported by AMC on the Questor system with the exception of
the one test reported in 1971.
6-5
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Durability Program - '76
AMC has not initiated any durability testing of their 1976
prototype concept. No schedule was submitted to indicate
when testing will be initiated.
Catalyst Screening Program - '76
AMC did not report any catalyst screening program for 1976.
Progress and Problem Areas '-' '76
Progress
The progress that AMC has made in the last year on 1976
systems has apparently resulted in a decision to use the
GM system. Both possible 1976 systems described by AMC
are the two systems given highest priority currently by GM.
Problem Areas
AMC reported that their three major problem areas were
(1) they are unable to meet the emission levels re-
quired for 1976, (2} the over-temperature protection system
is unsatisfactory, and C.3) AMC has no durability test
results.
AMC reported only 11 emission tests on 1976 systems.
Apparently, having this small number of tests completed
was not considered as serious a problem as the others
listed above.
Conclusions - '76
The report team concludes that AMC's chances of certifying
for 1976 are questionable. They have been grouped into
class 76-2.1, Catalytic System Approach - Average Develop-
ment Status. Not enough data was available on which any
6-6
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firmer conclusions could be based. As is the case for
1975, AMC's chances for 1976 are highly dependent on
GM's ability to supply emission control systems which
AMC could successfully adapt to their vehicles.
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6.1.2 CHRYSLER
6.1.2.1 1975 Development Status
Systems to be Used - r75
The Chrysler first choice system consists of engine
modifications, EGR, modified carburetion and a noble
metal monolithic oxidation catalyst with air injection.
As possible back-up systems, Chrysler is considering
replacing the non-proportional EGR system of the first
choice system with a proportional system and/or replacing
the standard exhaust manifolds with partial thermal reactors,
Some consideration is still being given to using pellet-type
catalysts in place of the monolith units.
The precious metal monoliths, especially palladium^con-
taining catalysts, are receiving the most attention at
Chrysler currently.
Chrysler did not specify what they consider to be important
design constraints; however, they seem to be concerned about
fuel economy, performance and cost penalties. Chrysler
reported an 8% power loss due to emission control is anti-
cipated for 1975. An EPA test of one of Chrysler's 1975
prototypes indicated, however, that the acceleration times
of the prototype were almost identical to the prototype
car's 1972 counterpart which was rented by EPA for the
purposes of comparison. Chrysler is also claiming an 8%
fuel economy penalty comparing 1975 systems to 1972 systems.
Limited data on the 1975 prototype tested by EPA does not
support this claim as the fuel economy measured was as
good as current vehicles. In the opinion of the report
team, cost seems to be the major reason for the deletion
of partial thermal reactors and proportional EGR from the
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first choice system. Apparently, the electronic engine
control (EEC) concept was also deleted for cost reasons.
Chrysler stated that the cold start retard feature did
not provide enough improvement when using.monolithic
catalysts to justify including EEC in the first choice
system.
Low mileage tests on Chrysler vehicles using complete
systems have been as low as .12 gpm HC, .9 gpm CO, and
1.32 gpm NO . Tests run using the partial thermal
ji
reactors without catalysts resulted in emission levels as
low as .56 gpm HC and 5.6 gpm CO. A major point of
difference between the Chrysler systems and the systems
of the other manufacturers has been in the development
of partial thermal reactors rather than quick heat intake
manifolds to lower the level of the emission reaching the
catalyst. The Chrysler approach is just as effective but
may be more expensive and for that reason, may not get
into production.
Chrysler did not supply any information on the use of
modulating devices. A catalyst by-pass system was formerly
under development but is no longer being considered.
Chrysler estimated the cost of their first choice system
for 1975 to be $363 more than no control system at all or
about $260 more than the system for '73-74 vehicles.
Durability Program - '75
The primary thrust of the Chrysler durability program at
this point is one of establishing catalytic deterioration
information based on vehicle mileage accumulation. A 10
vehicle fleet is operating at the Chelsea proving ground.
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At the time of the Chrysler submittal none of these
had completed 50,000 miles, although several were
nearing completion. One vehicle (car #333), which
is not included in the current fleet but which previously
completed 50,000 miles, will also be discussed in this section.
Three out of the five 1972 Chrysler engine families are
currently involved in the program. The 400 CID and small
displacement Cricket vehicles have not been reported to be
on mileage accumulation.
The test vehicles are equipped with several types of mono-
lithic catalysts and most still use 1973 carburetion and
exhaust gas recirculation. Thus, it cannot be assumed
that these vehicles are typical of complete 1975 models.
Three major considerations of Chrysler's test procedures
are necessary to fully evaluate the significance of
their testing thus far. First, the fuel used for mileage
accumulation is Indolene Clear. While trace lead level
data on individual batches was not included, it must be
assumed that some of the mileage may have been run on fuel
with a level of less than 0.01 grams per gallon, considerably
lower content than the assumed average lead-free fuel of
1975 - 0.03 grams per gallon. Second, Chrysler is basically
using an accelerated mileage accumulation driving schedule
which is more severe than the AMA schedule, and reportedly
more typical of customer-type usage. The Power Plant
Endurance test and the General Endurance test were used
on at least seven out of the 10 reported vehicles. The
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use of this type of.mileage accumulation, while cer-
tainly necessary prior to a production run, may have
introduced so many non-catalytic problem areas as to
have reduced the usefulness of the catalytic durability
program. It is significant that four of the ten vehicles
suffered rod or bearing failures, requiring engine replace-
ment or rebuild during the mileage accumulation. Third, and
somewhat related to the previous point, the maintenance pro-
cedure utilized on this fleet of vehicles cannot be considered
to be the type of maintenance allowable during a certification
run.
Of the 10 vehicles running and car #333, the following cal-
culated or projected deterioration factors appear most
significant. Included in the following table is the latest
mileage reported and as close to a 4,000-mile data point as
could be found in the submittal:
Deterioration Factors & 4000-Mile Emissions
Car
#
414
467
333
Mileage
33096
25814 '
49438
HC gpm
HC DF 4000
1.82
1.03
less than
1.0
.31
.24
.25
CO DF
1.45
CO gpm
4000
4.20
less than 9.40
1.0
2.14
1.42
.N0v DF
X
1.05
2.26
less than
1.0
NO gpm
4UOO
1.94
1.17
V
2.17
While a number of assumptions as to data point selection had
to be made due to numerous cases of unscheduled maintenance,
it does appear that car #333,in light of its developmental
character,did successfully demonstrate 50,000 miles of
operation approximating the 1975 requirements. Car #467
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had inordinately high low mileage carbon monoxide emissions
but appears to be headed toward relatively low HC and CO
deterioration factors. Car #414 thus far has demonstrated
deterioration factors lower than the Chrysler design goal
of HC DF of 2 and CO DF of 2.
Catalyst Screening Program - '75
Chrysler uses both a laboratory test apparatus (called a
tube furnace) and a single cylinder engine test rig for
catalyst screening.
The tube furnace is essentially a heated container in
which catalyst effectiveness for an artificial exhaust
gas can be measured. The catalyst is aged for 16 hours
at each of the following temperatures:
1500° F
1700° F
1800° F
1900° F
2000° F
The physical crush strength of the fresh and aged catalyst
is compared. Catalytic activity is determined as described
below on the fresh catalyst and after the 1900° F and 2000° F
exposures. Chrysler feels this environment is similar to
that encountered in a vehicle over 6,000 miles of gentle
driving. However, Chrysler did not provide catalyst temper-
ature or other data for vehicle operation to substantiate
this claim.
After this aging, Chrysler measures steady state conversions
for two hours under each of the following test conditions:
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1500° F
1700° F
1800° F •
1900° F
2000° F
The light-off temperature for 50% conversion of HC and
CO, as well as the temperature for 90% conversions,is
measured. A synthetic exhaust gas containing 2% CO,
200 ppm HC, 3% oxygen, and 3% water vapor is used.
Catalysts which remove 90% or more of the CO at 800° F
when fresh are considered to have passed the test if
the temperature for conversion of 90% of the CO does not
increase more than 100° F upon aging. Platinum-and
palladium-containing catalysts have performance superior
to other catalysts on this test.
Successful candidates are moved to a single cylinder
engine test. If the catalyst continues to perform well
here, it then is a candidate for engine dynamometer and
durability testing.
Progress and Problem Areas - '75
Progress
Chrysler has made significant progress in the last year.
Some durability vehicles have run 50,000 miles although
whether the tests were successful or not is somewhat un-
clear (see Problem Areas below). Chrysler has made
progress in the area of catalyst screening. More information
on catalyst screening was supplied by Chrysler than by any
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other manufacturer. Chrysler has also made progress
in the area of catalyst selection, having secured a
supply of precious metal for use in catalytic converters
and also having reached an agreement with UOP in the
area of catalyst production technology.
Problem Areas
Chrysler has reported serious problems in the area of
catalyst substrate mechanical durability, particularly
with the extruded Corning W-l substrate. The problems
are heightened because Chrysler reported that they do
not know why the failures occur. The failures do not
appear to happen as frequently with other types of sub-
strates in the testing done by Chrysler.
Chrysler also may have some problems in the area of
emission measurement. Recent correlation tests at EPA
of two Chrysler prototypes that had completed 50,000
miles showed relatively large differences in the CO results,
with the EPA results being lower. Discussions with Chrysler
personnel revealed that the instruments, calibrations and
procedures used by Chrysler were inadequate to accurately
measure CO at the low levels that result from systems per-
forming at or below 1975 CO levels. Chrysler indicated
that they were in the process of installing better CO
instruments in their facilities. It is not known how much
of the CO data that Chrysler has presented to EPA was
generated with the inadequate CO instrumentation. Chrysler's
review of data collected using the inadequate instrumentation
may have created undue pessimism on their part.
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Conclusions - '75
The report team concludes that Chrysler will probably
be able to certify for 1975. They have been grouped into
class 75-2.1, Catalytic System Approach - Above Average
Development Status. One Chrysler prototype has been
tested by EPA in the Ann Arbor laboratory which was
below the 1975 levels after a 50,000-mile durability
run. This vehicle completed the 50,000 miles without
a catalyst change. The vehicle was not a full effort
system in our opinion, since partial thermal reactors
were not installed and only a single catalyst was used.
Our analysis of data on another Chrysler prototype, still
not equipped with a full effort system, which completed
50,000 miles, indicated that the 1975 standards were
achievable. This vehicle, car #333, also achieved the
1975 levels in EPA1s laboratory but one of the two catalysts
installed on the vehicle had less than 50,000 miles on it
at that time.
Other Chrysler prototypes which have completed or nearly
completed 50,000-mile durability tests have demonstrated
deterioration characteristics which indicate certification
of full effort systems with lower "untreated" emission
levels is probable.
6.1.2.2 1976 Development Status
Systems to be Used -' '7£
Chrysler's first choice system for 1976 is essentially the
1975 system with the addition of noble monolith NO catalysts
X
on each side of the engine. This is the same approach being
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used by most other manufacturers. The EGR system may
be more sophisticated than the 1975 version. No tests
of the first choice system reported were below the 1976
levels.
Four back-up systems were reported:
1. Metallic NO catalysts
X
2. DUAC system, both NO and HC-CO catalysts
X
in the same can.
3. Dual catalyst system used on one side of the
engine only.
4. Questor system
Chrysler is currently seeing better durability with back-
up system number one (metallic NO catalyst) than with the
A,
first choice system, but they reported: "...its required
high operating temperature for both reducing and warm-up
oxidation places heavy demands on other components."
This is the only Chrysler system to meet the 1976 levels.
The best test was .38 gpm HC, 2.1 gpm CO, and .26 gpm NO .
rfS.
Back-up system number two (DUAC) is reported to aggravate
temperature problems while back-up system number three has
impaired performance due to excessive heat losses.
Concerning the Questor system, Chrysler reported: "We
consider this system a less attractive back-up....because
of the fuel consumption and durability problems." It
should be noted that Chrysler compared the fuel economy
of the Questor vehicle (5000 Ib class) to the fuel economy
of a lighter weight vehicle (4500 Ib class). The fuel
economy measured by Chrysler on the 1972 FTP was 8.46 mpg.
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Compared to the average of all the 5000 Ib 1973 certi-
fication vehicles tested by EPA, this represents only a
9.6% fuel economy penalty. Compared to the average 1973
Chrysler certification cars at 4500 Ib (500 pounds lighter
than the test weight of the Questor vehicle) the penalty
is 15%. Chrysler claimed, however, "...The fuel economy
penalty is extreme (about 30%)." It is the judgment of
the report team that Chrysler is overestimating the fuel
economy penalty of the Questor system.
It is also not apparent why Chrysler reported "durability
problems" as a reason for giving less consideration to.
the Questor system because they have never reported any
durability testing of this type of emission control system.
A partial thermal reactor (PTR) is also considered as a
back-up to the standard exhaust manifold of the first
choice system. The use of a PTR would shorten the light-
off time of the NO catalyst in the opinion of the report
H •
team, but Chrysler claims they would need improved catalysts
which could withstand higher temperatures with this approach.
By switching the air-injection point after warm-up from
in front of the PTR to behind the PTR, it may be possible,
in the judgment of the report team, to realize the benefit
of reduced light-off time without experiencing an increase
in system temperatures during "stabilized" operation.
Chrysler did not report any development of this approach,
however.
A potential back-up system, no longer under consideration,
consisted of a dual catalyst system with a start catalyst.
Start catalysts can trade off durability performance
for good light-off characteristics because they can be
switched out of the system after warm-up and they are not
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subjected to the deteriorating effects of the exhaust gas
most of the time. Chrysler reported: "...this arrange-
ment was discarded when it was discovered that the reducer
catalyst could function as an oxidizer during the warm-up
cycle and thus simplify the basic system." No data was
reported which would indicate that a NO catalyst can do
ji
as good a job of warming up the system as a start catalyst
designed specifically for that purpose. In the judgment
of the report team the start catalyst approach may be
superior.
A 3-way-type catalyst system was also investigated. Results
were rather discouraging because a conventional carburetor
was used on the engine. 3-way approaches require tight
control of the air/fuel ratio which is impossible with con-
ventional carburetors. Chrysler did not report whether they
knew about these air/fuel ratio requirements before they
initiated the 3-way testing.
A maximum fuel economy penalty of 15% has been established
as a design constraint. Chrysler reported, however, "...
it seems that the 1976 systems are likely to force the total
penalty well over the 15% level, using 1971 as a base." No
Chrysler data substantiated this claimed problem area.
Packaging is another area given considerable attention.
Chrysler apparently desires to make as few chassis modifi-
cations as possible.
Chrysler has explored the Texaco stratified charge engine
(TCCS) but the level of development effort is rather low.
Other alternate approaches, including the turbine engine,
have also been explored by Chrysler, but the short period
of time remaining before 1976 vehicles must be in production
has eliminated "alternate" approaches from consideration.
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The cost of the first choice system for 1976 was estimated
at $530, $430 more than the cost of the emission control
system for 1973-74 Chrysler vehicles. The fuel consumption
penalty is estimated to be greater than 15% compared to
uncontrolled cars. It is difficult for Chrysler to determine
a very definite penalty at this time because none of their
current systems appear to be capable of meeting the 1976
levels at high mileage. More alterations will be required
which may have some effect on fuel economy.
Durability Program - '76
The Chrysler durability program on 197& prototypes has been
quite limited. Of the three systems tested on mileage
accumulation, none met the 1976 requirements at low mileage.
However, to determine problems of durability, Chrysler
initiated mileage accumulation on the General Endurance
Cycle. Two dual catalyst concept vehicles and one thermal
reactor vehicle were run, Neither of the catalyst-equipped
vehicles had exhaust gas recirculation which at least
partially accounts for their poor zero-mile oxides of
nitrogen emissions. The deterioration of NO emissions
X
for the catalyst vehicles was quite high and resulted in
termination at low mileage. The thermal reactor vehicle
through 50,000 miles of operation consistently exceeded
the 1976 levels by a factor, of about three on all pollutants.
Deterioration did not appear severe; however, many mechanical
problems resulted in frequent maintenance.
Catalyst Screening Program v *76
The first portion of Chrysler's catalyst screening program
for 1976-type catalysts involves use of the tube furnace.
The tube furnace involves aging the catalyst at elevated
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temperatures. The ability of the catalyst to reduce NO
is then assessed. Following these tests, the catalyst
is further tested using single-cylinder engine exhaust.
Chrysler feels an important criterion for reduction catalysts
is their ability to act as oxidation catalysts during the
cold start part of the FTP and such catalysts must therefore
be resistant to oxidation in an oxidizing atmosphere. Only
precious metal catalysts appear to meet this criterion
according to Chrysler. Chrysler did not submit data
correlating the oxidizing conditions in the tube furnace
with oxidizing conditions occurring during warm-up of a
vehicle.
A second important criteria in selection of an NO catalyst
^t
is minimal ammonia formation. More ammonia forms at lower
(richer] air/fuel ratios. Noble metal catalysts containing
platinum and palladium give higher reductions of NO at
optimum air/fuel ratios Cwhere ammonia formation is minimal)
than base metal catalysts. Additives such as ruthenium
are needed for these noble metal catalysts to prevent a
phenomenon called "carbon monoxide poisoning." This type
of "poisoning" Chrysler feels^ involves preferential
absorption of CO on the catalyst surface, which reduces
the NO conversion efficiency.
To date, the two best candidates from the Chrysler screening
tests are the following catalysts:
1. Johnson-Matthey AEC8A
2. Chrysler Precious Metal Catalyst
Two other candidates seem promising because of their ability
to operate at higher temperatures with improved durability.
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However, these two other catalysts have lower activity
than the two listed.above. The runners-up are:
1. Gould GEM 45
2. Chrysler Base Metal Catalysts
These catalysts also require higher operating temperatures
for NO removal than the precious metal catalysts listed
above. Unfortunately, Chrysler did not supply any com-
positional information on the Chrysler precious metal or
base metal catalysts. Chrysler also did not indicate the
criteria on which they found their own catalysts to be
superior to those of the catalyst companies.
Chrysler also mentioned that they had a laboratory apparatus
to evaluate metallic alloy compounds as NO catalysts. This
device was called the ME-CEE (Materials Evaluation -
Controlled Exhaust Environment). A catalyst is placed
in a ceramic-lined pipe. The ability of this sample to
reduce NO with varying amounts of HC and CO was determined.
Metallic reduction catalysts are further evaluated using
an engine dynamometer set-up. This involves testing a
catalyst at various steady state conditions of simulated
speeds up to 70 mph.
The effect of acceleration-type transient conditions on the
catalysts were considered. Testing is continued on another
engine dynamometer for the equivalent of 25,000 miles at
simulated speeds up to 100 mph and maximum temperatures
of 1800 F. These tests, which were done on metallic alloy-
type catalysts only, showed these catalysts to have very
acceptable durability. However, Chrysler feels the useful-
ness of this type of catalyst is seriously limited since
they do not become active for NO reductions until temperatures
of 1000-1200° F are reached.
6-21
-------
Chrysler has tested many NO catalysts from other companies.
These companies include: American Oil, Brunswick, Corning,
Ethyl, Gould, W. R. Grace, ICI, Kali-Chemie, Johnson-
Matthey, Shell, Aeroban, Air Drop Co., Catalyst and Chemicals
Inc., Champion, DuPont, Engelhard, Girdler, Gulf Oil,
Houdry, Huyck, Mobil, Pechiney, Michigan Seamless Tube
Co., Union Oil and UOP.
Progress and Problem Areas - '76
Progress
Chrysler has made progress in the area of system selection,
low mileage emission performance and catalyst screening.
In the area of system selection, Chrysler has identified
a system for 1976 that has a fewer number of significant
problems than other systems they have studied. This system
is a typical 1976 system using precious metals for both the
NO and HC/CO converters. The low mileage emission results
Xt
reported by Chrysler show some progress, 1976 emission
levels having been achieved a few times at low mileage
on a back-up system which used metallic NO catalysts.
X
Chrysler reported the most extensive amount of catalyst
screening test results. It appears that they have made
extensive progress in this area, having tested most of
the materials considered promising for use as NO catalysts.
H
Problem Areas
Chrysler reported severe durability problems with all types
of the NO catalysts that they have tested. Both physical
X
destruction and/or loss of efficiency in a very few thousand
miles have been experienced to date.
6-22
-------
Chrysler also reported major problems in vehicle installation,
Some engine/body combinations could not use some emission
control systems due to packaging problems.
Another problem is that the 1976 levels have not yet been
achieved on their first choice system. Chrysler reported
that the metallic NO catalyst approach is not their first
.A,
choice because of the higher light-off temperatures. How-
ever, the metallic NO catalyst system has achieved the
J\
1976 levels.
The CO measurement problem discussed in the 1975 Problem
Areas section also may be a problem with the emission
results reported with the 1976 systems.
Conclusions - '76
The report team concludes that Chrysler's chances of
certifying for 1976 are questionable. They have been
grouped into class 76-2.1, Catalytic System Approach -
Average Development Status. The only tests reported
below the 1976 levels were not on the first choice system
and no- vehicles placed on mileage accumulation have been
able to maintain 1976 levels for even 4000 miles of
operation.
6-23
-------
6.1.3 FORD
6.1.3.1 1975 Development Status
Systems to be Used - '75
Fordrs first choice system consists of engine modifications
(including quick heat intake manifold, solid state ignition,
improved carburetion] EGR and noble metal monolithic
oxidation catalysts with air injection. To back up the
first choice system the use of another catalyst in series
and a thermal reactor is being considered. An additional
back-up system of thermal reactor without catalysts is
being considered for four cylinder vehicles since there
are more substrate durability problems on these vehicles
and catalysts may not be effective. The Engelhard catalyst
seems to be receiving the most attention followed closely
by the Matthey-Bishop catalyst. Catalysts supplied by
W. R. Grace and Universal Oil Products (UOP) are also
receiving consideration.
The first choice EGR and air injection systems have non-
proportional or backwards flow characteristics but Ford
reported more sophisticated systems are being contemplated:
"...depending on the problems encountered in
achieving the required emissions at acceptable
levels of performance/ economy and vehicle drive-
ability, controls and control circuitry may be
added on a selective basis to modify spark timing,
control EGR, and possibly to modify secondary air
flow as dictated by catalyst feed gas composition
and temperatures."
No data was reported by Pord on any 1975 prototypes using
proportional EGR systems.
A quick heat intake manifold is included in the first
choice system yet no data was reported on cars using quick
6-24
-------
heat manifolds and catalysts. Data was reported on two
vehicles having quick heat manifolds but catalysts were
not used on these vehicles. The average of fifteen tests
on these two vehicles was 1.32 gpm HC, 8.73 gpm CO and
2.53 gpm NO . Hydrocarbon levels were under 1 gpm and
J^
carbon monoxide levels were as low as 5.68 gpm on some
tests.
The best low mileage data reported on vehicles with "partial"
systems was .2 gpm HC, 1.69 gpm CO, and 2.52 gpm NO for
J^
the first choice system, .22 gpm HC, 1.8 gpm CO and 1.58 gpm
NO for the twin catalyst back-up system.
J\:
Ford considers driveability, performance, cost, packaging,
and fuel economy important constraints. They are expecting
a 5% loss in fuel economy for their *75 system compared to
'73 vehicles. No data was reported, however, to substantiate
this penalty. The cost increase over *73 vehicles was
estimated at $290,bringing the total cost of emission
control (compared to uncontrolled vehicles) to $370.
Ford is intending to use several "modulating devices" on
their 1975's. Among those discussed were speed-spark
and speed-EGR.
Durability Program - '75
Ford Motor Company's 1975 prototype durability evaluation
basically includes three separate fleets of passenger
vehicles. Two of these programs, Dearborn and Riverside
West, are well underway. The third, Riverside East, is
currently well behind schedule and Ford did not report
much emission from that program in their status report.
Thus, only the first two programs can be discussed
6-25
-------
here. The Riverside West fleet is a 50,000-mile durability
fleet while the Dearborn fleet serves as a 4,000-mile
emission data fleet. Thus, the overall goal is essentially
one of a "mock certification" program. A total of 38
vehicles are included in the "certification" program; 26
in Riverside West and 12 in Dearborn. While the Dearborn
4,000-mile vehicles have completed their mileage run, only
17 vehicles in the Riverside fleet exceed 36,000 miles with
7 having accumulated 50,000 miles. The bulk of the Riverside
program is scheduled for completion by December 15, 1972,
and will be totally finished on January 22, 1973. The
mileage accumulation rate at Riverside has been very slow.
apparently partially due to the fact that not enough test
facilities may have been planned for at the start of the
program.
To "encompass the full range of Ford Motor Company products",
a selection of 5 vehicle/engine types was made for inclusion
in the durability program. The following list details
those types:
2.0 L Pinto (not fully represented)
250 CID Maverick
351 CID Ford ("Cleveland" engine only)
360 CID F-100 Truck
460 CID Lincoln
While these engine/vehicle types do tend to span the Ford
line, they do not fully .represent all the engine configur-
ations currently marketed by Ford Motor Company.
The prototype system configuration which is included in the
Dearborn and Riverside West fleets is broken into three
major categories:
6-26
-------
Group I - Front catalysts only
Group II - Thermal reactor and front and rear
catalysts.
Group III - Front and rear catalysts
Each vehicle in the Riverside West fleet was also equipped
with:
Thermactor Air Injection
1973 EGR System
BreaJterless Ignition
1973 Carburetor (modified calibration)
1973 Evaporation Control
These vehicles were calibrated at about 2.0 gpm NO .
X
The Dearborn fleet vehicles, on the other hand, were
equipped with lean limit carburetion and a 1.50 gpm NO
X
level. Significant is the fact that neither fleet was
equipped with quick heat manifolds, advanced carburetion,
or advanced EGR systems.
While it appears that both fleets followed AMA durability
schedules in mileage accumulation, attention should be
drawn to much unscheduled and, in many cases, unallowable
(from a certification point of view) maintenance. For
purposes of deterioration factor calculation no unscheduled
maintenance points were used (as per current certification
procedures). Since the fleet of vehicles was used primarily
for purposes of catalyst evaluation, and because no direct
catalyst maintenance was performed, the use of the fleet
to develop catalyst deterioration characteristics appears
valid.
6-27
-------
Of the 17 vehicles with 36,000 miles or more accumulated,
12 demonstrated reasonably lovr deterioration factors.
CAR
HC DP
CO DF
NO DF
C-l Maverick
C-2 Maverick
C-l F-100
C-2 F-100
C-l Lincoln
C-2 Lincoln
CRC-1 F-100
CC-1 Maverick
CC-2 Maverick
CC-1 F-100
CC-2 F-100
CC-1 Lincoln
1.58
1.34
1.68
1.66
1.-69
1.25
1.00
1.19
1.25
1
1.2
1.00
1.86
1.29
less than 1.0
less than 1.0
1.62
1.46
less than 1.0
1.05
1.89
less than 1.0
less than 1.0
less than 1.0
1.10
less than
1.08
less than
less than
1.26
1.03
less than
1.02
1.09
1.23
less than
1.0
1.0
1.0
1.0
1.0
Results on the 351 C engine family have been less encouraging;
CAR
HC DF
CO DF
NO DF
CRC-2 Ford
C-l
C-2
CC-2
CC-1
Ford
Ford
Ford
Ford
CRC-1 Ford
2.
3.
2.
2.
2.
1.
52
98
51
21
03
72
2
4
4
2
3
2
.85
.54
.18
.49
.61
.18
1.12
less
less
less
less
less
than
than
than
than
than
1
1
1
1
1
.0
.0
.0
.0
.0
6-28
-------
None of the 7 vehicles in the Riverside fleet which have
completed 50,000 miles of operation has successfully
complied with the Federal regulations for 1975.
If the deterioration factors presented previously are applied
to the 4,000-mile data values reported for the Dearborn
emission data cars (no adjustment for different NO calibration)f
three vehicles appear to comply with the 1975 emission standards
(none of the three types have completed a full 50,000-rjnile
run) :
Group II 360 CID F-100 CRC
Group III 360 CID F-100 CC
Group III 460 CID Lincoln
With the possible exception of these 3 vehicles/engine
systems, the Ford 1975 durability program has not clearly
demonstrated a capability of complying with the Federal
requirements. The absence of the more advanced emission
control components, especially quick heat intakes on the
prototype test cars, however, may cause more pessimistic
conclusions to be drawn than are actually warranted.
Catalyst Screening Program - '75
At this time, Ford is still screening a limited number of
oxidation catalysts although they realize there is no time
for this effort to have a major input for their 1975 cars.
Ford has done extensive screening of both base and non-
platinum noble metal catalysts searching for a potential
replacement for platinum.
To date, only cobalt oxide has been found to be as effective
for oxidation but cannot, as yet, be applied to a support.
6-29
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The unsupported cobalt oxide fuses together too extensively
for vehicle use. Platinum-containing catalysts continue
to be the most effective oxidation catalysts. Ford is
also continuing efforts to develop better monolithic
support materials for these platinum-containing catalysts.
New catalysts submitted to Ford undergo a laboratory
screening test followed by engine dynamometer tests. Both
procedures are described below.
In the laboratory testing apparatus, Ford measures the
effectiveness of both fresh and aged catalysts for HC and
CO oxidation. The efficiency of a catalyst for converting
HC and CO at constant temperature in a simulated exhaust
gas is measured. The steady state conversion measurement
is then repeated at 75° temperature increments. Ford
then calculates a parameter called the activity index
from the temperatures (° F) requirei
conversion using the formula below:
from the temperatures (° F) required for 25, 50 and 75%
T + T 4- T
125% * ^50% * I75%
AI *
300
Typical values range from 1, for a highly effective catalyst,
to 10, for an inactive one. As a rule, activity indices
are higher for HC than CO conversion. This parameter is
a good measurement of fast warm-up which is necessary for
good results on the FTP.
The laboratory aging process mentioned above is a thermal
aging in the presence of air containing 10% water vapor,
about the value found in automotive exhaust. This aging
is done at higher temperatures (about 1500° F) for periods
of about one week. Aging frequently numerically increases
the HC activity index number mentioned earlier more than
that for CO, i.e., greater deterioration of HC effectiveness.
6-30
-------
In addition to the above laboratory test/ promising catalysts
are further screened by an engine dynamometer durability
test. The exhaust from a 240 CID six-cylinder engine is
passed through six catalysts in parallel. The engine is
run at 1800 rpm and partial load for 300 hours. Catalyst
temperatures are unusually high at 1850° F. Conversions for
HC and CO under steady conditions are frequently measured.
Also, a simulated cold start is included to measure catalyst
effectiveness during light-off conditions. The temperature
at which 50% of the HC is converted can be used to compare
catalysts and can be correlated to a large degree with
effectiveness over the PTP. However, Ford provided no
specific numbers to prove or illustrate this correlation.
Progress and Problem Areas - '75
Progress
Ford has made progress in two areas in the last year,
durability testing and system development. Ford's Riverside
West durability program is nearing completion, except for
the Pintos. The progress attributable to this year-long
development durability program has been mainly in the area
of experience in durability testing of emission control
systems employing catalytic converters.
Ford has also made progress in the development of a quick.
heat intake manifold, similar in concept to GM's EFE
manifold.
Problems
Ford's greatest problems with respect to 1975 emission con-
trol systems lie in the lack of durability testing of full
1975-type systems. While the results from Riverside are
6-31
-------
most extensive that Ford has generated to date on 1975-
type systems, the catalysts used on these vehicles have now
been superseded by a later version which Engelhard considers
to be superior and none of the vehicles was equipped with
Ford's own recently developed quick heat manifold. Ford's
status report on their 1975 development did not indicate
that any vehicles had yet been tested with the quick heat
manifold incorporated into an emission control system that
included a catalyst.
Ford's Group IV (Riverside East) fleet is intended to be
a demonstration of more current technology with more up-to-
date catalysts and improved control systems. These vehicles
were originally scheduled to be ready to start mileage
accumulation by May 31, 1972. However, at the time of the
writing of this report, the vehicles in Group IV had just
begun the durability testing and Ford did not report any
emission data from the Group IV vehicles. Ford did not
report that any of the Group IV vehicles were equipped
with a quick heat manifold.
The reason given by Ford for this greater than six-month
delay in the initiation of the Group IV durability testing
is that there were some unexplained low mileage catalyst
failures requiring replacement.
Conclusions - '75
The report team concludes that Ford will probably be able
to certify for 1975. They have been grouped into class
75-2.1, Catalytic System Approach - Above Average Develop-
ment Status. Most of the vehicles run to high mileage
have demonstrated reasonably low deterioration factors.
Many vehicles have extrapolated 50,000-mile emission values
6-32
-------
close to the 1975 levels despite the fact that they are
not equipped with full effort systems. Data supplied by
Ford on vehicles equipped with quick heat intake manifolds
(but no catalysts) indicates that significant emissions
reductions are likely to be realized when the quick heat
intakes are installed on catalyst-equipped vehicles.
The data which will be generated on Ford's Group IV fleet
will provide a better indication of their potential for
certifying than have previous fleets since these vehicles
will have more complete systems and later generation catalysts
6.1.3.2 1976 Development Status
Systems to be Used - '76
The prime 1976 system for Ford is basically the 1975 system
with the addition of a NO catalyst. This approach is
X
typical of that being taken by all other U. S. manufacturers
and most foreign manufacturers. More extensive modifications,
however, may be made to the 1975 system for 1976. Ford
reported the possibility of using programmed air injection
and programmed EGR flow on the 1976 system. Some 1976
prototypes also use low thermal inertia (LTIJ exhaust
manifolds and modified combustion chambers. The combustion
chamber modifications will feature higher compression ratio
and increased turbulence.
If the "programmed" EGR control under consideration provides
fullHzime proportional recirculation then higher compression
ratios may be possible, in the judgment of the report team,
without increasing the octane of unleaded fuel since EGR
acts as mechanical octane. Many current engines with EGR
systems require low compression ratio because the EGR is
not proportional to inlet air flow and under some conditions,
6-33
-------
particularly high, load, there is very little or no
recirculation and therefore no mechanical octane effect.
Several different types of NO catalysts have been considered
rfX
by Ford, but work is now concentrated on the noble metal
monolithic units. Metallic catalysts are receiving less
attention. The best low mileage results reported by Ford,
however, were on a vehicle using metallic NO catalysts.
J^
The average of four tests was .33 gpm HC, 2.27 gpm CO,
and .28 gpm NO . The best results reported for the noble
J^ '
monolith system were .36 gpm HC, 3.24 gpm CO, and .38 gpm
NO (average of 5 tests). Based on the data reported it
l£
is not apparent why the metallic NO catalyst system is
ji
not the first choice system.
It is difficult to discuss details of the Ford 1976 system
since the Ford program, like that of most manufacturers,
is still in the research and development state. Although
there was very little data reported in their status report,
it appears that Ford is not experiencing significant fuel
economy penalties with the 1976 systems they are developing.
Estimated cost of the 1976 system has not yet been reported.
No other U. S. manufacturer is closer to production on
"alternates" to the conventional pre-mixed charge, spark
ignition engine than Ford. The stratified charge (PROCO)
engine has been able to achieve the 1976 NO level without
Jt
the use of NO catalysts on a 4500 pound vehicle. The
Ji
PROCO engine uses direct cylinder fuel injection and high
EGR rates to achieve this control. The stratified charge
combustion itself results in lower NO levels due to the
-------
a rich, zone where NO does not form easily. More importantly,
X
the stratified charge operation increases the EGR tolerance
of the engine allowing higher EGR rates than are practical on
conventional engines. High HC and CO emissions are a problem
with the engine. Oxidation catalyst technology, however, is
significantly further developed than reduction catalyst tech-
nology. Because of this, an engine such as the PROCO, which
requires catalysts for HC and CO but not for NO , currently
Ji
has a better chance of success than an engine which might
require catalysts for NO but not for HC and CO.
n
At low mileage, a 4500 Ib PROCO-powered Mercury Montego
equipped with noble metal oxidation catalysts has achieved
.33 gpm HC, 1.08 gpm CO, and .39 gpm NO . A small PROCO-
J^
powered vehicle (2500 Ib Capri) has achieved .11 gpm HC,
.27 gpm CO, and .32 gpm NO . Both of these vehicles had
j£
better fuel economy than current 1975 model vehicles of the
same weight.
The PROCO system is not considered by Ford to be a serious
1976 system because of lead time constraints. Earliest
possible model year for limited production is estimated by
Ford to be 1977.
Another Ford engine concept under development is reported to
have similar lead time problems. The "Fast Burn" engine achieves
low NO levels without catalysts by employing high turbulence
J±
to shorten combustion time (hence the term "fast burn") and
by using high EGR rates. As with the PROCO engine, high HC
and CO levels are the major problem. The engine uses a cupped
piston to obtain high turbulence but this piston increases the
surface-to-volume ratio and, therefore, causes HC problems.
The high EGR rates used adversely affect both the HC and CO
emissions. The rapid combustion of the Fast, Burn process also
tends to lower the exhaust temperature which makes it more
difficult for the catalysts to work effectively.
6-35
-------
Using oxidation catalysts, Ford has achieved .35 gpm HC,
1.59 gpm CO, and .37 gpra NO at low mileage on a 4500
^£
Ib Fast Burn powered vehicle.
Questor has reported that Ford has also tested their Reverter
system and three consecutive tests run on Questor's vehicle
at Ford were all below the 1976 levels. Ford's status re-
port, however, made no mention of the Questor testing or
of any development planned for the system.
Durability Program - '76
Ford Motor Company has reported that a limited 1976 durability
program has been initiated. This program is not nearly as
comprehensively designed as that for their 1975 prototype
system. No vehicles have completed 50,000 miles of dur-
ability. Basically Ford's primary system approach at this
time appears to be a dual bed catalyst with an exhaust
gas recirculation system. The purpose of their current
testing is to evaluate those catalysts which have performed
well through a screening process on an AMA-type durability
schedule. Apparently, no attention has been paid at this
point to the experimental design with respect to vehicle
mix and maintenance. Rather the current effort is a
purely developmental one. Several of the vehicles in the
program were designed as IIEC (Inter-Industry Emission
Control Program) systems with an oxides of nitrogen goal
of 1 gram per vehicle mile, more than double the 1976
Federal requirement.
All of the vehicles in the Ford program thus far have
demonstrated high deterioration of NO control, with the
X
possible exception of the 141 CID PROCO vehicle being run.
At 22,000 miles it remains below the 1976 Federal require-
ments although an oxidizing catalyst change was required
at about 13,000 miles.
6-36
-------
Ford Motor Company has riot reported the successful attain-
ment of 50,000 miles of operation on any 1976-type emission
control system.
Catalyst Screening Program - '76
The NO catalyst screening program at Ford is similar to
ji
that used for HC and CO catalysts. This program involves
laboratory screening tests, engine dynamometer durability
screening, and low mileage vehicle tests.
The laboratory screening test involves measuring HC, CO
• - r
and NO removal using an artificial exhaust gas. This
removal is measured as a function of temperature for fresh
and aged catalysts. The catalyst samples are aged by
placing them in an atmosphere containing 10% water vapor
and heating the sample at 1145° for a week. The rest of
the atmosphere was not specified but it should, in the
opinion of the report team, be different from that used
for aging the oxidation catalysts (air) since NO catalysts
X
in the field would usually experience highest temperatures
under reducing rather than oxidizing-type conditions. The
activity index is calculated from the net NO conversion data
. x
accounting for any ammonia production from the following
formula:
AT T25% + T50% * T75%
AI = -300"
The values in the numerator are the temperatures ( F) for
25%, 50% and 75% NO conversion.
•2t
The next stage in the Ford catalyst screening program is
engine dynamometer tests. Steady state conditions are
used in this test for monolithic units. The HC, CO, and
NO conversions for various A/F ratios (from 13:1 to 15:1}
X
6-37
-------
are determined. The test apparatus is sized to contain
PTX3-sized catalysts which does not permit other sizes
of catalysts to be used in this test. Since only mono-
lithic units are tested in the apparatus, this shortcoming
is smaller than it would be with testing of both monolithic
and pelleted catalysts.
A more serious limitation of this test which Ford did
point out is that it is not as effective in evaluating
base metal catalysts as it is for noble metal catalysts.
Apparently/ base metal NO catalysts do not perform as
^k
effectively in steady state tests as in cyclic-type tests
characteristic of road operation. For example, a base
metal catalyst may have lower steady state conversion
efficiency than a noble metal catalyst yet perform
equally well on a CVS-type test. Apparently, base metal
NO catalysts function especially well with variations in
X
A/F ratios that would be seen on cyclic tests. Ford,
therefore, verifies the initial screening tests for base
metal NO catalysts with vehicle testing.
X
Ford evaluated 25 monolithic catalysts by this procedure
and found that only 10 could remove 80% or more NO . One
X
of these was a base metal catalyst which had especially
high NO reductions during richer operations when much
X*
ammonia was produced. When the ammonia conversion was
subtracted from NO conversion,the net efficiency (defined
X
as total NO reduction minus NH~ production) was below
X J
80%. Another general conclusion of this test is that
maximum NO conversion occurs at 14.1:1 A/F ratio which
X
is about 0.3 units richer than stoichiometric. Ford
did not name the 25 units tested but did indicate one
6-38
-------
of them to be a raonel-type catalyst which was not one of
the ten best. Aside from this specific program for
monolith catalysts/ Ford specifically screens both mono-
lithic and pelleted catalysts for NO reduction efficiency
on an engine dynamometer. The conditions used are
slightly different for monolithic and pelleted catalysts.
For monolithic units, the following is done.
MONOLITHIC CATALYST TEST CONDITIONS
Engine Operating Conditions
65 mph, steady state, medium load
1400° F catalyst inlet temperature
800-1200 ppm NO , 200,000 hr space velocity
H
Procedure:
1) Vary A/F ratio 13.1:1 to 16.1:1
2) Lower engine load (and space velocity)
and repeat 1.
3) Repeat 1 at 1000° F catalyst inlet
temperature
4) Add short pulses of secondary air into
NO catalyst
PELLETED CATALYST TEST CONDITIONS
Engine Operating Conditions
1} 40 mph steady state road load, 900° F
catalyst inlet temperature, 800-1200 ppm
NO , 35,000 hr space velocity
X
2) 70 mph steady state road load, 1300° F
catalyst inlet temperature, 800-1200 ppm
NO , 70,000 hr space velocity
X
6-39
-------
Procedure - not specified
Both inlet and outlet NO are measured. The ammonia
formation is also measured.
The second major aspect of the catalyst screening program
is to measure warm-up activity. The procedures used for
monolithic and pelleted catalysts are similar and described
below.
CATALYST WARM-UP TEST
Conditions - 40 mph road load, 1.5% CO, 2.5% 02,
125 ppm HC, 1000 ppm N0x«
Procedure - pass exhaust gas through catalyst cooled
to 100° F - measure NO conversion as a
X
function of time.
The third major engine dynamometer test done to screen NO
catalysts is a thermal cycling-type operation. This
procedure is slightly different for monolithic and pelleted
catalysts and is as follows:
MONOLITHIC CATALYST THERMAL CYCLING TEST
Part 1 - steady state rich operation - 55 mph, 1.5% CO,
1500 F catalyst inlet temperature, 150 hours
Part 2 - oxidizing - reducing transients
same as in part 1 but add air (1% oxygen)
for two 15 minute periods each hour
Part 3 - high temperature cycle - 100 hours total
A. Acceleration to 90 mph for warm-up
B. 90 mph steady state, 1700° F catalyst
inlet temperature, 43 minutes
C. 15 mph, 1100° F catalyst inlet temperature,
5 minutes
D. Cool to 300° F with air, 10 minutes
6-40
-------
Part 4 - AMA durability cycle - time unspecified
Part 5 - higher speed (48 mph) durability cycle
PELLETED CATALYST THERMAL CYCLING TEST
Part 1-70 mph, 1.5% CO, less than 0.4% oxygen,
1400° F catalyst bed temperature, 10 minutes
Part 2 - cool to 100° F, 10 minutes
Part 3 - repeat 1 and 2, 120 times
The catalyst attrition is determined for pelleted catalysts
as well as the standard NO conversion measurements. In
X
addition, Ford has a separate test for pelleted catalysts
to measure the effect of variations in the CO/O- ratio on
the exhaust NO conversion. It is unfortunate that identical
thermal cycling tests were not used on the pelleted and
monolithic units which would provide a common base for
comparison. Ford did not provide any data relating the
two methods.
Ford provided no identification of the catalysts they
tested as to manufacturer or specific type of catalyst.
As a result it is not possible to identify the data developed
here with screening tests of the catalyst companies.
Ford has set the following criteria for their pelleted NO
H
catalysts from the above tests:
1) Warm-up activity test (fresh)
50% HC conversion in 100 sec.
80% CO conversion in 75 sec.
2) Activity test - NO conversion
H
70% net NO conversion between 0.8-2% CO
space velocity) and/or 1300° F (70,000 hr
(or 2-8 C0/02 ratio) at 1000" F (35,000 hr
space velocity)
space velocity)
6-41
-------
3) Thermal cycling test
less than 5% attrition
4) Warm-up activity after thermal cycling
45% HC reduction in 100 sec.
70% CO reduction in 75 sec.
5} Activity test - NO conversion
J^
60% efficiency under conditions
outlined in (2)
HC and CO activity criteria are probably based on the need
for this catalyst to operate as an oxidation catalyst
during vehicle warm-up. Ford did not give the criteria
of acceptance for monolithic catalysts from the tests
described above.
Pellet catalysts that meet the criteria above are then
subjected to vehicle tests. The emission level goals for
vehicle tests after 100 miles are 1.0 gpm HC, 4.0 gpm CO,
and 1.0 gpm NO (1975 CVS test procedure). Catalysts
X
meeting these criteria are subject then to vehicle durability
tests.
Ford has conducted dynamometer durability tests for catalysts
but did not mention how these tests fit in with the ones
described earlier. The test takes 300 hours and is composed
of the following three modes:
Speed (rpm)
A/F ratio
Space velocity (hr"~ )
Exhaust 02 (%}
Time (minutes }
Mode 1
2200
13.5-14.0
20,000
0.2
42
Mode 2
675
13.5-14.0
10,000
0.2
5
Mode 3
675
13.5-14
10,000
0.2
5
Catalyst inlet
temp. (° Fl 1300 700 650
6-42
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The HC, CO, and NO conversion efficiency are evaluated
x ...
every 50 hours at steady state conditions of 1000 F
_n
catalyst inlet temperature, 60,000 hr space velocity, and
various A/F ratios (13, 14 and 15:1). Ford did not
specify what the criteria for passing these tests were.
Frequently throughout the Ford section on catalyst
screening they did not describe the criteria for passing
nor give any indication on how such criteria could be
derived.
Progress and Problem Areas - '76
Progress
Ford has made enough progress during the past year on
1976-type emission control system development to be able
to indicate a "prime" or first choice emission control
system. The system in its present configuration is a
typical 1976 system (dual catalyst, air injection,
engine modification, EGR, improved induction system)
and the catalysts both have ceramic monolith substrates.
The active material for the HC/CO catalyst will be
platinum, but the NO catalyst may have either a base
X
metal or a precious metal as active material. Ford has
progressed enough to be able to rule out the other approaches
that they have investigated. They have done this by making
some progress in catalyst screening and durability testing.
In fact, the 21,000-mile durability run reported by Ford
is one of the longest reported to date.
Problem Areas
Ford's largest single problem area with respect to 1976-type
system development is the lack of a NO catalyst with
J^
adequate durability. The durability of the other components
of the 1976 system, including the HC/CO catalysts, do not
at this time appear to be unsatisfactory.
6-43
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Conclusions - '76
The report team concludes that lord's chances of certifying
in 1976 are questionable. They have been grouped into
class 76-2.1, Catalytic System Approach - Average Develop-
ment Status. Although the 1976 levels have been achieved
at low mileage on at least five different systems (dual
catalyst, dual catalyst with metallic NO catalyst, PROCO,
Jx
Fast Burn and Questor), Ford has not demonstrated the
required levels at high mileage on any of these systems.
The two systems which do not require NO catalysts to
jt
achieve .4 gpm are not considered feasible because of
lead time constraints. The first choice system seems to
have more severe deterioration problems than the two
systems which employ metallic NO catalysts.
6-44
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6.1.4 GENERAL MOTORS (GM)
6.1.4.1 1975 Development Status
Systems to be Used - '75
Two different systems.are receiving 'primary consideration for
GM's 1975 production. Engine modifications including high energy
ignition (HEI), modified carburetion, quick heat intake mani-
folding (called the Early Fuel "Evaporation or EFE manifold),
EGR, and air injection are common to both systems.
One system, the .."underf loor system", utilizes a pellet-type
oxidizing catalyst located under the passenger compartment.
The other system, the "Manifold Emission Control System"
(MEGS), uses either pellet or monolithic catalysts housed in
a modified exhaust manifold. GM did not report whether or not
either of these systems is their first choice system or
whether or not both might be used in 1975.
Several of the non-catalytic components being developed by GM
are worthy of comment. The GM Early Fuel Evaporation
manifold allows significantly leaner carburetor calibration
during cold start and warm-up. The exhaust of either four,
six or eight, cylinders is diverted through crossover passages
in the intake manifold during start-up.
The intake charge is vaporized with the assistance of. heat
transferred from the exhaust gas through a high heat transfer
section which divides the intake passages and the exhaust cross-
over. The following emission levels have been obtained without
catalysts:
6-45
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1975 FTP
No. of cylinders
diverted through intake
during cold start
8
6
4
HC
.70
.68
.54
Grams Per Mile
CO NOV
X
5.2 1.64
5.4 1.41
6.4 1.38
The NO levels reported above indicate that EGR was probably
X
used on the vehicle.
The high energy ignition system allows plug gaps of .060 inches
compared to .030 - .035 used with conventional ignitions. This
reduces the engine's tendency to misfire with lean or non-uniform
mixtures. The high energy system is also more resistant to
misfire induced by spark plug fouling. The possibility of
catalyst over-temperature problems is significantly reduced.
50,000-mile spark plug life may be possible with this system,
when unleaded fuel is used. To determine whether or not this
is feasible, GM is currently running several vehicles on
durability which are not receiving spark plug changes at
24,000 miles.
Besides working on modifications for their current carburetors,
GM has two new carburetors under development. One of the new
units, the APACHE (Anti-Polluting Altitude Compensating High
Efficiency) carburetor is an offshoot of the current Quadrajet.
It features adjustable primary metering which allows tailoring
of each carburetor individually.
6-46
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The other new carburetor is based on a totally different con-
cept. The Integrated Fuel Circuit (IFC) carburetor replaces
the conventional idle, cruise, and power circuits with a
single metering system. Transition problems between different
circuits are eliminated. The IFC carburetor utilizes a dia-
phragm controlled air valve to maintain a constant depression
above the throttle. The constant depression feature should,
in the judgment of the report team, facilitate the use of
proportional EGR systems.
Three different EGR systems are being considered for 1975.
Two provide proportional control. The final selection will,
in the opinion of the report team, probably be the result of
a driveability/cost trade-off. GM may be able to obtain
adequate driveability with the non-proportional system and
the proportional system may not be used until 1976.
Almost all of the 1975 system data reported was on the under-
floor catalyst system. This system has been under development
much longer than the MECS and GM personnel have told members
of the report team that the availability of the MECS compo-
nents is currently not as good as the availability of under-
floor components. The best low mileage results reported were
on the underfloor systems. One of the better vehicles has
achieved .22 gpm HC, .70 gpm CO, and 1.13 gpm NO . -GM tests
Ji
show, however, that the MECS system has the potential for
lower emissions than the underfloor system because of the
superior warm-up characteristics obtained by locating the cata-
lyst in the exhaust manifold.
In their emission control status report submitted in November
of 1972, GM did not report test data on rotary engine Vegas
with 1975 control systems, although data was reported on
rotarys with 1976 control systems.
6-47
-------
GM considers cost, packaging, driveability and compatability
with 1976 systems important design constraints. Compatability
with the 1976 system is giving the MEGS system its biggest
boost since the quick warm-up characteristics of the manifold
converter location will be even more important in 1976. It
is the opinion of the report team that cost constraints may
have delayed GM's current intensive investigations of noble
metal catalysts.
Fuel economy penalties, as claimed by many manufacturers, have
not been a problem for GM: "Results to date indicate the fuel
economy on these advanced emission control systems is essentially
the same as on the 1973 systems on the basis of fleet fuel usage
data." GM estimated the retail price increase over uncontrolled
vehicles, for the 1975 control system, to be $250-315. Compared
to 1973 vehicles we estimate this to be about a $150-215 retail
price increase. It should be pointed out, however, that the
use of unleaded fuels and high energy ignitions could reduce
the maintenance (mufflers and spark plugs) cost of the 1975
vehicle by as much as $100 compared to a 1973 vehicle.
GM's design of the basic engine, carburetion arid ignition
systems has resulted in no fuel economy penalty and lower
untreated (no catalyst) emissions than most other manufacturers
using conventional engines.
GM did not provide many details on the "modulating devices"
they plan to use in 1975. However, they may run in the
reactor (catalyst by-pass) mode during wide open throttle,
above 60 mph and above 1500°F catalyst temperature. This
type of system may not have significant effects on HC levels,
but CO would increase significantly during the by-pass opera-
tion. GM's own data indicates there is no direct relationship
between catalyst over-temperature problems and vehicle speed.
Over-temperature is more related to load and engine misfire.
EPA regulations will undoubtedly have an impact on the type
of modulating devices used.
6-48
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Durability Program - '75
The major portion of the General Motors durability program
is being conducted at the Milford Proving Grounds. There
are four significant objectives behind this effort:
1. To determine overall durability of the proposed
prototype emission control systems.
2. To evaluate 5 different catalyst material candi-
dates .
3. To evaluate 3 different converter sizes.
4. To identify problems incidental to an actual
certification program.
Currently 39 vehicles have initiated mileage accumulation in
this effort with 10 additional units still scheduled for
mileage accumulation. Only seven vehicles have been operated
24,000 miles or more. From the records submitted by GM it
appears that approximately 200 days are needed for 50,.000
miles to be accumulated.
The vehicles selected to be operated in this program repre-
sent all of the engine displacements and vehicle weight classes
that GM is anticipating to sell in 1975.
The system configurations involved in the program and some emis-
sion data are presented in the following tables. Basically two
major system concepts are being investigated: The MEGS approach
and the more conventional underfloor oxidation catalyst approach.
Mileage accumulation is being run according to -standard Federal
certification procedures. Two different fuels are being used,
both at lead levels of .03 grams per gallon. Maintenance
cannot be considered as typical of certification practice but
after reviewing the maintenance performed, it appears that it
should not greatly affect the validity of the program.
6-49
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CORPORATE EMISSION SYSTEM TEST MATRIX
(J\
O
Catalyst
Systems
AIR EGR
AIR EGR EFE
AIR EGR EFE HEI
AIR EGR HEI
AIR EFE HEI
CCS EGR HEI
TRIPLE MODE SYSTEM
Noble
X
X
X
X
X
X
Mixed Base
X
X
X
X
X
Conv. Volume
260 160 80
X X
X
X
X
X
XXX
240 in.3
Fuel
Amoco
X
X
X
X
X
X
Chevron
X
X
X
X
X
Emission systems are installed in 49 cars representing all displacement and weight
classes.
-------
DETERIORATION AND 4000-MILE EMISSIONS
Vehicle Number ... ., .
(catalyst number) Major System
HC DF
HC 4000
CO DF
CO 4000
DF
NOV 4000
X
#2240 @ 28000 mi. Air/EGR
(HN 1646)
#82147 @28000 mi. Air/EGR/EFE less than 1.0 .46
(HN 1290)
#2262 @ 24000 mi. Air/EGR/EFE less than 1.0 .40
(HN 1646)
less than 1.0 .41 gpm less than 1.0 1.77 gpm less than 1.0 1.61 gpm
#2932 @ 24000 mi. CCS/EGR
(HN 1646)
#2931 @ 24000 mi. CCS/EGR
(HN 1655)
#2928 @ 24000 mi. Air/EGR
(HN 1646)
#2616 @ 24000 mi. Air/EGR
(HN 1652)
1.93 .31
1.40 .39
less than 1.0 .38
less than 1.0 .23
less than 1.0 2.28
1.45 1.64
3.38 1.45
1.64
1.83
2.21
1.49
1.54
1.26
2.1 1.80
less than 1.0 1.89
1.54 1.54
.1.37 1.46
less than 1.0 2.48
less than 1.0 .217
The deterioration factors were calculated by the report team by extrapolating the existing data.
The vehicles used were the seven vehicles reported to have completed 24,000 or more miles.
6-51
-------
It appears that a number of these first seven vehicles have
excellent potential of completing the program successfully.
None of these vehicles is equipped with the GM Triple Mode
(MEGS) System.
Catalyst Screening Program - '75
The General Motors basic catalyst screening program is divided
into three major areas: (1) laboratory tests, (2) vehicle
emission tests/ (3) the AC transient efficiency test.
The initial laboratory tests measure the following physical
strength parameters of the catalyst:
Compacted bulk density
Impact attrition
Abrasion resistance
Screen analysis
The compacted bulk density measures, in effect, the density of
a pelleted catalyst after it has been compacted by limited
mechanical vibration. The GM specification for any catalyst is
that its compacted bulk density be less than 45 Ib/ft and is
related to rapid catalyst warm-up.
The crush strength test is a measure of the resistance of a
pelleted catalyst to being crushed in a vice-type machine.
A similar test has been developed for monolith units.
The impact attrition test is for pelleted catalysts only and
is a measure of weight loss of a catalyst after a 3-4 CFM gas
flow has passed through the catalyst for 5 minutes. The cata-
lyst is contained in an experimental glass apparatus designed
so that the gas flow causes the pellets to be "fluidized" which
leads to attrition. Less than 5% attrition must result for the
catalyst to be acceptable.
6-52
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The abrasion resistance is a somewhat similar test with the
catalyst loosely packed in a metal container with wire mesh
screen bottom. The sample is shaken vigorously for 30 minutes
and must lose less than 0.5% weight to pass the GM criteria.
The screen test is a test involving shaking the catalyst
pellets through various mesh size screens to determine the size
distribution of the pellets.
For monolith units, tests are run on crush strength (mentioned
above), thermal shock (ability of the catalyst to withstand
temperature changes), thermal expansion and water absorption.
The second major area of laboratory tests involves measuring
HC and CO conversion with a bench-type apparatus with simulated
exhaust gas. The simulated exhaust gas has the following
composition:
CO
°2
HC
NO
No
1.0%
2.5%
0.02%
0.1%
remainder
The temperature at which 50% conversion occurs is measured
and must be lower than 600°F and 500°F for HC and CO respec-
tively, to successfully pass this test. In addition to this,
the effect of 1600°F, 1700°F, and 1800°F temperatures for 24
hours on light-off temperature is measured. The change must
be less than 100°F for both HC and CO. Limited vehicle emission
tests are then done to obtain the actual emissions on a 1975
FTP. The goals for these tests are as follows for a fresh cata-
lysts :
0.2 gpm HC ' .
2.0 gpm CO
3.0 gpm NO,
x
6-53
-------
For an aged catalyst, any levels below those of the 1975-76
standards are satisfactory. These vehicle tests are the
second major catalyst screening tests used by GM.
The third major type of catalyst screening test is called
the AC transient efficiency test which is an engine dyna-
mometer test. Little detail was given on this test procedure.
However, a measure of warmed-up catalyst efficiency is obtained
which supposedly correlates with the 50 mph steady state conver-
sion on a vehicle. Also, a prediction is made of the results
on the 1975 FTP from a specified dynamometer driving schedule.
The engine dynamometer tests involve the measurement of emis-
sions with the following type tests:
1. Simplified limited durability test with a 50 mph
average speed.
2. Catalyst stability evaluation with lower speed
and temperature conditions realized in urban-
type driving which result in sulfur deposition
and poisoning.
3. Temperature and time effects.
4. Measurement of lead, phosphorus, and poisoning
caused by oil contaminants.
5. Transient efficiency under either oxidizing or
reducing conditions.
6. Extended dynamometer durability test consisting
of eleven 4-mile laps under varying speed
conditions (30-70 mph). This test can be run
for the equivalent of 50,000 miles.
Catalysts which successfully complete the screening programs
are then installed on vehicles for more extensive tests.
6-54
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Progress and Problem Areas - '75
Progress
GM has made significant progress in several areas during
the past year. The major areas in which significant pro-
gress has been made are: (1) possible catalyst choices,
(2) durability testing, (3) new system development.
In the area of possible catalyst choices, GM is actively
testing precious metal pellet, promoted base metal pellet,.
and precious metal monolithic catalysts.
The precious metal catalysts use platinum and/or palladium
as active materials in various proportions. The promoted
base metal catalysts use primarily base metals as active
materials, with a small amount of precious metal as a
"promoter" to enhance the catalytic activity of the com-
bination of active materials. The precious metal mono-
liths are similar to those being tested by many other
manufacturers.
The reason for the expanded interest and progress in cata-
lysts containing precious metals is the poor durability
performance of the base metal catalysts that GM had been
concentrating most of their effort on in the past.
The durability testing program that GM is conducting shows
the superior performance of the more recent catalyst choices,
and also shows the progress that GM has made in the last
year in durability testing. Moreover, GM has made signifi-
cant progress in durability in the last eight months. Since
the April 1972 Suspension Hearings when GM reported very
little in terms of extended mileage durability results, due
to poor catalyst durability performance, GM has initiated a
durability fleet test program which is the most comprehen-
sive in the industry. The test program, involving more than
6-55
-------
50 vehicles and including most of GM's engine families,
appears to be being conducted in an efficient manner. At
the time that this report was written the results appear
to be encouraging (see the section on durability testing
program).
Another area in which GM has made significant progress is
in the area of new system development. GM's typical 1975-
type emission control system has consisted of, among the other
items, a catalytic converter of the "underfloor" type - a
wide flat type of container in which the pellet catalyst is
placed. However, in the last eight months GM has developed
an entirely different catalyst system which is now considered
by GM to have at least as much potential as the underfloor-
type. This system is the so-called "MECS" system (MECS for
Manifold Emission Control System). Since GM made no mention
of this system in their April 1972 suspension application, or
at the ensuing hearings, it must be assumed that the develop-
ment of this system has taken place in the last eight months.
The rate of progress that appears to have taken place with
this system, from essentially an idea to the position of being
considered a serious candidate for production for model year
1975, is extremely rapid, and perhaps unprecedented. The
underfloor converter concept has been under development for
at least 22 months, as a comparison.
Problem Areas
At the time of the writing of this report it appears that
GM has two major problem areas with respect to the develop-
ment of their 1975 emission control systems.
1. The HC control demonstrated to date in GM's durability
fleet is not as good as the CO and NO control. That is, the
•X
HC levels of many of the durability vehicles is much closer
to the .41 gpm HC standard than either the CO or NOV levels
X
are to their standards of 3.4 gpm and 3.1 gpm respectively.
6-56
-------
2. GM will shortly have to make major decisions concerning
the type of emission control systems to be used in each of
their many engine families to ensure that the remaining
time for development and production of the chosen systems
and components is adequate to meet model year 1975 require-
ments.
Conclusions '75
The report team concludes that GM will probably be able to
certify for 1975. They have been grouped into class 75-2.1,
Catalytic System Approach - Above Average Development Status.
The data reported on the vehicles undergoing durability
testing indicates that system deterioration is low enough
that the 1975 levels can be maintained for 50,000 miles.
Many of these vehicles are not even full effort systems em-
ploying quick heat intake manifolds and proportional EGR.
Data available from a quick heat manifold development vehicle
indicated that the 1975 levels could be achieved with only 40%
cold start catalyst efficiency for both HC and CO. It should
be noted that this particular vehicle was also running at one
half the 1975 NO standard. Many catalysts tested by several
X
different manufacturers (including GM) have retained at least
40% cold start conversion for 50,000 miles.
6.2.4.1 1976 Development Status
Systems to be Used - '76
GM's primary 1976 systems are the basic 1975 systems, under-
floor and MECS, with NO catalyst added. Carburetion will be
Ji
richer to produce a reducing atmosphere before the NO cata-
X
lysts. The MECS system will have both the oxidation and
reduction catalysts mounted in the exhaust manifold. The
underfloor system will also have the NO catalyst mounted
J^
in the exhaust manifold but the oxidizing converter will
be under the passenger compartment as in the '75 system.
6-57
-------
Also reported was the development of a 3-way catalyst with
oxygen sensor on a fuel injected Opel engine. The oxygen
sensor aids in the achievement of a constant air/fuel ratio
near stoichiometric. At this air/fuel ratio simultaneous
reduction of NO and oxidation of HC and CO can be accomplished
X
in a single catalyst.
GM is also working on the Questor Reverter emission control
system. This system uses thermal reactors to control HC and
CO with a high temperature metallic reduction catalyst for
NO . A more complete description of the Questor system
X
appears in Section 5 of this report.
Data was also reported on the rotary engined Vega equipped
with a manifold dual catalyst system.
The best low mileage results reported on the underfloor system
were .17 gpm HC, .99 gpm CO and .19 gpm NO . This vehicle used
X
a OOP noble metal oxidation catalyst and a titanium phosphide
reduction catalyst.
The best MEGS results were .15 gpm HC, 1.9 gpm CO and .34 gpm
NO . This vehicle used Matthey-Bishop AEC 8A catalysts for
X
oxidation and reduction. GM reported that tests have been run
using a metallic NO catalyst in the MECS system but no data
X
was provided.
The Opel 3-way catalyst, oxygen sensor, electronic fuel injection
system has achieved .22 gpm HC, 2.45 gpm CO and .26 gpm NO
^C
using a Degussa catalyst.
The best results with the Questor system (full-size vehiclel were
.05 gpm HC, 2.65 gpm CO and .27 gpm NO .
X
None of the rotary data reported was below the 1976 levels. No
tests were reported with hydrocarbon levels at or under the
required .41 gpm.
6-58
-------
Of all of these tests the Questor results are the only results
obtained with a system that is lead tolerant. Lead contamination
is a big problem with the other systems but the Questor system
is known to have a high level of lead tolerance. The biggest
question with the Questor system is durability. GM has mentioned
that some Questor system vehicles may be starting durability shortly.
Another important problem with the system may be fuel economy.
GM did not mention this area or any development work, to improve
the fuel economy of vehicles equipped with this type of system.
It might be noted that even though the Questor system has lower
emissions than the MECS system and has been under development
longer than the the MECS system it has not been put on durability
by GM as yet but the MECS system has. GM has, however, done more
work on the Questor system than any other manufacturer.
The use of "auxilary devices" on GM's 1976 systems could cause
emission levels to be higher than those from uncontrolled vehicles
during certain operating conditions. Most of GM's candidate
systems for 1976 operate richer than stoichiometric. HC and CO
emissions could be quite high if the oxidation catalysts are
by-passed. By-passing of the NO catalyst is planned for high
ji
speed operating modes. Data previously reported by GM indicated
the 1976 MECS system could have higher NO emissions at 60 mph
X
than uncontrolled cars.
GM estimated that the retail price increase due to the 1976
system would be about $315-430 compared to uncontrolled vehicles.
No estimate was made of the change in fuel economy expected.
This will depend on which system is used and how well it is
refined and developed. If the 3-way catalyst approach is success-
ful then there may be, in the judgment of the report team, no
fuel economy penalty at all.
6-59
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Durability Program - '76
General Motor's 1976 durability program is treated as a direct
spin-off of their 1975 program since the corporate philosophy
of developing a 1975 system involves designing a system which
can be simply integrated into the 1976 system concepts. Thus,
the basic approach to a 1976 durability program is as was
outlined previously in their 1975 program. Currently the
1976 program has only just been initiated. 39 low mileage
experimental vehicles were reported with three vehicle systems
accumulating as much as 13,000 miles. A second program is
being initiated with the cooperation of the California Division
of Highways. A fleet of 25 Chevrolets and 25 Oldsmobiles will
be operated by state personnel and tested at specific mileage
intervals by the GM California lab. 37 of these vehicles will
be 1976 prototypes, the remainder being 1975"s. The purpose of
this program is to measure system durability in quasi-consumer
use.
Of the three vehicles GM has run thus far, all have been equipped
with EGR and EC/CO and NO converters. All three were 350 CID
X
Chevrolets. In each case the .40 grams per mile 1976 standard
was exceeded before 3000 miles was accumulated. Due to these
poor conversion characteristics only one of the three systems is
still under mileage accumulation.
Due to the preliminary nature of the 1976 program to date no
realistic assessment of GM's durability characteristics is
feasible currently.
Catalyst Screening Program - '76
The GM catalyst screening program for their 1976-type catalysts
is very similar to that described earlier for the 1975 oxidation-
type catalysts. This program consists of initial laboratory tests
followed by vehicle emission tests and engine dynamometer durability
tests.
6-60
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The initial laboratory test involves the following tests to
measure physical characteristics of the catalysts:
Compacted bulk density test
Crush strength test
Impact attrition test
Abrasion resistance test
Screen analysis test
These tests and the criteria for passing them were more fully
described in the 1975 section on catalyst screening tests.
Following completion of the above tests and measurement of NO
reducing ability using a synthetic exhaust gas, the catalyst
is subject to the same vehicle and dynamometer durability tests
described earlier for oxidation catalysts.
Progress and Problem Areas - '76
Progress
GM has made progress in the past year in the areas of system
development and catalyst selection/screening for 1976 systems.
The development of 1976 systems is now concentrated on two
system types, the 1975 HC/CO underfloor converter with NO con-
J±
verters in the exhaust system ahead of it, and various configura-
tions of the MEGS system. Enough progress has been made in the
past year on 1976-type emission control systems to warrant limited
durability testing of some more promising configurations. Last
year GM reported little success in meeting the 1976 levels even
at very low mileage.
GM has made progress in the testing of a control system that is
different from their more typical systems. GM is working with the
Questor Corporation on the development and testing of their
Reverter system. Pontiac is the lead division in this effort.
6-61
-------
GM is also working on the lambda sensor-type emission control
system (3-way catalyst) which shows some promise of achieving
1976 emission standards with good fuel economy (operation as
rich as dual catalyst^systems is not required). Work on this
system, however, was reported only for the Opel.
GM has also made progress in the catalyst selection/screening
process for NO catalysts for 1976-type systems. Precious
^t
metal catalysts have been tested that minimize the ammonia
formation problem, and much progress has also been made in the
area of metallic NO catalyst testing.
X
Problem Areas
GM's major problem with 1976-type emission control systems is
the durability of the NO catalyst. Even the most promising
J\,
system that has achieved the 1976 emission levels at low mileage
has exceeded the required levels in a few thousand miles. Beside
the problem of not maintaining adequate conversion efficiency,
the physical durability of the monolith is also reported by GM
to be a serious problem.
Conclusions - '76
The report team concludes that GM's chances of certifying for
1976 are questionable. They have been grouped into class 76-2.1,
Catalytic System Approach - Average Development Status. GM
has not demonstrated any system which could achieve the 1976
levels at high mileage. Data reported by GM indicated that
their two primary systems cannot consistently achieve the 1976
levels even at low mileage. The system which appears to be
the most consistent at low mileage (Questor) has not yet been
run on durability by GM.
6-62
-------
The report team also concludes that GM may have a slight ad-
vantage over many manufacturers with respect to 1976 system
development, due to their association with Questor.
6-63
-------
6.1.5 INTERNATIONAL HARVESTER (IH)
6.1.5.1 1975 Development Status
Systems to be Used
International Harvester's first choice 1975 emission control
system consists of engine modifications (including quick heat
intake manifold and solid state ignition), EGR and an oxidizing
catalyst with air injection. There are no back-up systems as
such but IH still has eight or nine different catalysts and
four different EGR systems under consideration which could be
used in the first choice system. The catalysts under considera-
tion are supplied by five different sources: UOP, Monsanto,
W.R. Grace, Engelhard and Matthey-Bishop. Promoted base metal
pellets, noble pellets and noble monoliths are all under
consideration. Most other manufacturers are not still this inde-
finite about their catalyst preference.
The four EGR systems consist of the non-proportional 1973 system
and three new proportional systems. It was not clear how many
of IH's 1975 prototypes are equipped with one of the proportional
systems, but it is the judgment °f the report team that not
very many vehicles are so equipped. IH realizes the deficiencies
of the 1973 system: "The current system does not enable optimiza-
tion of driveability at a given NO level, due to its inherent
2C
non-proportionality as a function of engine load." IH considers
driveability an important constraint, so they may use one of the
proportional systems on their 1975 models. They also, however,
consider cost an important constraint and this may be why they
have been reluctant to decide on a proportional system.
IH will begin phasing in a new series of larger V-8 engines in
1975. Cylinder heads on the new engine will be designed to
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minimize heat loss, thereby, reducing the time necessary to
achieve "light-off" of the catalyst. In 1976 the new series
large V-8 will completely replace the current large V-8 and
a new series of smaller V-8's will be introduced.
The best low mileage results reported by IH were i21 gpm HC,
2.39 gpm CO, and 2.56 gpm NO . Most other manufacturers have
X
done better than this. IH has claimed they are severely handi-
capped because many of their vehicles must be tested at the 5,500
pound inertia weight. There is a definite disadvantage in having
a high test weight, but other manufacturers are doing much better
at this same weight. The IH vehicles have a relatively high gross
vehicle weight (GVW = vehicle weight + maximum cargo load), but
an air pump diverter valve to protect the catalyst from
over-temperature when the vehicle is heavily loaded or pulling
a trailer can and will be used.
No data was reported on fuel economy. The retail cost estimate
for the 1975 system was $309 over the 1973 system.
Durability Program - '75
International Harvester is currently operating three fleets of
vehicles under their durability program. While one fleet is
utilized for complete system durability evaluation, the other
two fleets are designed to evaluate component durability. The
Tbrt Wayne component durability fleet is primarily used for
catalyst testing but as other more advanced 1975 systems become
available they will be integrated into the vehicles. The Phoenix
Proving ground fleet is also used primarily for catalyst evalua-
tion. The third durability fleet which will incorporate com-
pleted 1975 systems on six vehicles is currently being built up,
but is not yet in operation.
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Currently IH has three different engine types in vehicles
reported to be under way in their durability program: 345 CID,
392 CID, and 440 CID. All are tested at 5500 pounds inertia.
These engines represent two of four families used in 1972. The
440 CID is a new engine line. It appears that IH has not
included small displacement engines in their development testing
program.
Three different mileage accumulation routes are available for
use. In Phoenix the two routes are non-standard with higher
average speeds than the route available in Fort Wayne which has
been accepted as a suitable certification route. Currently there
are vehicles being operated on each of the three road routes.
No discussion of maintenance practices being used was made in
the IH submittal. Of the four vehicles currently under test
only one has accumulated in excess of 20/000 miles and has
consistently demonstrated levels of hydrocarbon and carbon monoxide
in excess of the 1975 Federal standards along with high carbon
monoxide deterioration. Thus, at this time, none of the IH
vehicles reported have demonstrated the ability to control
emissions below the 1975 levels at high mileage. However,
the vehicles under test are not full-system vehicles.
Catalyst Screening Program - '75
International Harvester did not include any information on catalyst
screening in the report they submitted to EPA.
Progress and Problem Areas - '75
Progress
IH reported that they have made substantial progress in low
mileage emissions. IH reported that they are now able to reach
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1975 emission levels, using prototype components, especially
assembled and tuned by engineering personnel, at low system
mileage.
Problem Areas
IH has not been able to demonstrate adequate durability in any of
their emission control systems. Highest mileage to date without
exceeding any one of the standards is approximately 4,000 miles.
IH also voiced concern regarding the mass production of unproven
components, the.lack of firm fuel contaminant regulations, and
the problem of converter over-temperature when heavy loads, such
as trailer pulling, are experienced.
Conclusions - '75
The report team concludes that it is unlikely that IH will be
able to certify for 1975. They have been grouped into class
75-2.3, Catalytic System Approach - Below Average Development Status.
IH has not been able to demonstrate the capability of staying
below the 1975 levels beyond 4000 miles.
6.1.5.1 1976 Development Status
Systems to be Used - '76
The IH 1976 system is basically the 1975 system with a NO
catalyst added and air injection and carburetor calibration
modified to maintain a reducing atmosphere at the NO converter
inlet. NO catalysts from Matthey-Bishop, Gulf, Solar, Gould,
and Engelhard are being considered. Only the Gulf and Matthey-
Bishop catalysts have been tested.
IH indicated that proportional EGR systems are being considered
for 1975. They were more definite about the possibility of using
proportional EGR for 1976, than for 1975, stating, "The 1976
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EGR system will- require more precise metering relative to engine
air flow demand as compared to the 1975 system."
The best low mileage results obtained to date have been .438 gpm
HC, 6.63 gpm CO, and 1.20 gpm NO . This was using the Matthey-
X
Bishop monolithic NO catalyst and a Monsanto pelletized oxida-
X
tion catalyst in an AC container. All other U.S. manufacturers and
most foreign manufacturers have done better than this.
Work on electronic fuel injection (EFI) was also reported.
Production design prototypes are to be available in March of
1973. No data was reported on any vehicles using EFI. IH
reported that they are "...keeping abreast of development on
the Questor system through a signed confidential disclosure
agreement with the Questor Corporation." The possibility of
installing a Questor system on an IH vehicle was reported.
It is the judgment of the report team that the Questor system
combined with EFI might be the easiest way for IH to meet the
1976 levels. This is perhaps an example of an approach they
may take since their development approach seems to be that
much of the componentry necessary to meet the emission standards
must be supplied by vendors rather than the IH engineering
organization.
They will have to accelerate their pace of 1976 system
development since their program is judged to be well behind
a schedule which would be necessary to meet 1976 model year
production deadlines.
Durability Program - '76
Currently International Harvester has not initiated any
durability program on a 1976-type system. Only one vehicle
currently has 1976 hardware installed and it is demonstrating
high oxides of nitrogen in a zero mile test.
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Catalyst Screening Program - '76
International Harvester did not report on any catalyst screening
program for NO catalysts. They did indicate that they are
Ji
working with the following catalyst suppliers:
Matthey-Bishop, Inc.
Gulf
Solar Division, IH
Gould/ Inc.
Engelhard
Progress and Problem Areas - '76
Progress
IH reported progress in the design and development of various
system components to be used in their 1976 emission control
sys tern.
IH is also discussing the possible application of a Questor
Reverter emission control system with the Questor Corporation.
Problem Areas
The 1976 development is proceeding slowly due to the fact that
much effort is being expended on the 1975 system. Catalytic
converter availability is also a problem. The lowest emission
result of the three tests reported by IH was HC = .438,
CO = 6.63, and NO =1.20. The HC and CO results are over
X
the required 1975-76 levels and the NO is three times higher
Ji
than the required 1976 NOX level. IH did not report any
durability testing results.
Conclusions '76
The report team concludes that it is unlikely that IH will
be able to certify for 1976. They have been grouped into
class 76-2.2, Catalytic System Approach - Below Average
Development Status. IH has not been able to achieve the
1976 levels even at low mileage.
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6.2 FOREIGN MANUFACTURERS
6.2.1 ALFA ROMEO
6.2.1.1 1975 Development Status
Systems to be Used - '75
Alfa Romeo markets three different vehicles in the United
States. They are developing an emission control system
which will be common to each vehicle, since all three vehicles
are of similar weights and use a similar engine. The Alfa
first choice system will consist of engine modifications,
mechanical fuel injection, a base metal pellet oxidizing
catalyst and a dual point distributor with provisions for
retarding the ignition timing during cold start. Sub-
stitution of a noble metal, monolithic oxidation catalyst
for the base metal catalyst is being considered as a back-up
to the first choice system.
No other manufacturer has reported so many compromises in
emission control to retain current levels of driveability,
performance and fuel economy. Because Alfa is reluctant
to use after-treatment devices which would affect the tuning
of their exhaust system, the catalyst has been located
relatively far from the exhaust ports. The heat capacity
of the exhaust system between the exhaust valve and the
catalyst is probably delaying achievement of the "light-off"
temperature significantly. Alfa commented on moving the
catalyst closer to the cylinder head by saying,"This could
be help in warm-up certainly, however, it is almost disasterous
in performance loss (15%)." Experiments with thermal reactors
were only marginally successful because the "...thermal reactor
in parallel with the exhaust manifold was designed in such
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a way as to not compromise or endanger the engine's per-
formance." Alfa did not report on any plans to close-
couple after-treatment devices and then restore performance
by enlarging the engine displacement, a possible tradeoff,
in the opinion of the report team. Considering the com-
promises Alfa is making, their emission results at low
mileage are better than we would have expected. The
first choice system produced .51 gpm HC, 3.25 gpm CO,
and 1.99 gpm NO . Fuel economy of the '75 system is
X
reported to be the same as the '73 vehicles. Emission
control may not be as good when the vehicle is in the
hands of the customer as when it is tested according to
Federal procedures since Alfa is developing several
"modulating devices" to be installed on production vehicles.
These modulating devices include catalyst by-pass which will
be activated above 4000 rpm and apparently there will be a
dashboard switch for enrichment of the mixture at the
driver's discretion. Alfa says that the enrichment device
is necessary for operation in cold ambients. No development
was reported on automatic devices to provide enrichment at
cold ambients.
Durability Program - ' 75
Alfa Romeo's basic durability test program acts as a direct
spin-off of successful low mileage demonstrations of a
vehicle/system. If promising low mileage data is indicated,
the vehicle will be placed on mileage accumulation. The
results of one vehicle with slightly more than 15,000 miles
has been reported to EPA. Further testing and mileage
accumulation is planned.
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The single mileage accumulation vehicle that has been run
demonstrated poor initial conversion efficiency and exceeded
the 1975 hydrocarbon and carbon monoxide standards at low
mileage. The following deterioration factors calculated
by the report team were based on only 15,000 miles of
durability testing.
HC DF less than 1.0
CO DF less than 1.0
NO DF 1.1
H
Insufficient durability data is available to more adequately
assess Alfa Romeo's durability accomplishments.
Catalyst Screening Programs - '75
Alfa Romeo did not include any information on catalyst testing
in the information they submitted to EPA.
Progress and Problem Areas - '75
Progress
Alfa Romeo has made progress in the areas of system optimization
and selection and in durability testing.
Enough progress has been made to enable Alfa Romeo to select
a first choice and a back-up system. The two systems are
typical 1975 systems. The first choice incorporates a
pelleted catalyst/ the back-up system employs a precious
metal monolithic catalyst. Neither system uses EGR. Alfa
Romeo has conducted a durability test of their first choice
system. The mileage reported was approximately 15,000 miles.
Very little emission performance deterioration was experienced.
Problem Areas
Although the limited durability testing done to date has shown
little deterioration, the emission levels reported were above
the required 1975 levels, especially in HC. Part of the lack
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of emission control may be due to the placement of the
converter. In the opinion of the report team, some
emission control may have been sacrificed for this
reason. Lead time is also a problem reported by Alfa
Romeo.
Conclusions '75
The report team concludes that Alfa Romeo has not yet
demonstrated the capability to meet the 1975 standards.
They are grouped in class 75-2.3, Catalytic System Approach -
Below Average Development Status, because of their poor low
mileage emission results, their apparent decisions to sacrifice
emission control to maintain performance, and the limited
durability testing reported.
6.2.1.2 1976 Development Status
Systems to be Used - '76
The Alfa Romeo 1976 system is basically the 1975 system with
the addition of a NO catalyst. Both pellet and monolithic
ji
converters are being considered. Replacement of the mechanical
fuel injection system with a Bosch electronic system is being
considered. No data was available from any vehicle or engine
dynamometer tests.
Alfa also reported development plans for a 1976 control
system for the Alfasud line of vehicles, which are not yet
imported into the United States. No data was reported on
this system either.
Durability Program - '76
At this time Alfa Romeo has not initiated any durability
program on any of their 1976 prototype systems.
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Catalyst Screening Program - '76
Alfa Romeo did not include any information on catalyst
testing in the data they submitted to EPA on their 1976
systems.
Progress and Problem Areas - '76
Progress
Alfa Romeo has made enough progress in the past year to be
able to indicate their choice of emission control system
for 1976. It is now planned to be the addition of a NO
X
catalyst to the 1975 system.
Problems
Alfa Romeo reported that they have not yet been able to achieve
the 1976 emission levels.
Conclusions '76
The report team concludes that Alfa Romeo has not yet
demonstrated the capability to meet the 1976 standards.
They are grouped in class 76-2.2, Catalytic System Approach -
Below Average Development Status due to their 1975 system's poor
performance, the fact that 1976 emission levels have not yet
been reported (even at low mileage)^ the magnitude of the
task of developing another emission control system for the
Alfasud vehicle and the lack of any durability results on
1976 systems.
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6.2.2 BMW
6.2.2.1 1975 Development Status
Systems to be Used - '75
BMW has seven 1975 systems still under consideration.
Continuing development was reported on the following
systems:
1. 2 liter (121 cubic inches) engine, carbureted,
engine mods (EM) , electric choke, EGR, air
injection (AI), rich thermal reactor (RTR).
2. 2 liter engine, carbureted, EM, electric
choke, EGR, AI, noble metal monolithic
oxidizing catalyst (NMOC), RTR.
3. 2 liter engine, electronic fuel injection
(EFI), EM, oxidizing catalyst (OC) , EGR.
4. 2 liter engine, carbureted, EM, electric choke,
catalyst temperature booster, pellet OC, AI, EGR.
5. 3 liter engine, EFI, EM, EGR, AI, RTR.
6. 3 liter engine, EFI, EM, EGR, RTR, NMOC.
7. 3 liter engine, EFI, EM, EGR, OC.
BMW reported that system number 4, which employs the catalyst
temperature booster, has been "less successful" than the
other systems because the air injection system cannot supply
an adequate quantity of air during cold start operation.
BMW reported ranges of results rather than the specific
results of individual tests. Systems 2 and 6 were consistently
below the 1975 levels at low mileage. Both of these systems
employ rich thermal reactors and oxidation catalysts. System
1, the two liter engine equipped with a rich thermal reactor,
was able to achieve CO levels below the 1975 requirements
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without a catalyst. Hydrocarbon levels ranged from .25 to
.5 gpm on this system. All the systems were consistently
under the 1975 NO requirement.
X
The use of several "modulating devices" is anticipated by
BMW. An engine rpm signal will be used to de-clutch the
air pump and restore vacuum spark advance. This will cause
a loss of emission control during high speed operation.
Emissions may also be higher in urban driving than on the
Federal test procedure, depending on how the vehicle is
driven.
Other than indicating that the catalyst temperature booster
system may be dropped, BMW has not specified which system
or systems are "first choice" systems and which are back-up
systems. They are waiting longer than most manufacturers
to begin concentrating their development on the most pro-
mising systems.
BMW also considers the maintenance of good driveability,
performance and fuel economy important constraints. BMW
may utilize control methods which most manufacturers
consider too expensive. BMW's estimate for the retail
price of the '75 control system was $1500, the highest of
all manufacturers who submitted estimates.
Durability Program - *75
As of the date of BMW's submittal, October 25, 1972, no
evaluation of the durability of their proposed 1975 prototype
systems had been initiated. The reported reason for the
current lack of a program is the unavailability of acceptable
catalytic systems. Optimization studies are continuing.
While no durability testing has yet been initiated, BMW plans
emission testing at 1,000-mile intervals. This type of
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testing could significantly impact the length of time it
takes to complete a program.
Due to the lack of any durability data, it is not possible
to make any assessment of the potential deterioration
characteristics of the BMW system approaches.
Catalyst Screening Program - '75
BMW did not include any information on catalyst screening
programs in the information they submitted to EPA.
Progress and Problem Areas - '75
Progress
BMW has made progress in the last year in the area of system
development and low mileage emission results. BMW has tested
several different emission control systems that might be
applied to meet the 1975 standards.
Some low mileage emission results have been reported to be
below the 1975 levels.
Problem Areas
BMW did not report the results of any durability tests.
Catalyst failures at low mileage have prevented extensive
mileage accumulation.
Conclusions '75
The report team concludes that BMW has not yet demonstrated
the capability to meet the 1975 standards. They have been
grouped into class 75-2.2, rCatalytic System Approach -
Average Development Status, because of their possibly
adequate low mileage emission results and their lack of
durability data.
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BMW may be planning to use an emission control system that is
significantly more costly than that planned by most manu-
facturers. BMW may be developing too many systems at this
point in time, instead of concentrating on the most attractive
systems as have most other manufacturers.
6.2.2.2 1976 Development Status
Systems to be Used - '76
Two different 1976 systems are under development at BMW. It
is not known which is the first choice system. One system
uses a three-way catalyst and an oxygen sensor. The output
of the oxygen sensor (called a X-rprobe by BMW) is used to
maintain a constant engine air/fuel ratio (near stoichiometric)
At this air/fuel ratio it is possible to simultaneously reduce
NO and oxidize HC and CO with a single catalyst. This system
X
is being used on both the four and six cylinder engines.
The other system is basically the number one 1975 system
described previously with a NO catalyst replacing the rich
H
thermal reactor. Development work is apparently limited
to the four cylinder engine at this time. A precious metal
monolithic NO catalyst is used.
ji
No vehicle emission test data was reported on either 1976
system. Based on catalyst screening test data, BMW estimates
the low mileage emission levels of the three-way catalyst
system will be .2-.3 gpm HC, 2.5-3.5 gpm CO and .3-.5 gpm NO .
Ai
The dual catalyst system estimate is .3-.4 gpm HC, 1.2-2.2 gpm
CO and .3-.4 NO .
-A.
BMW's forecasted cost increase for the 1976 control system
was the highest reported by any manufacturer, $1900 more than
systems on current vehicles.
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Durability Program - ' 76
BMW has not initiated a 1976 durability program as optimization
work has not advanced to a degree which would warrant mileage
ac cumu1ation.
Catalyst Screening Program - '76
BMW did not include any information on a reduction catalyst
screening program in the information they submitted to EPA.
Progress and Problem Areas - '76
Progress
BMW has made some progress in system development and low
mileage emission results.
Problem Areas
No durability data was reported.
Conclusions '76
The report team concludes that BMW has not yet demonstrated
the capability to meet the 1976 standards. They have been
grouped in class 76-2.1, Catalytic System Approach - Average
Development Status, because of their estimated low mileage
results which may be equivalent to what the rest of the
industry is demonstrating.
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6.2.3 BRITISH LEYLAND
6.2.3.1 1975 Development Status
Systems to be Used - '75
British Leyland Motor Corporation (BLMC) manufactures many
different vehicles including MG, Jaguar, Austin, Triumph,
and Rover. Unlike the "Big Three" U. S. manufacturers
the vehicles manufactured by British Leyland have few
similarities. Both the chassis and engines are radically
different among individual divisions. This makes the task
of developing emission control systems more difficult be-
cause a system that is applicable to a Jaguar may be
impossible to install on an Austin, for example.
All British Leyland divisions are, however, developing
similar systems. Both pelletized and monolithic catalysts
are being tested but most of the development is on the noble
monolithic Johnson-Matthey and Engelhard catalysts. Some
BLMC vehicles (the lightest ones) do not use EGR, others do.
Most EGR systems used are the AC-Delco types although some
work on a proportional system under development by the S. U.
carburetor division was reported. Many other non-proportional
EGR systems are also under development.
All BLMC vehicles will use air injection with their catalysts.
No development of modulated air injection systems was reported,
A variety of engine modifications are used on BLMC vehicles.
Most divisions have been able to achieve emission levels about
one-half of the 1975 requirements at low mileage. No fuel
economy penalty over 1973 vehicles is anticipated. A retail
price increase of $330 was forecasted by BLMC.
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Durability Program - '75
British Leyland's durability program to date has been guided
by the need to identify a durable catalytic system. 17 vehicles
were reported to be involved in mileage accumulation testing.
None of the vehicles have accumulated 50,000 miles. Only one
vehicle at 25,000-plus miles demonstrated continued low emission
performance (this vehicle subsequently suffered a failure of
the catalyst substrate). Durability testing is being per-
formed through a joint effort including 7 vehicles tested at
the Pollution Control Research Laboratory. In addition, each
division of British Leyland—Austin-Morris, Triumph, Jaguar,
and Rover—is conducting its own durability program. Cur-
rently it does not appear to the report team that British
Leyland will be able to successfully complete any 50,000-
mile program by January 1973, the date they have identified
as the deadline for selection of a catalyst supplier.
Currently no Rovers or Jaguars have initiated mileage accumu-
lation. The bulk of the work to date has been done using
Austin-Morris Marinas as test vehicles. Plans call for the
inclusion of other product lines and the Marina is projected
to have the greatest 1975 sales volume. Thus, it appears
that British Leyland has designed their durability program
to eventually cover their anticipated 1975-type model sales.
The vehicle configuration used in the durability testing to
date have included the most advanced hardware available to
British Leyland - both catalytic reactors and EGR systems.
However, the need for better carburetion, choke, and ignition
systems have been identified as problems. Thus, the vehicle
systems not directly catalyst related cannot be judged as
typical of 1975 systems.
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To accelerate mileage accumulation rates a route with an
average speed of 40 mph has been used. This average
speed is higher than that used for certification purposes.
It was reported that emission testing is conducted after
tune-ups which implies more frequent than allowed maintenance
on these fleets. Much of the durability mileage has employed
essentially lead sterile fuel and thus doubt is cast on the
magnitude of the catalytic deterioration demonstrated to
date.
None of the vehicles has successfully completed 50,000
miles of operation. One car operated 25,000 miles remaining
below the 1975 Federal levels. Deterioration of the emission
performance on this vehicle, a Marina with an Engelhard spiral
wound PTX, was slight. However, the catalyst substrate had
failed and eroded by 28,000 miles and the vehicle test was
discontinued.
British Leyland's greatest hurdle apparent from their reported
durability program is that of mechanical catalyst failure.
The frequency of these failures at best has left their current
program of marginal usefulness in selecting a catalyst supplier,
in the opinion of the report team.
Catalyst Screening Program - '75
British Leyland has no specific catalyst screening practices.
However, they do measure warm-up performance of catalyst samples
in a laboratory warm-up rig using an engine dynamometer. Both
the time needed for light-off and the HC and CO effectiveness
for catalysts when fresh and during durability tests are
measured with this apparatus.
Progress and Problem Areas - '75
Progress
BLMC has made progress in system development and some lesser
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amount of progress in durability testing. The basic 1975
prime system configuration for most of the vehicle/engine
combinations of BLMC appear to have been chosen, at least
conceptually. Most of the systems are typical 1975 systems.
Some of the lighter weight vehicles may not use EGR.
One vehicle was reported to have reached 25,000 miles of
durability testing.
Problem Areas
BLMC has experienced severe catalyst durability problems.
The substrate has failed in nearly every test. Even the vehicle
that completed 25,000 miles, and was under the 1975 levels at
that time, had a catalyst substrate failure shortly thereafter.
BLMC also expressed concern about the lead content in the
proposed EPA rule, indicating that they feel it may be too
high.
BLMC had experienced two problems which were not reported as
major problems by other manufacturers. One problem resulted
in cylinder head replacement being a common occurrence, and
the other problem is the apparent difficulty in the develop-
ment of an automatic choke.
Conclusions '75
The report team concludes that British Leyland has not yet
demonstrated the capability to meet the 1975 standards.
They are classed in group 75-2.3, Catalytic System Approach -
Below Average Development Status because of their continuing
severe substrate durability problems, their system's apparent
problems with lead contamination even at low lead levels,
their slowness in the introduction of engine modifications
like hardened valve seats, their cylinder head cracking problems
and their apparent gap in the development of as common a device
as an automatic choke.
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The number of different engine family combinations and the
number of apparently independent emission control develop-
ment programs within BLMC may be diffusing their efforts
somewhat.
6.2.3.2 1976 Development Status
Systems to be Used - '76
The British Leyland system for 1976 is essentially the same
as the 1975 system with the addition of a NO catalyst. BLMC
J^
indicated that the 3-way catalyst plus oxygen sensor is being
investigated but no data was reported.
Only one model in the BLMC line has been able to achieve the
1976 levels at low mileage. This was accomplished on an
Austin vehicle using two International Chemical Company
catalysts, one for NO and one for HC and CO. The best
X
results were .20 gpm HC, 1.89 gpm CO, and .26 gpm NO . EGR
X
was not used and BLMC only plans to use EGR if its use is
absolutely necessary. Almost all of BLMC's EGR development
has been on non-proportional systems, therefore, they must
associate some fuel economy and driveability problems with
the use of EGR.
Durability Program - 76
No durability vehicles with 1976 prototype systems were re-
ported on mileage accumulation by BLMC in their status report.
Catalyst Screening Program - '76
British Leyland included very little on NO catalyst screening
H
programs other than to say they were similar to the tests they
use for oxidation catalysts. For oxidation catalysts, warm-up
performance in a laboratory apparatus and engine dynamometer
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are measured. The time required for light-off and NO
conversion for,both fresh.and aged catalysts would be
measured.
Progress and Problem Areas - '76
Progress
BLMC has progressed to the point where the 1976 emission
levels have been achieved at low mileage. BLMC has also
apparently decided that the typical (dual catalyst) system
is their prime 1976 system at this time.
Problem Areas
BLMC reported that the deterioration in emission control
system performance was even more severe than the deterioration
of 1975 system performance. No vehicle has met 1976 levels
for any extended mileage.
Conclusions '76
The report team concludes that British Leyland has not yet
demonstrated the capability to meet the 1976 standards. They
are grouped in class 76-2.1, Catalytic System Approach '--
Average Development Status because of their ability to meet
the 1976 levels at low mileage, their 1975 development status,
and their orally reported durability results of more than
10,000 miles below the 1976 levels.
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6.2.4 DAIMLER-BENZ (MERCEDES)
6.2.4.1 1975 Development Status
Systems to be Used - '75
The Daimler-Benz first choice system for their gasoline
vehicles consists of engine modifications, EGR, noble metal
monolithic oxidation catalyst and air injection. Some
models use electronic fuel injection while others use
carburetion. Neither the fuel injection nor the carburetion
system were reported to be significantly different than
current systems.
A back-up system utilizing a "start catalyst" is reported to
be under development but no data was provided on this system.
A start catalyst can be a catalyst that "lights off" at a low
temperature but is not practical for continuous use because
of durability problems or hot efficiency problems. The start
catalyst can be switched out of the system as soon as the main
catalyst is warmed up and ready to take over. The start
catalyst system has its merits from an engineering viewpoint
but the added cost and complexity compared to a single catalyst
system discourages many manufacturers from working on it, in
the opinion of the report team.
Low mileage emission levels on Mercedes vehicles using electronic
fuel injection have been as low as .08 gpm HC, .75 gpm CO, and
.79 gpm NO . These levels are lower than those achieved by
X
most other manufacturers. No details were provided on the
exact configurations tested and no comments were made on any
of the tests reported.
Daimler-Benz did not specify any information about specific
design constraints but they did seem to be concerned about
fuel economy and performance. An 8% power loss was claimed
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for the 1975 systems and a 20% fuel economy penalty,
compared to 1972 vehicles was reported. Compared- to
uncontrolled vehicles, Daimler-Benz reported that the
fuel economy penalty is 40%. EPA data on the tests of
hundreds of uncontrolled and controlled vehicles, however,
shows very little change in fuel economy from uncontrolled
to 1972. Daimler-Benz did not present data to substantiate
any of the claimed fuel economy problems.
Daimler-Benz is planning to by-pass the catalyst during
high engine speed, high vehicle speed and high temperature
operation. No other information on modulating devices was
provided.
Daimler-Benz also uses Diesel engines in some of their vehicles.
They are the only manufacturer who currently sells a Diesel-
powered passenger car in this country. Combustion in the
Diesel engine is significantly different than in conventional
gasoline engines because of the unthrottled, heterogeneous
mixture operation. Combustion is initiated by the heat of
compression in the Diesel engine, rather than by a spark
plug. Unlike the gasoline engine, the fuel in the Diesel
is not homogeniously mixed with the air, rather it is in
the form of tiny droplets. As the heat of compression vaporizes
these droplets a combustible mixture is formed and burning is
initiated. It is not necessary to throttle the Diesel engine
because the burning of the droplet, like the burning of a
match, depends on the local, not total, air supply. A gasoline
engine cannot operate without throttling because its homogenous
mixture would be too lean to burn at lighter engine loads.
Carbon monoxide emissions from the Diesel are very low because
of the overall lean operation. CO formed during the droplet
burning is easily oxidized into CO- during the expansion stroke
because of the presence of high temperatures and excess oxygen.
6-87
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Hydrocarbon emissions can be very low in a properly designed
Diesel engine if the fuel spray is kept away from the
boundaries of the combustion volume to avoid quenching
on the "cold" surfaces of the cylinder walls and pistons.
Oxides of nitrogen emissions from Diesels can also be quite
low if the fuel spray pattern and droplet sizes are controlled
to reduce the availability of oxygen and nitrogen during the
initial phase of the combustion.
A 1972 Mercedes Diesel, tested repeatedly at low mileage by
EPA, met the requirements for 1975 easily. This testing
included the use of the modified test procedure which is
proposed for Diesel vehicles. Mercedes has developed an
inexpensive modification for the injection system which
reduces the hydrocarbon levels even further. With the
modified injection system the Mercedes Diesel car emits
levels of HC, CO, and NO approximately one-half those re-
J\:
quired for 1975.
An additional attraction of the Diesel passenger car is its
inherently good fuel economy. While being tested at 3500
pounds inertia weight the fuel economy of the Mercedes Diesel
was measured to be 24 miles per gallon during urban driving.
No other 3500 pound or heavier vehicle ever tested by EPA has
achieved urban fuel economy close to this level, the average
1973 vehicle being 14.0 miles per gallon in the 3500 pound
class.
Durability Program - '75
Daimler-Benz reported that three vehicles had been placed on
mileage accumulation. The highest mileage indicated was
9,000 miles and all three vehicles exceeded the 1975 Federal
6-88
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requirements relatively early in the mileage accumulation
programs. Low mileage emission data was reported on three
different engines: the 4-cylinder, 134 cubic-inch;
6-cylinder, 167.5 cubic-inch; and the 8-cylinder, 276 cubic-
inch. Due to the total lack of program detail supplied by
Daimler-Benz, it is impossible to assess the adequacy of the
Daimler-Benz durability experimentation.
Catalyst Screening Program - '75
Mercedes supplied no information on catalyst screening
activities for their 1975 systems in their October 1972,
submittal to EPA. They did, however, refer back to the
information they submitted at the April 1972, hearings. The
only non-vehicle catalyst tests mentioned by Mercedes are
engine dynamometer tests done to simulate mild, medium
severe, and severe driving conditions. These test results
are used to evaluate various catalysts.
Progress and Problem Areas - '75
Progress
Daimler-Benz has added a possible back-up system to their
1975 first choice system. Testing on both systems is con-
tinuing, although data was only presented from the first
choice system at low mileage. Not enough information was
presented by Daimler-Benz to indicate whether or not any
progress has been made on the durability performance of
1975-type emission control systems.
Problem Areas
Daimler-Benz reported problems of rapid deterioration of
emission performance of their first choice system. The
back-up system employing a "start" catalyst may alleviate
6-89
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this problem. Part of the problems that Daimler-Benz
is encountering may be due to the fact that their vehicle
tests show that the NO level that they are trying to meet
X
is approximately 1.5 gpm, not the Federal standard of 3.1
gpm.
Conclusions '75
The report team concludes that Daimler-Benz has not yet
demonstrated the capability to meet the 1975 standards with
their gasoline engine emission control systems. Daimler-Benz
will, in the judgment of the report team, be able to meet
the 1975 standards with their Diesel-engined vehicles.
Daimler-Benz is, therefore, grouped into two classes, 75-1,
Non-Catalytic Approach and 75-2.2, Catalytic System Approach -
Average Development Status. Their inclusion in class 75-2.2
is somewhat arbitrary since Daimler-Benz submitted little
useful information upon which to assess the status of their
development program.
6.2.4.2 1976 Development Status
Systems to be Used - '76
The Daimler-Benz 1976 system is basically the 1975 system
with the addition of a NO reduction catalyst. No mention
X
was made of use of the start catalyst which is being con-
sidered as a back-up for 1975. NO catalysts from Kali-Chemie,
H
and Heraeus are being considered.
The best low mileage data on the 1976 system was obtained on
a carbureted MB 250 model: .12 gpm HC, 1.10 gpm CO, and
.15 gpm NO . Best results for the fuel injected V-8 MB280
X
were reported to be .36 gpm HC, 1.98 gpm CO, and .36 gpm NO .
X
6-90
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A variety of auxiliary devices on their 1976 vehicles will
include: speed-EGR, rpm-EGR, rpm-air injection, and water
temperature-air injection.
Daimler-Benz is predicting essentially the same fuel economy
for the 1976 system as the 1975 system. Normally, a dual
catalyst system uses richer carburetion than a single
catalyst system. Significant fuel economy penalties are
usually expected. Daimler-Benz did not report any reasons
for the essentially equivalent fuel economy of the 1976
system and the 1975 system.
The biggest inconsistency in the Daimler-Benz 1976 status
report concerned the question of durability. Mileage
accumulation apparently has not yet been attempted and
D-B reported:
"Starting a durability run on a higher (higher than low
mileage targets of ..15, 1.5, .20} basis of emission values
would result in exceeding the standards shortly after the
beginning."
They also reported:
"...we have not yet had made available to us any reduction
catalyst with an acceptable rate of deterioration."
It is not clear to the report team how Daimler-Benz can
be sure none of the catalysts supplied to them have acceptable
deterioration when they have not yet run them on durability.
Development of a 1976 control system for the Diesel-powered
vehicle was not reported. During a presentation made to the
National Academy of Sciences Committee on Mobile Source
Pollution Control Programs on August 30, 1972, Daimler-Benz
reported that the "best" they can do in laboratory is .8-.9 gpm
NO with the modified Diesel. On March 30, 1972, however, a
J\
modified Diesel was measured at .25 gpm HC, 2.28 gpm CO and
•37 N0x by Daimler-Benz. Not one test reported to EPA last
6-91
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spring was over .7 gpm NO when EGR was used. Daimler-
^t
Benz's attitude toward the Diesel is curious, in the opinion
of the report team. They have achieved impressive emission
levels in their own testing but seem reluctant to follow the
results up with more extensive durability testing.
Durability Program - '76
Daimler-Benz has not initiated durability testing of their
1976 prototype concepts. No schedule was submitted to
indicate when such testing might be initiated.
Catalyst Screening Program - '76
Daimler-Benz presented limited information on their NO catalyst
X
screening programs. The following general screening tests are
conducted:
Test Objective of Tests
bench scale initial catalyst activity
laboratory determine light-off temperature
bench scale test mech. durability and chem. activity
CVS test exhaust emission
Mercedes gave no additional details on these tests. However,
the charts in the back of the Mercedes submittal indicate they
measure HC, CO, and NO emissions from all catalysts they
J±
receive versus air/fuel ratio. It is not known if laboratory
apparatus or an engine dynamometer is used for these tests.
The following catalysts have been received and tested by Daimler-
Benz:
Degussa OM722 OM506 OM721
Engelhard PTX3/121 3119
PTX3/121 3118
PTX4/121 2978
PTX4/121 3008
PTX4/121 3112
PTX423S/121 2771
PTX423S/121 2916
PTX423S/121 2965
PTX423S/121 2979
PTX423S/121 3122
PTX523S/121 2903
6-92
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W. R. Grace
Heraeus
Kali Chemie
Johnson-
Matthey
Sud-Chemie
Champion
502F
721
722
721
722
721
4035
3368
4023
4035-6
4035S3
4023/Febral 80
3368/Febral 80
EC1/4
EC3A/12
EC 8 A
EW3A/4 m.b.
EW3A/4
EW8A/4 m.b.
A4
Monel
501F
97
04
96
03
9312
Progress and Problem Areas -'7(5
Progress
Daimler-Benz has made progress in system selection and low
mileage emission results. The first choice system for 1976
has been chosen. It is a typical dual catalyst system.
The low mileage emission test results reported indicate
that Daimler-Benz has been able to achieve the 1976 levels,
at low mileage.
Problem Areas
No durability testing was reported because of the inability
of Daimler-Benz to achieve their own low mileage goals.
Deterioration of NO control is a severe problem. Daimler-
Ai
Benz reported that in order to meet lead time schedules for
1976, contracts with suppliers would have to be signed in mid-
November 1972. No such agreement was reported in their status
report.
6-93
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Conclusions '76
The report team concludes that Daimler-Benz has not yet
demonstrated the capability to meet the 1976 standards
with their gasoline engine. In the judgment of the report
team, the Diesel engine development reported by Daimler-
Benz has much more potential to meet the 1976 standards,
based on their achievement of the 1976 levels at low
mileage and oral claims by Daimler-Benz that the Diesel
has very little emission control deterioration with mileage.
Daimler-Benz is grouped into class 76-1, Non-Catalytic
Approach and 76-2.1, .Catalytic System Approach - Average
Development Status. The reason for their grouping in 76-2.1
is the same as the reason for grouping them in class 75-2.2.
6-94
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6.2.5 FUJI HEAVY INDUSTRIES LTD. (SUBARU)
6.2.5.1 1975 Development Status
Systems to be Used - '75
The Subaru first choice system will consist of engine mods
(including electric choke), rich thermal reactor, oxidizing
catalyst, air injection, and EGR. Catalysts will be supplied
by either Degussa (pellets), Engelhard (noble monolith), or
Johnson-Matthey (noble monolith). The Degussa pellets seem
to be receiving the most attention at this time. Two back-up
systems under consideration could be used only if the emission
performance of the first choice system is good enough to allow
the deletion of either the thermal reactor or the catalyst.
Subaru has not been able to achieve adequate CO control with
the thermal reactor, no catalyst approach. They feel that the
use of a catalyst without a thermal reactor will not provide
enough HC and CO control as the catalyst efficiency deteriorates
at higher mileages. At low mileage the catalyst, no thermal
reactor system was achieving .24 gpm HC, .9 gpm CO, and .88 gpm
NO , while the catalyst plus thermal reactor is achieving .16
X
gpm HC7 1.4 gpm CO, and .64 gpm NO . While these levels do
2i
not look significantly different it should be noted that the
catalyst only results were generated with a 2250 test weight
and the catalyst plus thermal reactor results were with a
2750 test weight. Subaru did not report tests using a 2750
test weight with catalyst only.
It is not clear to the report team why Subaru is using an
EGR system since NO levels are typically under 1.0 gpm with
J\.
a system that provides a maximum of 6% EGR at light loads and
almost none at higher loads where NO emissions are high. NO
A ' X
emissions may be under the proposed California level of 1.5 gpm
without any recirculation. The heaviest Subaru vehicles fore-
casted for 1975 production will be tested at 2750 inertia weight.
6-95
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Vehicles in this weight class can often achieve low NO
X
levels without EGR because of the lower power requirements
required to drive the cycle compared to heavier cars. One of
the 2250 test weight vehicles under test has been consistently
under the 1976 NO requirement of .4 gpm without a reduction
Ji,
catalyst.
Subaru does not seem to be working under many constraints
which could affect their ability to meet the 1975 requirements.
To retain performance they have decided to increase the displace-
ment of their engine by 17%. To facilitate system packaging
they have gone to a dry sump lubrication system to allow place-
ment of the thermal reactor under the engine in an area normally
occupied by the oil pan. A tunnel has been added to the floor
of the vehicle to provide space for the catalytic converter.
A fuel economy penalty with the rich thermal reactor is antici-
pated but is being accepted until improvements can be made
which will not compromise emission performance. Subaru has
consistently chosen to accept major cost, performance, and
passenger accommodation penalties rather than compromise
emission performance. Few manufacturers appear to be willing
to take this approach, in the opinion of the report team.
Subaru plans to use a catalyst by-pass valve "...in case of
an emergency such as overheating of a Hang-On device due to
misfire,..." if it is allowed by EPA. No other "modulating
devices" are planned. Subaru reported that "...irrespective
of ambient conditions, engine revolution and load, each device
works exactly in the same manner as in the 1975 Federal Test
Procedures." The emissions of Subaru vehicles should be as
low on the road as during the Federal Test Procedure, in
the judgment of the report team.
6-96
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.The retail cost of the 1975 control system was estimated to
be $370. Should catalyst changes be required, Subaru estimates
the replacement cost (including labor) of a noble metal monolith
will be $37. Replacement cost of a pellet catalyst was esti-
mated to be $16. These were the lowest replacement cost
estimates provided by any manufacturer.
Durability Program - '75
Subaru had not, at the time of their submittal, initiated
durability testing of their first choice system: thermal
reactor, oxidizing catalyst, exhaust gas recycle and engine
modification. Durability mileage has, however, been initiated
on five vehicles to determine the deterioration associated
with major system components. Subaru's planning calls for
the initiation of first choice system durability testing in
October 1972. Six vehicles have been built up for this purpose.
Of the five vehicles which have undergone at least some mileage
accumulation, three were equipped with EGR/oxidizing catalysts
and two with EGR/thermal reactors. All testing is being done
with the 83 cubic inch displacement engine with vehicle inertia
weights of either 2250 pounds or 2750 pounds. It is assumed
by the report team that these test vehicle configurations are
representative of the contemplated Subaru 1975 vehicles.
Subaru did not supply any details on the test fuel type or
maintenance procedures used during their program. Of the
five cars started in the program, one was terminated due
to engine trouble, two others due to high emission degradation.
Currently one thermal reactor vehicle and one catalyst vehicle
are continuing in the program with reported mileage under
15,000 miles.
6-97
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Catalyst Screening Program - '75
Fuji reported three different types of screening tests
which are used to evaluate pelletized catalysts:
1. Catalysts are tested to determine the
temperatures required to attain 10, 50, and
90% conversion efficiencies. The criteria
for acceptance of a catalyst are that it
achieve these efficiencies (10, 50 and 90%
at 250, 325 and 500°C respectively for HC
and 175, 250 and 275°C for CO.
2. A heating and vibration test determines
attrition. The details of the test were
not reported. To be acceptable a catalyst
must have less than 5% weight loss after
300 hours.
3. Test to determine the effect of lead have
also been run. No details of the procedure
or criteria for acceptability were reported.
The only conclusions reported were that
"...lead contamination of catalyst (sic) is
a serious problem."
No procedure for evaluating monolithic catalysts were reported,
Progress and Problem Areas - '75
Progress
Subaru has progressed to the point where a first choice 1975
system has been identified. This system includes both a
thermal reactor and a catalyst. Low mileage test results
on this system are below the 1975 levels.
6-98
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Problem Areas
Because of the nature of their vehicle, Subaru has been forced
to make major changes to the engine and body to accommodate
the 1975 emission control system. .The major engine changes
are: 1) changing to a dry sump lubrication system and 2)
changing the exhaust port location. Both engine changes
have been made to accommodate the thermal reactor. The body
also is planned to be modified extensively, with a tunnel in
the floor to accommodate the catalyst. Subaru now has a flat
floor because of the front wheel drive of their vehicles.
No extensive durability data has yet been generated on the
first choice system.
Conclusions '75
The report team concludes that Subaru has not yet demonstrated
the capability to meet the 1975 standards. They are grouped
in class 75-2.2, Catalytic System Approach - Average Develop-
ment status because of their good low mileage results and
their lack of extensive durability data.
6.2.5.2 1976 Development Status
Systems to be Used '76
Subaru has not yet selected a first choice 1976 system. Two
systems are being developed; a dual catalyst, EGR, and partial
thermal reactor system, and an EGR and full thermal reactor
system. Best low mileage results with the two systems were
.15 gpm HC, .76 gpm CO and .34 gpm NO for the catalytic
J^
system, and .13 gpm HC, 4.3 gpra CO, and .41 gpm NO for the
X
non-catalytic system. Both systems are in the early stages
of development.
6-99
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Durability Program '76
No durability testing has as yet been initiated by
Subaru on 1976 emission control systems.
Catalyst Screening Program '76
Subaru's catalyst screening program for 1976 is the same
as the program described for 1975.
Progress and Problem Areas '76
Progress
Subaru has made some progress, achieving 1976 levels at
low mileage on a catalytic system.
Problem Areas
Subaru reported many problems for 1976, the major ones
being catalyst durability and efficiency; and the size,
fuel economy penalty and durability of the thermal
reactor system.
Subaru reported that they have essentially paused in their
1976 development to reassess the whole program.
Conclusions '76
The report team concludes that Subaru has not yet demonstrated
the capability to meet the 1976 standards. They are grouped
in class 76-2.1, Catalytic System Approach - Average Develop-
ment Status, because of their good low mileage results and
lack of adequate durability.
6-100
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6.2.6 HONDA
6.2.6.1 1975 Development Status
Systems to be Used - '75
The Honda approach for 1975 is the most unique in the
industry. The Compound Vortex Controlled Combustion C.CVCC)
engine burns a heterogeneous air/fuel mixture. The CVCC
concept is similar in some respects to the more well-known
stratified charge engines of Ford (PROCO) and Texaco (TCCS).
While the Ford and Texaco engines use direct cylinder fuel
injection to obtain charge stratification, the Honda CVCC
engine obtains stratification with the use of a prechamber
and a carbureted mixture.
Two separate intake valves are used on each cylinder of the
CVCC engine. One valve is located in the prechamber and the
other in the main chamber. During the intake stroke a rich
mixture is drawn into the prechamber and a lean mixture is
drawn into the main chamber. Combustion is initiated by a
spark plug located in the prechamber. The heat of combustion
causes the burning gases to expand into the main chamber
where they ignite the lean mixture. Combustion of the air/
fuel mixture is completed in the main chamber, resulting in
low emissions of CO, HC, and NO .
X
CO control is achieved because the engine is operated at a
very lean air/fuel ratio overall (A/F> 20). Conventional
engines cannot be operated this lean because of the difficulty
in igniting mixtures leaner than about 18:1 A/F. Ignition
is easily achieved in the CVCC engine by locating the spark
plug in the fuel rich prechamber.
6-101
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Hydrocarbon control is achieved because of the condition in
the main chamber and the operating parameters of the engine.
The temperature, oxygen concentration and gas dynamic flow
characteristics in the main chamber all favor hydrocarbon
oxidation. The timing of the valve events in this three
valve engine is also important.
N0x formation is a function of air (N« + OO availability
and .temperature. A significant portion of the combustion in
the CVCC engine occurs in the rich region of the prechamber
where the air availability is kept low because of the mixture
richness. By the time the combustion is occurring in the
main chamber, where there is high air availability, the
temperature has dropped because of expansion.
Vehicle test data reported by Honda indicates that overall
vehicle performance has not been compromised by using the CVCC
engine. To avoid a loss in power output the displacement of the
CVCC engine has been made larger than the conventional engine
currently used by Honda. With the new two-liter (120 cubic
inches) displacement the Honda CVCC car will accelerate through
a quarter mile in 17.8 seconds, faster than some large American
cars with V-8 engines. Top speed is reported to be 93 mph and
urban-suburban fuel economy is 24.2 mpg. Since the emission
control does not depend on after-treatment devices or an EGR
system, it is not anticipated that Honda will employ any
"modulating devices" which compromise emission performance
to achieve improved driveability and fuel economy during
operation atypical of the Federal emission test procedures.
Honda CVCC vehicles should be as clean on the road as during the
Federal test, in the opinion of the report team.
6-102
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Emission data reported by Honda was remarkably consistent.
The wide variations in test results reported by other manu-
facturers have not been experienced by Honda. The variability
problems of others are caused to a degree by their particular
emission control systems, rather than by inherent deficiencies
in the Federal test procedure. One of the lowest sets of
emission values ever measured from a CVCC powered vehicle
was obtained in EPA's own Ann Arbor laboratory. A Honda
vehicle with 50,000 miles on it was tested at .19 gpm HC,
1.73 gpm CO, and .65 gpm NO . Fuel economy on the Federal
X
driving cycle was 20 mpg. This is about 20% lower than the
average of the 2000 pound 1973 models, however, it should
be noted that the power-to-weight ratio of the Honda car
was higher than the average 2000 pound 1973 car. At
equivalent power-to-weight ratios the fuel economy should
be similar to conventional uncontrolled engines, in the
judgment of the report team.
Honda has experimented with catalytic control methods in .
the past, but they have decided to abandon the catalyst work
in favor of focusing more effort on refining the CVCC engine
for production. There are no back-up systems under develop-
ment any longer. •
Honda has also studied the.possibility of adapting the CVCC
process to larger engine and vehicles. A 1972 Chevrolet Vega
(2500 pound inertia weight) was purchased by Honda, thoroughly
evaluated, and then adapted to CVCC operation. Horsepower
after the modification was 1.0 horsepower higher, vehicle top
speed was the same (94 mph) and fuel economy was improved by
8%. Exahust emissions were measured at .26 gpm HC, 2.62 gpm CO,
arid 1.16 gpm NO . Computer simulation by Honda of a 350 CID-
X
4500 pound vehicle predicted HC and CO levels just under the
1975 requirement and about 1.5 gpm NO .
6-103
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This work was done to prove the adaptability of the process to
other engines.
The estimated cost increase reported by Honda for the 1975
engine is one of the lowest reported at $100 - 150.
Durability Program - '75
Honda Motor Company has basically had a two-phase durability
test program. Phase I involved the durability evaluation
of various catalytic approaches. Due to recurring failures
of these approaches (highest reported mileage about 30,000
miles), Phase I catalytic testing has been abandoned as a
plausible approach. Phase II testing involves extensive
evaluation of the Honda CVCC engine system. At this time
many low mileage vehicles have been tested with this system.
Four vehicles have completed or are close to completing a
50,000-mile durability program. Two mileage accumulation
techniques have currently been employed on the four durability
vehicles. One car was operated for 50,000 miles on a chassis
dynamometer following the AMA schedule. The other three
vehicles were operated on the proving ground Suzuka circuit.
The engine currently being tested with the CVCC concept is a
1,948 cubic centimeter, four-cylinder engine. It is assumed
that this is the only configuration which will be available
in Honda vehicles. Enough statistical confidence is attached
to the fleet low mileage testing to indicate Honda's capability
of complying at low mileage with Federal specifications.
During the mileage accumulation, Honda has reported minor
mechanical problems but has assured in their submittal that
these problems have been remedied. Also, certain modifications
were performed on three of the four durability vehicles at
high mileage. These modifications were minor and did not
6-104
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significantly affect the emission characteristics. The
following table reports the actual 4000-mile emission data
and the calculated deterioration factor for each vehicle
that has completed high mileage accumulation. This factor has
been calculated only using emission data up to the occurrence
of the modifications mentioned previously.
„ T Emission Data and Deterioration Factor
l^aJL INUUUJC-L
and Mileage
HC
4000
#1006
50,000
#2033
20,000
#2034
44,000
miles
miles
miles
0
0
0
.20
.21
.25
HC
DF
1.16
1.15
1.06
CO
4000
2
2
2
.30
.74
.50
CO
DF
1.
1.
1.
07
08
01
NOX
400U
0
0
0
.96
.95
.89
NO
DFX
1.03
1.04
1
#2035
32,000 miles 0.21 1.12 2.38. 1.12 0.95 1.00
Car #2034 was tested in the EPA laboratory subsequent to minor
modifications and completion of 50,000 miles of operation.
The following table indicates a comparison between the reported
Honda 50,000-mile data point and the average of data measured
by EPA.
Car #2034 50,000-mile Data
Honda
HC
CO
NO
0.
2.
0.
22
25
70
gpm
gpm
gpm
EPA
0
1
0
.24 gpm
.75 gpm
.65 gpm
6-105
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Catalyst Screening Program - *75
Honda does not have an active catalyst screening program
for 1975 because they do not plan to use a catalyst.
Progress and Problem Areas - '75
Progress
Honda has made the most significant progress of any auto-
mobile manufacturer in the past year. Last year Honda
was working on typical 1975 systems using various com-
binations of after-treatment devices such as catalysts
and thermal reactors. Because of the poor durability
performance of the after-treatment devices that Honda
was working with, they decided to abandon that approach
and to try to clean up the basic engine emissions using
their CVCC engine.
Honda has been successful in reducing the engine emissions
to levels below the requirements for 1975 for 50,000 miles.
Research and development work on this system for 1975 has
been essentially completed and the work is now concentrated
on the production aspects of the engine. No production
problems are foreseen by Honda.
Problem Areas
The following is a quote from Honda:
"In the course of the durability test, we have faced
several minor troubles, which are simple mechanical
malfunctions of some components of certain additional
devices. And, steps have already been taken to
rectify them. Such troubles, common in any develop-
ment processes, do not basically affect the emission
control capability."
"We see no difficulty, therefore, in assuring the
durability and reliability of the CVCC engine system."
6-106
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Conclusion's-' '75
Honda will be able to meet the 1975 standards. Honda may
also be able to have 100% of their production be below
the 1975 standards. EPA evaluation of the data from Honda
indicates that the average emissions of the 25 stage-3
vehicles plus three standard deviations times the highest
DF reported for each of the pollutants results in predicted
emissions for Honda which are still below the 1975 levels.
Compared to all other manufacturers surveyed, in the judg-
ment of the report team, Honda has developed the best 1975
system. No other manufacturer has achieved this combination
of low emissions, good vehicle performance, and fuel economy.
Honda has also been the boldest and most innovative. No
other manufacturer is developing an alternative to the
premixed charge gasoline engine for 1975 production. Most
have relied heavily on their suppliers for emission control
systems and hardware.
6.2.6.2. 1976 Development Status
Systems to be Used - '76
The Honda 1976 system will be essentially a recalibrated
1975 CVCC engine. No after-treatment devices such as NO
.X
or oxidation catalysts will be used. An EGR development
program is underway but Honda was reluctant to release
test data from that program because the results are too
preliminary. Without EGR or catalysts Honda has achieved
.25 gpm HC, 2.5 gpm CO, and .43 gpm NO . This was an
Ji
average of three consecutive tests. No other manufacturer
has reported results this encouraging without EGR.
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Durability Program - '76
Honda has not yet initiated mileage accumulation of any
CVCC equipped vehicles which have been calibrated or
modified to comply with the 1976 Federal oxides of nitrogen
requirement.
Catalyst Screening Program - '76
Honda does not plan to use catalysts for 1976.
Progress and Problem Areas - '76
Progress
Honda has decided to concentrate on meeting the 1976 standards
in much the same way in which they have already done with
the 1975 system, i.e., work on the basic engine and not use
after-treatment devices. Work is just beginning on an
intensive basis, now that research and development work on
the 1975 system has been completed.
Since the basic 1975 system already gives NO emissions under
X
1.0 gpm NO , the .4 gpm NO level is not too far away. Very
X X
preliminary tests have yielded NO emissions of .43 gpm NO
*i ' J±
with HC and CO under the 1975 levels.
Problem Areas
Honda has yet to demonstrate NO control consistently below
X
.4 gpm NO and has not yet demonstrated the required durability.
H
Conclusions - '76
Honda will probably be able to meet the 1976 standards, in
the judgment of the report team. There is very little data
from Honda on their 1976 development,since it is just beginning,
but even the first preliminary results reported are encouraging,
especially since EGR was not used. Honda has been grouped into
class 76-1, Non-Catalytic Approach.
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6.2.7 MITSUBISHI
6.2.7.1 1975 Development Status
Systems to be Used - '75
Mitsubishi manufactures the Colt vehicle which is marketed
by Chrysler in the U. S. The 1975 system under development
for this vehicle consists of engine modifications (including
altitude compensated carburetion), thermal reactor, and
oxidation catalyst with air injection. A solid state
ignition with provisions for spark retard during cold starts
may also be included. Because the Colt vehicle requires
only a 2500 pound test weight, EGR is not required to achieve
the 1975 Federal requirements for NO . A variety of catalysts
j£
have been,tested. Some of the best low mileage results were
with the use of a UOP noble metal pellet type catalyst, .10
gpm HC, .79 gpra CO, and 2.42 gpm NO . Other catalysts tested
Ji
include Engelhard, Mobil, Air-Products, Kali-Chemie, Mitsubishi,
Osaka, Tokyo Roki, and Johnson-Matthey. The several types of
manifold oxidation systems under consideration range from a
standard exhaust manifold with air injection to a large
volume, baffled thermal reactor. In between these extremes
is a medium volume, cored-reactor similar to the Chrysler
partial thermal reactors. No data was provided on any
vehicles run with one of these manifold oxidation systems
without catalysts so it is difficult to comment on the system's
effectiveness.
The most outstanding feature of the Mitsubishi 1975 system
is the air injection modulation system. An air control valve
which senses both intake manifold vacuum and exhaust back
pressure is used to provide air injection proportional to
engine load. Data exist which show there is an optimum air
6-109
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injection rate for each engine loading condition. Lighter
loads require less air injection than heavier loads for
optimum emission control. Most manufacturers' systems,
however, provide more air injection at lighter loads than
at heavier loads. This is exactly the opposite of the air
injection characteristics required for best emission control.
Toyo Kogyo was the only other manufacturer, besides Mitsubishi,
to report some type of air modulation system under development.
No mention was made of "auxiliary devices" which might impair
the system's emission control during some operating modes.
A catalyst by-pass valve which would be activated above 1470°F
catalyst temperature is being developed. Mitsubishi reported:
"The use of the by-pass valve, in the converter system, is
entirely dependent on the approval of EPA." It should also
be noted that the air modulation system reduces the air
injection to the catalyst at high loads to prevent high
temperatures. A graph of the air injection rate as a function
of load and engine speed seemed to indicate to the report team
that the air flow may be completely cut off at higher power
levels. This may not be as desirable,in our opinion, as just
reducing the rate somewhat. The graph seems to indicate that
air would still be injected during moderately hard acceler-
ations and expressway cruise. Wide open throttle operation,
however, could result in very high emissions.
The Mitsubishi basic approach is one of the best, in concept,
of all manufacturers using conventional engines.
Mitsubishi's cost estimate for the 1975 system was $245-376.
Fuel economy is estimated by Mitsubishi to be 10-22% worse
than current vehicles.
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Durability Program - '75
After successful completion of catalyst screening evalu-
ations, Mitsubishi normally subjects candidate catalytic
systems to a 50,000-mile durability evaluation. The pur-
pose of this testing is to measure actual vehicle/system
deterioration. As of this writing 25 test vehicles are
involved in this mileage accumulation program.
For its test purposes Mitsubishi utilizes 1972 and 1973
Dodge Colts. Two engines are used, 98 and 104 CID. These
vehicles represent Mitsubishi's current.U. S. market.
The durability testing thus far has basically been a
catalytic converter evaluation procedure. Most of the
vehicles have been equipped with prototype catalytic con-
verters only. Of particular significance is the fact that
none of the durability systems have yet included the manifold
reactor with the modulated air injection.
Mileage accumulation is achieved through the use of an AMA
equivalent procedure. Fuel used has been lead sterile
rather than a trace lead containing fuel.
Only one vehicle (#111) has been reported with over 36,000
miles accumulated. This car has completed its 50,000-mile
program with converter 4023k. Deterioration factors are:
HC DF less than 1.0
CO DF less than 1.0
NO DF less than 1.0
,Ai
Carbon monoxide levels at the 4,000-mile point and at 50,000
miles exceeded 3.4 grams per vehicle mile. Hydrocarbon and
oxides of nitrogen remained below the 1975 Federal require-
ments for 50,000 miles.
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Use of one vehicle only does not allow confidence in
production decision making, in the opinion of the report
team.
Catalyst Screening Program * '75
Mitsubishi has a very simple, effective, and quick screening
program involving laboratory tests followed by engine dyna-
mometer tests. The laboratory tests involve measuring HC
and CO conversion efficiencies at different temperatures.
The resulting comparison of temperature versus conversion
will show promising candidates which will then be checked
for durability. Durability testing is also a laboratory-
type procedure and involves exposing small quantities of
catalyst to engine exhaust. This system is constructed
with 34 parallel tubes to examine 34 different catalysts.
The effectiveness of the catalyst for HC and CO conversion
is measured after 100, 200, and 1,000 hours.
Following this test, successful candidates are tested in
a full converter system on an engine dynamometer for 10
hours. The purpose of this brief test is to confirm the
emission numbers obtained previously. The catalyst is then
subjected to a 50,000—mile vehicle durability test.
Progress and Problem Areas - '75
Progress
Mitsubishi has made enough progress in the last year to
enable them to select a "best choice" system, and begin to
test a fleet of vehicles with this system on them. The
test fleet was at approximately 8,000 miles at the time of
this writing, with all 7 vehicles reported under the 1975
levels at that time.
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Mitsubishi is also one of the two manufacturers to have
progressed to the use of modulated air injection.
Problem Areas
The durability results on other 1975-type systems reported
by Mitsubishi have not been successful in maintaining the
emissions below the 1975 levels. Mitsubishi also expressed
concern at the .05 gpg maximum lead level proposed by EPA.
They will run their durability vehicles on .03 gpm from
now on, but they.anticipate that the results may not be as
good as the lead sterile results they achieved earlier.
Conclusions '75
The report team concludes that Mitsubishi has not yet
demonstrated the capability to meet the 1975 standards.
They have been grouped in class 75-2.2, Catalytic System
Approach - Average Development Status. While their system
concept is judged good and some emission levels are also
good, the lack of extensive durability results at .03 gpg
lead on the most advanced system does not permit a more
optimistic evaluation.
6.2.7.2 1976 Development Status
Systems to be Used - '76
The Mitsubishi 1976 system is basically the 1975 system with
the addition of a NO catalyst, EGR and a "start catalyst"
X
located before the NO catalyst. The EGR system will have
J^
"proportional" flow characteristics. Mitsubishi is one of
the few manufacturers to report any development on start
catalysts. The function of the start catalyst in this
system is to provide HC and CO control before the main
catalyst is warmed up and to help the NO catalyst warm up
X
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faster. It would be desirable, in the opinion of the
report team, to switch the start catalyst out of the
system after the main catalysts are warmed up to
isolate it from the deleterious effects which could be
caused by lead and high temperature. This is not done, how-
ever, on the Mitsubishi system. The start catalyst is left
on stream but air is not injected into it after the rest
of the system is warmed up. The start catalyst may have
little effect on emissions when air is no longer injected
into it.
The best low mileage results reported on this system were
obtained with an American Oil base metal pellet NO
it
catalyst, a Kali-Chemie noble pellet oxidation catalyst,
and an Engelhard PTX-5 noble monolithic start catalyst.
The results were .07 gpm HC, 1.33 gpm CO, and .26 gpm NO .
X
Only 6% EGR rate was used. Other NO catalysts investigated
jt,
include those of Johnson-Matthey, Kali-Chemie and Mitsubishi.
Mitsubishi reported that the rich carburetor calibration
causes a 15-25% fuel economy penalty for these systems.
The cost estimate for the 1976 system was $430-700.
Apparently the only "auxiliary devices" being considered
by Mitsubishi are those which are necessary to prevent
catalyst over-temperature situations. Data from Mitsubishi
and many other manufacturers indicates that the exhaust
emissions without air injection can be as high from the
1976 vehicles as from uncontrolled cars.
Mitsubishi's '76 approach is among the best of those manu-
facturers using reduction catalysts. The use of both a
start catalyst and modulated air injection is unique in the
industry. . , .
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Durability Program - '76
Mitsubishi has conducted very limited durability testing
of promising reducing catalyst systems. Their testing
procedures are identical to those followed during their
1975 durability testing. Lead sterile fuels were employed
until October of 1972 at which time gasoline with .03 grams
per gallon of lead was introduced. The vehicles employed
to date have been equipped with only a reducing catalyst,
thus hydrocarbon and carbon monoxide levels consistently
exceed the 1976 requirements. Both vehicles reported
at the time of their submittal were operated to 36,000
miles before the testing was terminated. Throughout this
testing the vehicle demonstrated NO levels exceeding the
H
1976 levels. A second car was run to 22,000 miles before
termination. At low mileage this vehicle demonstrated
1976 NO levels. At approximately 20,000 miles this vehicle
H
exceeded the NO requirements and had shown high deterior-
j£ , •
ation.
Catalyst Screen Program - '76
Mitsubishi has a very direct and quick catalyst screening
program for reduction catalysts before starting actual
vehicle tests. This program involves initial laboratory
tests followed by engine dynamometer tests.
The first part of the laboratory test involves passing por-
tions of exhaust gas from a test engine over small samples
of catalyst (either monolith or pelleted) kept in a furnace.
The NO conversion as a function of temperature (from 390-1100°F)
is then recorded. A durability test is then run which is
similar to that used for the oxidation catalysts. This
system involves passing engine exhaust through an apparatus
containing 34 small tubes in parallel, each containing small
6-115
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amounts of catalyst sample. The NO conversion effective-
ness is then measured at 100, 200, and 1,000 hours.
Catalysts which perform satisfactorily on this durability
test are then tested in a full-size catalyst converter
on an engine dynamometer. A simulated 1975 CVS FTP is
used for this test.
A limited 10-hour durability test is run on this dynamometer
which should uncover any obvious discrepancies between the
laboratory apparatus performance and what would happen on
a vehicle. After this test, the catalyst is tested on a
vehicle for a 50,000-mile durability test. Some of the
results of these screening tests are considered promising
by the report team. Mitsubishi clearly noted both the
catalyst they tested and the 1975 CVS emission results.
Progress and Problem Areas - '76
Progress
Mitsubishi has progressed to the point where two systems
are under serious consideration for use in 1976. One system
is a typical 1976 dual catalyst system, the other system is
a three catalyst system, with the third catalyst being a
"start" type oxidation catalyst for use during the cold
start. The three catalyst system has achieved 1976 levels
at low mileage.
Problem Areas
Mitsubishi reported problems in the area of NO catalysts,
H
(efficiency and durability) vehicle installation (limited
room), and in their opinion, probably poor reliability
in the field. No durability results have as yet been
generated on the three catalyst system.
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Conclusions '76
The report team concludes that Mitsubishi has not yet
demonstrated the capability to meet the 1976 standards.
While their start catalyst system approach is considered
good, lack of acceptable durability results prevents a
more optimistic classification for them than 76-2.1,
Catalytic System Approach - Average Development Status.
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6.2.8 NISSAN (DATSUN)
6.2.8.1 1975 Development Status
Systems to be Used - '75
The Nissan first choice system for 1975 consists of engine
modifications, EGR and a noble metal monolithic oxidation
catalyst with air injection. The engine modifications
include altitude compensated carburetion with a quick choke,
a quick heat intake manifold and a solid state ignition
system with provisions for retarding timing during cold
starts. Most of Nissan's development work has been with
Engelhard catalysts and in light of the recent public
announcement of a Nissan-Engelhard agreement it appears
to the report team that Nissan will use the Engelhard
catalysts in production.
The addition of a thermal reactor to the first choice system
is being considered as a possible back-up system. None of
their latest fleet (Phase IV) of prototypes, however, are
equipped with thermal reactors.
One of the best low mileage tests reported for the most
advanced prototype was .19 gpm HC, .43 gpm CO, and .99 gpm
NO . Earlier prototypes using the thermal reactor plus
X
catalyst back-up system were tested as low as .30 gpm NO
H
without NO catalysts. These earlier prototypes were
J^
generally somewhat higher than the standards on HC and CO
emissions, but the vehicles did not include modifications
such as quick chokes, cold start retard or quick heat
manifolds.
Nissan considers fuel economy, performance, cost, and com-
patibility with 1976 systems important constraints. The
lack of compatibility with 1976 systems was given as one
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of the reasons for diminished interest in the thermal
reactor plus catalyst approach. 10% is considered by Nissan
the maximum fuel economy penalty acceptable. Current 1975
prototypes meet that constraint. To maintain vehicle per-
formance, Nissan is planning to increase engine displacements
on some models. Retail cost of the 1975 system was estimated
by Nissan at $350-450.
Nissan is currently behind schedule on their 1975 program
because much of their earlier work was based on the
assumption that fuel with a lead content of .01 grams per
gallon would be acceptable for certification testing.
Because Nissan was seeing low DF's with .01 gpg fuel, they
did not intensify the development of systems with sufficiently
low zero mile emissions until they finally accepted the fact
that they had to run higher lead levels. Testing of fuel
with .03-.05 gpg lead did not begin until the middle of 1972.
It was not clear whether Nissan is intending to use auxiliary
emission control devices on their 1975 vehicles to make it
easier for them to satisfy their design constraints. A
system intended for use in 1975 vehicles, however, apparently
may defeat some of the emission control systems during cer-
tain operating modes, in the opinion of the report team.
Nissan reported:
"This system aims to optimize exhaust emissions and
driveability under every driving condition by using
ambient temperature sensor, water temperature sensor,
engine speed sensor, vehicle speed sensor, acceleration
switch, etc., and controlling air/fuel ratio, spark
timing, EGR flow rate, secondary air flow rate, fuel
cut-off, etc." (Emphasis added)
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The exhaust emissions during non-LA4-type driving patterns
and high and low ambients were not reported by Nissan.
No development work was reported on any alternatives to
the conventional spark ignition engine.
Durability Program - '75
Nissan has employed a four phase program as a durability
evaluation tool. Subsequent to successful completion of
screening and bench testing Nissan has introduced successful
components into a durability program. The following is a
brief description of each of the four phases of the program.
Phase I - The objective of this test is to evaluate each
component/ at the initial stage of development,
that has appeared promising in initial screening
evaluation. This fleet included 7 durability
vehicles.
Phase 2 - The objective of this .test was to evaluate
primary design concepts (B and AB described later)
with improvements designed to avoid EGR and other
problems encountered in Phase 1. This fleet
included 6 durability vehicles.
Phase 3 - The objective of this test was to evaluate
Nissan's first choice system (B) using a fuel
with a more realistic trace lead content.
The durability fleet consisted of 5 vehicles.
Phase 4 - The objective of this test which has just been
initiated is to evaluate the first choice system
modified to minimize the drastic lead effects
apparent in Phase 3. This fleet contains 9
durability vehicles.
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Phases 1, 2, and 3 have been terminated while Phase 4 has
only recently been initiated. If Nissan accumulated
mileage at a normal rate, this final phase should be
completed during the spring of 1973. The following
indicates the durability fleet representation employed
by Nissan for each phase:
Phase 1 - Datsun 510 1600 cc.
Phase 2 - Datsun 510 1600
& 610 and 2000,cc.
Phase 3 - Datsun,610 2000 cc.
Phase 4 - Datsun 610 2000 cc.
It does not appear, therefore, that any of the fleets to
date have fully represented Nissan's current United States
production since an engine currently marked by Nissan, a
2400 cc six-cylinder, is not represented.
Phase 1 and 2 contained vehicles with prototype concepts
AB and B while Phase 3 and 4 utilize concept B only. The
following describes these concepts:
AB B
Engine Modifications Engine Modifications
Air Injection Air Injection
Exhaust Gas Recycle Exhaust Gas Recycle
Thermal Reactor Oxidizing Catalysts
Oxidizing Catalyst (noble monol*th>
(noble monolith)
All of the durability test vehicles in all phases had full
system concepts installed.
Mileage accumulation was performed according to the AMA
procedure. Phase 1 and 2 vehicles were fueled on gasoline
with a lead content of less than .01 grams per gallon.
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Phase 3 and 4 vehicles used fuel of .03 to .05 grams per
gallon. Maintenance performed during mileage accumulation
was not in accordance with Federal procedures, but satis-
factory with respect to a developmental fleet.
Phase 1 vehicles had high initial emission levels and re-
latively high deterioration. None of these vehicles
appeared to comply with the 1975 Federal requirements.
In Phase 2 one of the six vehicles had emission levels
lower than as required for 1975 through 50,000 miles of
operation. At 25,000 miles the average of all 6 vehicles
was lower than the required levels indicating potential
compliance with a catalyst change. However, this fleet
was operated on lead sterile fuel. Phase 3 vehicles all
demonstrated high deterioration in hydrocarbon or carbon
monoxide levels attributed by Nissan to the higher fuel
lead content. None of these vehicles remained below the
standards for 25,000 miles of operation. The fleet
operation was terminated at low mileage due to this high
deterioration. Thus no projection of the continued rate
of deterioration, if any, is possible. Phase 4 designed
to avoid the severe lead effects experienced in Phase 3
has just been initiated. All of the vehicles are
currently at low mileage.
Catalyst Screening Program - '75
Nissan has done limited catalyst screening work using an
engine dynamometer and a modified AMA route driving pattern.
Actually, Nissan has not screened a large number of oxidation
catalysts according to the information they submitted to
EPA. Instead, they have examined only the Engelhard PTX
unit (model was not specified) and Johnson-Matthey AEC3A.
After mileage was accumulated on the engine dynamometer,
the catalysts are transferred to a vehicle for a 1975 CVS test.
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Progress :ahd Problem Areas "- '75
Progress
Nissan has made progress in the past year in gaining
durability experience with 1975-type control systems.
At least 4 different fleets of vehicles have been or
are being tested with different types of control systems.
The Phase IV fleet appears to incorporate Nissan's first
choice 1975 emission control system.
Nissan has also been reported to have signed an agreement
with Engelhard to supply catalysts for their future require-
ments.
Problem Areas
Nissan's biggest problem appears to be the lead content of
the gasoline. Most of their durability testing on the Phase 1
and Phase 2 fleets was done on fuel containing less than .01
gpg lead. Phase 3, run on .03 gpg to .05 gpg fuel was not
very successful. Phase 4 is an attempt to overcome the
problem that Nissan attributed to the lead level. Not
enough data has been generated yet to determine whether
or not they will be successful.
In attempting to meet both Federal HC and CO standards and
the assumed California 1.5 gpm NO level/ Nissan may be
Ji.
creating more of a problem with the control of HC and CO
to within the Federal levels than is necessary.
Conclusions '75
The report team concludes that Nissan has not yet demonstrated
the capability to meet the 1975 standards. They are grouped
into class 75-2.2, Catalytic System Approach - Average
Development Status, because of their problems with the
lead level in their durability testing, although their low
mileage results have been adequate.
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It is the judgment of the report team that Nissan could
achieve better emission control if their development was
not aimed at meeting the 1975 Federal HC and CO and the
1975 California NO requirements.
X
6.2.8.2 1976 Development Status
Systems to be Used - '76
The Nissan 1976 system is basically the 1975 system with
the addition of a NO catalyst. Jbhnson-Matthey and
X
International Chemicals NO catalysts seem to be receiving
J±
the most consideration. The best low mileage results have
been .27 gpm HC, 1.57 gpm CO, and .13 gpm NO . No car
H
has yet been able to reach 4000 miles with sufficient NO
X
conversion efficiency to stay below .40 gpm. In spite of
the fact that they formerly achieved NO levels below .4
J^
gpm with their old Phase 1 1975 system at high mileage,
Nissan has not reported any development work on an EGR plus
oxidation catalyst approach for 1976. The old Phase 1
vehicle did not even use proportional EGR. It is not
apparent to the report team why Nissan is not investigating
the advanced EGR approach. The Phase 1 1975 system which
achieved the 1976 NO levels utilized a thermal reactor.
H
Nissan's first choice '76 system has only a 3% fuel economy
penalty compared to their '75 system. The Nissan vehicles
are light enough that there may be potential for achieving
adequate NO control without NO catalysts and to still
X X
maintain fuel economy and driveability, in the opinion of
the report team. No development work on advanced engine
modifications, modulated air injection systems or proportional
EGR systems which might achieve this result was reported.
One of Nissan's constraints for 1976 is apparently to rely
heavily on the catalyst approach.
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Durability Program - '76
Nissan is approaching the evaluation of candidate 1976
prototypes systems in a fashion similar to their 1975 program.
Subsequent to promising screening evaluations, .systems are
installed on vehicles for mileage accumulation. At the
present time 3 vehicles have been used to evaluate 5
different reducing catalyst approaches.
For test purposes Datsun 610 vehicles with 2000 cc. engines
are being used. These cars are equipped with concept
package C including: engine modifications, exhaust gas
recycle, air injection, oxidizing catalyst and reducing
catalyst. The test procedures being followed are identical
to those used in Nissan's '75-type fleet with fuel lead
levels of .03 - .05 grams per gallon.
Four of the five reducing catalysts evaluated to date have
significantly deteriorated prior to 10,000 miles of operation.
The fifth system is at zero miles.
The program is not advanced to the point where any kind of
assessment can be made as to the potential for successful
completion of the durability testing.
Catalyst Screening Program - '76
Nissan included little specific information on their catalyst
screening program. They did list the two major goals of
their screening tests which are given below:
1) Determine NO conversion efficiency over wide
X
ranges of inlet CO concentrations.
2} Determine if there is a sufficiently wide
temperature difference between the temperature
of 80% reduction of NO and the maximum allowable
X
temperature for catalyst durability.
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Progress- :and Problem Areas
Progress
Nissan has chosen the typical dual catalyst approach for
1976. Some test results at low mileage have been below
the 1976 levels.
Problem Areas
All of the durability tests have been stopped due to high
NO deterioration. Nissan has not yet been able to find a
X
suitable NO catalyst.
Ji
Conclusions '76
The report team concludes that Nissan has not yet demonstrated
the capability to meet the 1976 standards. They are grouped
in class 76-2.1, Catalytic System Approach - Average Develop-
ment Status, because of their adequate low mileage results
and lack of acceptable catalyst durability.
The report team also concludes that Nissan's dual catalytic
system is not markedly superior to the non-NO catalytic
X
approaches that Nissan has demonstrated that also meet 1976
emission levels at low mileage.
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6.2.9 RENAULT
6.2.9.1 1975 Development Status
Systems to be Used
Renault is developing two different 1975 control systems.
Both will use engine mods, air injection, a noble metal
monolithic oxidation catalyst and EGR. One system will use
carburetion (altitude compensated) and the other will use
electronic fuel injection (L-Jetronic). Carburetors will
employ quick chokes. They will be used on the R12 and
R15 model vehicles. The fuel injected engine will be used
in the R17 model. The EGR systems to be used will apparently
be purchased rather than manufactured by Renault. Solid
state ignitions may be used with one or both systems. All
Renault vehicles will be tested at the 2750 pound class.
The best low mileage results reported were ..008 gpm HC, 1.009
gpm CO and 1.456 gpm NO . It was not clear from the Renault
J\.
report whether this vehicle used fuel injection or carburetion.
Results obtained on one of the R12 vehicles (carbureted) were
.17 gpm HC, .92 gpm CO and 2.36'gpm NO . EGR was not used on
*x
this test. Other tests were reported with NO levels as low
^t
as 1.20 gpm without EGR, HC and CO emissions were still under
the 1975 levels at .33 gpm HC and 1.53 gpm CO. Renault did
not report the manufacturer's name for each catalyst they are
testing. One of them, however, is the Engelhard noble monolith.
Only modest fuel economy and performance penalties were re-
ported. The fuel economy loss was estimated at 3%. The retail
cost increase over '73 vehicles was estimated at $215-350.
No data was reported which would allow the emissions before
the catalyst to be determined. Since some results with cata-
lysts were above 10 gpm CO and 2 gpm HC it appears to the
report team that Renault is relying heavily on the catalyst
rather than lowering the basic emissions of their engines.
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Durability Program - '75
The Renault submittal was not explicit as to purpose or pro-
cedures used in their 1975 prototype durability. From the
data supplied it appears that durability testing of candidate
oxidizing catalysts was initiated in November 1971, and has
continued. A total of eight mileage accumulation runs were
made and reported on two catalyst, types, code-named Ren 15
and Ren 17. Testing was performed only on carbureted engines
while Renault did identify fuel injection as a possible 1975
approach. For test purposes one Renault 16 and three Renault
12 vehicles were utilized. All but one of the eight test runs
reported indicated high hydrocarbon and carbon monoxide at
relatively low mileage. Vehicle 316 equipped with a Ren 17
converter was reported to be at 19,383 miles on October 12,
1972. At that time the vehicle was below the 1975 levels
and hydrocarbon and carbon monoxide deterioration appeared
minor. It appears that this vehicle is continuing to operate
under mileage accumulation.
Catalyst Screening Program - '75
The oxidation catalyst screening program for Renault is divided
into two major parts, laboratory tests and engine bench tests.
The following laboratory tests are performed.
Measurement of attrition
Surface area measurement
Density and porosity measurement
HC and CO oxidation activity
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The attrition measurement test is divided into two parts. The
first part consists of submitting the catalyst to a vertical
shaking motion for five hours. The second part of the test
involves horizontal shaking motions (200 cycles/minute). The
small particles are then strained from the larger ones and the
weight loss is noted.
The specific surface area is determined by the standard BET
method involving measuring gas absorption on the surface at
a specified pressure. The density and porosity are then deter-
mined. The catalytic activity is determined by measuring HC
and CO removal from a synthetic laboratory gas mixture under
constant temperature conditions. The efficiency of the cata-
lyst as a function of temperature for 10%, 50% and 90% conver-
sion are noted.
Promising candidates are then tested on an engine bench test.
No further details were given on the engine bench tests.
Renault listed only nine oxidation catalysts and two catalysts
for oxidation or reduction that have been tested to date.
Renault identified these catalysts only by number and did not
indicate who supplied them.
Progress and Problem Areas - '75
Progress
Renault has made progress in achieving lower low mileage emis-
sion results. Renault has picked a first choice system, a
typical 1975 system employing a platinum monolithic catalyst.
Some durability testing has been performed.
Problem Areas
Some of Renault's earlier durability testing was conducted with
fuel with 27 ppm of lead. The more recent tests use 10 ppm
lead content fuel, close to .03 gpg.
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Renault reported problems in the area of mechanical durability
of the catalyst. Renault anticipates the need to replace the
catalyst at 25,000 miles.
Conclusions '75
The report team concludes that Renault has not yet demonstrated
the capability to meet the 1975 standards. They are grouped
in class 75-2.2 Catalytic System Approach - Average Development
Status because of their good low mileage results and limited
durability.
6.2.9.2 1976 Development Status
System to be Used - '76
Three different systems are under consideration by Renault for
1976. A dual catalyst system, which is basically the 1975
system with a reduction catalyst added,is being considered
for both the R-12/15 models and the fuel injected R17 model.
A single bed, three-way catalyst is being considered for the
fuel injected R17 model. This system employs an oxygen sensor
which is used to maintain a nearly stoichiometric air/fuel
mixture. At this air/fuel ratio it is possible to simultaneously
reduce NO and oxidize HC and CO in one catalyst.
J\.
A thermal reactor-reduction catalyst system was also reported to
be under development. Almost no information was supplied on this
system. It appears to be similar to the Questor system in some
respects, including the use of an NO catalyst and the lack of
Ji
an oxidation catalyst.
No data was reported on either the 3-way catalyst system or the
thermal reactor-NO catalyst system. The best low mileage
H
results reported on the dual catalyst system were, .31 gpm HC,
2.10 gpm CO and .32 gpm NO .
a
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Under the 1976 section of their submittal Renault reported:
"The addition of a supplementary catalyst intro-
duces an additional increase in fuel consumption
of approximately 3%, but the definitive overall
result has not been established because optimiza-
tion of the system has not been completed."
They also reported that the dual catalyst system would be
run at X = .8-.9 (12.5:1 Air/fuel ratio). Considerably more
than a 3% loss would normally be expected by the report team
at this air/fuel ratio.
Durability Program - '76
Renault has reported that the results of screening tests to
date have not warranted the initiation of any durability test-
ing.
Catalyst Screening Program - '76
The reduction catalyst screening program for Renault is simi-
lar to the screening tests done on oxidation catalysts. Both
laboratory and engine bench tests are performed.
The laboratory tests make the following general measurements
described previously.
Attrition
Surface area
Density and porosity
NO reduction activity
These catalyst are further tested by an engine bench test which
was not described. Renault indicated that only five reduction
catalyst have been tested to date.
Progress and Problem Areas - '76
Progress
Renault is presently considering two possible systems for 1976;
the dual catalyst and the 3-way catalyst "A -sensor" system.
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Low mileage results on the dual catalyst system are below
the 1976 levels.
Problem Areas
Very little durability testing has been completed, due to
catalyst problems.
Conelusions '76
The report team concludes that Renault has not yet demonstrated
the capability to meet the 1976 standards. They are grouped
in class 76-2.1 Catalytic System Approach - Average Development
Status because of their low mileage results and their limited
durability. They were not grouped in class 76-2.2 because of
the reported work on the oxygen sensor, three-way catalyst
system, considered by the report team to be a promising
approach.
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6.2.10 SAAB
6.2.10.1 1975 Development Status
Systems to be Used - '75
The Saab first choice system consists of engine mods, pellet
oxidation catalyst and air injection. Both carburetion and
electronic fuel injection will be used in 1975. Carbureted
engines will utilize EGR, injected engines will not. Even
on the carbureted engine EGR is not required to meet 1975
NO levels since the Saab vehicle, even though a full five
X
passenger sedan, weighs only 2500 pounds. EGR development
is probably being done to meet the proposed California NO
^t
standard of 1.5 gpm, in the opinion of the report team.
Pellet catalysts from three suppliers: Monsanto; Kali Chemie;
UOP; are being investigated. Both promoted base metal and
noble metal pellets are being considered. Noble metal mono-
liths from Engelhard and Johnson-Matthey are receiving some
consideration as possible back-up catalysts but Saab has had
many substrate durability problems in the past. Substrate
durability problems are aggravated on Saab vehicles since all
Saab engines are four cylinder. Attempts to isolate the
catalyst from the vibration of the engine were not reported.
Saab considers the maintenance of good fuel economy, drive-
ability, and performance important constraints. Thermal re-
actor systems were investigated and 1975 levels were achieved
but this work has been abandoned, "...it was decided that
this work should be discontinued mainly because of increased
fuel consumption characteristics as well as incompatability
of the thermal reactor with probable 1976 emission control
systems." The fuel economy penalty of the first choice system
was estimated to be 10% compared to 1972 vehicles. Saab
reported that cost and sheet metal changes required for a parti-
cular system also receive much consideration. Total retail
cost of the first choice system was estimated by Saab to be,
$166 over the 1973 system.
6-133
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Data reported by Saab indicates that the emissions of the basic
engine before catalyst treatment may not have received adequate
consideration. No data was reported for vehicles without cata-
lysts but even with catalysts hydrocarbon emissions were as
high as 2.29 gpm and CO emissions were often higher than 15
gpm and as high as 43.9 gpm, in one case. Other manufacturers
have developed engine modifications which result in HC levels
below 1 gpm and CO levels below 10 gpm without catalysts.
Saab, like many other manufacturers, may be relying heavily
on the catalyst approach.
Despite relatively high "feed gas" levels Saab has been as
low as .09 gpm HC, .47 gpm CO, and 1.18 gpm NO at low mileage.
X
With EGR emissions have been as low as .08 HC, .61 CO, and
.84 NO at low mileage.
J^
Saab did not report the intended use of any "modulating devices"
for 1975 other than a system which would dump air pump discharge
if the catalyst temperature became too high.
Durability Program - '75
Saab's durability program is predominantly a catalyst evaluation
experiment. Seven vehicles are being subjected to mileage accu-
mulation equipped with different catalyst candidates. While two of
the seven vehicles are being tested with monolith types, Saab's
primary system for 1975 consists of pellet catalysts with air
injection. Catalysts for test are chosen on the basis of
those which have shown the highest success in preliminary
screening. All of the test vehicles being operated are Saab
99's with either 2.0 liter or 1.85 liter engines. Emphasis
is placed on manual transmission vehicles. The single greatest
problem associated with Saab's current testing procedures
appears to be their practice of replenishing catalytic material.
It was reported that three of the six bead-type catalyst systems
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received this type of treatment. On Saab's single high mile-
age prototype material was added 11 times in 35,000 miles.
It cannot be anticipated that this type of maintenance would
be allowed during certification procedures. Lead sterile
fuel has been used to evaluate what has proven to be Saab's
most successful durability vehicle and thus causes further
reservation as to the vehicle's true deterioration charac-
teristics.
Looking at the reported data, Saab only has two vehicles at
high enough mileage to be fairly commented upon. Vehicle
#385, equipped with a Monsanto type 404 catalyst, demonstrated
high hydrocarbon and carbon monoxide levels frequently during its
33,500 miles of operation thus far. The vehicle's catalyst
was topped off 13 times and the fuel used was lead sterile.
Vehicle #341 has been run 41,500 miles on lead sterile fuel.
The catalyst material is identical to that previously men-
tioned. A total of 11 catalyst refill operations were
performed. While carbon monoxide levels have exceeded the
standard several times, this vehicle appears, in the judg-
ment of the report team, to have an excellent chance of
completing 50,000 miles successfully.
Saab identified two areas of consideration which they feel will
determine the feasibility of compliance with the 1975 require-
ments-one catalyst change at 20-24 thousand miles and the use
of lead sterile fuel. From the data presented; however, it
would, appear to the report team that catalyst attrition may
represent another major problem for Saab.
Catalyst Screening Program - '75
Saab measures six basic points of parameters in their catalyst
screening test which are listed below:
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1) HC and CO conversion versus oxygen concentration
2) HC and CO conversion versus A/F ratio
3) Warm-up test - temperature versus HC and CO
conversion with air injection (2% oxygen in
resultant mixture)
4) Warm-up test - temperature versus HC and CO
conversion without air injection
5) Warm-up test - time versus HC 'and CO conver-
sions with air injection (2% air in resultant
mixture)
6) Warm-up test - time versus HC and CO conversion
without air injection
These tests are run on an engine dynamometer set-up. An optimum
air/fuel ratio was determined before running each test sample.
A total of 19 catalyst samples from 8 different manufacturer's
have been tested, most of which are listed below:
Degussa OM 506
Degussa 506E
Degussa OM506ET
Engelhard PTX323S
Engelhard PTX4
W.R. Grace Davex 45V ^
W.R. Grace Davex 136
W.R. Grace Daves 140
Johnson Matthey AEC3
Johnson Matthey AEC8
Johnson Matthey AECSa
Kali Chemie KC4035K
Kali Chemie KC4035K-S3
Monsanto ECA401
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Monsanto ECA404
Monsanto 404
Monsanto 406
UOP PZ-1-216-MZ
Progress and Problem Areas - 1975 Systems
Progress
Saab has chosen their first choice system and has accumulated
some durability testing with it. The results to date indicate
that, on the basis of the Saab testing, they believe that the
durability requirements can be met for 20,000 to 25,000 miles
provided that the container is big enough to allow for the
attrition with their beaded catalyst.
Problem Areas
Saab has experienced severe problems with monolithic catalysts
and has abandoned their use for the time being. Saab reported
that they are very concerned with the permitted lead level in
the fuel, and are not optimistic about the results that they
will obtain using what Saab calls "EPA fuel" of .04 gpg lead
content.
Conclusions - '75
The report team concludes that Saab has not yet demonstrated
the capability to comply with the 1975 standards. They are
grouped in class 75-2.2 Catalytic System Approach-Average
Development Status. The nature of the catalyst attrition
problem experienced by Saab and the fact that sterile fuel
was used for durability testing do not permit a more opti-
mistic assessment at this point in time, although Saab's re-
sults have been generally good.
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6.2.10.2 1976 Development Status
Systems to be Used - '76
Two different approaches for 1976 are under consideration
by Saab. One approach uses dual catalysts and is basically
the 1975 system with the addition of a NO catalyst. The
X
other approach is the 3-way catalyst with an oxygen sensor.
This second approach requires the use of the Bosch L-Jetronic
fuel injection system.
The best low mileage results on the dual catalyst system re-
ported were .21 gpm HC, 1.82 gpm CO, and .33 gpm NO . Best
X
results on the 3-way catalyst system were .23 gpm HC, 9.07
gpm CO, and .36 gpm NO . All other manufacturers reporting
Ji
results on 3-way catalysts systems have reported better emis-
sion results than Saab reported.
Saab did not provide information on fuel economy, performance
or driveability on either of these systems. Saab has formerly
(1971) reported emission results below the 1976 requirements
without the use of NO catalysts. Over one year ago they had
H
achieved .14 gpm HC, 2.65 gpm CO, and .29 gpm NO . It is not
H
clear to the report team why Saab has not followed-up the
development of this system which used EGR for NO control.
J^
The Saab vehicles are light enough that there is potential
for achieving .4 gpm NO without the use of a reduction
X
catalyst, but for some reason Saab does not like to use EGR.
In their status report to EPA they stated:
"The extent of EGR, if any, will be subject to and
dictated by the state of the art of the catalytic
NO -control at the time of the preparations of that
moael year production. We will clearly not use any
unnecessary EGR rate, over what would be required to
bring the system performance down to the engineering
goal for NO ."
X
No data was reported that indicated any significant problems
associated with the use of EGR nor was any information reported
6-138
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on the development of proportional EGR systems which might
achieve low NO emissions, low CO and HC emissions and accept-
Ji
able fuel economy simultaneously. The reason for the lack of this
type of EGR development work is not known.
The Saab retail price increase for the 1976 emission control
systems are the lowest of all manufacturers.reporting. The
dual catalyst system was estimated at $255 higher than the
1973 system. The 3-way catalyst system was .estimated to be
only $115 higher than a 1973 system.
Durability Program - '76
Saab is continuing to develop a 1976 system approach. At
this point the development has not progressed to the point
where mileage accumulation has been initiated.
Catalyst Screening Program - '76
Saab is continuing to develop a 1976 system approach. At
for 1976 catalysts are similar to those used for 1975 oxidation
catalysts. This includes tests run on an engine dynamometer to
determine NO reduction as a function of air/fuel ratio and
warm-up capability of the NO catalyst.
J^
Progress and Problem Areas - '76
Progress
Saab has progressed in their 1976 development to the point at
which two systems are under serious consideration for 1976.
The systems are the A sensor 3-way catalyst system and the
more typical dual catalyst system. Saab has been able to
achieve 1976 levels at low mileage with the dual catalyst
system.
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Problem Areas
Saab has not yet been able to decide on the catalyst type for
either of the two systems. Saab has been experiencing problems
with both the monolith and the pellet type of catalyst. Saab
has not generated any durability data on 1976 systems, so the
actual durability problems with their 1976 system is not
known. Saab has also been unable to achieve their own low
mileage in-house emission goals for 1976.
Conclusions r^ '76
The report team concludes that Saab has not yet demonstrated
the capability to meet the 1976 standards. They are grouped
in class 76-2.1 Catalytic System Approach-Average Development
Status because of their low mileage results and lack of
durability data.
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6.2.11 TOYO KOGYO (MAZDA)
6.2.11.1 1975 Development Status
Systems to be Used - '75
Toyo Kogyo is the only manufacturer who currently sells a
rotary engine powered vehicle in this country. The emissions
and production cost characteristics of the rotary engine have
been the subject of much speculation in recent years. The
emission levels of an uncontrolled rotary engine are different
than those of the conventional reciprocating engine. Rotary
HC levels tend to be much higher (more than double) than those
of the reciprocating engine while NO levels are somewhat
J*
lower. CO levels are essentially the same. While Toyo Kogyo
is developing emission control systems for both the rotary and
the reciprocating engine for 1975, the rotary development is
more complete.
The 1975 control system for the rotary is almost identical to
that used on current rotary-powered Mazdas. It consists of
engine modifications, rich thermal reactor and air injection.
EGR is not required since the rotary has very low NO levels,
jt
especially when run rich, and the Mazda vehicles are light
weight. One of the most significant differences between the
current Mazdas and the 1975 prototypes is the air injection
modulation system. Toyo Kogyo and Mitsubishi are the only
ones who have reported that they have developed an air injec-
tion modulation system for 1975. Modulated air injection is
especially desirable with a rich thermal reactor system because
it allows the engine to be calibrated leaner, thereby minimizing
fuel consumption penalties, without sacrificing emission control.
6-141
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Toyo Kogyo worked with the following self-imposed constraints
while developing their 1975 control system for the rotary:
1. Maximum fuel economy penalty, 10%
2. No safety hazard
3. $100 maximum cost increase
4. Driveability same as 1973 (excellent)
5. System must be packageable in 1973 chassis
6. Same maintenance requirement as 1973
7. Same performance as 1973.
All of these constraints have been met. The fuel economy pen-
alty is 6% and the low mileage emissions are as low as .22 gpm
HC, 2.08 gpm CO, and .77 gpm NO on some cars.
j£
Two different systems are under consideration for the 1975 re-
ciprocating engines. One system consists of engine modifica-
tions, rich thermal reactor and modulated air injection. The
other system uses a noble metal monolithic oxidation catalyst
instead of the thermal reactor. Engelhard and Johnson-Matthey
catalysts are receiving the most consideration. Air injection
is apparently not modulated with the catalyst system. It appears
that the air injection with the thermal reactor system is some-
times partially diverted into the intake system to lean the
mixture.
Toyo Kogyo's self-imposed design constraints for the recipro-
cating engine are similar to those for the rotary except that
they are willing to accept a 10% performance drop on the recip-
rocating engine and one rank lower driveability. They are also
willing to accept a larger ($300) cost increase.
These constraints are all being met with the rich thermal re-
actor system but Toyo Kogyo is not yet certain that the main-
tenance constraint can be met with the catalyst system. At low
6-142
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mileage the thermal reactor system has achieved .13 gpm HC,
2.31 gpm CO, and 1.19 gpm NO and the catalyst system has
X
been measured at .15 gpm HC, 1.5 gpm CO, and 2.35 gpm NO .
J^
Toyo Kogyo has reported their intentions to use "auxiliary
devices" on the 1975 models which would divert air pump dis-
charge from the thermal reactor or catalyst when the engine
speed exceeded 4000 rpm or the vehicle speed exceed 60 mph.
Toyo Kogyo's own data shows that this will result in signi-
ficant increases in HC and CO emission levels. Toyo Kogyo
has stated that the reason for the air pump diversion is to
control the thermal reactor temperature. It is not apparent
to the report team why the single variable of engine speed
is the most proper parameter to sense in order to control
the air pump discharge. There may be operating conditions
when the engine speed would be above 4000 rpm but the thermal
reactor would not be in danger of overheating. Under such
conditions, emission control is needlessly sacrificed, in our
opinion.
Durability Program - '75
Currently Toyo Kogyo is utilizing a durability program to
assess the suitability for 1975 production of three different
engine/emission control system concepts. Included in this pro-
gram is the rotary engine/thermal reactor, conventional engine/
thermal reactor, and conventional engine/catalyst approach.
The rotary engine program was initiated in April 1972 and the
first of four vehicles are scheduled to be finished with the
program by January of 1973. The conventional engine programs
have only recently been initiated and there is not sufficient
information available to assess this part of Toyo Kogyo's
program.
6-143
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Basically, two vehicle/engine types are being employed for the
rotary engine durability program: a 35.0 x 2 CID engine in a
3,000 pound inertia vehicle. Both automatic and manual trans-
missions are represented. The conventional engines that are
being prepared for, or just begun on, a mileage accumulation
program include 97 and 110 cubic-inch displacement engines with
both automatic and manual transmissions. Thus, all three of
Toyo Kogyo's current engine families are represented.
While the details of the conventional engine systems initiating
testing were not reported, the rotary system tests do include
full 1975 components.
Mileage accumulation on the rotary engine vehicles has been
run according to standard AMA procedures. Toyo Kogyo reports
that maintenance on the rotaries thus far is normal "..with
the exception of non-substantial defects" which were attri-
buted to inadequate design or fabrication. The single rotary
vehicle, MCC III No. 1, which has completed 50,000 miles of
operation demonstrated the following deterioration factors:
HC DF 1.14
CO DF less than 1.0
NOV DF 1.05
it
Low mileage emission data reported for that vehicle was:
HC 0.34 grams per mile
CO 2.45 grams per mile
NO 0.90 grams per mile.
X
It appears, at this time, that barring unforeseen incidents
involving the remaining three rotary durability vehicles, that
Toyo Kogyo has successfully demonstrated 50,000-mile durability
with their rotary engine.
6-144
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The vehicle MCC III No. 1 has been tested in the EPA Labora-
tory after over 50,000 miles had been accumulated. The emission
levels measured were below the 1975 standards, thus verifying
the reported good emission control performance reported by Toyo
Kogyo.
Catalyst Screening Program - '75
Toyo Kogyo has the following general catalyst screening and
dynamometer tests:
Initial screening
Low mileage test
Warm-up
High temperature aging test
50,000-mile durability (constant speed)
50,000-mile durability (cyclic test)
The first test uses synthetic exhaust gas while the other tests
use an engine dynamometer to provide the exhaust for the cata-
lyst.
The initial screening test involves measuring HC and CO conver-
sion at fixed temperatures of about 570°, 750°, and 930° F.
The catalyst is then aged with exhaust from an engine at constant
speed. After the equivalent of 2,500 and 5,000 miles, the
activity is measured again at these temperatures. The criteria
set for passing these tests are given below.
Initial Screening Test
Percent HC Conversion Temperature °F
Catalyst Condition 570° 750° 930°
fresh 60% 65% 75%
2,500 miles 55% 65% 75%
5,000 miles 50% 60% 70%
Percent CO Conversion
Catalyst Condition
fresh 60% 82% 92%
2,500 miles 55% 65% 75%
5,000 miles 50% 60% 70%
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In addition to these levels, there should be less than 3%
attrition and no cracks in the catalyst.
The next major tests used by Toyo Kogyo involve low mileage
emission tests on an engine dynamometer. Light-off temperatures
are measured. The criteria for light-off temperature is that
it be below 400°F. Also/ 90% CO conversion should be attained
in 90 seconds.
The next major test involves high temperature aging which
measures CVS emissions after 10 hours at about 1800°F. Also,
shrinkage and cracking of the catalyst are noted.
Following these tests, engine dynamometer durability tests
are run to 50,000 miles at a 50 mph steady state condition.
Catalyst temperatures range from 1100°-1350°F. Deterioration
of CO effectiveness should be less than 10% using the CVS.
Toyo Kogyo uses a second dynamometer durability test for cata-
lyst screening which involves a cruise condition, transient
driving, and cool down. The desired specification is that for
50,000 miles the CO activity deteriorates less than 10% using
the CVS.
To date, several catalyst candidates show little deterioration
for 50,000 miles only if the temperature is kept below 1100°F.
These catalysts deteriorate rapidly at temperatures over 1200°F.
Progress and Problem Areas - '75
Progress
Toyo Kogyo has made significant progress on their rotary
vehicles in the period of time since the suspension hearings
in April 1972. At that time they had met their low mileage
goals and had just started durability testing. The test fleet
consists of four vehicles. One vehicle has now completed the
50,000-mile test, with satisfactory results. The other vehicles
6-146
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are at intermediate points in the mileage accumulation, also
continuing satisfactorily. The results to date show no prob-
lem whatsoever in the durability of the thermal reactors.
Toyo Kogyo continues to have a "very bright outlook" with
respect to meeting the 1975 standards. Durability testing
is also continuing on the reciprocating engine.
Problem Areas
Toyo Kogyo has not yet been able to demonstrate that they
can meet the 1975 standards with .their reciprocating engine,
although the results are below the 1975 levels at 6,000 miles.
Conclusions - '75
Toyo Kogyo will be able to meet the 1975 standards with their
rotary engine plus thermal reactor emission control system.
Toyo Kogyo has been grouped in class 75-1 Non-Catalytic Approach
because of the performance of their rotary engine system.
6.2.11.2 1976 Development Status
Systems to be Used - '76
There are two 1976 control systems under development for the
rotary engines. The first is basically the 1975 system with
the addition of EGR. The second system could be considered
a backup system as it will probably only be used if the first
approach fails to produce the required NO levels with accept-
,K,
able performance, driveability and fuel consumption. The
second system adds a NO catalyst and an oxidation catalyst
^t
to the first choice system. Toyo Kogyo is hoping for success
with the first system as it would be much lower in cost and
would not have the durability problems associated with catalyst
devices.
6-147
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Three different 1976 systems for the reciprocating engine are
under consideration. The first uses a thermal reactor and EGR.
The second uses a thermal reactor, EGR, a NO catalyst and an
J^
oxidation catalyst. The third uses a NO catalyst, and oxida-
A,
tion catalyst and EGR.
Tests results, at low mileage, on the first choice system for
the rotary engine are averaging .35 gpm HC, 2.17 gpm CO and
.49 gpm NO . These levels are at what Toyo Kogyo considers
X
an acceptable fuel economy, driveability and performance
penalty. At .49 gpm NO the fuel economy loss was 12% com-
A.
pared to 1973. Driveability was degraded about 15%f lowering
it into the "fair" category. The 0-60 mph acceleration time
was increased by .7 seconds but the vehicle's top speed (111
mph) was not affected. Data was reported, in graphical form,
which indicates that .29 gpm NO can be achieved with the first
J?t
choice system but Toyo Kogyo considers the driveability un-
acceptable at that NO level. A program to improve the EGR
X
mixing is now underway to improve EGR tolerance. The increase
in retail cost of the '76 system over the '75 system should
be modest, in the judgment of the report team, since EGR
is the only additional component.
Very little information was supplied on the backup system for
the 1976 rotary-powered vehicle. The results of one test
using the thermal reactor, dual catalyst and EGR approach:
.1 gpm HC, .8 gpm CO and .35 gpm NO . A problem with this
JC
system, besides the added cost and complexity, is the 40%
increase in NO which is being measured across the oxidation
X
catalyst. Since this is a catalytic system the emissions
can be expected to increase significantly with mileage accu-
mulation. Toyo Kogyo plans to work hardest on the first choice
(no catalysts) system until they repeatedly achieve below .4 gpm
NOV as it is a much more desirable system, in their opinion.
X
6-148
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The first system for the reciprocating engine (thermal reactor
plus EGR) is similar to the first choice system for the rotary
but the results are not as low. The lowest NO level "practi-
X
cally achievable" is .7 - .8 gpm. Toyo Kogyo reported "the
potentiality of the EGR system would be limited accordingly."
It was indicated that NO levels as low as .1 - .2 grams can
Ji
be achieved by combining the thermal reactor system with a
NO catalyst and an oxidation catalyst but it was reported
J^
that, "...the bed temperature of the catalysts become (sic)
extremely high, causing problems with respect to durability,
and these systems, therefore, would not be suitable for prac-
tical use." Low mileage emission levels of .25 gpm HC, 2.8
gpm CO and .27 gpm NO were reported on the thermal reactor
X
plus dual catalyst approach using a Kali-Chemie NO catalyst
Jt
and an Engelhard oxidation catalyst.
The dual catalyst plus EGR system (no thermal reactor) was
reported as low as .14 gpm HC, 2.7 gpm CO and .14 gpm NO
X
using Johnson-Matthey catalysts AEC-3A and AEC-8A for NO
X
and HC-CO respectively. This system employed a "quick warmup
system" which was not on the thermal reactor plus dual cata-
lyst car.
Although not mentioned in their text, a graph in the status
reported indicates that the 1975 *-type single catalyst system
maybe a possible way of achieving 1976 NO levels on the re-
•rV
ciprocating engine, since NO levels of approximately .65
2*
gpm were achieved. The bed temperature, however, of the
oxidation catalyst was over 800°C at that NO level. Maxi-
X
mum bed temperatures are over 100° lower with the dual cata-
lyst system and durability might be better, with the dual
catalyst system.
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No data was reported on the driveability, cost, fuel consump-
tion and performance penalities associated with the first
choice system since the program is in its infancy. Actually
all of the information on 1976 systems is rather prelimi-
nary as Toyo Kogyo reported:
"...with respect to both the rotary engine and the
reciprocating piston engine, almost all of Toyo
Kogyo1s research and development efforts is (sic)
now being concentrated in the achievement of the
1975 emission standards and we do not at the present
have the reserve capacity to perform all of the
research projects considered to be worthwhile in
developing the 1976 system. In our opinion, we would
not be able to exert our efforts for these projects
in full scale until we have made a definite decision
regarding the development of our 1975 system."
There may be a problem with certain "auxiliary" devices under
consideration. As mentioned in the 1975 Development Status Section,
an air pump diverter is under consideration. Toyo Kogyo
also reported:
"With regard to both the rotary engine and the conven-
tional engine for 1976 model, the EGR may hereafter
be controlled by ambient temperatures depending on
the test results on the relation between the ambient
temperature and driveability when EGR is adopted."
Durability Program - '76
Since Toyo Kogyo has not yet achieved their desired low mile-
age oxides of nitrogen level no mileage accumulation has been
initiated. Plans call for this program to begin early in
1973.
Catalyst Screening Program - '76
Toyo Kogyo has the following general catalyst screening and
dynamometer tests for reducing catalysts:
Initial screening
Low mileage test
6-150
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Warm-up test
High temperature aging test
50,000-mile durability (constant speed)
50,000-mile durability (cycle test)
All of the tests use an engine dynamometer except the first
test which involves synthetic exhaust gas.
The initial screening test involves measuring NO conversion
from a synthetic exhaust gas (1000 ppm NO, 1% H-, 1% 02) at
fixed temperatures of about 570°, 750°, and 930°F. After
the equivalent of 2,500 and 5,000 miles, the activity is
measured again at these temperatures. The criteria set for
passing these tests are shown below.
Percent NO Conversion
Catalyst Condition 570°F 750°F 930°F
fresh 70% 75% 85%
2,500 miles 55% 60% 70%
5,000 miles 50% 55% 60%
The test results for four NO catalysts, presumably the better
X
candidates, were given in the data submitted and, when the
ammonia correction is applied, are well below the set criteria.
A typical value is about 50% net NO conversion even with a
J\.
fresh catalyst. Neither the suppliers nor composition of
the four catalysts was indicated. Toyo Kogyo mentioned that
they tested several noble metal monolith NO catalysts, but
X
no more details were provided.
Progress and Problem Areas - '76
Progress
Toyo Kogyo has identified two possible 1976 systems for their
rotary engine: one, the 1975 system with EGR, and the other,
a more typical 1976 dual catalyst system. The dual catalyst
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system has achieved emission levels below the 1976 levels at
low mileage. Some NO values were reported for the 1975
X
system plus EGR that were below the 1976 NO levels, but since
J+
HC and CO data from those tests were not reported, it is
unclear whether or not the 1975 system plus EGR has attained
the 1976 HC, CO, and NO levels. Toyo Kogyo reported that
J^
the NO levels attainable without deterioration in driveabi-
X
lity are .5 to .6 gpm.
Problem Areas
Toyo Kogyo has been unable to put forth a full effort on
1976 systems, due to the fact that a very large fraction of
their capability has been used to develop the 1975 system.
Work on the 1976 system at a high level of effort is just
beginning.
Problem areas that remain to be solved with the 1975 system
EGR are: achieving results below .4 gpm NOV with no sacrifice
X
in the HC and CO control at acceptable driveability and
demonstrating the durability of the system.
The problems with the dual catalyst system, both rotary and
reciprocating,are much the same that other manufacturers are
facing, primarily rapid deterioration of the NO catalyst.
X
Conclusions '76
The report team concludes that Toyo Kogyo has not yet demon-
strated the capability to meet the 1976 standards.
The report team also concludes that the potential for success
of the Toyo Kogyo rotary engine development is better than
the potential of the reciprocating engine. Since the 1976
development was reported to be just beginning, little data
was available. Toyo Kogyo is grouped in class 76—1 Non—Catalyst
Approach because of the potential of the rotary engine.
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6.2.12 TOYOTA
6.2.12.1 1975 Development Status
Systems to be Used - '75
Toyota's first choice system consists of engine modifications,
EGR, noble metal oxidation catalyst and air injection. To -
back up the first choice system a rich thermal reactor system
and a rich thermal reactor plus catalyst system are being
considered. No data was reported on the backup systems.
In the judgement of the report team, the Toyota first choice
system is less sophisticated than systems being developed by
some other manufacturers. Development work to significantly
lower the basic engine's emissions was not reported, propor-
tional EGR system development was not discussed and catalysts
are not close-coupled to the engine. Toyota reported serious
problems with performance, driveability, fuel economy, and
maintenance. The best low mileage values achieved were .15
gpm HC, 1.40 gpm CO, and 1.3 gpm NO . A 15% fuel economy
X
penalty and a retail cost increase of $230 were reported
by Toyota for the first choice system.
All development reported by Toyota to date has been on only
one of the engine families.
Durability Program - '75
Toyota Motor Company utilizes a vehicle mileage accumulation
program to evaluate systems which have, in preliminary labora-
tory screening, demonstrated potential for successful applica-
tion to 1975 prototype systems. Currently, their durability
program includes mileage accumulation on six vehicles with
eight additional vehicles scheduled in a further phase of the
program. Toyota reports that their durability program is
several months behind schedule.
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All of the vehicles utilized in the program, thus far, have
been 96.9 cubic-inch displacement Carinas at a 2,500 pound
inertia setting. The usage of this engine system represents
only one engine family of five being marketed in the United
States in 1973. This program is, therefore, not representa-
tive of Toyota's current vehicle mix.
The basic system concept which has been employed on the Toyota
durability fleet consists of engine modifications, air injec-
tion, exhaust gas recycle and oxidation catalysts. NO set-
X
tings tend to be less than 1.5 gpm.
The single greatest area of concern when analyzing the Toyota
testing procedure is maintenance. In addition to questionable
unscheduled maintenance events, Toyota has reported that
"careful maintenance" has been performed at every 4,000-mile
point.
Three vehicles (Phase I) have completed in excess of 36,000
miles. All three vehicles demonstrated reasonable success at
low mileage points in complying with the 1975 goals. Deterio-
ration, however, was excessive with respect to hydrocarbon
and carbon monoxide.
Phase II vehicles currently have reached the 16,000-mile mark.
Even at this fairly low mileage point deterioration appears
severe.
Catalyst Screening Program - '75
Toyota has a very effective screening program which can be
performed in a short time period. They do an initial labora-
tory screening test, a thermal stability durability-type test,
and an engine dynamometer test. Following these tests,
vehicle durability tests are run on successful candidates.
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The initial laboratory screening test consists of passing
an artificial exhaust gas over a small catalyst sample and
measuring HC and CO conversion efficiency at a specific tempera-
ture. The thermal stability test is in two stages. The
first stage involves measuring catalyst activity, as above.
After the catalyst has been in an oven at 1470°F. In the
second stage the catalyst is kept in the oven at 1470°F
for 100 hours but engine exhaust gas is also added.
Promising catalysts from these tests are then run on an engine
dynamometer in a thermal cycling-type test. Two catalysts
in parallel can be tested simultaneously. Engine exhaust from
the engine running at constant speed goes through one catalyst
while room air is pulled through the other. Every 10 minutes
the engine exhaust is put through the other catalyst while
air pulled through the first catalyst cools it. These tests
determine the effect of thermal cycling on catalyst performance
and durability. To date, platinum-and palladium-containing
catalysts seem to be most effective for higher activity at lower
temperatures. However, Toyota reported that noble metal cata-
lysts are not as durable at higher temperatures (over 1400°F)
as base metal catalysts.
Progress and Problem Areas - '75
Progress
Toyota has decided to use a precious metal monolithic catalyst
for 1975, and has recently signed an agreement with Engelhard
to supply the needed components. Toyota has been able to
achieve the 1975 emission levels at low mileage.
It has been reported in the press that Toyota has signed a
license agreement with Honda regarding the CVCC engine.
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Problem Areas
Toyota reported problems in several areas including fuel
economy, safety, cost, driveability, packaging, maintenance
performance and durability.
There may not be enough lead time remaining to adapt the CVCC
process to all of Toyota's engines for 1975 should their own
in-house development prove unsuccessful.
Conclusions - '75
The report team concludes that Toyota has not yet demonstrated
the capability to meet the 1975 standards. They are grouped
in class 75-2.2, Catalytic System Approach-Average Development
Status because of their adequate low mileage results and
lack of successful durability.
The report team also concludes that many of the problems are
exacerbated by Toyota's desire to meet Federal HC and CO stan-
dards and the assumed California NO level of 1.5 gpm, rather
than the Federal NO standard of 3.1 gpm.
*•>
6.2.12.2 1976 Development Status
Systems to be Used - '76
The Toyota 1976 approach is essentially to use the two 1975
systems with NO catalysts added. No work was reported on
X
advanced engine modifications or proportional EGR systems to
lower the basic emissions of the engine. Toyota is relying
primarily on the catalyst approach, in the opinion of the
report team. While other manufacturers, with heavier vehicles,
have obtained NO levels below the 1976 requirements without
X
reduction catalysts, Toyota reported that they did not believe
they could certify at a NOV level of even 1.0 grams per mile
X
with NO catalysts. The best low mileage results reported
^««w^^— J£
were .24 gpm HC, 1.40 gpm CO, and .34 gpm NO . It was not
•!t
reported whether or not this vehicle used a thermal reactor.
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Since they have reportedly signed an agreement with Honda
to license the CVCC process, Toyota may be planning to develop
a CVCC powered vehicle for 1976 production. No development
work on the CVCC engine was reported, however.
Durability Program - '76
The background and rationale behind Toyota's 1976 prototype
durability program is identical to their 1975 program. Three
vehicles are equipped with engine modifications, air injection,
exhaust gas recycle, reactive exhaust manifold, oxidation
catalyst and reducing catalyst. The schedule of mileage
accumulation has been pushed back by six to eight months
due to persistent failures of both 1975 and 1976 system
approaches.
The 1976 prototype vehicles were exposed to the same rigorous
maintenance at 4000-mile intervals as was reported for the 1975
fleet. In addition, reduction catalyst changes were performed
on two of the three vehicles, the third was terminated at 20,000
miles due to high NO deterioration. All three systems are
J^
demonstrating high hydrocarbons and carbon monoxide deteriora-
tion as indicated in the 1975 report. In addition, unaccept-
ably high oxides of nitrogen deterioration have been indicated
on all three vehicles.
Catalyst Screening Program - '76
The Toyota catalyst screening program involves 1) laboratory
bench test with a simulated exhaust gas, 2) thermal durability
tests, and 3) engine dynamometer tests.
The synthetic exhaust gas used in the first test has the
following composition:
CO 1%
HC 0.05%
NO 0.1%
O2 0.3%
N2 remainder
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Ammonia formation is measured with both this gas and a similar
gas with 1% hydrogen added. Catalysts with Palladium (Pd),
Platinum (Pt) and Palladium-Ruthenium (Pd-Ru) active materials
were tested and found to have high amounts of ammonia formation.
However, the amount of ammonia formatiion is strongly dependent
on the gas composition. No tests were done in the laboratory
bench apparatus to investigate the ammonia formation as a
function of gas composition. Toyota also measures ammonia
formation as a function of A/F ratio in engine dynamometer
tests.
The thermal stability tests are run by exposing the catalyst
to air at 1470° for 15 hours and measuring its efficiency after-
wards in terms of HC conversion. By contrast, 100 hours aging
at 1470° is done on the oxidation catalyst. A more realistic
test for thermal stability of NO catalysts in the opinion of
the report team would be the exposure to exhaust gas at 1470°
and then measuring HC, CO, and NO conversion efficiency. This
condition is more realistic for actual catalyst aging
exposes the catalyst to less oxygen and measures conversion
efficiency for NO, the parameter of interest.
The final catalyst screening process is an engine dynamometer
test. The steady state NO conversion efficiency is determined
as a function of air/fuel ratio. The following general pelleted
type catalysts have been tested for NO removal: Pd-Ru (90%) ,
Pt-Ru (88%), unspecified base metal (45%), chromium base metal
(95%), chromium-cobalt base metal (92%). The first three
catalysts were tested at 840° temperature. Similar tests were
done on a monolithic NO catalyst of unspecified composition
and NO conversion efficiencies of about 60-85% were found.
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Progress and Problem Areas - '76
Progress
Toyota has progressed to the point where two systems are under
serious consideration for 1976. The first choice system is a
typical 1976 dual catalyst. The second back-up system consists of
the first choice system plus a thermal reactor. A few of
Toyota's low mileage results have been below the 1976 levels.
Toyota probably has as much experience as anybody in the industry
in durability testing of 1976 emission control systems. The
reported agreement with Honda may allow the consideration of
the CVCC engine for 1976.
Problem Areas
None of Toyota's durability testing has been encouraging to
date. Rapid loss of efficiency in the NO catalyst is the most
X
severe emission control problem. Toyota claims that even with
catalyst replacement there would be very little possibility
of satisfying a NO standard of 1.0 gpm.
j£
Toyota also reported problems with fuel economy, safety, cost,
driveability, and performance.
Conclusions - '76
The report team concludes that Toyota has not yet demonstrated
the capability to meet the 1976 standards. They are grouped
in class 76-2.1 Catalytic System Approach-Average Development
Status because of their durability problems.
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6.2.13 VOLKSWAGEN (VW)
6.2.13.1 1975 Development Status
Systems to be Used - '75
VW is the only manufacturer reporting that a NO catalyst
X
is under consideration for 1975 production. They are also
the only manufacturer reporting that a three-way catalyst
is under consideration for 1975 production. Altogether
four systems are being considered:
1. Electronic fuel injection (EFI), thermal reactor
(TR), NO catalyst (RC), oxidation catalyst (OC),
J±
air injection (AI), EGR?
2. Carburetion, TR, RC, OC, AI, EGR?
3. Carburetion, RC, OC, AI, EGR?
4. Advanced EFI, 3-way catalyst, EGR?
Systems 2 and 4 are reported to be receiving the most attention.
VW reported that they are developing a carburetor similar to
the IFC carburetor reported by GM which operates on the constant
depression principle. It is not clear to the report team
whether VW expects to have the carburetor in production by 1975.
Different EFI units are used on systems 1 and 4. System 1 uses
the conventional D-Jetronic unit which meters fuel as a function
of manifold vacuum and engine speed. System 4 uses the new
L-Jetronic system which meters fuel as a function of inlet air
velocity.
It was not clear if any of the four VW systems would use EGR.
It is possible that VW has a proportional EGR system (since it
is admitted above the throttle) but the flow characteristics
of the EGR were not reported.
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Only one set of data was reported by VW and the type of
system under test was not identified. The low mileage emis-
sions reported were .35 gpm HC, 2.99 gpm CO, and .41 gpm NO .
J\.
VW considers performance and fuel economy important design
constraints. System 4, using the 3-way catalyst has the
greatest potential of retaining good fuel economy in the
opinion of the report team because a rich mixture is not
required.
It was difficult to determine whether or not VW plans to use
"modulating devices" which would adversely affect emission
control during non-LA4 operation, since the section of their
report discussing such devices was in German.
Durability Program - '75
Volkswagen's durability investigations of 1975 prototype
systems have been very limited. Their program was disastrously
impacted by the premature selection and stockpiling of a cata-
lytic monolithic substrate which lacked mechanical integrity.
Thus, no high mileage durability data of catalytically controlled
prototypes is available. Tests of only one durability vehicle
was reported. At 3400 miles this vehicle exceeded the 1975
carbon monoxide level.
It is not possible to reliably assess the prospects of the
Volkswagen durability testing programs at this time.
Catalyst Screening Program - '75
VW referred to their submission to EPA during the April 1972
hearings for information on their catalyst screening program.
This submittal contained only limited information on these
tests. VW has an initial screening test involving measure-
ment of HC and CO conversion on fresh and aged catalysts. VW
also measures the resistance of the catalyst to both thermal
shock and mechanical vibration and light-off temperature.
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After these laboratory tests are completed, the catalyst is
run on an engine dynamometer test and then, if it is pro-
mising, on a vehicle. VW provided no additional details.
Progress and Problem Areas - '75
Progress
VW has made some progress in system selection for 1975. They
apparently have narrowed down the field to two choices, a
typical dual catalyst system and a X sensor system.
Problem Areas
VW did not report any durability results on 1975-type emission
control systems. If, in fact, they have not run any durability
they are behind most other manufacturers in gaining actual test
experience from durability vehicle testing. VW also mentioned
problems with respect to fuel economy, power loss, and drive-
ability.
Since VW has always maintained that their development is a
1975-76 development, they have not reported 1975 results
separately. Since, in our opinion, VW will not use a NO
Jt
catalyst for 1975, it is not known if any durability problems
will crop up if they introduce a system for 1975 which is
essentially a 1976 system without the NO catalyst and with
a
different system calibrations. VW did not report any test
results on such a system.
Conclusions - '75
The report team concludes that VW has not yet demonstrated
the capability to meet the 1975 standards. They are grouped
in class 75-2.2 Catalytic System Approach - Average Develop-
ment Status rather arbitrarily, since VW provided little
information and data about their development programs.
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The report team also concludes that VW will not use a NO
Jt
catalyst for 1975 since in our opinion it is not necessary
for VW to use a NO catalyst to meet the 1975 Federal NO
X X
standard.
6.2.13.2 1976 Development Status
Systems to be Used - '76
Refer to the 1975 Development Status section 6.2.13.1 for a
description of the VW systems. VW reported on 1976-type con-
trol systems with either a reducing catalyst or a 3-way cata-
lyst for both 1975 and 1976.
Durability Program - '76
VW's durability program is discussed under 1975 Durability
Program.
Catalyst Screening Program - '76
VW did not include any details in their submission on catalyst
screening programs for 1976 NO catalysts. The IIEC work on
jC
NO catalysts being done by American Oil Co. was mentioned
X
as being a part of their NO catalyst program.
X
Progress and Problem Areas - '76
Progress
VW has made progress in system selection for 1976. They will
probably use either a dual catalyst system or a \ sensor
system.
Problem Areas
VW reported only one durability test on an unspecified 1976
system for an accumulated mileage of less than 3200 miles.
It is not known if this is the same system on which VW reported
durability data last year (1971) up to 24,000 miles.
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Such limited durability testing, especially considering that
the vehicle was over the 1976 NO standards to begin with,
a
puts VW behind most manufacturers in this area. The problem
areas mentioned by VW are the same for the 1976 system as
for the 1976 system, namely, fuel economy, power loss, and
driveability.
Conclusions - '76
The report team concludes that VW has not yet demonstrated
the capability to meet the 1976 standards. They are arbi-
trarily grouped in class 76-2.1 Catalytic System Approach
Average Development Status, since limited data was reported.
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6.2.14 VOLVO
6.2.14.1 1975 Development Status
Systems to be Used - '75
Volvo's first choice system consists of engine modifications,
electronic fuel injection, EGR, noble metal monolithic
oxidation catalyst and air injection. Back-up systems are
identical to the first choice systems except for the sub-
stitution of different catalysts for the Engelhard or Johnson-
Matthey catalysts which will be used in the first choice system.
The first back-up system would use either Kali-Chemie, UOP,
or Grace noble monoliths while the second back-up system would
use either base or noble metal pellets.
A new "KA" fuel injection system will be introduced on the
four-cylinder engines by 1975. The "Jetronic" system currently
used on 1973 model Volvos will still be used on the six-cylinder
engines. The KA system is another Bosch system similar to the
Jetronic but it controls fuel delivery as a function of inlet
air velocity rather than intake manifold vacuum measurement.
This could be a desirable feature on an engine using EGR, in
the opinion of the report team, since the EGR flow rate in-
fluences manifold vacuum. Current Volvo EGR systems have a
"backwards" calibration (higher than desirable flow at light
loads, lower than desirable at heavier loads where NO control
it
is more important) but proportional systems are under develop-
ment. Apparently the catalyst-equipped test vehicles reported
did not use the proportional system. Levels of 1.6 gpm HC,
10.6 gpm CO and 1.6 gpm NO have been achieved without catalysts
X
or air injection using the proportional EGR.
The Volvo air injection system like that of all other manu-
facturers, except Toyo Kogyo and Mitsubishi,is a "backwards"
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system which supplies more air than is desirable at lighter
engine loads. Volvo's own data indicates that there is an
optimum air injection rate for each load. Emission control
has been compromised, in the judgment of the report team,
by using air injection systems that are not modulated.
Low mileage results on Volvo's first choice system have
been as low as .16 gpm HC, 1.2 gpm CO, and 1.36 gpm NO .
X
Very low results have also been obtained with a rich thermal
reactor system which is no longer under consideration. A
vehicle equipped with a rich, turbulent thermal reactor
achieved .05 gpm HC, 1.43 gpm CO, and 1.30 gpm NO , but
X
Volvo abandoned the work, on this system because "...cracking,
breaking, and distortion of the insulation and reactor core
parts was a continuous problem which prevented any meaningful
durability testing," and "...investigations showed that
thermal reactors could not be successfully combined into
any emission system to pass 1976 limits." This last statement
indicates that one of Volvo's design constraints is that a
1975 system must be adaptable to a 1976 system configuration.
Volvo also considers the avoidance of power loss an important
constraint. They also report that the shortage of lead time
has been an important constraint. "...difficulties were
caused by the lack of timely information on test procedures,
the fuel specification to be available in 1975, on the allowable
or required maintenance on emissions systems, and whether the
averaging of production test results was to be permitted or
not."
Locating after-treatment devices on their vehicle with a
minimum of frame and sheet metal changes has also been difficult.
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Volvo estimated the fuel economy penalty associated with
their 1975 system will be 10% compared to '73 or 20% com-
pared to uncontrolled vehicles. The cost of the '75 system
was estimated at $140 (manufacturers cost, not retail price).
Durability Program - '75
Volvo's durability program is designed to determine the
deterioration associated with their basic prototype system
designs for 1975 model year vehicles. Of most significance
in the program is the demonstration of catalyst deterioration
characteristics. Thus far, Volvo reports that 11 different
vehicles have been run, at least to low mileage, in their
durability program. Seven other vehicles are currently under
preparation for introduction into the durability program.
The test cars in the Volvo durability fleet have been selected
to be as mechanically representative of the cars planned for
sale in 1975 as possible.
Basically, the systems under evaluation consist of exhaust
gas recirculation and oxidizing catalysts. However, not all
of the vehicles in the program currently are equipped with EGR.
Volvo is employing three distinct mileage accumulation pro-
cedures: the standard Federal,high speed durability, and taxi
service durability. The addition of two non-standard procedures
for mileage accumulation is to quantify deterioration different
from that associated with the Federal procedure but possible
in consumer use.
Maintenance performed on the vehicles was designed so as to
maximize the development data to be obtained, rather than
in strict conformity with Federal procedures. Cars in the
program have been updated to maintain the best representative
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systems on the vehicles. Changes in EGR design will be
incorporated on all of the durability vehicles subsequent
to completion of optimization study.
Three vehicles to date have in excess of 24,000 miles
accumulated:
OB 46234/1 - high deterioration in HC, CO, and N0v
X
OB 46232/2 - high deterioration in CO
OB 44085/1 - high deterioration in CO
converter failure at 29,980 miles
Catalyst Screening Program - '75
The catalyst screening program at Volvo includes both laboratory
and engine dynamometer testing.
The laboratory test uses a synthetic exhaust gas composed of
exhaust from a small Honda engine to which oxygen and CO
are added to simulate automotive engine exhaust. This gas
is passed over a heated catalyst and HC and CO conversions are
measured. Also, the following parameters are being investigated:
Optimum bed dimensions
Space velocity
Conversion temperature
Amount of oxygen needed
In addition to these basic tests, attrition and thermal shrinkage
are also measured. For thermal shrinkage tests, the catalyst
is heated for 24 hours at each of the following temperatures:
1600°, 1700°, and 1800° F. Volume change is then measured.
The engine dynamometer tests involve measuring HC and CO con-
versions with various catalyst candidates. The following
measurements are also taken:
1. Gas temperature before and after the converter
2. Catalyst temperature
3. Pressure drop across catalyst while varying rpm
rpm (1800-3000), A/F ratio (13.5-15.5), and
air injection rate
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Also, a simulated cold start is done using different rates
of air injection. A limited durability test of 50 hours at
steady state conditions (3000 rpm) is also carried out.
Progress and Problem Areas - '75
Progress
Volvo has made some progress in system selection, catalyst and
durability testing. The system to be used by Volvo is a
typical 1975 system (except for electronic fuel injection).
The platinum monolithic catalyst in the Volvo system will be
sourced from Engelhard. It has been reported that a contract
has been signed between Volvo and Engelhard for approximately
100,000 units for the 1975-77 time period. Volvo has accumulated
more durability experience with their systems, some having more
than 28,000 miles on them.
Problem Areas
Although some vehicles are still running after more than 28,000
miles, other vehicles that Volvo has tried have failed at much
earlier mileages. Volvo also reported much greater catalyst
deterioration with fuel containing .046 gpg lead compared to
their earlier tests with fuel of a lower lead content (.01 gpg).
Volvo did not report any testing at a lead level more typical
of the average lead level expected for 1975 (.03 gpg).
Volvo also reported problems in getting catalysts from the
catalyst manufacturers on a timely basis.
Conclusions - '75
The report team concludes that Volvo has not yet demonstrated
the capability to comply with the 1975 standards. They are
grouped in class 75-2.2, Catalytic System Approach - Average
Development Status, because of their continuing durability
problems.
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6.2.14.2 1976 Development Status
Systems to be Used - '76
The Volvo 1976 first choice system is basically the 1975
system with the addition of a NO catalyst. Both pelleted
Ji
and monolithic catalysts from several different manufacturers
are being investigated. Unlike the 1975 EGR system, the 1976
system will be proportional. The "KA" fuel injection system
which senses inlet air velocity rather than manifold vacuum,
will be used on both the four-and six-cylinder engines in
1976. For 1975 the "KA" system is scheduled only for the
four-cylinder models.
The best low mileage results achieved on the dual catalyst
system were .26 gpm HC, 1.68 gpm CO, and .28 NO . This
X
particular vehicle used Johnson-Matthey catalysts for both
reduction and oxidation.
Volvo is also working on a 3-way catalyst system with an
exhaust oxygen sensor to feed back information to the fuel
injection system which will allow a stoichiometric mixture
to be maintained.
At low mileage impressive results have been obtained: .0,8 gpm
HC, 1.94 gpm CO, and .13 gpm NO . Again the catalyst was a
.A,
Johnson-Matthey. Volvo reported many problems with this
system including high catalyst temperatures, poor driveability,
and oxygen probe durability problems.
Volvo claims that their biggest constraint for the 1976 model
is the lack of adequate time to complete the system develop-
ment. Volvo indicated that a catalyst temperature warning
device will be used on the 1976 model. The use of "auxiliary
devices" was not reported.
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The EGR system, however, may not be a full-time system
as it apparently is designed to provide high EGR rates
only for a short period of time at higher loads. A
schematic of the system provided by Volvo revealed a
vacuum chamber connected to the intake manifold through
a tiny orifice. When the load is increased, as in
accelerating the vehicle away from rest, a vacuum is
maintained in the chamber long enough to hold the EGR
valve open during the acceleration. When the engine is
kept highly loaded for a long enough period of time the
vacuum in the chamber will be reduced:to the point where
it closes the EGR valve because the higher pressure air
from the intake manifold will bleed into the vacuum
chamber through the orifice.
Durability Program - '76
Volvo has reported that no vehicle durability testing has
yet been initiated due to the very early state of develop-
ment of 1976 prototype systems.
Catalyst Screening Programs - '76
The catalyst screening program at Volvo includes tests on
an engine dynamometer to determine optimum performance
characteristics for dual catalyst systems as well as con-
version of HC, CO, and NO . The secondary air flow into
- Jt
the catalyst in these tests is about 15% of engine air
consumption. A number of NO catalysts are seen to have a
90% efficiency when they are new and used under steady state
conditions. The difference in the NO conversion after stage
1 and 2 is probably the amount of ammonia formed in stage
1 that is reoxidized to NO after stage 2. The large dis-
crepancy of effective NO conversion for the Kali-Chemie
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4035K pellets with two different oxidation catalysts was
not explained. These two widely different numbers (about
50% and 85%) show that it is important in NO catalyst
-------
the capability to meet the 1976 standards. They are
grouped in class 76-2.1, Catalytic System Approach -
Average Development Status, because of their adequate
low mileage results and durability problems.
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6.2.15 PEUGEOT
The status report from Peugeot was received just as this report
was in the final stages of production. Necessarily, the dis-
cussion of Peugeot's development status is somewhat more
limited than that of the other manufacturers. The late arrival
of their response is the reason that the placement of Peugeot
is out of alphabetical order.
6.2.15.1 1975 Development Status
Systems to be Used '75
Two systems are under consideration for 1975. Both are typical
1975-type systems. The "first class" system uses a precious
metal monolith catalyst. The "second class" system uses a
precious metal pellet catalyst. Aspects of the Peugeot system
that are significantly different in detail from the typical
1975-type system are the type of air pump and the location of
the catalyst. Peugeot plans to use an air pump of the Rootes
type as opposed to the Saginaw—type pump being considered by
most other manufacturers. Peugeot also contemplates positioning
the catalyst more than 108 inches away from the exhaust ports,
a distance significantly longer than that planned by most
manufacturers. The wheelbase of the Peugeot 504 model is 108
inches, as a comparison.
Low mileage emission results are typically .1 to .3 gpm HC,
below 1.0 gpm CO and below 1.0 gpm NO . Peugeot is achieving
X
the low NO results in an attempt to meet California *75 NO .
x x
Tests without EGR are typically less than about 2 gpm NO .
A,
Peugeot reported that without EGR the vehicle top speed is
reduced by about 5 mph and the fuel consumption is increased
between 9 and 25 percent depending on the speed. The comparison
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was made to European specification vehicles. The estimated
first cost of the '75 first choice system was estimated by
Peugeot to be about $270, the second choice system about $250.
Durability Program '75
Peugeot is currently conducting endurance tests on their 1975
system. Some vehicle tests appear to be durability tests,
others appear to be system optimization tests. Peugeot re-
ported durability results from 6 vehicles. Three vehicles
are reported to be still running at 18,800, 11,300 and 4,000
miles respectively. No EGR is used on these 3 vehicles.
The most significant vehicle, M.1876, at 18,774.3 miles had
.19 gpm HC, .74 gpm CO and .83 gpm NO . The support for 'the
X
catalyst on this vehicle was cracked at 11,100 miles. Many
catalyst failures were reported by Peugeot. The vehicle with
the most accumulated mileage, M.2899, had a melted catalyst
due to an ignition problem at 21,416 miles. No vehicle was
reported to have progressed farther.
Catalyst Screening Program '75
Peugeot"s catalyst screening program involves four stages.
Catalysts are laboratory tested for chemical and mechanical
properties, then if successful, pass on to an engine dynamometer
test, a CVS test and finally durability testing. The manu-
facturers of the catalysts tested by Peugeot were not identified
by Peugeot.
Progress and Problem Areas '75
Progress
Peugeot has progressed to the point where a prime '75 system
has been identified and some durability testing is underway.
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Problem Areas
Catalyst durability is a major problem for Peugeot. No
vehicle has yet been reported to have run even 25,000 miles
without failure. Peugeot also reported problems in the area
of over-temperature protection systems and lead contamination.
Conclusions '75
The report team concludes that Peugeot has not yet demonstrated
the capability to meet the 1975 standards. They are grouped
in class 75-2.2, Catalyst System Approach - Average Development
Status, because of their good low mileage results and inadequate
durability.
6.2.15.2 1976 Development Status
Systems to be Used '76
Peugeot plans to use a dual catalyst system for 1976. Use of
a thermal reactor in addition to the two catalysts is still
under consideration. The lambda-sensor, three-way catalyst
is also under consideration. Peugeot may use the new engine
under joint development by Peugeot,Renault and Volvo for
1976. Using a NO catalyst, but without EGR, a NO level of
X X
.36 gpm was reported. The engine type and HC and CO emissions
were not specified. The first cost of the 1976 system was
estimated by Peugeot to be approximately $400 over 1973 as
a base, or approximately $125 more than the 1975 system.
Durability Program '76
Due to the early stage of development, no "76 durability
program is yet underway at Peugeot.
Catalyst Screening Program '76
Peugeot's catalyst screening program for NO catalysts is
A.
essentially the same as the 1975 catalyst screening procedure.
NO conversion efficiency of NO catalysts is also measured in
J\,
addition to the HC and CO conversion.
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Progress and Problem Areas '76
Progress
Peugeot has made enough progress to enable them to consider
using a typical dual catalyst system for 1976.
• Problem Areas
Catalyst mechanical durability and efficiency are expected
to be serious problems by Peugeot. Other problems are yet
to be encountered, since the r76 development program is in
the early stages. With respect to NO catalyst efficiency,
X
Peugeot stated:
"It should be noted that the efficiency of the
reduction catalysts which we tested, wanes as
time passes."
Conclusions '76
The report team concludes that Peugeot has not yet demonstrated
the capability to meet the 1976 standards. They are grouped
into class 76-2.1, Catalyst System Approach - Average Develop-
ment Status, rather arbitrarily since little detail on the 1976
development program was presented.
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SECTION 7
APPENDIX
Reproduced below is a sample of the letter that was sent
to the manufacturers on September 8, 1972. Copies of the
letter were sent to American Motors, Chrysler, Ford,
General Motors, International Harvester, Daimler-Benz,
Volkswagen, and the Automobile Importers of America.
Responses were received from 20 automobile manufacturers.
Also reproduced below is a sample of the outline identifying
and discussing the type of information requested.
Dear Sir:
As part of its continuing overview of the industry's
efforts, and in order to implement sections 202 (b) (4) and
202(b)(5) of the Clean Air Act, the Environmental Protection
Agency needs current information on efforts by automobile
manufacturers to meet the 1975 and 1976 light duty motor
vehicle emission standards. Accordingly, pursuant to
section 307(a)(1) of the Clean Air Act, you are requested
to provide us with information regarding your development
status and progress toward meeting these standards.
The information requested, which is described in the
enclosed outline, is divided into five main areas: (a)
organizational structure of your company's emission control
program; (b) information describing emission control systems
design, (c) information describing experimental testing and
development programs, (d) emissions data, and (3) cost data.
The information provided by your company regarding 1975
system development should follow this outline, but may be
limited to a discussion of changes made in design, testing
protocol, or organizational structure, and to new test data
and other information which has not been previously reported
to EPA. Other information may be incorporated by reference
to the earlier documents including responses to our request
of September 1971, or to material submitted at the April 1972
public hearings on the suspension request for the 1975 standards,
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The information regarding 1976 systems development should
follow the enclosed outline and should represent a complete
discussion of your 1976 system development program. Trade
secret information submitted by you will be kept confidential
by the Administrator to the extent and under the conditions
set forth in the enclosed outline.
Two copies of your response to the request for emission
control system information should be received at the following
address by October 13, 1972, for the model year 1975 system
development activities, and by November 1, 1972, for the model
year 1976 system development activities.
Responses should be addressed to:
Director, Division of Emission Control Technology
Attention: Technology Assessment
Environmental Protection Agency
Motor Vehicle Emission Laboratory
Ann Arbor, Michigan 48104
U.S.A.
Any questions concerning the data requested should also
be addressed to the above office, which has primary responsi-
bility within EPA for acquiring and analyzing data on the
status of technology for automotive emission control. Also,
staff from that Division may need to contact you for additional
information or explanations, and such request should be deemed
by you as an integral part of the data gathering effort
initiated by this letter.
Your cooperation in ensuring that the Environmental
Protection Agency receives clear, detailed, and understandable
information describing the efforts of your company in the
design, development, and testing of 1975 and 1976 emission
control systems will contribute materially to the decision-
making process related to the implementation of Title II of
the Clean Air Act.
Sincerely yours,
Original Signed by:
Eric 0. Stork
(for) Robert L. Sansom
Assistant Administrator
for Air and Water Programs
Enclosure
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OUTLINE FOR EMISSION CONTROL STATUS REPORT
The following outline should be followed in submitting
the requested information. Any information not identified
in the outline or the discussion of the outline that you
feel is necessary for an accurate description of the emission
control technical effort of your company may also be included.
I. Light Duty Emission Control Organization
A. Discussion of organization
B. Description of the critical path for system
development
C. Organization chart
II. Emission Control Systems
A. Identification and description of the systems
B. Discussion of system optimization
C. Description of system operation
III. Development and Testing Program
A. Description of test program and organization
B. Test program basis and rationale
C. Test vehicle description
D. Test program status
IV. Experimental Data
A. Vehicle Data
B. Non-vehicle data
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V. Cost Information
A. First cost
B. Operating cost
VI. Confidentiality of Trade Secret Information
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DISCUSSION OF OUTLINE
I. Light Duty Emission Control Organization
A. Discussion of organization
This is a discussion of how your company's effort
in light duty emission control is organized. What
functions are carried out by what groups in the research,
design, development and testing of emission control systems?
Identify their separate areas of responsibility. Special
attention should be given to the description of the
functions of the group responsible for interfacing with
catalyst manufacturers. Also identify if any functions
are performed outside your company, such as testing,
consulting or component development.
B. Description of the critical path for system development
This should include a description of the evolution of
a system from concept to production. The path that the
system takes should be described for a hypothetical system,
following it through from concept to production, and a
specific description should be provided of the path for
each separate system identified in II below. Included
in the discussion of the systems should be the identifi-
cation of key decision points in the evolution of the
system, identification of the person(s) responsible for
such decisions, and for the systems described in II below
the actual history with calendar dates of the decisions
in the evolution of the systems described.
C. Organization chart
This is a chart of the organization described and
discussed in A and B above. It should be presented in
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enough detail to identify personnel down to the
first supervisory level.
II. Emission Control Systems
A. Identification and description of the systems
This should include both a generic and specific
description of each system (first choice and all backup
systems) under consideration for the model year under
discussion. If any feature of the emission control
system differs between model lines it should be treated
as a different system. An example might be the emission
control system for a 2000 Ib vehicle as contrasted to the
emission control system for a 5000 Ib vehicle. An
example of a generic 1975 emission control system is
engine modifications, EGR, air injection and an oxidation
catalyst. The detailed description should include enough
information about the system to distinguish it from other
systems in the same generic category. The description
should be accompanied by engineering drawings and pictures
when appropriate to more fully identify and describe the
system or subsystem. At least the following topics should
be discussed and fully identified.
1. Engine type - reciprocating 4-stroke, rotary, etc.
2. Engine modifications - compression ratio, com-
bustion chamber shape, valve timing, bore/stroke
ratio, spark plug location.
3. Intake system - detailed description of carburetor(s)
fuel injection system, choke and choke control,
intake manifold and intake port.
4. Exhaust port description
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5. Ignition system
6. EGR system - flow rate, type of control, take-off
location, introduction location, type of cooling
(if cooled).
7. Air injection - type of pump, supplier, flow
rate vs. engine speed, modulation and switching
control, location of air injection nozzles.
8. Thermal reactor - type (lean/rich), configuration,
materials, internal flow geometry.
9. Catalysts - type (reducing/oxidizing), active
material (general class or specific, if known)
loading and weight of catalyst material, sub-
strate structure type (monolith/pellet),
substrate composition, location, shape and
size, geometry, manufacturer and manufacturer's
identification number, nominal space velocity
and space velocity range.
B. Discussion of system optimization
1. This should include a discussion of the design
constraints within which each system was optimized
in emissions. Examples of such constraints are,
fuel economy, safety, cost, driveability,
packaging, maintenance, and performance.
Quantitative values should be identified for
all of the constraints for which your company
has determined such quantitative values. Others
should be discussed in the manner in which they
were set down for the design engineer.
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2. This should provide a discussion of all
designs that were not successful in surviving
the optimization studies that your company
performed, giving the criteria by which they
failed.
3. Of the systems that are under consideration
for the model year being discussed identify
and explain any tradeoffs that have been made
within the emission control system. Quantify
any examples by including design calculations or
engineering reports. An example might be catalyst
location, where one emission control related
tradeoff could be the tradeoff between a location
close to the exhaust port for fast light-off
versus a more remote location that might have
less of an over-temperature problem.
Description of system operation
1. The sequence of operations of the entire emission
control system during the 1975 Federal Test
Procedure should be discussed in detail, with
special attention given to those parameters
which vary during the cycle, for example,
spark timing, the choke position, air injection
(if modulated or switched ) and EGR flow rate.
2. The way in which the system operates under the
following other conditions should be discussed;
the emissions under such conditions should be
quantified in IV-A below.
a. Operation in low (less than 60 degrees P)
or high (greater than 86 degrees F) temper-
ature ambient conditions.
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b. Operation under conditions of speed and/or
load which do not occur during the 1975
Federal Test Procedure.
III. Development and Testing Program
A. Description of test programs
1. This should include a general description of
the type of laboratory or bench scale testing
carried out on emission control subsystems or
components.
2. This should include a description of any
catalyst screening tests and the basis for
selecting/rejecting catalysts.
3. This should include a discussion of any tests
made for optimization purposes described in II-B
above, a general description of the variables
that were changed, the range over which they
were varied, and the inferences drawn from the
system optimization tests.
B. Test program basis and rationale
1. This should include general discussion of the
use of vehicles for component testing and trade-
off studies, especially as it affects system
optimization. Distinction should be made
between vehicles used for component testing
versus complete system tests.
2. This should include a complete description of
all vehicle emission test programs for the model
year under discussion, including the number and
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type of vehicles, the reasons for choosing the
vehicle mix, the mileage accumulation schedule
for each vehicle and the number of emission tests
at each mileage point.
C. Test vehicle description
This should include an identification of the vehicle
nameplate, test weight, transmission type, axle ratio
and an identification of the emission control system
as outlined in II-A.
D. Test program status
This should include a discussion of the current
status of each emission durability vehicle and a com-
parison of its status with respect to the original
planning. Significant problem areas, if they exist,
should be identified.
IV. Experimental Data
A. Vehicle Data
1. Include 1975 FTP data on all durability fleet
vehicles described in III-B above.
2. Include a description of the reasons for any
vehicle not completing the full scheduled
durability mileage.
3. Include a complete discussion of vehicle fuel
economy during the testing. If fuel economy
is not measured on the same mileage accumulation
schedule as the durability schedule, a complete
description of the fuel economy test and data
from current model year and uncontrolled vehicles
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of the same weight for comparison purposes
should be supplied. Also, include discussion
of the driveability and performance of the test
vehicles, again with quantitative data and with
quantitative comparisons to current model year
vehicles.
B. Non-vehicle data.
1. This should include the results from any catalyst
screening tests, with a description of test
methodology, and must include the test results
from the catalysts that were selected for the
durability vehicles.
2. Include any other non-vehicle data considered
important such as engine dynamometer studies
on the effect of fuel contaminants on catalyst
durability.
V. Cost Information
A. First Cost
1. The cost breakdown should be in the same form as
that used by the National Academy of Sciences
Committee on Motor Vehicle Emissions in Appendix H
of their January 1, 1972, semi-annual report to the
EPA. This should also be specific as to what
fraction of the various product lines will require
specific devices.
B. Operating Costs
This should include expected extra costs to the
customer over the vehicle lifetime (assume 50,000 miles)
due to:
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1. Fuel and lubricant cost, specifying the miles
per gallon fuel economy assumed for each
engine family.
2. Maintenance cost other than catalyst replace-
ment. Such estimate should break out parts and
labor cost separately providing the ratios of
parts cost for OEM versus replacement cost.
The estimate should also indicate the expected
level of required maintenance on each major
emission control component which results in
such costs.
3. Catalyst replacement cost, if planned. This
estimate should separate labor and material
costs. Material costs should break out
catalyst and container costs.
VI. Confidentiality of Trade Secret Information
A. Information submitted in response to the request
which accompanies this outline will be deemed to have
been obtained pursuant to section 307 (a) (1) of the
Clean Air Act.
B. This means that only information which "would divulge
trade secrets or secret processes" will be kept in
confidence. (Even this information will not be kept
confidential in two situations: (1) when the information
is emission data, or (2) if and when the information
becomes "relevant" to a pending suspension proceeding.
See paragraph D.) In order to assure that such informa-
tion will be kept confidential prior to any suspension
proceeding, you must identify with particularity the
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data you regard as likely to "divulge trade secrets
or secret processes" if disclosed, and you must present
information to substantiate such claims. Such claims
and supporting information must be submitted at the
time of submission of the requested information or
such claims will be deemed to be waived.
C. If the Administrator determines that a satisfactory
showing has not been made that the information would
disclose trade secrets or secret processes, you will
be notified by certified mail. No sooner than 30
days following the mailing of such notice, any information
with respect to which trade secret status has not been
established will be placed in a public docket. Any
information as to which the Administrator determines
that a satisfactory showing has been made will be held
confidential in the period prior to commencement of any
suspension proceeding.
D. As in the case of the previous suspension proceeding,
if any trade secret information becomes pertinent to the
issues raised in a new proceeding on an application for
suspension, it may be disclosed by the Administrator.
In order to retain confidential treatment of such informa-
tion, you must show to the satisfaction of the Administrator
that non-disclosure of such information is justified by
"exceptional considerations", as that phrase was defined
in the course of the previous suspension proceeding. The
showing that must be made is that the information is of
such slight probative value in resolving the issue being
considered by comparison to the harm likely to result
from disclosure that public release of the information
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is not justified. If the Administrator determines
that a satisfactory showing has not been made, you
will be notified by certified-mail. No sooner than
10 days following the mailing of such notice and
telephone notice to a representative of your General
Counsel's office, such information will be placed in
a public docket. Any information as to which the
Administrator determines that a satisfactory showing
has been made will be held confidential and will not
be considered by the Administrator in deciding whether
to grant or deny a pending application for suspension.
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