EPA-420-F-72-OQ1a
W
w
BM
o
H
tc
-------
INDEX OF FACT SHEETS ON MOBILE SOURCE SUBJECTS
Motor Vehicle Ai-r Pollution Control FS-1
Oil Consumption Of Vega Automobiles FS-2
Factors Affecting Automotive Fuel Economy FS-3
Conversion Of Motor Vehicles To Gaseous Fuel FS-4
To Reduce Air Pollution
Requirements For EPA Confirmatory Testing Of FS-5
Motor Vehicle Emission Control Devices
Summary Of Responses To EPA Request For Information FS-6
On Effects Of Lead and Lead Scavengers In' Gasoline
On Automotive Exhaust.Catalysts
Facts About Methane Gas For Automotive Use FS-7
Kendig Carburetor FS-8
Suppressed Carburetors That Improve Fuel Economy FS-9
Hydro-Catalyst FS-10
Fuel Economy Of Mazda Rotary Engine Vehicles FS-11
Use of Alcphol As A Motor Fuel FS-12
Automobile Fuel Economy FS-13
Ring Of Power Emission Control Device . FS-14
The Effect Of Vehicle Weight On Automotive FS-15
Emissions
The Two-Car Strategy FS-16
The EMA Motor (Edwin V, Grey) FS-17
Removal Of Emission Controls FS-18
Electric Vehicles As A Solution To Air Pollution FS-19
And Fuel Shortages
Flywheels For Motor Vehicles FS-20
gasoline/Water Emulsions For Emission Control FS-21
-------
-2-
Introduction Of Diesel Powered Passenger Automobiles FS-22
Motorcycle Fact SKeet Revised FS 23
Diesel Odor FS-24
Comparison Of Japan/U.S. Test Procedures FS-25
Hydrogen Fuel Foe Automobiles FS-26
Octane Requirements For 1975 Model Year FS-27
Cars Operating On Unleaded Gasoline
Fire Hazards With 1975 Catalyst-Equipped Cars Revised FS-28
New Pollutants From Oxidation Catalysts For FS-29
Automotive Emission Control
Dresserator Fuel Induction System FS-30
Summary Of Responses To EPA Request For Information FS-31
On Octane Requirement Increases For 1975 Model Automobiles
Comparison Of Union Oil Company and EPA Fuel Economy TestsFS-32
EPA Evaluation Of The LaForce Car . FS-33
Diesel Powered Automobiles FS-34
Objectionable Odors From Catalyst-Equipped Vehicles FS-35
LaPan Carburetor ("Gizmo) Revised FS-36
Emissions From Heavy Duty Trucks and Buses FS-37
Pogue Carburetor FS-38
Fuel Economy, Emissions, and Safety Of Small And FS-39
Large Cars
Emissions and Fuel Economy Characteristics Of The FS-40
Honda CVCC Engine
Health Hazards Associated With 1975 Catalyst Equipped FS-41
Cars Operating In Confined Areas
Need For Warning Devices For Catalyst Over Temperatures FS-42
The Clean Air Coalition "Clean Air Car" FS-43
-------
-3-
(Obsolte) FS-44
Validity Of EPA Highway Fuel Economy Data FS-45
Future Emission Standards? FS-46
Fuel Penalty Caused By Emission Control (Barrens) FS-47
Replacement Of Oxidation Catalysts FS-48
Hydrogen Cyanide From Catalyst Cars FS-49
Mobile Source Air Pollution Control Programs(Barrens) FS-50
Office Of Mobile Source Air Pollution Control FS-51
The Portland Study: Control Of Air Pollution FS-52
From Motor Vehicle Emissions
Interchange Of Engines On General Motors Cars FS-53
EPA's Processes For Evaluation. Of Inventions For FS-54
Which Claims Of Improved Emission Control And
Fuel Economy Are Made
Lead Anti-Knock Compounds Continue To Be Utilized FS-55
In Gasoline To Conserve Fuel
Claimed Health Hazards From Palladium Content Of FS-56
Catalysts
Emissions From Motorized Bicycles (Mopeds) FS-57
Proposed Rulemaking On Fuel Economy Labeling FS-58
Procedures For 1979 And Later Model Year Automobiles
Limited Adjustment On Fututre Cars Revised FS-59
-------
£ if% \ UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
$ lOMM^t J
' WASHINGTON, D.C. 20460
OFFICE OF
AIR AND WASTE MANAGEMENT
Motor Vehicle Air Pollution Control
This fact sheet has been prepared to respond to the most frequently
asked questions received by the Environmental Protection Agency about . ,
various aspects of the control of emissions from automobiles. Although
you may have only asked about one or two of the questions covered in this
fact sheet, you may also be interested in the other issues that are dis-
cussed.
1. Why is it necessary to j'^gulate_Jajjitpcpbile__exhaust_ emissions?
The concentrations in the ambient air of carbon monoxide '(CO),
photochemical oxidants (smog) and nitrogen dioxide (N02) exceed health
related air quality standards in many areas of the United States, and
are particularly high in heavily urbanized areas. Furthermore, due to ,
the growth of pollution emitting sources, the potential exists for even
higher concentrations.
Hydrocarbons and nitrogen oxides react in the atmosphere'in the
presence of sunlight to form toxic photoeaeraieal oxidants. These oxidants
have detrimental effects on persons with respiratory Illnesses, cause eye
irritation and watering, and have destructive effects on rubber products,
synthetic fabrics, and plant life. Nitrogen dioxide and other nitrogen
oxides' can also cause adverse health effects•
Carbon monoxide is absorbed,In blood through the lungs and thereby
reduces the oxygen carrying capacity of the blood. The carbon monoxide
in the blood takes the form of carboxyhemoglobin (COHb). Increased COHb
levels have been shown to have adverse effects on heart patients, and
possibly asthmatic and lung patients.
Although It is extremely difficult to assign a dollar cost to some
of the damages caused by pollution, the Rational Academy of Sciences has
estimated that the total annual costs due to pollution caused by the
automobile is in the range of $2.5 to $7 billion dollars. These damages
FS-1
-------
-2-
Include the value of work lose due to pollution-induced sickness, earnings
lose to pollution-Induced death, plant and material damages, and other
costs. The NAS has also estimated that air pollution damage from all
sources in the U.S. costs $15 to $30 billion dollars annually.
To achieve and then maintain healthy air, the emission pollutants
and pollution precursors (such as HC) must be reduced and maintained at
reduced levels. Oxidants and NQ2 are formed in the atmosphere from
hydrocarbons (HC) and nitrogen oxides (NOx). Therefore, emissions of
HC, CO and NOx must be reduced in order to improve air quality.
It may, in the future, become necessary to regulate other exhaust
emissions from automobiles, such as particulate matter, or other currently
unregulated emissions. EPA is continually monitoring the emissions of
these pollutants and conducting health effects studies on these pollutants,
in order to be able to regulate their emission from autos and other sources
should there be a public health need for such regulation.
In urbanized areas, where the auto pollution is concentrated, autos
contribute about 95% of total CO emissions, and about 50% of the HC and
NOx emissions. Further, unlike other sources of pollution such as power
plants or factories, automobiles pollute at ground level in areas where
people are highly concentrated (e.g., on city streets). Therefore, auto
emission reduction must be a major part of any plan to reduce HC, CO, and
NOx emissions.
2. Does^ EPA tell^autpmakers^ how to build ears?
No. Individual vehicle manufacturers are free to employ any design
approach that will enable their vehicles to meet the emission, control
standards.
Federal emission standards require that a vehicle emit no more than
a specific amount (mass) of pollutants per mile of vehicle travel (expressed
as grams per mile). The standards are the same for all cars regardless of
vehicle size, design, or fuel consumption. Emission standards are different
for ,light duty trucks and for heavy duty vehicles, but are required by law
to be, in future model years, equivalent in stringency to the auto emission
standards.
3. Vhat are the auto emission standards?
Past, present, and potential future auto emission standards are
ahown in the following table:
-------
-3-
Emission Standards for Automobiles
Date
Average precontrol emissions
1970-71
1972
1973-74
1975-76 (Federal)
1975-76 (California)
1977-79 (Federal)
1977-78 (California)
1980 (Federal)
1981 and later (Federal)
HC
8.7
4.1
3.0
3.0
1.5
0.9
1.5
0.41
0.41
0.41
(grams per mile)*
CO
87
34
28
28
15
9
15
9
7
3.4
NOx
3.5
5.0**
5.0**
3.1
3.1
2.0
2.0
1.5
2.0
1.0
* All values expressed in terms of the 1975
Federal Emission Test Procedure
** There was no NOx standard until 1973. NOx
emissions increased due to the methods chosen
by automakers to meet the CO and HC standards.
Complete information on the emission standards and how cars are
tested to assure that they meet these standards is contained in the
Code of Federal Regulations (40 CFR 86) that is available in any
Federal Depository Library (such as most big public libraries and
university libraries).
-------
-4-
4, How have cars been modified to meet the emission standards, and
what ttindsof modifications can be expected for future _cars?
Prior to the 1975 model year, most manufacturers used engine
modifications such as changes to the carburetor, choke, idle speed,
distributor and Ignition timing, as well as changes to the internal
engine design. In addition, many manufacturers employ exhaust gas
recirculation (EGR) to control NOx emissions.
Most 1975 and later model year cars employ:
a. An oxidizing catalyst and (on some models) an air pump
to remove excess hydrocarbons and carbon monoxide from
the exhaust gases after they leave the engine.
b. An exhaust gas recirculation system that lowers combustion
temperatures and reduces the formation of nitrogen oxides.
c. A quick warm-up manifold and a fast-acting choke to reduce
emissions during the engine start and warm-up period.
d. An Improved carburetor and ignition system to provide more
complete fuel-air mixing and better combustion characteristics.
Beginning with some 1978 model year cars to be sold in California,
and for most cars that will be sold nationwide in the next several years,
new emission control systems will be used. These new systems offer
improved emission control capability over the emission control systems
used on 1975 and later model years cars, and offer the potential for
better fuel economy and performance than current model year cars.
These future cars are likely to employ I
a. A "three-way" catalyst (instead of an oxidation catalyst) that
controls all three regulated emissions from cars (HC, CO, and NOx). On
some models, an additional oxidation catalyst and air pump may be used
to achieve even lower levels of HC and CO than can be achieved by a three-
way catalyst alone.
b. A highly modified fuel system, using either a carburetor or fuel
injection system, to provide extremely close control of air-fuel mixture
that is supplied to the engine. This is necessary for the proper func-
tioning of the three-way catalyst.
-------
-5-
c. Electronic control of several engine and emission control
system operating functions, such as spark timing, cold-start operation,
and control of the fuel system.
5. What is the cost of these emission control systems?
There are three types of costs that can be considered to be costs
attributed to emission control systems, Those costs are the costs to
purchase the emission control system hardware found on new cars, the
incremental maintenance costs and the costs of any fuel economy change
due to the use of emission controls.
Purchase and maintenance costs for several past and future model
year cars are presented in the table below, The costs presented are
estimates which may vary due to vehicle weight, type of emission control
system used, and the individual nanufacturer's pricing practice, Ae can
be expected, as emission control systems become more and more complex in
future rsodel years, the purchase coats of those systems increases.
However, the use of unleaded fuels and the resulting decreasing need for
maintenance means that the costs to maintain emission control systems on
1975 and later model year cars is not increasing.
Costs of Emission ControlSystems —
(in 1977 dollars)
2/
Model Year Purchase Cost Maintenance Coat —
1973-1974 $100 $160
1975-1976 . |200 ($70) -^
1977-1979 §215 ($70)
1980 $285 ($60)
1981 and later $435 ($20)
Notes:
ij Additional costs over uncontrolled, pre-1969 cars.
2/ Maintenance costs are lifetime costs (i.e., costs for 100,000
miles).
31 Coats in parenthesis indicate cost savings.
-------
-6-
The third cost assoclaced with emission control systems, the fuel
economy change due to emission controls, is difficult to assess. Generally,
fuel economy suffered in the model years up to 1975 due to the use of emission
controls. Although not indicated in the table below, fuel economy of smaller
cars did not suffer due to emission controls because the lower exhaust gas
volumes of smaller cars reduce the need for stringent exhaust emission con-
trol measures. With the introduction of the catalyst emission control system
in the 1975 model year, however, manufacturers were able to gain back all of
the fuel economy that was lost in prior model years. Continued use of catalysts,
both the oxidation and three-way catalysts, should allow achievement of future
emission standards without adversely affecting fuel economy. In fact, recently
mandated fuel economy standards, which require that the average fuel economy
increase from 18.0 mpg in the 1978 model year to 27.5 mpg In the 1985 model
year, will have a much greater effect on the fuel economy of the average car
than use of emission controls.
Average Fuel Economy Trends
Model Year
City-Highway MPG
Pre-controlled (1967 model year)
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
Actual KPG
15.5
14.0
13.9
15.6
17.8
18.6
I/
Fixed Weight Mix MPG -'
15.6
13.9
13.9
15.9
17.5
17.9
Fuel Economy Standards
18.0
19.0
20,0
22.0
24.0
26.0
27.0
27.5
Note:
I/ "Fixed Weight Mix MPG" means that all mpg values have been adjusted auch
that the effects of changing model mix have been eliminated. Thus, the
mpg values represent fuel economy Improvements that can be attributed to
emission control system optimization and new engine Introductions, because
weight mix shift effects are eliminated.
-------
-7-
6. Do catalytic converters jjroduce dangerous emissions?
As noted earlier, the catalytic converters used on most 1975 to
1978 model year cars are oxidation catalysts. These catalysts oxidize
the exhaust gases, converting carbon monoxide (CO) to carbon dioxide
(C02), and convert hydrocarbons (HC) to carbon dioxide and water. That
±3 how the oxidation catalysts used on current cars controls HC and CO
emissions- by converting most of those emissions into harmless carbon
dioxide and water.
In the process of oxidizing the HC and CO found in exhaust gases,
an oxidation catalyst under certain operating conditions can also oxidize
some of che small amount of sulfur dioxide in the exhausc, and thus
form sulfur trioxide. This gas then combines with the water vapor in
the exhaust to form sulfuric acid (H2S04.). H2S04 has always come from
non-catalytic cars, but at lower levels than is emitted from oxidation
catalyst-equipped cars.
Emissions of H2S04 from one car, even at the slightly higher emission
rate from a catalyst-equipped car, are much too low to be dangerous. In
addition, the combined emissions of H2S04 from large numbers of catalyst-
equipped cars, such as might occur if all the cars on a freeway were to be
catalyst-equipped, do not appear to present a health hazard. EPA has, since
1973, conducted extensive monitoring of H2S04 emission rates from individual
catalyst-equipped cars, and has monitored since 1975 the H2S04 emission
levels at the roadside of a major freeway in Los Angeles, California. These
roadside measurements, while showing increasing concentrations of H2S04 (as
is to be expected due to the increasing numbers of catalyst-equipped vehicles
in California), have not shown concentrations of H2S04 that would present a
public health risk.
EPA has also conducted extensive health reaseach into the effects of
low concentrations of H2S04 on public health, EPA expects to continue to
monitor air concentrations of this pollutant, and to proceed with research
of the health effects associated with H2S04. At this time, however, EPA
has no reason to believe that there is any health risk associated with the
emissions of H2S04 from catalyst-equipped cars.
Future catalysts, called either as "three-way" or "dual" catalysts,
will not only oxidize HC and CO emissions as is done in an oxidation
catalyst, but will reduce emissions of oxides of nitrogen (KOx) to elemental
nitrogen. In a manner opposite to the oxidation process, which adds oxygen
to some exhaust pollutants, the process of reduction chemically subtracts
oxygen from other pollutants. These future catalyst systems expected to be
used on most cars beginning with the 1981 models have been shown by researchers
to emit much lower levels of H2S04 than do cars with oxidation catalyst
-------
-8-
syscenfis. However, It is possible for other unregulated pollutants to be
formed in three-way catalysts when these catalysts operate under overly-
rich (i.e., too much gasoline) conditions, including hydrogen cyanide
(HCN) and hydrogen sulfide (H2S). However, extensive testing of three-
way catalyst-equipped cars under both normal and malfunctioning conditions
has not to date measured either of these pollutants at high enough levels
to warrant any concern about adverse health effects from three-way catalyst
cars.
7. Will future motor vehicles have to burn unleaded gasolineI
The catalytic exhaust reactors used on many 1975 and later model •
year passenger cars are rapidly deactivated by lead and phosphorous
gasoline additives. Because of this the EPA has published regulations
requiring the nationwide availability of unleaded gasoline to supply
these cars. And, because future emission standards are likely to be
met using catalysts, future cars will most likely need to burn unleaded
gasoline.
The EPA has also published regulations which require phased reduction
in the lead content of leaded grades of gasoline, because lead emissions
from motor vehicles present a hazard to the health of the urban population,
especially children. These regulations were set aside ty a court decision
in 1973 following a law suit by the manufacturers of lead anti-knock
additives, tut re-instituted following a court review and approval of the
regulations in 1975.
The increased cost of unleaded gasoline associated with its production
is more than offset by the savings in vehicle maintenance which result from
the use of unleaded gasoline, and by the fuel economy gains achieved by cars
equipped with catalytic emission control systems.
8. Do emission control systems reduce performance?
Pre-1975 model year emission-controlled vehicles sometimes perform
differently in certain respects than do older uncontrolled cars. Problems
frequently mentioned include difficulty in cold starting, slower warm-up,
less acceleration, and "dieseling" (continued engine firing after the
ignition is turned off). These problems are partially attributable to
techniques selected by auto manufacturers to meet emission standards prior
to the 1975 model year. Most of these problems have been greatly reduced,
if not eliminated, beginning in the 1975 model year.
-------
-9-
However, even pre-1975 cars were designed by manufacturers to be
capable of performing properly. It seems that the imposition, of emission
controls may have afforded a few mechanics a new excuse for failing to
Identify and properly repair norraal defects in automobiles. Better
supervision and training of mechanics may be required to assure that the
driving public benefits from the built-in performance potential of emission
controlled cara,
9. Do eicission^-contrplled vehicles _shpv_pgprer,_fue_l_ economy?
Studies on automotive fuel consumption conducted by EPA show that
emission controls have had an Impact on fuel economy. The studies estimate
that the average loss in fuel economy for 1974 model year vehicles over
those with no emission controls is about 10% with a maximum of 22% for the
largest cars.
The fuel economy loss due to pre-75 emission controls must be compared
to the 2%-15% fuel economy penalty associated with automatic transmissions,
and the 9Z to 201 penalty that is experienced by an air-conditioned car
operating on a hot day in urban traffic. And of course, the most significant
factor affecting fuel economy was the general Industry trend toward greater
vehicle size and weight, for example, on the average, a 5,500-pound vehicle
gets only about half the miles per gallon (in city driving) that are obtained
from a 2,500 pound vehicle. In that context, vehicle owners should recognize
that until recently models with the same name plate have tended to Increase
In size, and therefore in weight, with each succeeding model year and that
this trend has adversely Influenced fuel economy.
The introduction of the catalytic converter In 1975 allowed the auto-
makers to retune the engine for better fuel economy. EPA tests have indicated
an average fuel economy Improvement of 12£ for 1975 vehicles over 1974
vehicles, and as much as 25% Improvement for some individual models. Thus,
just about all of the fuel economy losses first caused by emission controls
had been regained in 1975 cars. Fuel economy has continued to increase In
the 1976 and 1977 models, which have shown 28% and 34% increases respectively,
over 1974 vehicles.
The fuel economy of future cars will be more Influenced by the federal
fuel economy standards than by factors such as emission controls. Manufac-
turers are required to obtain as an average for all cars they produce, 18
miles per gallon In the 1978 model year, increasing to 27.5 miles per gallon
In the 1985 model year. Manufacturers are expected to meet these average
fuel economy standards by improving engine efficiencies, reducing vehicle
weight, Improving drivetrain efficiency, and using smaller engines. Of these
methods, reducing vehicle weight will have the most marked effect on vehicle
fuel economy. Effects on vehicle fuel economy due to emission control systems
will be negligible compared to the effects from the vehicle weight reduction
programs and other programs described above.
-------
-10-
10. How Is it possible foramissions to be reduced when some cars burn
more fuel than pre-emiasion controlled models?
The mass of pollutants emitted by new automobiles is related to
engine/control system design and not directly to fuel consumption. The
amount of fuel which is incompletely burned (which makes up the base of
HC and CO emissions) is an extremely small fraction of the total fuel that
goes through the engine. Even if this fuel were fully burned in the engine,
it would not significantly increase the efficiency of the engine in a way
that could be measured in terms of lower fuel consumption.
Until catalysts became available (and until better engine designs
that could operate very lean were developed) most automakers met the
emission standards by continuing to burn the fuel in the exhaust manifold.
To get the sufficiently high temperature needed to sustain such burning
outside the engine itself, the spark timing was retarded from the point of
maximum engine efficiency; in that manner, many cars—especially the larger
ones—had poorer fuel economy even though they had lower levels of pollutant
emissions.
Control of the third automotive pollutant—NOx—involved (in addition
to the spark retard that is also used to control HC) the recirculation of
small amounts of exhaust gas into the intake manifold, to cool the burning
process. Early exhaust gas recirculation (EGS.) systems were relatively
inefficient and thus tended to reduce overall fuel economy more than
necessary. EGR systems on 1975 cars are much better designed, and even
better EGS. designs are expected to be used on future cars. These improved
EGR systems allow greater reduction of NOx with the potential to achieve
that reduction without a fuel economy loss.
11. Do small cars and engines pollute less than large vehicles?
All cars built today are subject to the same emission standards, which
are expressed in terns of grams of pollutants per mile. Prior to the imposi-
tion of emission controls all cars greatly exceeded the current emission
standards for hydrocarbons and carbon monoxide, and all but the smallest cars
exceeded the current emission standard for oxides of nitrogen. Today's
vehicle emissions are not related to vehicle size, because each manufacturer
tries to come as close as he can to the applicable emission standards, without
exceeding them, so as to minimize his overall costs.
Prior to the imposition of emission controls, smaller cars did emit
less carbon monoxide and oxides of nitrogen than did large carsj emissions
of hydrocarbons were unrelated to vehicle size. In a sense, this means
that it was easier to reduce CO and NOx emissions from a small car to the
level of the emission standards than it was to reduce the emissions from a
-------
-11-
larger car, and that helps to explain why smaller cars did not show fuel
economy losses even before catalytic emission, control was used. But from
the standpoint of vehicle performance, the larger cars usually had engines
that had more power to spare than did smaller cars; thus, to retain accept-
able vehicle performance, the small car makers may have had an equally tough
engineering task. In short, meeting emission standards is a significant
challenge for car makers regardless of the size of the car they make.
12. Why doesn't the Federal Government do something about emissions
from used cars?
Even though major reductions in emissions have been achieved on late
model cars, older cars that are still in use contribute disproportionately
to their numbers to the problem of motor vehicle air pollution. In the
Clean Air Act, the Congress left the States the responsibility to take
action to control emissions from in-use vehicles, to the extent that such
action is necessary to achieve national ambient air quality standards. EPA
has evaluated various methods that can be used to control the emissions from
older cars, and has published the results of this work as guidance to the
various States. The States of Oregon., New Jersey, Arizona, and California,
and the City of Chicago, Illionis, already inspect cars in use for emissions,
A number of other States, those that have major urban air quality problems,
are considering the adoption of in-use vehicle emission inspection programs.
OMSAPC/EPA
45581
-------
A Report on
Automotive Fuel Economy
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
-------
A Report on
Automotive
Fuel Economy
Reprinted
February 1974
INTRODUCTION
This report is the second of two EPA
reports on automobile fuel economy. The
first report, entitled "Fuel Economy and
Emission Control," was published in No-
vember of 1972, and dealt with the sub-
ject of automobile fuel economy primari-
ly as it was affected by vehicle weight,
convenience devices, and emission con-
trols. This report is a sequel to the earlier
report in that it contains discussion of
automobile fuel economy, hut it differs
in some respects, reflecting the results
of further study. The data base has been
expanded, the calculation procedures have
been refined, certain areas have been re-
examined using newer data and/or dif-
ferent analysis techniques, and additional
vehicle design and operating parameters
that affect fuel economy are discussed.
Since the earlier report was published,
.interest in the subject of automobile fuel
economy has increased greatly. The ear-
lier report was the subject of comment
from within EPA, other Federal agen-
cies, the Congress, State and local govern-
ments, citizens, fleet purchasers, motor ve-
hicle manufacturers, and fuel producers.
This report is intended to be of use to
these same groups. While this report does
not discuss the detailed technical analyses
and background from which much of the
data were derived, it does provide suffi-
cient information upon which to make in-
formed decisions regarding the purchase
and operation of an automobile, and from
which an understanding can be had of
the most important parameters affecting
automobile fuel economy.
For those seeking a more technical and
detailed presentation of the topics dis-
cussed here, additional information can
be obtained from the references listed in
the bibliography at the end of this re-
port.
CONTENTS
Summary uad Conclusions 1
Dftta Sources iind Calculation Procedures __ 2
Genera! Factors Affecting
Automobile Fuel ISconomy 3
EDgino / Vehicle Design S
Vehicle Operation an<3 Use ft
Trends !n Aatomoi>l!e Fuel Ecoaomy li
Appendices . . . 13
U.S. ENVIRONMENTAL PROTECTION AGENCY * WASHINGTON, D.C. 20460
-------
SUMMARY & CONCLUSIONS
Summary
The Environmental Protection Agency
has analyzed fuel economy data front
more than 4,000 cars {of which over 1500
were equipped with emissions controls)
tested on the Federal Driving Cycle, A
carton balance equation was used to cal-
culate fuel economy. Statistical regression
techniques were used to determine the
effect of various design parameters on
fuel economy.
The data were derived from EPA cer-
tification, surveillance and in-house eval-
uation testing. This is the most extensive
data analysis known to have been per-
formed on this subject to date. It is also
considered by EPA to be the most ac-
curate for the purpose of comparing
change! in vehicle fuel economy because
of the use of a single consistent driv-
ing cycle and controlled ambient condi-
tions.
In addition, the EPA has evaluated a
significant amount of new data which
have recently become available (see bib-
liography) as well as older date which
have recently come to light. Much of
this data was generated by automobile
manufacturers. Significant data were also
developed by the U.S. Department of
Transportation, Important information
also Cime from a study on vehicle weight
trends which was performed under con-
tract to the EPA. Much of this additional
data concentrated on the impact of changes
in vehicle design and vehicle operation
on fuel economy.
This study indicates that vehicle weight
is the single most important vehicle de-
sign parameter affecting fuel economy.
Past and future increases in vehicle weight
have had, and will continue to have, a
significant adverse effect on fuel usage.
Weight is a parameter over which the
car buyer has direct discretionary con-
trol, in terms of the size car he chooses
to purchase,
Other aspects of vehicle design (size,
tires, axle ratio, engine compression ratio,
air conditioning, transmission type, emis-
sion controls, and engine size and type)
and operation (speed, trip length, accelera-
tion, maintenance, road surface and grade,
and elevation) were also examined,
Changes in individual vehicle design pa-
rameters, including weight, are ihown to
affect fuel economy from — SOffc to over
4-100% of the nationwide average fuel
economy. The most important of the
operating parameters can individually
vary the fuel economy of a given weight
vehicle over a —60% to +25% range.
The sales weighted average fuel econ-
omy loss due to emission controls for
1973 vehicles compared to uncontrolled
vehicles is 10.1%. This penalty, while
significant, must be viewed in the con-
text of the other penalties being ex-
perienced by today's car buyer. These
include penalties of 9% to 20% for air
conditioning and 2% to 15% for auto-
matic transmissions. The loss due to emis-
sion controls has varied significantly with
vehicle weight, with lighter cars showing
a gain of about 3% and heavy vehicles
suffering losses up to 18%. Despite the
many statements regarding the loss in
fuel economy due to meeting the 197S/
1976 standards, it now appears that ve-
hicles equipped with catalytic converters
to meet the 1975 standards will have im-
proved (0% to 15%) fuel economy over
1973 vehicles.
The use of engines other than the
present spark-igniton, reciprocating en-
gine could have a significant impact on
vehicle fuel economy. Use of the spark-
ignition, rotary engine presently results
in significant losses in fuel economy, while
the diescl engine offers a significant in-
crease in fuel economy,
Clear trends have developed over the
past ten years in motor vehicle fuel econ-
omy and factors affecting fuel economy.
Vehicle weight has been increasing since
1962 for individual models and the popu-
lation as a whole. This steadily increas-
ing average weight trend has been ac-
companied by a steadily decreasing aver-
age fuel economy. The use of emission
controls has had little impact on this
trend. Whether the increasing market share
of small vehicles will have a noticeable
effect is yet to be seen.
Conclusions
I. Vehicle weight is the single most im-
portant parameter affecting urban fuel
economy; a 5,000-pound vehicle demon-
strates 50% lower fuel economy than a
2,500-pound vehicle.
2. Vehicle weight, for both individual
models and the sales weighted average,
has increased significantly from 1962 to
1973 and current trends indicate additional
increases in the future. This weight in-
crease has accounted for about one-half
of the total drop in the average fuel
economy of these model year vehicles.
3. The sales weighted average fuel econ-
I
-------
omy loss due to emission controls (in-
cluding reduction in compression ratio)
for 1973 vehicles, compared to uncon-
trolled (pre-lP68) vehicles, is 10.1%. How-
ever, vehicles less than 3,500 pounds show
an average 3% gain (attributable to car-
buretor changes made to control emis-
sions) while vehicles heavier than 3,500
pounds show losses up to 18%. The size
of these IOSKS, however, is highly de-
pendent on the type of control systems
the manufacturer has chosen to use.
4. Prototype conventional engine pow-
ered vehicles equipped with catalytic con-
verters designed to meet the statutory
HC and CO standards are expected to
show fuel economy improvement over
1973 vehicies op to 12%.
5. The fuel economy penalty due to the
use of convenience devices such as air
conditioning (a/e) or automatic transmis-
sion (a/t) is comparable to that due to
emission controls, and can range from
9% to 20% for a/c and 2% to 15% for
a/t.
6. The reduction in compression ratio
employed by most manufacturers to en-
able their vehicles to operate on 91 oc-
tane gasoline has resulted in a 3,5% fuel
economy loss.'' However, a large
of the cost penalty due to that loss can
be regained by using the (presently) less
expensive 91 octane fuel for which the
engine was designed,
7. The way in which a vehicle is oper-
ated significantly affects vehicle fuel econ-
omy. Among the most important param-
eters, high vehicle speeds and short trips
can have an adverse effect on fuel econ-
omy of up to 60%.
8. Future trends, including increased ve-
hicle weight and possible use of the ro-
tary engine, may result in significant (20%-
35%) fuel economy penalties.
9. The diese! and open chamber stratified
chirge engines show batter fuel economy
than the conventional engine with the die-
sel showing a fuel economy improvement
of more than 70%.
10. Today's car buyer has available a
choice of vehicles in terms of the size
and weight, engine type, and convenience
devices. These choices can influence a
vehicle's fue! economy over a range of
4 to 1.
DATA SOURCES AND CALCULATION PROCEDURES
The data to derive the fuel econ-
omy information for this report originate
primarily from EPA Certification and Sur-
veillance programs, as a byproduct of the
emission tests run to determine compliance
of new motor vehicles with the emission
standards and to determine emissions from
in-use vehicles. Other data originate from
in-house EPA testing of exhaust emis-
sion control retrofit devices and advanced
prototype vehicles, contracts funded by
EPA, statistics from the Department of
Transportation, the existing literature, and
information submitted to EPA by auto-
mobile manufacturers.
The fuel economy data derived from
the emission tests are obtained by the car-
bon baiance method. Basically this in-
volves taking the unbumed hydrocarbon
(HC). carbon monoxide (CO), and car-
bon dioxide (CO) emissions from the
emission test tnd calculating the fuel con-
sumption for the test, using the fact that
the HC, CO, and CO. represent al! carbon
containing constituents of the exhaust, and
the fact that the fuei itself consists of
hydrocarbon compounds. The formula
used to calculate the fuel economy from
the emission data from a 1972 Federal
Test Procedure (FTP) test is:
* miles per gallon, mpg =
2423
.866 (HC) + .429 (CO) + .273 (CO=)
where HC, CO, anil COa are the emis-
sions of HC, CO5 and COs expressed in
grams per mile. This formula is different
than the one that was presented in the
earlier report, and is more precise, due
to the inclusion of the HC term and the
fact that the numerator has been modi-
fled £o more closely reflect the actual
density of the fuel used in the tests.
The manner in which the average mpg
values for classes of vehicles are calcu-
lated also differs in this report compared
to the earlier report. The results in this
report are based on total miles traveled
by all vehicles in the class divided by the
• A ainr*1 <• funnel In
A|>j>rinli\ A.
-------
total gallons used by alt of them. The
example given in footnote * demonstrates
why this is important in attempting to
accurately determine fuel economy. In sta-
tistical terms, the harmonic mean of the
data is used rather than the arithmetic
'mean.
The test procedure from which the fuel
economy data are derived is the same test
procedure uted for determining exhaust
emissions, the 1972 Federal Test Pro-
* Sii[>yoae a motorist took a trip of 000
miles uud used three tanfcy of gasoHne. For
th« first 200-mile segment lie used 10 gallons,
in the second BOG-mile segment he used 20
gallons, nn& for the third 200-mile segment
he used 18 (jullans. If he just averages tee
Individual mfs results he Beta tn* wrong
answer, The Individual fuel economy values
for the three segments urc 20 MM (200flO),
10 mps <200/20> and 11.1 rupK (200/18).
The simple average Is (20 + 10 + 11.1 }/3 =
13.7 tnpg. But the trip was 800 miles long
and 10 + 20 + IS = 48 Billions were used.
so the trip fuel economy was 000^48 = 12.5
tnpe. not 13.1.
cedure. This procedure consists of simu-
lating a trip of 7,5 miles in length on
a chassis dynamometer, a device "which
allows tests simyliting actual driving to
bo conducted indoors under closely eon-
trolled exBftrimental conditions. The driv-
ing cycle used for this procedure repre-
sents a mix of urban and suburban driv-
ing including several cruises and speeds
up to 57 mph. One important feature of
this test procedure Is the "cold start," The
vehicle is allowed to sit or "souk" 12
hours before the test. As a result, the en-
gine temperature is about 70° F at the
time of the test (much below its normal
operating temperature of 1800-2Q(TF),
and the engine is not warmed up before
the test. Other components of the drive-
train are also at about 70*R Therefore,
the results of the test are influenced by
the warm-up characteristics of the en-
fine and vehicle, which have a significant
effect on fuel economy.
GENERAL FACTORS AFFECTING AUTOMOBILE FUEL ECONOMY
Fuel economy * in miles per gallon
(mpg) is a measure of efficiency. It is
the measure of what you get (miles trav-
eled) for what you put in (gallons of
fuel). Automobile engines produce the
work required for operation of the auto-
mobile by burning the fuel in th« cylin-
ders of the engine. Part of the chemical
energy in the fuel is converted to useful
work done by the engine; the rest ends
up as waste heat. This is why automo-
biles have hot exhausts and cooling sys-
tems and radiators to get rid of this heat.
The ratio of the useful work delivered
by the engine to the total energy in the
fuel defines the thermal efficiency of the
engine. Current vehicle engines show ther-
mal efficiencies between approximately 10
and 30 percent, depending on the engine
type, speed, and load.
Engine efficiency is only indirectly re-
lated to the fuel economy of an automo-
* Fuel economy should not IMJ cvufumjiJ with
flit?! consumption wht% less. The two
terms cannot be nscd ltit
bile because, although engine efficiency is
a measure of how well the engine converts
the energy in the fuel to useful work, the
total amount of work required of the en-
gine to drive the automobile depends on
the characteristics of the automobile (en-
line and vehicle deiign) and on how the
vehicle is operated. Therefore, the total
fuel consumed depends on the engine, the
vehicle, and the operator. Since the fuel
economy of the complete automobile is of
most interest, this report uses mpg values
to denote fuel economy, and not any
measure of engine efficiency by itself.
Engine/Vehicle Design
There are many aspects of automobile
design that influence the fuel economy of
automobiles. However, it is not a simple
matter to optimize all of the important
factors simultaneously in order to achieve
the best fuel economy.
Today's vehicle designers are faced with
a host of sometimes conflicting require-
ments. Since the automobile must sell, it
must incorporate features that appeal to
the buying public. Styling, convenience,
comfort, cost, durability, driveability, per-
formance, and fuel economy are among
the factors considered by the buying pub-
lic. Trends in these consumer preferences
-------
must be anticipated years in advance,
since the total automobile design and de-
velopment process takes several years be-
fore it reaches production and the con-
sumer,
Within the last five to ten years other
requirements have been added to the list
These requirements, which must also be
satisfied by the vehicle desifner, are Fed-
eral requirements in the areas of ve-
hicle safety and exhaust emissions. To-
day's automobile is a result of compro-
mises, tradeoffs, and judgments by the
vehicle designers as to what combination
of vehicle parameters best suits the over-
all requirements. Those parameters which
principally influence fuel economy are dis-
cussed in this report.
WEIGHT
Vehicle weight is the single most im-
portant factor affecting passenger car fuel
economy. Sub com pact cars in the lighter
inertia weight * classes (up to 2,500
pounds) generally achieve double the miles
per gallon of full size cars in the heavier
weight because a car's engine must
do more work to move a heavy vehicle
than a light vehicle. However, this is
not the only reason lighter (smaller) cars
achieved better fuel economy. Lighter cars
have also, customarily, been designed to
achieve good fuel economy by employing
relatively smaller engines, manual trans-
missions and fewer accessories.
The difference in fuel economy between
light and heavy vehicles has been increas-
ing as emission controls have become
more stringent. The fuel economy of light
vehicles has not been significantly af-
fected by emission controls, but heavy
cars have realized significant penalties.
Figure 1 and Table 1 illustrate this effect.
The solid line shows that, on the aver-
age, the lighter uncontrolled (pre-1968)
vehicles achieved much better fuel econ-
omy than the heavy uncontrolled vehicles.
The dashed line, representing the 1J73
vehicles, indicates the same trend but
shows that the fuel economy of the heavy
1973 vehicles is poorer than the heavy
uncontrolled vehicle* while the light 1973
vehicles are slightly better than the light
uncontrolled vehicles.
FIGURE 1
FUEL ECONOMY VS. INERTIA WEIGHT
The weight of most model automobiles
has been steadily increasing in recent
years- As can be seen in Figure 2, the
most popular standard size passenger cars
have gained about 800 pounds from 1962
to 1973. This trend in increased weight
has also been occurring among inter-
mediates, compacts, and sub com pacts.
FIGURE 2
VEHICLE WEIGHT VS. MODEL TEAR
STANDARD SIZE CARS
IBS less ma 1973
MODEL VEAR
These weight increases alone have caused
a significant drop in fuel economy of
given model vehicles. However, the in-
creased sales percentage in the lighter
TABLE 1
pyiL ECONOMY VS. INERTIA WEIiHT
FOR UNCONTROLLED (195? ^1867 AVERAGE) AND tf73 VEHICLES
INERTIA WEIGHT
2m 2150 2iB9 21X 3*00 3500 4000 4500 50OH S50D
•57 _ '67 m 23,2 21.7 19,1 17.1 15.4 13.5 12.6 11.7 10.9 10.5
73 MPG 23.8 21,9 19.7 17.5 15.6 13.9 10.8 W.1 93 8.8
* Th« term "inorttn weight" refers to the
t*»t weight of the vehicle that wa* simulated
on the chassis dynamometer during the «a!t-
«ion tests, Inertia wetprht corresponds to the
w«lcht of the automobile with a frill tank of
fnel and two liAssengws, These classes range
from 1750 to 5500 pounds for ear* tcatefl by
EPA.
-------
weight dasses- has held the "average"
weight increase for all ears sold in the
U.S. to about 25 pounds per year through
1972 as shown in Figure 3.
FIGURE 3
VEHICLE WEIGHT VS. MODEL YEAR
DOMESTIC, IMPORTS, AND TOTAL
PASSENGER CAR SALES
The amount of increased sales percent-
lie of light vehicles which will reverse the
upward trend in weight and the result-
ing downward trend in fuel economy will
depend on both the public's buying habits
and the auto industry's ability to im-
prove engine and vehicle efficiency. In-
creased sales of convenience devices (e.g.,
air conditioning, power steering) will con-
tinue to increase vehicle weight. Air con-
ditioners, for example, add approximately
100 pounds to the weight of a vehicle and
cause a 1% to 2% fuel economy penalty*
(depending on type of system and vehicle
weight) even when they are not used to
cool the car. Styling can also affect ve-
hicle weight. Vinyl tops, for example,
add weight Co the vehicle without perform-
ing any function other than styling. This
trend is particularly important for the
smaller cars, since it will lessen the sig-
nificant fuel economy advantages these
cars now have over larger vehicles which
arc already extensively equipped with these
optional convenience devices. The tech-
niques chosen hy the manufacturers to
meet future safety standards could also
have significant impact on the trend in
passenger car weight.
VEHICLE AND SHAPE
The size and shape of the vehicle has
an effect on fuel economy because the
automobile has to be pushed through the
air as It moves. At the low speeds ex-
perienced during city driving, this air drag
effect is small, but on the highway, at
higher speeds, if becomes important. Air
drag is related to the cross-sectional area
of the car when viewed from the front.
This is approximately equal to the prod-
uct of the height and width of the car,
This cross-sectional area is often referred
to as "frontal area." The shape of the
car is also important. Even if the frontal
areas of two automobiles are the same,
the one with the more streamlined shape
will have less drag and use less fuel. It
takes more fuel to push a fiat-faced box
at a given speed than it does to push a
streamlined shape, such as the body of
a jet plane.
ROLLING RESISTANCE AND TIRES
Even if there were no air drag, it
would still require power, and therefore,
fuel to drive an automobile because of
rolling resistance. Rolling resistance is
the aime given to the resistance due to
the tires, bearings, reir axle, and other
rotating components. This resistance is
more important to fuel economy during
city driving than is air drag.
Since the rolling resistance due to tires
has a significant effect on overall vehicle
rolling resistance, and since the selection
and care of tires are something over which
the automobile owner has control, the
effect of tires on fuel economy is im-
portant.
Two aspects of tires are most important
to fuel economy—inflation pressure and
type of construction. The correct amount
of pressure in tires varies depending on
the type of tire, automobile, and driv-
ing conditions. Information about cor-
rect inflation pressure can be found in
the owner's manual for the automobile,
and should be followed carefully. Incor-
rect inflation pressure can reduce fuel
economy and tire life. An underinflated
tire tendi to wear out on the edges more
quickly and results in a, fuef economy
loss. An overinflated tire while produc-
ing better fuel economy tends to wear out
in the center faster.
The way in which the tire is made can
also affect fuel economy. The type of tire
construction that appears to have the
most beneficial effect on fuel economy is
the so-called radial tire. Use of radial
tires results in about a 3% improvement
in fuel economy when compared to nor-
mal bias ply tires.
* Unless otherwise noted, the losses mid
giiins In fuel economy dtscnssei In this report
refer to urban/suburban driving iind not to
steady erwte* driving However, changes iH
d«slgn or operation which affect nr-
bnrbfin fit^I economy will hftvft the
relative elfeet on steady *FMtae fuel
-------
AXLE RATIO
One of the choices often available to
the purchaser of a new automobile is
lhat of axle ratio. This term refers to
the number of times the driveshaft turns
for each time the rear wheels turn. Nu-
merically this number ranges from about
2,50 to over 4.00 for current automo-
biles. Generally, a numerically lower axle
ratio will result in better fuel economy,
compared to a higher value because, al-
though it produces the same power, the
engine runs slower for any given vehicle
speed and therefore has less internal fric-
tion to overcome. Also, for a given power
output (vehicle speed) the engine is oper-
ating more efficiently at the lower en-
gine speed because of reduced throttling
losses. For example, changing the axle
ratio 10% (e.g. from about 3.0 to 2.7)
can improve fuel economy by about 1%
to 5%.
Another way to obtain the benefits
of making the engine run slower for a
given vehicle is the overdrive feature with
which some automobiles are equipped,
In essence this is another gear to shift
into once the vehicle is up to cruising
speed on the road, reducing engine speed
and improving economy. Fuel economy
gains of more than 10% during cruising
conditions are possible with overdrives,
However, despite its merits, overdrive has
fallen into disuse. This may be due in
part to increased driving in urban areas
where overdrive is not used, the greater
initial cost, and greater use of automatic
transmissions,
CONVENIENCE DEVICES
Of the many convenience devices avail-
able to the new car buyer the follow-
ing can have a negative effect on fuel
economy.
1. air conditioning
2. automatic transmission
3. power steering
4. power brakes
5, power seats
6. power windows
7. power sunroof
Ail of these devices can cause fuel
economy penalties in as much as they
alt add to the vehicle weight. In addition,
some of the devices consume significant
amounts of* energy directly during use.
Two of the more important devices, air
conditioning and automatic transmissions,
are discussed below.
Air conditioning has a two-fold effect
on fuel economy. As discussed earlier,
the addition of the approximate 100
pounds weight of the system causes a
1% to 2% penalty, A much larger pen-
alty is suffered when the air conditioner is
actually running, since the engine is re-
quired to produce additional power to
drive the compressor. The effect on fuel
economy will vary depending on the am-
bient temperature and the type of driv-
ing. Stop-and-go driving in hot weather
can result in a 20% penalty if the air
conditioning system is turned on. An
"average" lo&s associated with the use of
air conditioning is about 9%. Obviously,
this loss in fuel economy and the re-
sultant increased gasoline consumption
tends to occur during the summer months,
when recent fuel shortages were most
critical.
The intomatic transmission has often
been associated with significant fuel econ-
omy penalties. When other aspects of
vehicle design remain constant, the use
of an automatic transmission can result
in a fuel economy loss of up to 15%.
However, the data in the earlier EPA
report and in other studies failed to fully
consider the impact of transmission type
on exhansf emission controls. Vehicles
with manual transmissions sometimes re-
quire more severe (e.g. more spark retard)
engine calibration to meet a given level
of emission control than do vehicles with
automatic transmissions, Since the throttle
movement required during the shifting of
a manual-transmission-equipped vehicle
tends to increase HC emissions,
Analysis of the fuel economy data from
vehicles designed to meet the 1973 Fed-
era! emission standards shows that, on
the average, automatic-transmission-
equipped vehicles show only slightly worse
fuel economy (2% loss) than vehicles
equipped with manual transmissions.
Greater fuel economy advantage (6%) is
seen for the manual transmission in the
lighter weight classes. This may be due
in part to the use of less sophisticated
automatic transmissions in these light
weight categories and the increased use
of the energy consuming torque converter
in these vehicles which tend to have low
power-to-weight ratios.
ENGINE DESIGN
The design of a vehicle's engine can
have a significant effect on fuel economy,
This is particularly true in view of the
different techniques various manufacturers
have chosen to reduce manufacturing cost,
meet emission standards, reduce octane
requirements and produce additional
power.
One manufacturer may choose to meet
emission standards by the use of con-
trol techniques such as ignition spark
-------
retard, which will reduce fuel economy;
another manufacturer may use fuel in-
jection to meet the same standards with
a fuel economy improvement. The manu-
facturing cost of emission control sys-
tems which do not reduce fuel economy is,
however, generally higher than the cost
of systems which sacrifice fuel economy
for low emissions, hence fuel economy
tends to be sacrificed by automobile man-
ufacturers in favor of lower vehicle sate
prices.
Many passenger cars currently sold in
the U.S. have lower compression ratios
now than prior to 1971. This trend has
tended to reduce fuel economy somewhat.
The reduction in average compression ra-
tio from approximately 9.3:1 to 8.3 ;1 has
reduced fuel economy about 3.5%. This
change, however, has also reduced the
octane requirements of engines from 94
octane (regular leaded fuel) to 91 octane
(presently low lead). The customer can
usually purchase these low lead fuels for
one cent per gallon less than "regular
gasoline." This can result in approxi-
mately a 2.5% fuel cost savings which
makes up most of the cost penalty asso-
ciated with the compression ratio reduc-
tion, although the fuel economy penalty
(and the associated increased consumption
of petroleum) is still present.
Techniques to increase compression ra-
tio without increasing the engine octane
requirements could result in significant
fuel economy improvements without in-
creasing fuel costs. Such techniques in-
volving the use of proportional exhaust
gas recirculation systems and high swirl
combustion chambers have been investi-
gated by the industry and may be avail-
able to the public in the future.
The size (horsepower or displacement,
which are directly related for most con-
ventional engines) of the engine can also
have a significant effect on fuel economy.
When two vehicles are identical in all
other respects, the vehicle with the smaller
engine will usually show better fuel econ-
omy. This is because spark ignition en-
gines tend to be more efficient when oper-
ated at a higher percentage of full load
power. For a given driving condition, two
vehicles which are identical except for
their engines will have equal horsepower
requirements. The vehicle with the smaller
engine, however, will have to operate
nearer full load than the vehicle with
the larger engine, thus delivering better
fuel economy. But when the power re-
quired to drive the vehicles is so large, or
the engine's maximum available power
is so low, that the engine in one of the
vehicles is operating at full load, then
the larger engine may deliver better fuel
economy. This is because most engines
are inefficient when operated at full load,
where some fuel is intentionally wasted
in order to obtain maximum utilization
of the air passing through the engine. The
optimum load for a given engine depends
on many engine parameters (ignition tim-
ing, carburetor calibration, etc.) and can-
not be generalized.
CONTROL OF VEHICLE/ENGINE
DESIGN PARAMETERS TO ACHIEVE
IMPROVED FUEL ECONOMY
While engine displacement and horse-
power are directly related for most pas-
senger car engines today, this does not
have to be the case. Several different
techniques are available to increase the
horsepower of an engine by making high
pressure intake air available. This can
be done with turbochargers and super-
chargers. Efforts to improve fuel econ-
omy by restricting the allowable horse-
power could prevent the development of
engine concepts which result in good fuel
economy and higher horsepower simul-
taneously.
Controlling the displacement allowable
for passenger cars would be a more logi-
cal approach; however, even that would
be unfair to manufacturers who have
the talent to develop engines that are
highly efficient without being small. The
most obvious example of how different
engine designs can cause different effi-
ciency for a given displacement can he
seen in the case of the Mercedes 220
series automobiles.
Mercedes builds two 1973 models that
fall in the same weight class and have
the same size engines. Yet one model,
the 220D, delivers 24 mpg in urban/sub-
urban driving while the other model, the
220 gasoline, delivers only 13 mpg. Al-
though these two models were tested at
the same weight and with the same trans-
mission type, the fuel economy of one is
85% better than the other. The 220D
model uses a diesel engine which de-
livers much better fuel economy than con-
ventional gasoline engines of equivalent
displacement.
The use of nonconventtonal engines in
the marketplace will essentially eliminate
the correlation between horsepower and
fuel economy or displacement and fuel
economy. Differences in engine design
also make impractical the use of weight
as a possible control variable. Some 2,750-
pound vehicles powered by rotary engines
deliver worse fuel economy than many
4,000-pound vehicles with conventional
engines.
-------
Because design differences in engines
can have such a pronounced effect on
fuel economy, there is no simple and
equitable way to improve fuel economy
of passenger care by restricting the de-
sign (e.g.) horsepower limit, displacement
limit, weight limit) of the vehicle. Any
control measure, to achieve its objective
in tbe least limiting way in terms of
stifling innovation, should be based di-
rectly on the fuel economy achieved, in
terms of fuel required for miles driven
on a standardized test.
ALTERNATIVE ENGINES
Alternatives to the conventional gaso-
line engine may be produced in large
numbers in the future and the use of al-
ternative engines could have a signifi-
cant impact on fuel economy. However,
just because an engine is different than a
conventional engine does not mean its
fuel economy will be better. While the
development of alternate engines is con-
tinuing and progress in the area of fuel
economy will probably be made, the same
is also true for the conventional engine.
As shown in Table 2, as of today, some
alternate engines hive demonstrated im-
proved foel economy over the conven-
tional engine, some demonstrate equiva-
lent fuel economy, and some demonstrate
inferior fuel economy.
Of the available alternatives, the die-
sel engine offers the maximum potential
for improved vehicle fuel economy. Al-
though it has been in commercial pro-
duction for over SO years, it is imported
into this country in very small quantities,
and no domestic manufacturer has indi-
cated an intention of producing a diese!-
powered vehicle for domestic sales. How-
ever, a second foreign manufacturer has
indicated that he will import a diesel-
powered vehicle beginning in 1974.
EMISSION CONTROLS
Fuel economy penalties brought about
by emission control devices have been re-
ported by many different sources. The idea
expressed in many reports is that "every-
one knows" fuel economy has suffered
because of emission control, Uiuilly a
percent penalty, one number, is given
as "the penalty." Such report* we, how-
ever, generally not supported by a sta-
tistically significant data base.
EPA studies involving several thousand
tests of both uncontrolled (pre-1968) and
controlled cars indicate that the effect
of emission controls on fuel economy has
not been the same for all cars, Some
models have realized severe penalties, but
other models have realized improvements.
A definite trend can be seen from the
data. Figure 4 shows that the change in
fuel economy between 1973 ears and un-
controlled cars is strongly dependent on
the weight of the car. 1973 vehicles in
the lighter inertia weight categories (up
to 3,500 pounds) show slightly better fuel
economy than uncontrolled cars, but ve-
hicles in the heavier categories (4,000
pounds and above) have demonstrated
significant penalties, as much as 18% for
the heaviest weight class. These figures
include the impact of changes in com-
pression ratio.
FieURE 4
CHANGE IN FUEL ECONOMY
Between '57-'67 Ave. and '73 by
innrtia Weieht Class
Table 3 presents the same information
shown in Figure 4 in the tabular term.
The percent change shown for each weight
class was determined from the average
fuel economy of all cars tested in that
class. Trends may have been different
for individual models.
TABLE 2
FUEL ECONOMY OF VEHICLES EQUIPPED WITH ALTERNATIVE ENGINES
EXPECTED TO BE IN USE IN THE NEAR FUTURE.
% Change Compared to Average 1973 Vehicle of Same Weight
WORSE
1. ROTARY: 35% LOSS
EBUIMLENT
1. PRE CHAMBER
STRATI FIED
CHARGE {HONDA
CVCO)
BETTER
1. DIESEL 40% TO 70% GAIN
2. CONVENTIONAL ENGINE
EQUSPPEB WITH CATALYST:
0% TO 15% 6AIN
3. OPEN DHAMiER STRATIFIED
CHARGE {PRQCQ): 12% GftIN
-------
TABLE 3
CHAN IE IN FUEL ECONOMY DUE TO
EMISSION CONTROLS
1873 Vehicles compared to
Uncontrolled Vehicles
INERTIA WEIGHT CUSS
2000
2250
2500
2750
3000
3500
4000
4500
5000
5500
% CHANGE
+ 2.6
+ .9
+ 3.1
+ 2.3
+ 1.3
+ 3.0
-14.3
-13.7
-14.7
-18.1
The reason for the dramatic difference
in fuel economy change between the light
and heavy passenger cars appears to be
due in pari to the difference in the de-
gree of control required to meet the 1973
oxides of nitrogen (NQx) exhaust emis-
sion standard, 3.0 grains per mile. The
lighter cars need less control to meet
this standard than, do the heavy cars
because their smaller power requirement
results in a lower volume flow of their ex-
haust gas and therefore lower mass emis-
sions. Thus, while techniques used by the
industry to control NOx (e.g., spark re-
tard and nonproportional exhaust gas
re circulation, EGR) have adversely affect-
ed fuel economy, many light cars need
little or no NQx control to meet the
standard and therefore they have not real-
ized this fuel economy penalty. In fact,
since many light cars use emission control
techniques (e.g., mixture enleanment or
more precise fuel management through
the use of fuel injection) which can re-
duce HC and OO tmiisions while im-
proving fuel economy and need little ad-
ditional NOx control, slight improvements
in fuel economy are found in the lighter
weight classes. However, the step-change
between the 3,500 and 4,000 pound weight
classes is not fully understood at this time
since the same change is demonstrated
for other model years as well. The EPA
will continue to investigate this difference.
Because of this difference in fuel econ-
omy penalty, the average penalty realized
by the driving public will depend on which
cars the public buyi. If more heavy cars
are sold the penalty will be severe (up
to 15%). This penally coupled with the
already poorer fuel economy of heavy
cars would result in a drastic increase in
gasoline demand. If, however, more light
can are sold there will be less penalty
associated with emission controls, and
gasoline demand would be sharply re-
duced since light cars also get better fuel
economy than heavy cars. If the public
boys light and heavy cars in the same
proportiona aa they bought them In 1972
then the "average" penalty for the 1973
models will be 104%,* includes 3.3%
loss due to compression ratio changes dis-
cussed earlier.
The effect of future emission standards
on fuel economy has been considered by
EPA in making decisions on the feasibility
of the future standards. While there can
be disagreement on this issue, it appears
that the changes in engine/vehicle design
required to meet the HC and CO levels
Witt result in improved fuel economy.
Much of this improvement will be due
to the rapid release of the choke which
wilt be made possible through the use
of quick heat intake manifolds and higher
energy ignition systems. When a vehicle
is operated with the choke on, the fuel
economy is poor because the mixture
delivered to the engine is richer than
required for optimum economy. The choke
is necessary only when the vehicle is
being started and warmed up. When chok-
ing requirements are reduced, fuel econ-
omy is improved during vehicle warm-up.
Some of the improvements eipected
on vehicles designed to meet future stand-
ards will also be due to the use of im-
proved EGR systems and optimized igni-
tion timing which will allow heavy cars
to gain back some of the economy lost
in 1973. General Motors data on proto-
type vehicles indicates that the fuel econ-
omy of their vehicles designed to meet
the 1975 and 1976 interim standards
will be up to 15% better than 1973 ve-
hiclei,
Vehicle Operation and Use
The manner in which a vehicle ii used
has a significant effect on vehicle fuel
economy. This effect can be as, or more,
important than the.design of the vehicle
and engine itself. It is also one aspect
of vehicle fuel economy over which the
vehicle operator has control throughout
the vehicle's life and not only at the time
of purchase.
* The calculation of the aales weighted
aveimgo fuel economy lots due to smliitons
controls lisusuines tbe same market share for
the ¥orteu» weight classes for both 19T3 and
pre-lKOS, Thtu Is done to avoid the posirfble
confoundiuK effects at fuel economy clxiiigt's
duo Bolely to uhlftH towards lieaviur or llshtor
eon iHjIni? attributed to emission controls.
Thf IOBM was calculated bused on tlic bar-
moule ni«an» of th« fud economy dutn or. In
other words, based on average fuel consump-
tion data. If the calculations had been based
on the uverupre of tbe fuel economy data, toe
IIIKH due to enilBBiim controls would have heen
Hliuwii to he sienllii-iintly less.
-------
VEHICLE SPEED AND TRIP LENGTH
Vehicle speed has a significant effect on
fuel economy. The energy required to
drive a vehicle a given distance goes UP
as speed increases. The impact of air
drag and rolling resistance on fuel econ-
omy, plus the way in which the engine
efficiency varies with speed md load, corn-
bin* to produce the results for a. typical
domestic automobile shown in Figure 5
arM\ Table 4.
FIGURE S
FUEL ECONOMY VS. VEHICLE SPEED
""—ft-
TABLE 4
FUEL ECONOMY VS. VEHICLE SPEED
SPEED FUEL EDDHOMK
URBAN DRIVING 20 MPH 10 MPG
CRUISE
n MPH
30 MPH
40 MPH
50 MPH
80 MPH
70 MPH
16,5 MPG
22,0 MPG
22,5 MPG
21.5 MPS
19.5 MP6
17.3 MPG
This figure and table show tow fuel
economy is affected by the cruise
speed.* Two things cm be from this
information. The best fuel economy oc-
curs at a steady speed of between 30 and
40 miles per hour. While interesting, It
is not of much practical value because
few trips are made at a constant speed
between 30 and 40 miles per hour. The
most important knowledge to be gained
from this information is the effect of high
speeds. At a cruise speed of 70 miles
per hour, the fnel economy is significantly
worse than at 60 or 50. Cruising at 60 in-
stead of 70 miles per hour improves econ-
omy about 15%. Crnising at 50 instead
of 70 miles per hour increases the sav-
ings to about 25%,
Trip length also has a significant effect
on fuel economy. Figure 6 shows that
the fuel economy achieved during an ur-
ban trip is strongly dependent on the
length of the trip. Short trips result in poor
« The steady cruise foe! economy at a
gi¥en speed should nol: be confused m'lth fche
fuel economy obtained djiffnn stop and go
drH'Injf but at the same sureraip sspttd. This
difference Is shown In Figure B. The fuel
fuel economy. The engine is less efficient
while it is warming up, due primarily to
fuel enrichment (choking needed during
start up) and engine and driveline fric-
tion which are higher when the vehicle
is cold.
FIGURE I
FUEL ECONOMY VS. TRIP LEN6TH
gw-
TRIP LENGTH (MILES)
Figure 6 shows that the difference in
fuel economy between short trips and
long trips is dramatic. The vehicle used
to develop !his data had a folly warmed-
up fuel economy of 13.5 mpg under the
same driving conditions. Driven on a ten-
mile trip the economy would drop to
about II mpg and driven on a one-haif-
mile trip the economy would be only 5
mpg.
Figure 6 applies only to trips that are
started with a "cold" engine. The en-
gine can be considered "cold" if the ve-
hicle has been parked overnight or all day
long. The same trend would also apply
to engines which are warm when the
trip is started, but the fuel economy for
a short trip would be much better than
had the engine been cold at the begin-
ning of the trip.
Figure 6 must be interpreted carefully.
The graph indicates that a driver could
get better fuel economy by talcing a
longer route to his destination. This is
true but this is also false economy. The
mpg value would be higher but the total
fuel consumed would also be higher. The
total amount of fuel consumed in go-
ing from point A to point B is obviously
more important than the mpg value ob-
tained between points A and B.
OTHER DRIVING AND
MAINTENANCE HABITS
The manner in which an automobile
is driven can in0uence its fuel economy.
The driver who habitually accelerates
economy achieved during flotnnl "cruising"
will he less (relative to urban driving) than
that i ridiculed by Figure 5 Because of the
many speed changes' made (passing other
cars, wind conditions, hills, etc).
10
-------
cai
fc
^%:
away from a $top as fast as he can uses
up to 15% more fuel, compared to a.
driver who a moderate acceleration.
Other driving habits that can help fuel
economy are anticipating stoplights and
slowing down gradually, driving smoothly
and making as few as possible unneces-
sary speedups and slowdowns, and keep-
ing idle time to a minimum. At a speed
of 50 mph, one speed change per mile
can result in up to a 25% increase In fuel
consumption. Prolonged periods of idle
should also be avoided since an idling
automobile delivers zero miles per gallon
fuel economy.
Automobiles, like other machines, re-
quire maintenance to operate properly.
Lack of, or improper maintenance can
hurt fuel economy. The proper mainte-
nance items and frequency are described
in the owner's manual and should be fol-
lowed carefully. Areas requiring periodic
maintenance that can affect fuel economy
are; air filters, the ignition system (spark
plugs, distributor points, and ignition tim-
ing), carburetor and proper air-fuel mix-
ing, cylinder compression, and lubrication.
If any or all of these areas are not in pro-
per working order or the correct part is
not used, fuel economy will suffer. Keep-
ing an automobile tuned up can on the av-
erage improve fuel economy 6%, compared
to an untuned automobile. However, an in-
dividual vehicle which is grossly malad-
justed or unmaintained {e.g., spark plug
misfiring, clogged air filters, improper car-
buretor adjustment) can suffer a signifi-
cantly worse fuel economy penalty of
lore than 20ft.
BATHER AND ROAD CONDITIONS
The weather in which an automobile
is operated can have an effect on fuel
economy. Generally, the colder the tem-
perature the worse the fuel economy, This
is due to two effects. When it is cold,
it takes longer for the engine ind drive-
tram to warm up, thus hurting fuel econ-
omy. However, even when the engine and
drivetrain are warm, colder weather gen-
erally tends to reduce fuel economy. This
effect is about a 2% loss in fuel econ-
omy in each 10°F drop in temperature
at 50 miles per hour. Many current auto-
mobiles, became of emission control re-
quirements, have provisions for heating
the intake air. This helps to reduce the
adverse effect of low temperature on fuel
economy.
The wind can ate have an effect on
fuel economy. Cruising at 50 miles per
hour into a 20 miles per hour headwind
results in fuel economy much closer to
what would be obtained cruising at 70
miles per hour with no wind. This is be-
cause of the increased air drag due to the
wind,
The elevation at which an automobile
is operated will also affect fuel economy.
At high altitudes,, current design carbu-
retors get "fooled" and deliver more fuel
to the engine, compared to the amount
of air, than they should. The vacuum ad-
vance feature of the ignition system
falls lo function properly at high altitude.
This can reduce fuel economy up to 15%
at 4000 feet elevation. Modifications to
carburetors and ignition systems can elim-
inate the high altitude economy penalty
but the vehicle will then drive poorly at
low altitude. Altitude compensated car-
buretors and ignition systems are currently
being developed by several automobile
manufacturers. If these systems are put
into production in the future, fuel econ-
omy penalties will not be experienced at
high altitudes. Most vehicles currently
equipped with fuel injection already pro-
vide some compensation for altitude which
reduces the penalty.
The type of road surface and the grade
of the road have an effect on fuel econ-
omy. The poorer the road, the worse the
fuel economy. At 40-miles-per-hour cruise,
badly broken and patched asphalt causes
about a 15% fuel economy penalty, com-
pared to a good smooth road, Gravel
causes a 35% penalty, and dry sand has
a 45% penalty. Dirt roads probably fall
somewhere between the bad asphalt and
the gravel.
Going uphill reduces fuel economy be-
cause the engine hai to supply power not
only to move the automobile alonf Ihe
road, but also to lift it to the top of the
hill. The "grade" of a road is a. measure
of how steep it is. The maximum grade
on most interstate highways is about 5
to 7 percent Going 50 miles per hour up
a 7% grade results in a fuel economy pen-
alty of 55%, compared to going 50 uiph
on a flat road. On a 3% grade this pen-
alty is about 32%.
TRENDS IN AUTOMOBILE FUEL ECONOMY
Year-to-year trends in fuel economy are
the combined effects of trends in all of the
parameters which affect fuel economy.
For any given model year the average
fuel economy will depend on the design
characteristic of vehicles that are sold.
11
-------
which in turn depends, fa part, on what
emission and safety standards arc in effect
and on consumer preference as expressed
through buying habits.
By using sales and weight data from
vehicle registration lists and fuel economy
data from the EPA Federal Test Pro-
cedure, a "sales-weighted" average fuel
economy * for the model years 1957
through 1973 has been calculated. Figure
7 shows the trend in sales-weighted fuel
economy. The same data are presented
in Table 5. While market changes (e.g,,
the penetration of the subcompact car in
the early *60's) have had significant effects
on individual model years, the general
trend can be toward poorer fuel econ-
omy. It has been seen from Figure 7 that
the loss in average fuel economy dur-
ing the last 12 years (1962^1973) has been
about 16%. Prior to 1968 and the im-
position of Federal emisiion standards,
this loss was due largely to vehicle weight
increases and the associated changes in
engine size, and the increased usage of
convenience devices. This trend towards
parse fuel economy is slightly greater for
the model years after 1967 which were
subject to exhaust 'emission standards, and
during which there was an e%ten greater
rate of increase in the usage of conven-
ience devices and the trend toward higher
vehicle weight. However, the increase in
average vehicle weight (more than 350
pounds) and the associated changes in en-
gine size over the total 12-year period
alone have accounted for about % of
the total loss.
FIGURE 1
SALES WEIGHTED FUEL ECONOMY
VS. MODEL YEAR
on.
I !
i «
.1
H71 DATA
Hit tttWATEO
Another way to consider fuel economy
trends, that relates more directly to total
fuel consumption, is to examine the fuel
economy for all cars on the road, not
just the new models. This is the basis
of lie true national average fuel econ-
omy figures which are reported annually
* Sules weighted average fuel economy is
the nverage fuel economy of all cats sold in a
12
TABLE 3
SALES WEIGHTED FUEL ECONOMY
BY MODEL YEAR
SALES
MILES PER fitttJM
.13.87
...14.07
13.85
__13.36
...13.55
13.96
12.62
..,.13.49
¥f ftR
195?
1958,
1959
1960
1961
1982
1983
1984.
1985 - 12.98
1988 12.95
1987 12.86
1968 12.44
19S9 12.21
1970 12.51
1971 - - - -12.21
1972 12.03
19?3 - 11.57
by the Department of Transportation.
DOT'S values are calculated from total
miles travelled by passenger cars and total
gallons of fuel sold to passenger cars in
each calendar year. This is shown as the
upper curve In Figure 8. The nationwide
average fuel economy for all cats on the
road can also be determined using the
EPA test results, if the makeup of ibe
total passenger car population in any oae
calendar year is known. Using registra-
tion data, annual vehicle mileage as a
function of age, and vehicle attrition
rate information, a "national average" fuel
economy has been calculated for several
calendar years. The tread in national aver-
age fuel economy as determined by this
method is shown in the lower curve in
Figure 8.
FIGURE 8
NATIONAL AVERAGE FUEL ECONOMY
VS. CALENDAR YEAR
net* tm* 1*6*
1KB MB <8M 1HS
Bath sets of data show the same trend,
a downward shift in national average fuel
economy of from 3% to 6% depending
on the years chosen for comparison. In
addition to showing the same trend, it can
given model year, taking into nccount tftn
number of cam soid In it Riven weight cinss.
-------
be seen that the fuel economy values based tomer average driving. A modification (the
on the 1972 Federal Test Procedure re- inclusion of a hot start and about three
suits correlate closely with the absolute additional miles of operation} being made
value of the DOT results, indicating the to the Federal Driving Cycle for the 1975
driving cycle used for the Federal emis- and later model years resists in nearly
sion test is a good representation of cus- perfect correlation with DOT'S values.
Appendix A
The equation used to calculate the fuel econ- K.,/i=earbon weight fraction of CO, {mal,
omy of a vehicle, in miles per gallon (mpg), „,. r-i/<™j u« rv\i A
CO/mi) + (K3)
whtre:
2428
K, = carbon weight fraction of gasoline or nips; -- -- _^_ __ „ _ __ fA-4)
unburned HC (mo!, wt. C)/?mo!. wt. .866 igpm KC» + .429 (Bpm CO)
CHliSli) = .K«(i + .273 fapm CO2)
Appeodix B
Fuel Kconomy in Miles per Gulioii for Various Model Years*
and Inertia Weight Categories
Inertia Weight (__ indicates no data)
1750 2000 2230 2500 2750 3000 3500 4000 4500 5000 5800
~
2~7~2
24~fi
.
2(>.4
25.3
2S.G
20,4
29.4
35.S
23.3
22.S
2H.S
20,9
22.fi
19.3
22.2
23.4
22.8
2H.O
2H.fi
24.1
i£2
fS~5
2~5~7
2U.5
20.S
19.3
21.4
21.9
21.9
21.4
20.1
82, »
20.9
12.7
l¥.5
IK.K
17.5
18,3
Ift.6
19.7
18.7
17.4
life
24~5
1G.S
18.0
18.1
17.H
18.H
14. i)
18.7
151.7
iKs
1S.3
20.0
17.5
17.7
IB.fi
15.2
17 ."2
10. H
14.7
16.2
15.2
14.6
15. S
15.0
15.4
15.9
14.S
14.4
15.6
14.fi
^_
14.7
!».«
15.0
15.7
11.4
13.0
12.6
13.7
IS. 7
13. 9
13.1
18.3
1S.S
13.H
12.2
I8.S
13 .ft
13.7
14. :i
1S.O
15.2
13.2
12.4
14.0
13.8
12.0
12.8
12.3
12.:*
12.1
12.0
11.9
12,0
11,7
11.1
10.K
10,8
12,5
12.7
10.8
10.5
12.6
ll.I
11.4
11.7
12.1
11.6
11.3
11.3
10.9
10.7
10.7
10.1
9.6
10,1
8.6
18.S
10.9
10. 6
10.8
10.6
11.0
1Q.S
11.3
11.2
9.5
9.1
10.1
».e
9.H
8.3
9.1
9.8
12.5
9.3
10,3
tb's
9.9
10.8
9.3
8.6
8.2
S.4
57
5K
59
HO
61
-------
CONVERSION OF MOTOR VEHICLES TO GASEOUS
FUEL TO REDUCE AIR POLLUTION
U. S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF AIR PROGRAMS
APRIL 1972
-------
ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF AIR PROGRAMS
POSITION PAPER
CONVERSION OF MOTOR VEHICLES TO GASEOUS
FUEL TO REDUCE AIR POLLUTION
1. INTRODUCTION
This position paper sets forth, in summary form, the
position of the Environmental Protection Agency on the
conversion of existing vehicles to gaseous fuels to reduce
air pollution emissions from motor vehicles. Substantial
reduction in emissions from new motor vehicles powered by
gasoline engines is expected by the mid-1970*s, but the urgent
need for improvement of air quality in certain metropolitan
areas has focused attention on the possibility of conversion to
gaseous fuels of motor vehicles already in use in such metro-
politan areas. The conclusions expressed herein are based
on presently available technology and on the probable avail-
ability of gaseous fuels at motor vehicle refueling stations
during the next five years.
2. SUMMARY
The conversion of existing vehicles to gaseous motor
fuels is recommended for fleet-operated vehicles in those
metropolitan areas in which (a) logistical and economic
considerations are favorable in terms of availability of
fuel and conversion equipment, and (b) where major air
pollution problems are attributable to the use of motor
vehicles. Those vehicles likely to receive maximum usage
prior to being phased out of use should be converted first.
Except on the above terms, conversion of vehicles to gaseous
fuel is not warranted at this time for purposes of air pollution
control.
In developing implementation plans to achieve the ambient
air quality standards, each community must consider the most
efficacious use of potentially available natural gas. If diversion
of natural gas from electric power generation were required to
supply large quantities for automobiles, increased power plant
emission of SOx could more than offset the benefits from reduced CO
emissions. Also, conversion of space heating to natural gas
could produce important reductions in SOx, NOx and particulate.
emissions, and could be significantly;more effective in improving
overall air quality than conversion of fleet vehicles.
-------
2.
However, LPG is becoming available in larger quantities
as a result of removal of lead from gasoline. LPG is less
attractive than natural gas for space heating in urban areas
because of complexities associated with storage and transfer.
Fueling of fleet vehicles with LPG, therefore, could produce
significant reductions in CO without concern for a tradeoff
in the control of other air contaminants.
3, WHAT GASEOUSFUELS CAN BE USEDFOR AUTOMOBILES?
LPG (Liquefied Petroleum Gas) has been used as an automotive
fuel for many years, usually because it provided an economic
advantage. LPG is available in limited quantities in urban
areas across the Nation, About 300,000 LPG vehicles are estimated
to be in operation at this time.
Natural gas is also used as a motor fuel and has greater
capabilities for reducing emissions than LPG. Natural gas is
used in two forms, Liquefied Natural Gas (LNG) and Compressed
Natural Gas (CNG). More than 4000 natural gas fueled vehicles
are currently being operated experimentally throughout the
country, mostly using CNG.
i
4. ARE ADEQUATE QUANTITIESOF FUELS AVAILABLE?
A. LPG
LPG is a by-product in natural gas .processing and .petroleum
refining. In the past there have been wide swings in LPG prices
in response to supply conditions. Under present conditions it
is anticipated that the demand for LPG will exceed available
supplies and result in higher prices during the next few years.
The use of LPG for motor vehicle pollution control could hasten
this result,
With higher prices, however, it is possible that the
petroleum refinery industry may find it profitable to increase
the yield of LPG at the expense of gasoline, LPG from the refinery
is the only gaseous fuel that has a sufficiently large potential
source of supply to permit its use in the conversion of 'a large
portion of the motor vehicle population. In the process of
lowering lead levels in gasoline an increased supply of LPG will
result as a byproduct as the refining process is modified.
As regards natural gas, many marketing areas in the U.S.
currently have severe shortages of this fuel. While it has been
estimated that on a national basis a substantial number of
vehicles could be converted to natural gas usage -without adversely
affecting the total supply of natural gas, such estimates are of
little significance to an individual community contemplating
such conversions to abate local automotive air pollution problems.
-------
3.
Thus, in considering the feasibility of such conversions, each
community must make an assessment of its own situation as regards
the availability of the natural gas fuel.
5. ARE ADEQUATE ENGINES AND FUEL SYSTEMS AVAILABLE FOR
GASEOUS FUELS?
Engines that are fully optimized to take advantage of the
full emission reduction capability of gaseous fuels are not
currently available from the automobile manufacturers. Vehicle
manufacturers limit their warranty on vehicles converted by the
buyer to gaseous fuel operation so that they are not liable for
repair of engines which suffer malfunctions due to operation on
the gaseous fuel. Since the 1975 production models of gasoline
engines are expected to have emission levels substantially lower
than levels obtainable through conversion of existing vehicles
to gaseous fuels, it dqe^s_ not appear likely that_engine manufac-
turers will embark:.upon^an-extensiveTHesjgri program to optimize
existing light duty engines for gaseous fuels and to retool to
produce large numbers of such engines.
Components for conversion to gaseous fuel operation are
produced by several manufacturers. Some systems are more
successful than others in lowering emissions while maintaining
acceptable vehicle driveability. While gasoline-gaseous dual-
fuel systems greatly increase the driving range of the vehicle
and provide a reserve fuel supply for emergencies, they require
compromises for either fuel from performance, fuel consumption
and emission standpoints. The degree of compromise of one fuel
over the other depends on the utilization of the fleet vehicle.
The operating ranges of vehicles fueled by LPG or LNG are com-
parable to gasoline fueled vehicles, but CNG fueled vehicles
are usually limited in range to about 70 miles, although new
tank designs have increased the range to approximately 100 miles.
Heavy duty truck engines that have been modified to avoid
durability or performance penalties while operating on gaseous
fuel are presently available from manufacturers. Such engines
have not been optimized for minimum emissions. When converting
engines without such factory modification to gaseous fuel operation,
the fleet operator must evaluate whether the duty requirements
are severe enough to require special valve protection. Some ,
manufacturers offer high compression pistons that help in main-
taining performance under gaseous fuel operation.
-------
4.
6. ' ' -WHAT ARE THE EMISSIONS FROM AUTOMOBILES USING
CASEOUS FUELS?
It '••!£ 'difficult to define accurately the average reduction
in emissions that may be expected from a group of vehicles con-
verted to LPG, LNG, or CNG, Available data indicate that with
proper conversion a significant reduction in hydrocarbons and
carbon monoxide can be expected, and that there usually is some
reduction in oxides of nitrogen levels. The extent of emission
reduction shown in the data that follows is inconsistent since
there is some variation from one installation to the next due
to configuration of the carburetion and fuel system and the
vehicle's particular engine and drive train system. A portion
of the inconsistency, however, is due to difference in adjust-
ment of carburetion, spark timing, and engine condition at the
time the test data were taken. Further refinement to the
various components of gaseous fuel systems will enable better
adjustments to be made, thereby reducing inconsistencies of
the type illustrated by the following data:
-------
5.
1972 FEDERAL TEST PROCEDURE
(LA-4 cycle, constant volume sampler)
Emissions (grams per mile)
Vehicle
Converted 1968 Buick 350
Stock 1968 Buick 350
Percent Reduction
Converted 1969 Ford 351
Stock 1969 Ford 351
Percent Reduction
Converted 1968 Ford 302
Stock 1968 Ford 302
Percent Reduction
4 Converted 1969 Chrysler 318's
Stock 1969 Chrysler 318
Percent Reduction
2 Converted Rambler 343's
Stock 1969 Rambler 343
Percent Reduction
Converted 1969 Ford 429
10 Converted 1970 Ford 250(s
10 Stock 1970 Ford 250's
Percent Reduction
10 Converted 1970 Rebel 232's
10 Stock 1970 Rebel 232's
Percent Reduction
HC
CO
NOx
Type Conversion
3.5
1.9
(84)
3.1
7.4
58
2.4
3.1
23
2.4
3.4
29
3.0
3.0
0
1.3
0.69
3.70
81
.51
2.7
81
4.7
29.6
* 84
7.3
17.8
59
4.2
28.5
85
7.2
30.5
76
15.4
31.5
51
4.0
1.8
16.0
89
3.9
22.1
82
8.9
4.0
(123)*
8.6
5.2
(65)*
1.8
3.6
50
2.9
3.6
19
2.6
3.1
16
1.9
2.6
9.4
72
3.1
6.9
55
LPG
LPG dual fuel
LPG dual fuel
LPG dual fuel
LPG dual fuel
LPG
LPG
LPG
-------
6.
1970 FEDERAL TEST PROCEDURE
(Open 7-mode cycle, Continuous Analysis)
Emissions (grams per mile)***
Vehicle
HC** CO
NOx
2 Converted 1968 Chevrolet 230's 1.1
2 Stock 1968 Chevrolet 230's 3.7
Percent Reduction 70
2 Converted 1968 Ford 2SOfs
•2 Stock 1969 Ford 250's
Percent Reduction
10 California State Cars
10 California State Cars
Same Cars on Gasoline
Percent Reduction
5 Los Angeles City Cars
Same Cars on Gasoline
Percent Reduction
0.9
2.6
65
1.5
3,1
52
1.4
2.9
52
9.5
58.2
84
7.8
25.3
69
1.5 10.5 1.4
6.7
42.9
84
5.0
31.0
84
1.2
3.2
63
3.0
3.5
14
Type Conversion
CNG dual fuel
CNG dual fuel
LPG
CNG dual fuel
CNG dual fuel
Aft*
Figures in parenthes'es Q re-fleet increases in emissions.
Although it is generally agreed t-hat hydrocarbon emissions
from gaseous fueled vehicles are less photochemically- reactive
than those from gasoline fueled vehicles, a Federal reactivity
scale has not been defined which would allow quantitative
correction for this factor. Therefore, all hydrocarbon, values
are reported on the same mass basis as gasoline.
Data from Reference 2. and. 3.
-------
7.
Although these data do not represent a large population
of vehicles, they do illustrate the magnitude of emission
reductions that can be reasonably expected from various
types of gaseous fuel conversion. The U.S. General Services
Administration's experience with dual fuel (CNG-gasoline)
conversions coupled with spark advance vacuum line disconnected
on four cars> (1968 and 1969 models) in California yielded
total hydrocarbon reductions (when operating on CNG) of 681,
carbon monoxide reductions of 79%, and oxides of nitrogen
reductions of 65% in comparison with gasoline-fueled counter-
parts. Fifteen California State emission-controlled vehicles
with similar conversions gave reductions of 521 hydrocarbons,
84% carbon monoxide, and 47% oxides of nitrogen from emissions
before conversion. These conversions, which employed removal
of vacuum spark advance, resulted in some degradation in the
driveability that would be expected from a comparable vehicle
fueled with gasoline. The time to accelerate from 15 to SO
mph for the four GSA sedans increased by 50, 18, 48, and 80
percent respectively over comparable gasoline fueled control
vehicles.2 The California Air Resources Board also reports
poor driver acceptance of gaseous fueled vehicles.3
Data are available from eight 1968-69 model vehicles con-
verted to LPG-dual fuel usage and the average reduction from
these vehicles compared to standard gasoline counterparts is
25% for hydrocarbons, 69% for carbon monoxide and 13% for
oxides of nitrogen. Driveability impairment was noticeable
but not critical.
Twenty 1970 model GSA vehicles were converted to full-time
LPG operation and these vehicles approached 1975 Federal emission
standard levels. The vehicles were tested before and after
conversion, and emission reductions were 81% for hydrocarbons,
86% for carbon monoxide and 64% for oxides of nitrogen. Drive-
ability effects ranged from barely noticeable to hazardous.
Gaseous fuels have an additional advantage over a gasoline
fuel in the form of significantly less photochemical reactivity
of the hydrocarbons in the exhaust gases. Natural gas consists
primarily of methane and produces less reactive exhaust gases
than does LPG which is largely composed of propane.
-------
8.
If proper fuel transfer procedures ,are used, there are
few evaporative hydrocarbon emissions when using CNG or LPG.
"Boil-off" emissions may be encountered in using LNG, but
these emissions are largely methane and thus are more of a
safety consideration -than an air quality problem. It is
recommended that fleet operators contemplating the usage of
LNG control "boil-off" emissions. Approaches that are
presently being investigated include piping from LNG storage
to a natural gas utility system and the use of catalytic
burners on vehicle vent lines.
7. WHAT ARE THE OPERATIONAL, HANDLING, AND SAFETY
PROBLEMS WITH GASEOUS FUELff?'
The range capabilities of vehicles converted for LPG
or LNG operation are typically 220 miles and 240 miles
respectively. These distances are comparable to ranges
experienced with gasoline fueled passenger cars. The range
of vehicles fueled with CNG is approximately 70 miles. In
most automobile installations the gaseous fuel tank occupies
about one-third of the trunk space. Liquefied petroleum gas
is presently available in most parts of the country from dis-
tributors which supply it for heating requirements. However,
local safety regulations often force the distributor to ou.t-
lying areas, away from urban centers, so that refueling becomes
inconvenient. ' '
Compressed and liquefied natural gases are currently
available at only a limited number of locations in the country.
This is largely due to the expense of liquefaction or high
pressure compressing plants. For example, a compressor of
sufficient size to service a fleet of eight (8} CNG vehicles
costs approximately $4000. Liquefaction plants are only
economical for very large scale usage. The transportation
of LNG by trucks for storage in remote tanks is becoming more
common. However, LNG is still primarily available at the few
locations where reserve capacity equipment has been built by
gas companies or at points where foreign shipments of LNG can
be stored, LPG and LNG are normally transferred as liquids
from the distributer's fixed tanks into the vehicles* tanks.
Refueling of CNG is accomplished in two ways; one, slow filling
directly from compressors to vehicle, usually overnight; or,
two, from a high pressure storage module which is kept
pressurized by a compressor at all times and requires from
two to five minutes.
-------
9.
A comparison of safety between gasoline and gaseous
fuels is necessary. Gasoline is a hazardous product; yet,
in its wide usage as a motor fuel by the public the number
of accidents has been relatively low. This is partly due to
gasoline's distinctive odor and usually visible evidence of
leakage. Gaseous fuels are odorless» but odorants usually
can and should be added to both LPG and CNG, A promising
odorant for use in LNG is under development, but until soch
a material is available for routine usage, leakage can occur
without odor or visible evidence. This significantly increases
the care necessary to avoid accidents with LNG. All of the
gaseous fuels including LNG are stored under pressure. Extra
care must be exercised to assure that the entire fuel system
is leak-tight especially if the vehicles are to be parked in
confined areas. Recent impact barrier tests conducted by
GSA/DOT have shown that properly installed CNG and LNG
vehicle storage tank systems have survived intact a crash
at 30 mph into a concrete barrier, resulting in accelerometer
reading in excess of 40 G's.
Stringent local safety laws now in effect reflect a
general view that there is a safety problem with gaseous
fuels. Such laws can influence the cost of fueling stations
and storage equipment by requiring greater complexities in
the systems involved.
In summary, thousands of LPG fueled vehicles have been
in operation for many years and recently more than 4000
natural gas fueled vehicles have been placed in operation
in this country. Enough experience has now been accumulated
with gaseous fuel vehicles to demonstrate that under closely
controlled fleet-operation, the fuels can be used safely.
8. HOW DO COSTS COMPARE AMONG GASEOUS FUELS AND OTHER
FUELS?
The average market price of gaseous fuel in terms of cost
per operating mile is somewhat lower than the cost of gasoline
and more expensive than diesel oil.l However, one investigator
reports no difference in fuel cost among gasoline and the
gaseous fuels. Vehicle conversion costs are approximately
$300 for LPG and CNG kits and $700 for LNG due to the high cost
of the cryogenic tank.
-------
10,
In the past, many LPG vehicles have been converted on the
basis of economics alone. In some cases a favorable tax
situation has been involved. In fleet applications, operating
costs with natural gas can be competitive with gasoline even
including the added liquefaction or compression cost; this
is largely due to maintenance advantages including increased
life of spark plugs, exhaust systems and lubricating oil,
and increased time between overhauls.
9. WHAT AIR POLLUTION GAINS ARE LIKELY THROUGH FLEET
USAGE OF GASEOUS FUELS IN A MAJOR METROPOLITAN AREA?
No general statement is possible. In situations in which
supplying gaseous fuels to the converted vehicles can be done
without diverting natural gas from other uses, a rough
estimate of the potential benefits can be made by analyzing
the number of vehicle miles expected to be driven by the
converted vehicles, in terms of the emission reduction ranges
set forth above.
A different problem exists if the conversion of vehicles
to gaseous fuels would require the diversion of natural gas
from existing or potential space heating or power generating
uses. The type of analysis required is illustrated below,
A study by the Institute of Gas Technology indicated that
diverting one-half of the natural gas presently used for
generating electricity in New York City would furnish enough
fuel to operate all of the commercial fleet vehicles in the
City on natural gas. The IGT estimate of the resultant emission
reduction is shown below.
COMMERCIAL VEHICLES* EMISSIONS
(Tons per Year)
Pollutants Current Convert to Natural Gas Difference
HC 22,700 10,000 -12,700
CO 260,000 16,700 -243,300
NOx 16,700 10,000 -6,700
*Fleet of 172,000
-------
11.
IMPACT OF COMMERCIAL VEHICLE CONVERSION ON
TOTAL NYC VEHICLE EMISSIONS
(Tons per Year)
Current Total Reduction due to Percent
Pollutants Vehicle Emissions Commercial Conversion Reduction
HC 83,650 12,700 15.2
CO 959,527 243,300 25.4
NOx 61,507 6,700 10.9
The point of this illustration is to emphasize that the above
eitimates do not reflect the increases in SOx and particulates
that the additional burning of oil in electric power plants
would create. A roore complete picture is shown in the following
tables:
NEW YORK CITY ELECTRIC POWER PLANTS EMISSIONS
USING NATURAL GAS AS FUEL
(Tons per Year)
Replace 1/2 Natural Gas
Pollutants Current with 1% Sulfur Oil Difference
Part. 300 1,120 +820
SOx 12 22,260 +22,248
CO 8 6 -2
HC 800 700 -100
NOx 7,800 14,000 +6,900
NET GAIN OR REMOVAL OF POLLUTANTS
IF GASEOUS FUEL STRATEGY USED
Polluta.nt JTons per Year) ,- •
Part. +820
SOx +22,250
CO -243,300
HC -12,800
NOx +200
-------
12.
The increase in SOx emission shown in this example is
important because SOx poses severe problems in the New York
City area. While CO and hydrocarbon emissions are expected
to decrease during the 70's due to new vehicle exhaust control,
the problems of achieving SOx and particulate air quality
standards in New York present major challenges.
Any plan which requires the diversion of gaseous fuel
from power plants should compare favorably with other plans
which would use that scarce resource in a different way.
Small space-heating installations are a major source of SOx
and particulates because of their large numbers and because
they emit their pollutants at roof-top level rather than from
tall stacks. If additional gas is available from power plants
or elsewhere, it may be most effectively used to replace coal
and oil in space-heating.
The optimum use -of the available gas must be assessed
separately for each metropolitan area. The New York case
is cited to illustrate that use of gas by fleet vehicles may
generate as well as reduce problems and that air quality may
be more effectively achieved and maintained if a limited
supply of natural gas is used for other purposes.
-------
13.
REFERENCES
1. "Emission Reduction Using Gaseous Fuels for
Vehicular Propulsion", by Institute of Gas
Technology, IIT Center, Chicago, Illinois.
(Prepared under contract no. 70-69 for the
Environmental Protection Agency).
2. "Pollution Reduction with Cost Savings", a
report on the General Services Administration's
dual fuel vehicle experiment. GSA DC 71-10828.
3. "Emission Measurements from Vehicles Modified
to Operate on Natural Gas or Liquid Petroleum
Gas Fuel", State of California Air Research
Board, Staff Report, September 15, 1971.
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON. D C 20460
OFi-ici; OF
•MR A NO WASTE: MANAGILMGN i
REQUIREMENTS FOR EPA CONFIRMATION TESTING OF MOTOR
VEHICLE EMISSION CONTROL DEVICES
A preliminary technical assessment by EPA of motor vehicle emission
control devices Is required before EPA can determine whether confirmatory
testing Is warranted. Prior to considering testing, the following infor-
mation is required:
1. Complete technical description of the device, including
theoretical discussion of operating principles. All
claims should be substantiated by sound reasoning and/or
data.
2. Test results from competent laboratories using the 1972
or 1975 Federal Test Procedure (see Attachments I and II
for procedure description and list of recognized labora-
tories) . In the case of-add-on emission control devices,
at least one set of data should be generated on one vehicle
equipped with and without the emission control device.
This data allows for the demonstration of comparative
effectiveness. Since many engine calibrations such as
ignition timing and air/fuel ratio affect the level of
exhaust emissions, full documentation of such changes per-
formed in the evaluation should be roade and supplied with
the test data.
The above data and pertinent Information on the particular emission
control techniques should be sent to:
Environmental Protection Agency
Director, Emission Control
Technology Division
2565 Plymouth Hoad
Ann Arbor, Michigan 48105
The technical staff will review this information, determining whether
EPA should undertake confirmatory testing and will contact the developer.
Attachment 1 - Summary of Federal Emission Test Procedures
for Light-Duty Vehicles
Attachment II - List of Commercial Laboratories
FS-5
-------
Summary of
FEDERAL EMISSION TESTING PROCEDURES
FOR LIGHT DUTY VEHICLES
The Federal procedures for emission testing of light duty vehicles
Involves operating the vehicle, on a chassis dynamometer to simulate ~.
7.5 mile (1972 procedure) or 11.1 mile (1975 procedure) drive through
an urban urea. The cycle is primarily made up of stop and go driving
and includes some operation at speeds up to 57 mph. The average vehicle
speed Is approximately 20 mph. Both the 1972 and 1975 procedures capture
the emissions generated during a "cold start" (12—hour soak at room
temperature before start-up). The 1975 procedure also includes a "hot •
start" after a ten minute shut-down following the first 7,5 miles of
driving.
Vehicle exhaust is drawn through a constant volume sampler (CVS)
during the test. The CVS dilute;; the. vehicle's exhaust to a known
constant volume flow rate with filtered air. A continuous sample of
the diluted exhaust Is pumped into sample bags during the test.
Analysi.s of the diluted exhaust collected in the sample bags is
used to determine the mass of vehicle emissions per mile of operation
(grams per mile). A flame ionizatlon detector (FID) is used to measure
unturned hydrocarbon (HC) concentrations. Non-dispersive infrared (NDIR)
analyzers are used to measure carbon monoxide (CO and carbon dioxide
(C02). A chemiluminescene (CL) analyzer is used to determine oxides
of nitrogen (NOx) levels.
These procedures are used for all motor vehicles designed primarily
for transportation of property and rated at 6,000 pounds GVW or less, or
designed primarily for transportation of persons and having a capacity of
twelve persons or less. Each new light duty vehicle sold in the United
States In model years 1973 and 1974 must emit no more than 3.4 gpm HC,
39.0 gpm CO, and 3.0 gpm NOx when using the 1972 procedure. For 1975
and 1976 model passenger cars the Federal Standards are 1.5 gpn: HC, 15.0
gpm CO and 3.1 gpm NOx (as measured by the 1975 Federal Test Procedure).
For 1977 HC and CO standards remain unchanged and NOx is reduced to 2.0
gpm. For 1978 the standards .41 gpm HC, 3.4 gpm CO find .4 gpm HOx.
Beginning with the 1975 model year, light-duty trucks were subjected to
separate standards of 2.0 gpm HC, 20.0 gpm CO and 3.1 gpm NOx.
Persons intending to pursue exhaust emission testing of emission
control devices should obtain a copy of the EPA. Evaluation Test Policy
and Description of Tests. This document can be obtained from:
-------
Environmental Protection Agency
Director, Emission Control Technology Division
2565 Plymouth Road
Ann Arbor, Michigan 48105
Full description of 1972 and 1975 Federal Test Procedures may be
found in the Federal Register, November 14, 1972, Volume 37, Number 221,
Part II. Copies of this document as well as information pertaining to
updated or revised editions of the Federal Register may be obtained Crom:
EPA, OAF, FIB, Waterside Mall, Room 213W, Washington, D.C. 20460.
-------
Attachment T.'J.
INDEPENDENT LABORATORIES EQUIPPED TO
CONDUCT EPA EXHAUST EMISSIONS TESTS
While the Federal Government does not currently approve laboratories
for emission testing, certain Independent commercial and private labora-
tories have become recognized over the years as knowledgeable and properly
equipped to perform emission tests in accordance with the Federal proce-
dures. Their equipment Is similar or equivalent to that used In the ETA
Motor Vehicle Emissions Laboratory, For your Information and convenience
we list below several commercial laboratories.
AF Parts Company (Questor Company)
543 Matzlnger Road
Toledo, Ohio 43697
419-729-3958
ATTN: Mr. Michael Cl.egg
Automotive Environmental Systems, Inc.
7300 Bolsa Avenue
Westminster, California 92683
714-897-0331
ATTN: Dr. Dale Frederickson
Automotive Research Associates
5404-08 Handera Road
San Antonio, Texas 78238
512-684-2310
ATTN: Mr. Kenneth R. Kay
Automotive Testing Laboratories
19900 East Colfax Avenue
Aurora, Colorado 80010
303-343-8938
ATTN: Mr. Robert W, Sebring
Bureau of Motor Vehicle Pollution Control
New York City Department of Air Resources
75 Frost Street
Brooklyn, New York 11211
212-388-4997
ATTN: Mr. John Pinto
Ethyl Corporation .
1600 West Eight Mile Road
Femdale, Michigan 48220
313-564-6940
ATTN: Mr. William Brown
General Environments Corp,
6840 Industrial Road
Springfield, Virginia 22151
703-354-2000
ATTN: Mr. John Kochis
Olson Engineering, Inc.
Vehicle Test Facility
15512 Commerce Lane
Huntington Beach, CA 92649
714-894-9875
ATTN: Mr. Jerry Coket
Olson Laboratories,- Inc.
11665 Lcvan Road
Livonia, Michigan 48150
313-422-3160
ATTN: Hr..Robert A. Nesbitf.
Olson Laboratories, Inc.
421 East Cerritos Avenue
Anaheim, California 92805
714-956-5450
ATTN: Mr. Duane Gulick
FP/i
1970
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON. D.C. 20460
OFFICE OF
AIR AND WASTE MANAGEMENT
EPA RETROFIT AND EMISSION CONTROL DEVICE EVALUATION TEST POLICY
Evaluations by the Environmental Protection Agency of engines,
retrofit devices, emission control devices, and related products are
conducted for the purpose of keeping policy makers and technical per-
sonnel in government and industry, and the general public, abreast of
developments in the field of automotive fuel economy and pollutant emis-
sion control. For that reason all data developed as a result of EPA
testing is public information and will, as relevant, be included in a
test report.
EPA evaluates devices under two different authorities! Section
206(a)(2) of the Clean Air Act (42 U.S.C. 1857f-5) and Section 511 of
che Motor Vehicle Information and Cost Savings Act (15 U.S.C, 2011).
Due to the similarity in these two authorizations, EPA has established
a single evaluation and test program. The details of the program are
set forth in Federal Regulations under 40 CFR 610.
To obtain an evaluation, application is first made to EPA to work
out the details of the requested testing. Testing is performed at the
expense of the applicant st private labs, under EPA supervision, with
subsequent confirmatory tests by EPA if deemed necessary by EPA. EPA
engineers will use the test results and other data to evaluate the device
and report the results. In the discussion of the effectiveness of a pro-
duct, the test reports will make comparisons when appropriate between the
results and current or future Federal fuel economy and emission standards,
and with results from similar devices.
HOW, to Request an Evaluation
Individuals or organizations desiring an EPA evaluation of a fuel
economy retrofit device, an exhaust emission control device, fuel additive,
or prototype engine, should request an application format from:
Director, Emission Control Technology Division
U.S. Environmental Protection Agency
2565 Plymouth Road
Ann Arbor, Michgan 48105
FS-5
-------
In the application the developer provides EPA with all information
necessary to describe and explain the functioning of the device or
engine. Such information must include the theory of operation, drawings
and schematic diagrams. In addition, any standard test data performance
on the device that demonstrate the emission and fuel economy performance
of the system should be provided. The Federal Test Procedure (FTP) (40
CFR Part 86) is the only test which is recognized by the U.S. Environ-
mental Protection Agency for the evaluation of vehicle emissions, and
data'generated in accordance with the FTP are essential for the evalua-
tion of a device,
Preliminary Evaluation
A preliminary evaluation of a device will be made by EPA engineering
staff on the basis of information supplied by the developer in the appli-
cation. On the basis of this information EPA will determine if further
testing of the device Is needed or warranted. If upon the basis of the pre-
liminary evaluation, the conduct of testing would, in the professional
judgement of EPA engineers, not be likely to support the claims for the
device and that its cost would thus represent an unprofitable drain on
the developer's resources, EPA will so counsel the developer. However,
if the developer so elects, EPA will proceed with a test program.
If no further testing is necessary either because the developer has
submitted sufficient data to permit EPA engineers to draw conclusions
regarding the effectiveness of the device, or because the device is suf-
ficiently sirailar on the basis of design to devices already evaluated, EPA
will publish the results of the preliminary evaluation and will not design
a test program.
If further testing is needed to make an evaluation and the developer
decides to proceed with testing, EPA engineering staff will design a test
program to permit the drawing of valid conclusions regarding the device's
effectiveness. The developer will select from a list of technically com-
petent laboratories (see Attachment II) a testing laboratory at which the
device will be tested at his expense, in accordance with the EPA-developed
test program for his device.
Size of Sample and Test. Program Cost
A more detailed discussion of the EPA test program can be found in
Attachment I.
Sample size is a major determinant of testing cost. Sample siies
may range from as little as two vehicles to as many as 100 vehicles,
depending upon the type and potential variability of the effects that are
being measured, and on the accuracy and applicability of the final con-
clusions which are necessary. The cost to a developer will be approxi-
mately $3tOOO per test car.
-------
The conclusions drawn from small samples are necessarily of
limited applicability. A complete evaluation of the effectiveness of
devices in achieving performance Improvements on the many different
types of vehicles that are in actual use requires a large sample. The
conclusions from small scale tests can be considered to be quantitatively
valid only for the specific test cars used. However, it is often possible
to extrapolate the results from the test to other types of vehicles in a
directional or qualitative manner, i.e., to suggest that similar results
are likely to be achieved on other types of vehicles.
All of the costs of testing are borne by the developer. Testing
costs Include device and vehicle procurement as well as other costs in-
curred by the testing laboratory. There is no charge to the developer for
EPA staff time for the preliminary evaluation and subsequent analyses, or
for confirmation in the EPA lab of independent test laboratory results if
such confirmatory testing is deemed necessary by EPA. The EPA will not
conduct confirmatory tests without adequate test results first having been
generated by Independent laboratories* The function of EPA confirmatory
tests is solely to verify especially important data that may confirm the
claims made for a device, and to monitor the quality of testing performed
in the independent laboratories.
Conduct of Tests
The vehicles selected for testing of a device will be tested in at
least two configurations. One configuration is with the vehicles adjusted
to the original manufacturer's specification. The other configuration is
with the device installed on the vehicles. If any test vehicle engine
parameters (such as ignition timing or idle mixture) are different from
manufacturer specification when the device is installed, the vehicle will
also need to be tested with the equivalent changes to engine parameters
without the device installed. If a prototype engine is tested rather than
a device for retrofit to existing engines, the vehicle is adjusted to the
developer's specifications.
Emission tests will be run by a laboratory equipped with the
equipment specified in the Federal Register (42 FR 32906; June
28, 1977) for the 1975 FTP. Copies of the Federal Register may be ob-
tained from EPA at the address given previously. As a minimum require-
ment, a laboratory must have a chassis dynamometer capable of reproducing
road load and vehicle inertia weight, a constant volume sampling system,
and the following types of analyzers for measurement of exhaust emissions;
Hydrocarbons - flame ionization detector
Carbon monoxide and carbon dioxide - non-
dispersive infrared
Oxides of nitrogen - chemiluminescence
-------
Evaluations conducted in the EPA teat program are for the purposes
of demonstrating the effectiveness of developed devices and are not to
be construed as development testing. All development work must preceed
evaluation by the EPA, No adjustments by the device developer to the
test vehicle or the device will be permitted except to repair malfunctions,
Such repairs will be permitted at the discretion of the IPA test engineer.
1PA engineering staff will prepare a draft report on the evaluation
device. The draft report will be made available to the developer for
review to ensure accuracy of the information concerning the description
of the device, etc. The developers* comments to EPA should be made
promptly. Final test reports are distributed to technical personnel in
Federal and state governments, private industry and universities and are
also available to the general public through NTIS.
The developer may cite final EPA reports (but not draft reports) to
indicate the exhaust emission and fuel economy levels attained with the
device, but the developer may not claim that the EPA report constitutes
"approval" of an emission control system. Cases of misrepresentation of
IPA evaluation reports will be referred to the Department of Justice or
the Federal Trade Commission, as nay be appropriate.
EPA/455711
-------
Attachment I
General Description of Emission Tests
General
Device and engine evaluation tests conducted by EPA generally
include measurement of the following items:
a) gaseous emissions
b) particulate and other emissions
c) fuel economy
d) power/acceleration/driveability
Currently regulated gaseous emissions are unburned hydrocarbons
(HC), carbon monoxide (CO), and oxides of nitrogen (NOx). Particulate
and other emissions are currently unregulated, but EPA collects such
data for investigative purposes.
Unburned hydrocarbons and oxides of nitrogen react in the atmosphere
to form photochemical smog. Smog, which is highly oxidizing in nature,
causes eye and throat irritation, odor, plant damage and decreased
visibility. Certain oxides of nitrogen are alao toxic in their effect
on man.
Carbon monoxide impairs the ability of the blood to carry oxygen.
Excessive exposures to carbon monoxide during periods of high concentra-
tions (such as rush-hour traffic), can decrease the supply of oxygen to
the brain, resulting in slower reaction times and Impaired Judgement.
Particulate and other emissions include such things as sulfate
emissions, aldehyde emissions, and smoke emissions from Diesel—powered
vehicles. These emissions are generally not measured as part of a
routine device evaluation. They may be measured if the control system
or engine being tested could potentially contribute to particulate or
other emissions.
Exhaust emissions from passenger cars, light trucks, and motor-
cycles are measured on the 1975 Federal Test Procedure {'75 FTP) in
which vehicles are driven on a chassis dynamometer to .simulate urban
driving. The *75 FTP is the test used for the certification of new .
cars and has been used in the evaluation of prototype engines and emis-
sion control systems since 1971.
-------
A-*:
f'ntJ i-vmrjmy ;..- nir.adui e-d en a chassis Jynaxs omelet reproducing,
ijT'lial urhd" -niv! Ui^Way driving speeds cad loads. The lusJl
o' the r «?;,(•. v^'iC:le j,^ calculated from t.a-a exhaust cmis&Icii data
the c'l* hem bal^n>-t: method, U^biii fuel ecotiuinv is measured during f.h.6
JCi"T:> FeJctaL Isnt Ptocfdair., iud higltwa/ fuel ecenomy Is measuied 'jvaj;
th«? EPA Highway Fuel Econoray Test^
Engine power Is measured on a chassis dynamoraeter« I'ower is
usually not measured unless a device is expected to have a significant
eiTeec on engine power output. Engine power may alsc be measured to
substantiate power output, claims made for prototype engines.
Acceleration times (0-60,, 30-50 mph, etc.) mav be measured eithet
ao tli<; rndd or on a chassis dynamometer, Drjveability will be evaluated
by the test engineer, based on the behavior of the test vehicle during,
the (Ivnamotoeter cc.stine or under actual road conditions.
Figure: i: Vehicle Test Arrangement
-------
A-3
Driving Schedules
City - The Urban Dynamometer Driving Schedule or LA-4 is the
result of more than 10 years of effort by various groups to trans-
late the Los Angeles smog-producing driving conditions to dynamometer
operations. It is a non-repetitive driving cycle covering 7.5 miles
in 1372 seconds with an average speed of 19.7 mph. During the *75
FTP, the first 505 seconds of the LA-4 are rerun after the hot start
so the distance traveled during a full *75 FTP is 11.1 miles and the
average speed is 21.6 mph, However, the emissions collected during
the 11.1 mile trip are mathematically rewelghted to represent the
average results of several 7.5 mile trips made from hot and cold
starts with average speeds of 19.6 mph. The maximum speed attained
during the LA-4 cycle (or '75 FTP) is 56.7 mph. The LA-4 is derived
from data taken from a vehicle driving under actual city traffic con-
ditions, so it is typical of a vehicle operating in an urban environ-
ment. A copy of the LA-4 driving schedule can be found in Figure 2.
EPA Highway Cycle - Since the '75 FTP does not represent the type
of driving done in non-urban areas, especially on highways, a driving
cycle to assess highway fuel economy waa developed by the EPA, The EPA
Highway Cycle was constructed from actual speed-versus-time traces
generated by an instrumented test car driven over a variety of non-
urban roads, and preserves the non-steady-state characteristics of real-
world driving. The average speed of the cycle ia 48.2 mph and the cycle
length is 10.2 miles, close to the average non-urban trip length.
Steady States - Constant speed, road load tests are routinely
conducted on prototype systems to help give insight into the operational
differences and exhaust emission and fuel economy variations among
vehicles. Speeds between 0 and 60 mph are investigated., Steady state
data must be interpreted cautiously, because the vehicle is being
exercised in an unrepresentative manner. Many vehicle operation surveys
conducted by EPA and others have clearly shown that true steady state
operation rarely occurs in customer use.
Short Cycles - Short cycle tests of the type employed by state
motor vehicle inspection programs may be run during any device or engine
evaluation program. The two short cycle tests that are usually run are
the Clayton Key Mode and the Federal Short Cycle.
The Clayton Key Mode consists of three steady state operating con-
ditions from which exhaust emissions are measured by the CVS procedure.
The test vehicle is operated in each mode until the exhaust emissions
stabilize. The engine compartment hood is closed and the auxiliary
cooling fan is not in operation.
-------
Figure 2: Official Federal Test Cycle
EPA Highway Cycle
(used in Highway Fuel Economy Test)
IQO.OQ 200.00 300.00 100.00 SflQ.QO 600.00 700.00 800.00
SECONDS
LA-4 Urban Cycle
(used in *75 Federal Test Procedure)
800.00 1000.03 1100.00 1800.00 1300.00 KOO.OO
100.00 200,00 300.00 400.00 $00.00 600.CO 700.00 000.00 300.00 1000.00 1100.00 1200.00 1300.00 WOO.00
SECONDS
-------
A-5
The Federal Short Cycle is a 9-mode CVS test consisting of a series
of accelerations, decelerations and cruises, of 125 seconds duration.
The dynamometer loadings and transmission shift points follow the pro-
cedure as required for the '75 FTP.
Sulfate Cycle - The EPA Sulfate Cycle (Figure 2), known as the Con-
gested Freeway Driving Schedule (CFDS), is a low speed cycle with an
average speed of 35 mph. The cycle is 1398 seconds long and covers a
distance of 13.6 miles.
The CFDS represents the driving conditions of a high density ex-
pressway (i.e., low speed driving on a crowded freeway), and the sulfate
emissions measured on this cycle are utilized by air quality planners to
predict the effect of automotive sulfate emissions on air quality.
City and Highway Test Procedures
On the day before the scheduled '75 FTP, the test vehicle is pre-
pared for the next day's test by driving over the urban driving schedule
on a dynamometer. The "prep" drive is to insure that all vehicles have
been driven in a similar manner on the day preceding the exhaust emission
test. After the prep drive, the vehicle must be parked for at least 12
hours in an area where the temperature is maintained between 68°F and
86°F. This period is referred to as the "cold" soak.
The '75 FTP is a cold start test, so the test vehicle is pushed
onto the dynamometer without starting the engine. After placement of
the vehicle on the dynamometer, the emission collection system is attached
to the tailpipe, and a cooling fan is placed in front of the vehicle.
The emission test is run with the engine compartment hood open.
A chassis dynamometer reproduces vehicle inertia with flywheels and
road load with a water brake. Inertia is available in 250 Ib. increments
between 1750 Ibs. and 3000 Ibs., and in 500 Ib. increments between 3000
Ibs. and 5500 Ibs. Through the use of flywheels and a water brake, the
loads that the vehicle would actually experience on the road are repro-
duced. For each inertia weight class, a road load is specified which
takes into account rolling resistance and aerodynamic drag for an average
vehicle in each class.
The vehicle's exhaust is collected, diluted and thoroughly mixed
with filtered background air, to a known constant volume flow, using a
positive displacement pump. This procedure is known as Constant Volume
Sampling (CVS).
-------
A-6
The emission sampling system and test vehicle are started simul-
taneously, so that emissions are collected during engine cranking.
After starting the engine, the driver follows a controlled driving
schedule known as the Urban Dynamometer Driving Schedule (UDDS) or LA-4,
which is patterned to represent average urban driving. The driving
schedule is displayed to the driver of the test vehicle, who matches the
vehicle speed to that displayed on the schedule. (A copy of the LA-4
driving schedule can be found in Figure 2). The LA-4 driving cycle is
1372 seconds long and covers a distance of 7.5 miles. At the end of the
driving cycle, the engine is stopped, the cooling fan and sample collection
system shut off, and the hood closed. The vehicle remains on the dynamometer
and soaks for 10 minutes. This is the "hot" soak preceding the hot
start portion of the test. At the end of ten minutes, the vehicle and
CVS are again restarted and the vehicle is driven through the first 505
seconds (3.59 miles) of the LA-4 cycle.
Exhaust emissions measured during the ?75 FTP cover 3 regimes of
engine operation. The exhaust emissions during the first 505 seconds of
the test are the "cold transient" emissions. During this time period,
the vehicle gradually warms up as it is driven over the LA-4 cycle. The
emissions during this period will show the effects of choke operation
and vehicle warm-up characteristics. When the vehicle enters into the
remaining 867 seconds of the LA-4 cycle, it is considered to be fully
warmed up. The emissions during this portion of the test are the "stabili-
zed" emissions. The final period of the test, following the hot soak,
is the "hot transient" section, and shows the effect of the hot start.
The emissions from each of the three portions of the test are collected
in separate bags.
After completion of the '75 FTP, the vehicle is tested on the EPA
Highway Fuel Economy Test (HFET). The vehicle ia fully warmed up and
running at the start of the HFET. If the vehicle is shut off at the end
of the '75 FTP and allowed to cool for an appreciable amount of time, '
then a warmup Highway Cycle (see Figure 2) is run before the aatual
HFET. This insures that the vehicle drivetrain is at full operating
temperature.
A complete description of these procedures can be found in the Code
of Federal Regulations 40 CFR Part 86 and 40 CFR Part 600. Evaluation
tests made by EPA usually do not include measurement of evaporative
emissions.
-------
A-7
Sample Collection and Analysis
Figure 3 is a schematic diagram of a typical Constant Volume
Sampler (CVS) used to collect exhaust emissions. The vehicle exhaust is
transported from the tailpipe to a dilution box, where it mixes with
filtered background air. The diluted exhaust passes through a heat
exchanger that maintains the mixture at a constant temperature. After
passing through the heat exchanger, a sample of the exhaust mixture is
drawn off and collected in a bag constructed on an impermeable, chemically
inert substance called Tedlar. A sample of the background air is taken
concurrently with the exhaust sample, A constant displacement pump is
used to pull the exhaust through the dilution box and heat exchanger.
The pump revolutions are counted during the test, so the volume of
dilute exhaust can be calculated, Newer model sampling systems use a
critical flow venturi to control the flow rate of the exhaust mixture.
ZJWMtST TS ATTBSPWtM
Figure 3*, Constant Volume Sampler
-------
A-8
The driver of the teat vehicle operates the CVS using a remote con-
trol unit, with which he can start sampling at the beginning of the "75
FTP, switch from the cold transient to the stabilized sample bag at 505
seconds, and stop sampling at the end of the test.
After a sample has been collected, it is taken to an analyzer where
the concentrations of HC, CO, CC>2 and HOx in the sample bag are determined.
The analytical system provides for the determination of hydrocarbon con-
centrations by flame ionization detector (FID) analysis, carbon monoxide
and carbon dioxide concentrations by nondispersive infrared (NDIR) analysis
and oxides of nitrogen concentrations by chemilumineBcence (CL) analysis.
Calculations
To correct for background levels of HC, CO, CO™, and NOx the concen-
tration in the background bags are subtracted from the concentration in
the sample bags. The resultant values are referred to as corrected con-
centrations. The mass of each pollutant (HC, CO and NOx) is calculated
from the corrected concentration and the total volume flow during each
of the three test phases. Once the mass emissions for each test phase
are known, the emissions in grams per mile are calculated using the
following formula:
Y = (0.43 Y H- 0.57 Y, + Y ) t 7.5
wm ct ht s
where
Y = weighted mass emissions of each pollutant, i.e. HC, CO, or
wm
NOx in grams per vehicle mile.
.Y = mass emissions as calculated from the "transient" phase of
the cold start test, in grams per test phase.
Y, = mass emissions as calculated from the "transient" phase of
the hot start test, in grams per test phase.
Y = mass emissions as calculated from the "stabilized" phase of
c
the cold start test, In grams per test phase.
The cold start and hot start bags are weighted 0,43 and 0.57 respectively.
;
Detailed explanations of the calculations can be found in the Federal
Register.
-------
A-9
Fuel Economy Ca_IcuLat_io_na
Fuel economy is usually measured by either the carbon balance method
or by using a remote source of fuel (such as a can) which ia weighed
before and after the test. Unless a special teat requires the use of the
weigh method, the carbon balance method is used to determine fuel economy.
The carbon balance procedure for measuring fuel economy relates the
carbon products in the vehicle exhaust to the amount of fuel burned
during the test. The major assumptions in using this technique are;
1. The carbon contained in the HCt C0» and CQ~ in the exhaust
is the only carbon in the exhaust. This means that other carbon con-
taining compounds, such as oxygenated hydrocarbons that are not detected
by a flame ionization detector and carbonaceous particulates, are ignored.
2. All of the carbon that is measured in the exhaust in the form
of HC, CO and CC>2 came from the fuel; there are no other sources of
carbon.
3. All of the fuel consumed during the teat can be accounted for
by the carbon in the exhaust. This means that all of the fuel that leaves
the tank is assumed to pass through the engine and that no carbon leaks
out of the exhaust system before being analyzed or evaporates from the
vehicle.
Since the carbon weight fraction of the fuel is known, it is a simple
matter to calculate the amount of fuel consumed during the test. Agree-
ment between the carbon balance method and direct fuel consumption measure-
ment is normally within 2%.
EPA tests have demonstrated that dynamometer fuel economy can be
duplicated under "real world" road driving conditions.
Test Fuels
EPA tests are generally run on either Indolene HO or Indolene 30
gasoline. Indolene HO is an unleaded fuel with a research octane of
about 96. Indolene 30 is a leaded fuel with a research octane of 103
or higher. Indolene fuels are special in the sense that their production
characteristics are closely controlled. The fuel specifications must
fall within certain limits set by the EPA. Tight control of fuel quality
eliminates the fuel as a source of test variability. There ia no reason
to expect that the emissions from a vehicle running on Indolene fuel
would be significantly different from the emissions when running on a
summer grade of commercial pump gasoline.
-------
A-10
Occasionally it is necessary to use a commercial fuel because of
special test requirements, such as the need for a low octane fuel to
check vehicles for spark knock problems.
Sulfate Emissions Tests
Sulfate emissions are measured over the EPA sulfate cycle known as
the CFDS. The apparatus used to collect the vehicle exhaust is similar
to that used for the "75 FTP. However, there are some differences as
illustrated in Figure 4.
/
dilution S?
air ?J
vehicle
dilution air sample probe
fHter /— »uLf»ee filter
r
-L
'(j / 0
lj /
dilution
===
CVS
o o
to BUfnp
tunnel
Figure 4: Sulfate Measurement Apparatus
The vehicle exhaust mixes with the dilution air in a long tube
known as a dilution tunnel. At the downstream end of the tunnel, a
small sample of the mixture is drawn off through a filter, which is then
analyzed by the barium chloranilate procedure to determine sulfate
concentrations in the exhaust. Emissions of HC, CO and NOx are also
measured in the conventional manner using the CVS during sulfate emission
tests.
The fuel used for sulfate testing is Indolene HO (unleaded) with a
sulfur content of 0.03% by weight. In some cases, it is necessary to
use other fuels, such as for Diesel-powered vehicles.
Other Emissions
Occasionally it is necessary to test vehicles for emissions other
than those that have already been discussed. Emissions that may be
measured include aldehydes (by the MBTH method) and reactive and non-
reactive hydrocarbons. These tests are usually conducted only on pro-
totype powerplants.
-------
A-ll
Power, Driveability, Durability
Relative engine power output can be measured on a chassis dyna-
mometer. Power output can be determined for any engine speed, including
the maximum engine power point.
Driveability is evaluated by the test engineer. Items to be con-
sidered include acceleration, cold start performance, tendency to
stumble or hesitate, surge, and hot start performance.
Comments about the expected durability of a device or prototype
engine will be based on several considerations. Among these are;
exposure of the control system to severe operating conditions and
previously demonstrated durability of similar systems.
-------
Attachment II
INDEPENDENT LABORATORIES EQUIPPED TO
CONDUCT EPA EXHAUST EMISSIONS TESTS
While the Federal Government does not formally approve laboratories
for emission testing, certain Independent laboratories have become recog-
nized over the years as knowledgeable and properly equipped to perform
emission tests in accordance with the Federal procedures. Their equip-
ment Is similar or equivalent to that used in the EPA Motor Vehicle
Emissions Laboratory. The following list of several such laboratories
is published for the information and convenience of applicants for
evaluation of devices.
AP Parts Company (Questor Company)
543 Matzlnger Road
Toledo, Ohio 43697
419-729-3958
Ethyl Corporation
1600 West Eight Mile Road
Ferndale, Michigan 48220
313-564-6940
Automotive Environmental Systems, Inc.
7300 Bolsa Avenue
Westminster, California 92683
714-897-0331
Olson Engineering, Inc.
Vehicle Test Facility
15512 Commerce Lane
Huntington Beach, CA 92649
714-894-9875
EG & G Automotive Research Inc.
5404-08 Handera Road
San Antonio, TX 78238
512-684-2310
Olson Laboratories, Inc.
11665 Levan Road
Livonia, Michigan 48150
313-422-3160
Automotive Testing Laboratories
19900 East Coifax Avenue
Aurora, Colorado 80010
303-343-8938
Olson Laboratories, Inc.
421 East Cerritos Avenue
Anaheim, California 92805
714-956-5450
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
i OFFICE OP
AtR AND WASTE MANAGEMENT
EPA RETROFIT AND EMISSION CONTROL BEVICE EVALUATIQ8 TEST POLICY
Evaluations by the Environmental Protection Agency of engines,
retrofit devices, emission control devices, and related produces are
conducted for the purpose of keeping policy nakers and technical per-
sonnel in government and Industry, and the general public, abreast of
developments In, the field of automotive fuel economy and. pollutant esais—
sioa control. For that reason all data developed as a result of EPA
testing is public .information and will, as relevant, be Included in a •
teat report. . -
EPA evaluates devices under ttro different authorities: Section.
206(a)(2) of the Clean Air Act (42 U.S.C. 1857f-5) and Section 511 of
the Motor Vehicle Infcreation and Cost Savings Act (15 U.S.C. 2011).
Due to the similarity in these two authorizations, EPA has established
a single evaluation and teat program. The details of the prograa are
set forth in Federal Regulations under 40 CFR 610.
To obtain, an evaluation, application is first cade to EPA to work
out the details of the requested testing. Testing is performed at the
expense oj the applicant at private labs, under EPA supervision, with
subsequent confirmatory tests by EPA if deened necessary by EPA. EPA
engineers will use the test results and other data to evaluate the device
and report the results. In che discussion of the effectiveness of a pro-
duct, the test reports will sake comparisons when appropriate between the
results and current or future Federal fuel econoay and emission standards,
and with results fron similar devices.
Hoy to Requ ast _ao. Evalua tIon
Individuals or organizactons desiring an E?A evaluation oc a fyel
economy retrofit device, an exhaust emission coacrol device, fuel additive,
or prototype engine, should request an apolicaticn format froci:
Director, Emission Control Technology Division
U.S. Envirorj^sncal Proceciisn Agency
2565 Plymouth Road
Ann Arbor, MIchgan 48105
FS-5
-------
la Che application Che developer provides EPA wich all inf amadou
necessary Co describe and explain, che functioning °f Che device or
engine. Such information, cusc include che cheory of operaclon, drawings
acid schematic. diagracs. In addician, any scandard cesc daca performance
on che device chac deaonscrace che emission aad fuel econonsy performance
of Che syste= should be provided. The Federal Tesc Procedure (FI?) (40
CrK Pare 86) is che only cesc which is recognised by che U.S. Environ-
nencal ProCeccion Agency for che evaluacion of vehicle emissions, and
daca genaraCed in. accordance wich che FTP are essenclal f or che evalua,—
cioa of a device.
Pr e 1 tptnary Evalua c lo a
A preliminary evaluation of a device will be nada by EPA engineering
scaff on. che basis of iniomacion supplied by che developer la the sppll-
cacian. Oa Che basis of this information EPA will determine If furcher
cesting of Che device is needed or warraaCed. If upas che basis of che pre-
liminary evaluation, che conduct of. tescing vould, la che professional
judgeaenc of EPA engineers, noc be likely Co supporc che clalcg for Che
device and chac ics cose would chus represent an imp ro-fic able drala on
the developer's resources, EPA will so coi^isel che developer. However,
if che developer so elects, EPA will proceed vich. a CesC prograa.
• * • - "
If no furcher cescing is aecessary eicher because che developer has
subaicced sufficient daca Co peraic EPA engineers Co draw conclusions
regarding che effectiveness of che device, or because che device is suf-
ficiencly similar on Che basis of desigti co devices already evalumced, EPA
will publish Cha results of che preliminary evaluaciou and will noC design.
a cesc program.
If furcher Cescing is nasded ca cake an evaluacion and che developer
decides co proceed wich cescing, EPA engineering scaff vill design a Cesc
progran co perzsic che drawing or valid conclusions regarding che device's
ef f ecCiveness. The developer will select: frozi a. Use of Cechnlcally con—
pe'enc laboracories (see Accachnenc II) a Cescirig laboracory at which Che
device will be cesced ac his expense, is accordance vich che E?A-developed
Cesc prograa for his device, . :
Size of Sample ar.d Tesc Program _Cqs_C
A core derailed discussion of ^hs EPA cesz program can be found lc
Sample sir;: is a najor detemirLEcc of" tescing cose. Saaple sizes
^iy range free as liccle as c*-'o vehicles to as tzaay as 100 vehicles,
dcper.-iip.s upon che type and pOwCr^ial vsriabilicy of che effects chac are
be lag measured, ar.d on che accuracy 3.r.d apoLicibilicy of cha final con-
elusions '-hich are necessary. The c=s^ ca a developer will be approici-
:r-a.;:ely .53,000 per cesc car. - ' -'
-------
The conclusions drawn from small samples are necessarily of
limited applicability. A complete evaluation of che effectiveness of
devices in achieving performance improvements on. Che cany different:
typaa of vehicles chat are in actual use requires a large sacple. The
conclusions fron. scull scale tests can be considered to be quantitatively
valid only for the specific test cars used. Hovever, it Is often possible
to extrapolate the results froa Che test: Co other types of vehicles In a
directional or qualitative manner, I.e., to suggest Chat sinllar, results
are likely to be achieved on othar types or vehicles,
All of the costs of testing are boms by the developer. Testing
costs Include device and vehicle procuremaac as -well as other costs In-
curred by the testing laboratory. There is no charge to Che developer for
EPA staff time for the preliminary evaluation and subsequent analyses, or
for confirmation in the E?A lab of independent test laboratory results If
such confirmatory nesting is deemed necessary by EPA. The EPA will not
conduct conf ircatory tests without adequate test results first having been
generated by independent laboratories. The function of EPA confirmatory
tests is solely to verify especially important data that cay confirm the
claims made for a device, and to monitor the quality of testing performed
in the independent laboratories,
f Tes t
The vehicles selected for testing of a device will be tested in at
least two configurations. One configuration is with the vehicles adjusted
to che original manufacturer's specification. The other configuration is
with che device installed on. che vehicles. If any test vehicle engine
parameters (such as ignition timing or idle mixture) are different firoa
manufacturer specification whan the device is installed, the vehicle will
also need to be tested with the equivalent changes to engine parameters
without the device installed. If a prototype engine Is tested rather Chan
a device for retrofit to existing engines, the vehicle is adjusted to the
developer's specifications.
Emission tests will be run by a laboratory equipped with the
equipment specified in the Federal Register (42 FR 32906; June
23, 1977) Eor the 1S75 FT?. Copies of the Federal ?veglster cay be ob-
tained froa EPA at che address given previously. As a cinLcum require—
aent, a laboratory cusc have a chassis dyr. a^sriecer capable of reproducing
road load ard vehicle ir.ertia velghc, a constant volune sampling sysce^i,
ar.d the following cypes of analyzers for reasure^enc o£ exhaust emissions:
Hydrocarbons - fl^se ionizaclon ccceccor
Carbon monoxide and carbon dioxide - nor.—
dispersive infrared
0>:iclfis of r.t-rogcn - chenilue.inescer.ee
-------
Evaluations-conducted in the EPA case program" are rtir the
of demons era ting che ef feetlveness of developed devices 'and are not Co
be consinrued as developnent testing. Ail development vork nust preceed
evaluation by the EPA. No adjustnes.es by che device developer to the
cest vehicle or che device will be pemitted except to repair- calcunc clous.
Such repairs will be pemitted ar the discretion of the EFA test engineer*
'EPA engineering staff will prepare a draft report' on the evaluation'
device. The draft report will be cade available to- the developer for
review to ensure accuracy of the information- concerning the de script Ion
of the device, etc. The developers1 consents to E?A should be nade -. •
pronptly. Final test reports are distributed' to technical personnel in'.
Federal and state governoents,' private industry and universities and are
also available to the general public through NTIS. -
The developer nay cite £toa:l EPA reports Cbut not draft reports) to
indicate the eschaust enission and fuel eetmosy levels attained with the
device, but the developer cay not claia that the E?A report constitutes
"approval11 of an eeisslon control systea. Cases of aisr e present a clou- of •
EFA evaluation reports will be referred to che Department of Justice or
the Federal Trade- Cocaisston, as cay be appropriate.
EPA/-55711
-------
Attachment I
General Description of Eclasion Tests
General ..'•'.
Device and. engine evaluation cases conducted by EPA
include neasurenenc of che following itasis:
a) gaseous
b) particulate and other emissions
c) fuel econany
d) pouer/acceleratlan/driveablllty
Currently regulaced gaseous emissions are unbumsd hydrocarbons
(HC) , carbon monoxide (CO), and oxides or nitrogen (XQx). Particulate
and ocher emissions are currently ur.regul^ced, hut E?A collects such.
data for investigative purposes. •
Unburtied hydrocarbons and oxides of nitrogen react in tho atsoaphsre
to form photochemical scog. Saog, which is highly oxidi-ing i^1 nature,
causes eye and throac irritation, odor, plant damage and decreased
visibility. Certain oxides of nitrogen, are also toxic in chslr efface
on man.
Carbon sor-oxide impairs the ability of the blood to carry oxygen.
Excessive exposures to carbon nonaxide during periods of high concentra-
tions (such as rush-hour traffic), can decrease the supply of oxygaa Co
the brain, resulting in slower reaction tinas and impaired judgeaeat.
Particulace and ocher emissions include such things as sulfaca
enissions, aldehyde emissions, and s=oka emissions frs^ Diaaal-povared
vehicles. These emissions are generally ZDC measured as psrt of a
• routine device evaluation. They oay be neasured if ch$ control systoa
or engine being cesced could potentially contribute to parclculata or
other emissions.
Exhaust emissions froa passenger cars, light truck*, and co tor-
cycles are aeasured on che 1975 Federal Tesc Procedure (*75 FT?) in
which vehicles are driven on a chassis dyrar-.-rnst er to sinulato urban
driving. The '75 FT? is the test used, for the certification of nea
cars and has been us£d in. the evaluation of prccocype engines and emis-
sion control syscens since 1971.
-------
A-2
. Fuel economy is measured cm a chassis dynano;eater .reproducing
typical urban and highway driving speeds and loads* The fual economy
of the test vehicle is calculated fron the exhaust -emission- daca using
the carbon balance method. Urban. fuel economy is measured during che
1975 Federal Test Procedure, aad, highway fuel econaay is aeasured, over
the EPA Highuay Fuel Econoay Test. , -. • . . .
Engine pouer is naasured on a chassis dynaaaaeter . ' ' Powac is ' •
usually not ueasured unless a device is exp acted Co have a 'sigaificaiic
effect on engine po«ar output. Engine power may 'also be measured, Co
substantiate power output cLains tsade for. protO'typa engi
Acceleration tiiaas (0-6QP 30-5Q nph, etc.) nay be measured cither
on the road or on a chassis ' dynanooeter , Briveability will be evaluated
by the test engineer, based on the behavior of the tesc vehicla during
the dynaaosiecer testing or under actual road conditions. - ••
ra 1: Vehicle Tesc Arran'
-------
A-3
Delving Schedules_
City - The-' Urban Dynanoneter Driving Schedule or LA-4 is the
result of more Chan 10 years of effort by various groups to trans-
late the Los Angeles smog-producing driving conditions to dynasioseeer
operations. It is a .non-repetitive driving cycle covering 7*5 miles
in 1372 seconds with an average spaed of 19.7 nph* During the *75
FTP, the first 505 seconds of the LA-4 are rerun after tha hot scare '
so the distance traveled during a full *75 FTP is 11. 1 miles and the •
average speed is 21.6 taph. However, the eaiasions collected daring
the 11.1 nile trip are oathesatieally rewalghted co repreaant the
average results of several 7.5 rails crips eade froa hot and cold *-
starts with average speeds of 19.6 nph. The naxisun speed attained
during the IA-4 cycle (or '75 FTP) is' 56.7 mph. The LA-4 is derived
froa data taken from a vehicle driving ur.der actual clcy traffic con-
ditions, so it is typical of a vehicle operating In. an urban environ-
ment. 'A copy of the LA-4 driving schedule can be found in Figure 2.
EPA Highway Cycle - Since the *75 FT? does not represent the type
of driving doce in non-urban areas, especially on highways, a driving
cycle to assess highway fuel econoay vas developed by the EPA. The EPA
Highway Cycle vas constructed froa actual speed- versus—tide traces
generated by an instrumented test car driven over a variety of non-
urban roads, and preserves the non-stcady-stmte characteristics of real-
world driving. The average speed of che cycle is 48.2 cph and the cycle
length is 10.2 niles, close to the average non-urban trip ler.jjth-
Steady States - Constant speed, road load cests are routinely
conducted on prototype sysceas to help give insight into the operational
differences and exhaust emission and fuel econony variations acatig
vehicles. Speeds between 0 and 60 nph are iavescigscad. Steady state
data nust be interpreted cautiously, because the vehicle is being
exercised in an unrepresentative r.annar. Many vehicle operation surveys
conducted by EPA and others have clearly shown chat true steady state
operation rarely occurs in custcser use,
Short Cycles - Short cycle tcses of the type irsployad by state
vehicle inspection, programs say be run during any device or engine
evaluation pragma. The f.'o short cycle cases that are usually run arc
the Clayton Key Mode and che Federal Short Cycle.
The Clayton Key Mode consists si threa steady state operating cor,— .
dicions from vhich c;
-------
t' 2; Official Kcutval Tupc Cycle
EPA Highway Cyclu
(used In Highway Fuel Economy Test)
?00.00 300.00 1(03,00 500.00 COQ.OO 700.00 000.00
SECONDS
LA-4 Urban Cycle
(used In '75 Federal Test' Procetlu
IIM.M
-------
A-5
The Federal Shore Cycle is a 9-nsode CVS test consisting of a series
of accelerations, decelerations and cruises, o£ 125 seconds duration.
The dynamoaater loadings and transmission, shitt poin.es follow che pro-
cedure as required for the *75 FT?. " •
Sulfate Cycle - The EPA Sulfate Cycle (Figure 2), known as Che Con-
gested Freeway Driving Schedule (CFDS) , is a low speed cycle with an
average spaed of 35 tnph. The cycle is 1398 seconds long and covers a
distance of 13.6 miles. . • '
The CFDS represents the driving conditions of a. high density ex-
pressway (i.e., low speed driving on a crowded freeway), and Che sulface
emissions aeasured on this cycle are utilized by air quality planners to
predict the efEect of autonotive sulrace enissions on air quality.
City and^iig.hvay Test Procedures
On the day before the scheduled * 75 FTP, the test vehicle is pre-
pared for the next day's test by driving over che. urbaa, driving schedule
on a dynamometer. The "prep" drive is to insure that all vehicles have
been driven in a similar canner on the day preceding the exhaust enission
test. After the prep drive, the vehicle muse be parked .for at lease 12
hours in an area uhere che temperature is maintained between 68°F and
86°F. This period is referred to as che "cold" soak,.
The '75 FT? is a cold start test, so che test vehicle is pushed
onto the dynan-.onecer without starting che engine. After placement of
the vehicle on che dynamometer, the enission collection system is attached
to the tailpipe, and a cooling fan is placed in front -of the vehicle.
The emission test is run with the engine coapartsenC hood open.
A chassis dyna~;oaeter reproduces vehicle inertia with flywheels and
road load with a water brake. Inertia is available in 250 Ib. increments
between 1750 l.bs. and 3000 ibs., and in 500 Ib. increments between 3QQQ
Ibs. and 5500 Ibs. Through the use of flywheels and a water brake, tha
loads that, che vehicle would actually experience on the road are repro-
duced. For each inertia weight class, a road load is specified which
cakes inco accounC rolling resistance and aerodynamic dtag for an average
vehicle in each class.
The vehicle's exhausc is collected, diluted and thoroughly ciixed
uiLh filtered background air, to a kr.o'-Ti constant voiune £low, using s
dispi^cer.en: pt^np. This procedure is knc'-m as Constant: Volume
a£ (CVS) .
-------
. The emission stapling systen and tesc vehicle are starced simul-
taneously, so that emissions are collected.during eagles craaking-
After starting the engine, the driver follows a controlled driving
schedule known as the Urban. Dyuaicneter Brivf.ng Schedule (UDDS) or LA—4,
•which is patterned to represent average urban driving. The driving
schedule is displayed co the driver of the test vehicle, -who catches cha
vehicle speed to that displayed on the schedule. (A copy of the LA-4
driving schedule can be found in Figure 2) . Ihe LA—4 driving cycla is
1372 secocds lens and covers a distance of 7,5 ailes. At: the end. of the
driving cycle, the engine is stopped, the cooling fan and sanple collection.
syseen shut o£f» and the hood closed. The vehicle regains on tha
and soaks for 10 nicntes. This is the "hoc" soak preceding che hoc
start portion o£ che test. Ac the ead of tea mimices, che vehicle
CVS are again restarted and the vehicle is driven through the firsc 505
seconds (3.59 niles) oc the. LA—4 cycle.
Exhaust emissions neasured during the* *75 FT? cover 3 regines of
engine operation. The exhaust emissions during the first 505 seconds of
the test are the "cold transienc** enissiocs. tXiring this cime period,
the vehicle gradually warns up as it is driven over the LA—4 cycle. The
emissions during this period vrill show the effects of choke operation
and vehicle uam-up characteristics. When the vehicle enters into the
regaining 867 seconds o£ the IA-4 cycle, it is considered to be fully
uamed up. The enissions during this portion, of the cesc are the "stabili
zed" emissions. The final period of the tesC, following the hot soak,
is the "hot transient" section, acid shova the effect of the hot scare.
The emissions £ron each of. the three portions o£ the test arc collected
in separate bags, .
After co—.plecion of the *75 FT?, the vehicle is tesced or\ tha EPA
Highway Fuel Hconony Tesc (HFHT). The vehicle is fully warned up and
running at the start of che KFET. If che vehicle is shut off at the end
of the '75 FT? and allowed to cool for an appreciable amount of tise.
then a van^ep Highway Cycle (sea Figure 2) is run. before the actual
HFET. This insures chat the vehicle drivetrain. is ac full operating
temperature. • . '.-.••
A complete description of these procedures can be found in tha Code
of Federal Regulations 40 CTR Part: 86 and 40 CFR Part: 600. Evaluation.
tests niada by EPA usually do nac include aeasuzs^er.c. cf evaporative
emissions.
-------
A-7
Sangle Collection an.d Analysis
Figure 3 Is a schematic diagram oc a typical Cons cane Volume
Sampler (CVS) used co collect exhausc emissions. The vehicle exhaust Is
transported f roo. the callpipe co a dilution box, where it ,al=;es with
filtered background air. The diluced exhaust passes through 3 heae
exchanger that natatains the.nixcure at a conacaac temperature, After
passing through the heat, exchanger, a. saaple of che exhaust aixcure is
drawn off and collected in a bag constructed oa an Ispertaaabla, cheaically
Inert substance caLled Tedlar. A. sanpla of the backgsou^d air is takan
concurrently with the exhaust sample. A. constant displacenent pu=? is
used to puU. the exhaust through che dilution box and heat exchanger.
The pimp revolutions are counted during the cest. so the voli=ta o|
dilute exhaust caa be calculated. Kawer i^odel saapling systems usa a
critical flow venturi to control che flow rata of the exhaust
nii:ii
*vi:«c
Figure 3: Ccr.stanC Vol'-i-i Sappier
-------
The driver of the cest vehicle operates cha CVS using a.' reaaca-'ccm-
crol unit, with which he can scare sampling ac che beginning of the *75
FTP, switch fron the cold transient to che stabilized .saapia bag at 505
seconds, and stop sampling at che eud o£ the teat,
After a sample has been collected, it is cakart to an analyzer where
the- concentrations o£ EC, CO, CO2 zn<^ NGx in the saciple bag are determined.
The analytical system provides for1 che dereminacion o£ hydrocarbon con-
centrations by flams ionizatioa detector (FID) analysis, carbon monoxide
aad car baa dioxida con central: ions by noadisoersive infrared (NDIE) analysis
and oxides of nitrogen concentrations by cbenfJUaslnescenee (CL) analysis -
Calculations " ' . .
To correct lor background levels of EC, CO, CO_» and NGx the concen-
tration ia the background bags are subtracted froa che' concentration la
the sample bags. The resultant values are referred to as corrected con—
ceacratioos. The aass of each pollutant (HC, CO and. KOx) is calculated
from the corrected conceutracion and the total volisae flow .during.'each
of che three test phases. Onca the ciass emissions for each test phase
are known, the enissions in graas per nile are calculated using che
fallotting formula;
Y =» (0.43 Y -J- 0.57 Y, + Y ) -r 7.5
wo ct ht s
uhere
Y = weighted nass esissions of each pollticaac, i.e. HC, CD, or
, NOx in gratis par vehicle nile. • •
Y =» nass estissions as calculated froa the "tracisiant" phase of
C cbe cold start test, in grans per" test phase.
Y =• nass emissions as calculated frcn the "trao.sieu.ci" phase of
the hot start test, in grans par rest phase- :
Y = oass emissions as calculated fr=i the "stabilized" phase of
che cold start test, in grass- per test phase. . •
The cold s rare and hot start bags are weig:ic;e£ 0.43 aad 0.57 respectively.
Deiaiied- ex^lanaeians of the calculations can be four-d in. the Federal
-------
A-9
F.uel Ecgnoay _Ca. Icula t ions * .
Fuel econony is usually naasured by either the carboix balance method
or by using a remote source of fuel (such as a can) which is weighed
before and after Che test. Unless a special cssc requires the use of the
weigh nethod, the carbon balance nechod Is used to determine fuel
The carbon balance procedure for niiasuring fuel ecarjcy relates the
carbon produces in the vehicle exhaust to the at^uar. of fuel burned
during the test. The major assuapcloaa in using this cechaiqua are:
1. The carbon contained in tha EC, CO, and CO. in the exhaust
is Che only carbon in the exhaust. This ceans thac other carbon con-
taining compounds, such as oxygenated hydrocarbons thac arc sot detected
by a liana ionization detector and carbonaceous parciculstaa* are ignored.
2. All of the carbon that is measured in Che exhaust In. tha fora
of HC, CO and C02 cane frora the fuel; chars ar.a co cthar sources of
carbon.
3. All of the fuel consumed during the test can ba accounted foe
by the carbon in the exhaust. This neaps' thac all of the fual that leaves
the cank. is assigned to pass thcough the engine and chac no carbon leaks
out of the exhaust system before being analyzed or evaporates fron the
vehicle.
Since the carbon vei^hc fraction of the fuel is kco%-n, ic is a staple
natter to calculate the arrounc of fuel cnnsuried during Chs test. Agree-
ment between the carbon balance method az-d direct fuel consumption measure-
ment is nomally within 2*'.*
EPA tests have denor.strated that dy^2=s-eter fuel economy can, be
duplicated under "real world" road drivizg cor.ditiar.o.
EPA tests are generally run or. either Ir.ciaier.e HO or Indolena 3O
gasoline. Indoiene HO is an unleaded fuel vizh a resaarch ocrar.e o£
about 96, Ir.dolar.e 30 is a liadad fuel vith a research octane of 103
or higher.' Xndolene fuels arc special iz the S2n.se thac their produccion
characteristics are closely controlled, Tns fuel s?aci; icatiDns cusc
fall uichir. csrcain lirsics sec by the E?A. Ti^ht control of fuel quality
eli:nir.\3C£s the fuel as a source of cost variability. Th-sre is r,o reason
co expect chat the cjnisr.icr.s from a vehicle running on Ina^ie^s fuel
d be sijni: icar.tly different free che emissions --h^r. running oi\ a
er grade of co™.erci3l pu^p ^asoii^e.
-------
A-10
Occasionally ic is necessary- co use a coinaarcial fuel because of
special cest requirements» such as che r.eed for a low occane fuel co
check vehicles for spark knock problems. ;
Sjjlface Enlssions Tescs
Sulface enissions are neasured over Che EPA sulface cycle kno^m as
che CFDS. The apparatus used Co collecc the vehicle exhsuse is siziilat
co chac used for che '75 FT?. Houever, chere are soae differences as
illuscraced in Figure A,
Illt-r
vrnicl*
1,
if-
4
/
\
*»
i.
CTS,
Co 9u=t>
Figure i: Sulface Measarenen- Apparatus
The vehicle exhausc cixes uich chs dilucion air in a long Lube
as a dilution cunnel. Ac che QO'-mscrenni end of che cunnal, a
snail sample of che nixcure is drawn off through a filcer, which is then.
analysed by che barium chicranilace procedure co decerntine sulCace
concencracior^s in che exhausc. Entission.s of HC, CO and KOx are also
neasured in che conventional nannar using che CVS during sulfa^e en-.ission
cescs. •.../• . . •••',.
The fuel used for sulfane tcszir.g is Indolcne HO (unJ.eaded) uich a
S'.-.Lfur csr.ier.z of fl.flj"; by --eighi. In. sor.e cases, it is necessary co
use oilier fuels, such as for Diesoi-pover^d vehicles.
y ic is necessar
have airr.ndy
aid-::-v,-:-iE; (by i
rbor.r; . Those ~ti
to ccsc vehicles for emissions ocher
i-in disguised. 'dniiss ior.s thac may be
MET;: re~hcd) ar.d rcaccive and non-
-,r; usually ccr.ducccd only on pro-
-------
A-ll
Pouer ^ DriyeabilltTj
Relative engine power output can be measured, on a chassis dyca—
noaeter. Power output can be deteminad for any engine speed, including
che maximum engine power point.
Driveability is evaluated by the test .engineer. Itczis to be con-
sidered include acceleration, cold scare perfomasce, tendency to
stunble or hesitate, surge, and hot start performance,
CoamenCs about the e:
-------
LABORATORIES EQUIPPED TO
CONDUCT EPA EXHAUST EMISSIONS TESTS
While che Federal Government does not formally approve laborstories for
emission, testing, certain independent laboratories are known to be
capable" of. performing enissions tests in accordance with the federal
procedures. Their equipsactt is siuilar or equivalent Co that used in.
Che EPA Motor Vehicle Eaissions Laboratory. The following list of
several such laboratories is published for the information and con.—
veciance of aoolicants for evaluation of devices.
AP Pares Cospany (Onestor Coapany)
543 >!atzin^er Road
Toledo, OH 43597
419-729-3953
Automotive Environmental Systems, Ir.c
7300 Bolsa Avanua
Wescainscer, C.A. 92683
714-897-0331
Ethyl Corporation
1600 West Eight Kile Road
Femdale, lit 48220
313-564-6940 . -'
Olson Enginaerinj, Tac.
Vehicle Test Facility .
15512 Connarce Lane '
Huntingcon Beach, CA 92649-
714-894-9875
EG & G Automotive Research Inc.
5404-08 Handera Road
San Antonio, IX 78238
512-684-2310
Autoaotive Testing Laboratories
19900 Ease Coi£ax Avenue
Aurora, CO 8C011
Autonocive Testing "Laboratories
10S62 Metro Court
Maryland Heights, HO 63043
314-363-2795
Automotive Testing Laboratories
Trans pert 2 tier: Hasearch Center of: Ohio
E. "Liberty, OH 43319
513-656-3051
Systems Contro-1, .Inc.
11665 Levan Roat!
Livonia, HI 43150 .
313-591-0011
Systems Control, Inc.
421 East Cerritos Avenua
Anahcia, CA 92S05
U. R. Grace Co. ,
Division of BRC
7091 Belgrade
Garden Crox'e, CA S2S41
714-893-0421
Engineering and lesesrcp.
3995 Research Park Drive
Ann Arbor, XI 431Q4
313-665-2044
-------
ISB
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
Summary of Re5pons.es toi_ E_PA^_Reguest_ for Information
on Effects^ of LeadandL Lead^cavengers jji^ Gas^ollne
on Automotive Exhaust Catalysts
I n t r o d u ct i o n
Lead alkyl compounds (tetraethyl lead and tetramethyl lead)
are added to automotive gasolines to increase the gasoline's octane
number. However, because extended use of leaded gasoline can cause
excessive lead deposits in the engine, compounds known as "scavengers"
are also added to remove the lead from the engine. The scavengers
generally used in the typical leaded "motor mix" gasoline are ethylene
dibromide and ethyletie dichloride. Thus, leaded and unleaded gasolines
differ not only in terras of the former having substantial lead concen-
trations, but also with respect to the presence of scavengers.
The adverse effects of leaded gasoline on automotive oxidation
catalysts have been known for many years. Use of leaded fuel causes
deactivation of the catalyst's ability to oxidize hydrocarbons and
carbon monoxide.
In April 1974 a technical paper was presented by Dr. Max Teague
of the Chrysler Corporation which included data on the relative effects
in "poisoning" automotive catalysts of lead additives and ethylene
dibromide and ethylene dichloride scavengers. The data, which were
obtained in a series of engine dynamometer tests of catalysts with
various combinations of lead and scavengers in the fuel, were interpreted
by Dr. Teague as indicating that the ethylene dibromide scavenger,
rather than the lead alkyl additives, is principally responsible for
catalyst poisoning observed when leaded fuels are used.
To obtain further information on this subject, EPA wrote on
May 2, 1974, to Chrysler and several other firms. A copy of that letter
is attached. The responses have been reviewed by EPA and the principal
findings are discussed below. Copies of the responses are available
for inspection by the public at the Freedom of Information Center at
EPA headquarters in Washington, D.C.
Summary of Responses
The information supplied in the responses was gathered over
a variety of test conditions and catalyst types. Because of these
differences, it is not always possible to compare results from one
test with another. In addition, there are some cases where important
information, such as the response of a control catalyst to unleaded
gasoline, is lacking. However, Che respondents report tha following
findings:
FS--6
-------
L. The effect of presently formulated leaded gasoline
or. catalyst activity.
All tests with fuel containing lead, ethylene dichlorlde
and ethylene dibromide additives in combination resulted in serious
degradation of catalyst activity in noble metal oxidation catalysts
of the types expected to be used on 1975 model automobiles. Exxon,
Chrysler, and GM all reported that this poisoning is largely, but
not totally, reversible. This confirms that leaded gasoline as it
is presently formulated is incompatible with automobile oxidation
catalysts.
2. Catalyst response to gasoline containing lead and
ethylene dj-bromide.
Standard leaded gasoline contains ethylene dibromide
in a 1:2 ratio with ethylene dichloride. When tests were run using Just
lead and ethylene dibromide, significant catalyst poisoning was
found. Chrysler reported that this combination produced rapid
deactivation in the catalyst planned for use on 1975 model Chrysler
Corporation cars and that this effect is partially reversible.
Exxon Research and Engineering conducted engine dynamometer
tests on an Engelhard type IIB catalyst. The tests with lead and
ethylene dibromide showed a severe loss of activity for both HC and
CO conversion which proved to be only partially reversible. None of
the other respondents tested this particular conbination, but the
Chrysler and Exxon findings claarly indicate that lead with ethylene
dibromide poses a serious catalyst poisoning problem.
3. The impact of lead wi^hethylane dichloride on
oxidation catalyst activity.
Some serious disagreement arises on the question of a
catalyst's ability to perform satisfactorily with gasoline containing
both lead and ethylene dichloride. Chrysler found that this combination
caused no poisoning of their catalyst after 20 hours of running the
engine (equivalent to about 700 to 1000 miles) under cyclic
conditions (750 and 2400 RPM). Chrysler performed X-ray fluore-
scence analysis on the catalyst tested with lead and ethylene
dichloride (no ethylene dibromide) and on a catalyst tested with •*>
standard "motor mix" fuel. Chrysler considered the amount of lead
found on the ethylene dichloride sample to be "relatively substantial,"
although the lead content of the "motor mix" sample was higher.
Sharply different results were obtained by other test groups. CM
ran engine dynamometer tests using indolene clear fuel treated with three
-------
grans per gallon of lead and ethylene dichloride on a Pt-Pd noble metal
pelleted catalyst planned for use on 1975 vehicles. A very significant
decrease in HC efficiency (from 86% to 49% in two hours) was noted.
(This test strongly suggests catalyst poisoning, however GK did not
run a baseline test using or.ly indolene clear fuel,}
The combination of lead and ethylene dichloride was also "tested
by Exxon Research and Engineering on an engine dynamometer, using an
Engelhard 1IB monolith catalyst. After 7-10 hours at a steady 40 raph
condition, resulting in a catalyst temperature of IZOOT, the catalyst
exhibited a very significant loss in HC conversion and a smaller loss
in CO conversion. Both of these losses in conversion efficiency were
only partially reversible.
In some full throttle high speed single cylindet engine dynamometer
tests conducted by Ethyl, various fuel additive combinations were used
on Engelhard PTX noble metal monolith catalysts. These tests showed
identical deterioration for fuel with six grass per gallon lead and
ethylene dichloride and for fuel with just the six grams per gallon
lead. Howeverj no baseline case (i.e., fuel with no additives) was
run for comparison.
Even if the tests which indicate that lead and ethylene dichloride
do not poison catalysts are accurate, it is possible that over extended
mileages they could act as catalyst poisons. To answer this question,
Chrysler ran engine dynamometer durability testa for about 400 hours
(equivalent to 25,000 miles), using indolene clear fuel with no
additives in one case and indolene clear fuel with lead (1*5 grams per
gallon) and ethylene dichioride in the other case. Both tests were
run under cyclic conditions with the predominant mode being a 3300 KPM
(or 65 mph) condition, resulting in & 1550°F catalyst temperature.
Both tests showed identical deterioration of the catalyst, showing
that lead and ethylene dichloride did-not cause catalyst poisoning.
However, additional extended mileage tests are probably needed
at conditions resulting in lower catalyst temperatures. There exists
evidence that lead may not be able to deposit on and poison the catalyst
at higher temperatures. For example, the ncble metal pelleted catalyst
used in the HOP miniverter (a retrofit device) is thought to be
somewhat resistant to lead poisoning because of its high operating —
temperature. . '
Finally, even if lead and ethylene dichloride prove to be safe
for automotive catalysts for extended mileage, the engine oust be
able to operate properly with only the ethylene dichloride scavenger.
Chrysler feels that it may be possible to run an engine on this
combination without valve and other damage. Chrysler is continuing
studies on the feasibility of using only lead and ethylene
-------
- 4 -
A. The effect of Igadsjl_gi^e _pn _ca_taly3t^_actiy^ty.
Several test groups investigated the properties of lead
without any scavengers with respect to catalyst activity* Chrysler
reported various multi-cylinder and single cylinder engine dynamometer
tests which show that lead itself does not poison catalysts.
Ford conducted a series of tests using their pulse flame'
apparatus, where the test fuel is combusted in a burner set up to
give a mixture resembling vehicle exhaust. Cyclic conditions were
used to give the catalyst temperature a range front 700 ,to 1400° F,
with the activity tests done at 930° F. The pulse flame apparatus,
which is extremely sensitive'and can detect minute variations in
catalyst activity, indicated a severe drop in HC conversion and a
slight drop in CO conversion with isooctane fuel containing 0.5 grams
per gallon lead. After the test run of 9000 miles, the same catalyst
was operated vith isooct?ne fuel without additives for an additional
' 3000 miles. Wo recovery of HC and CO activity could be detected,
indicating the poisoning from lead alone is permanent.
Ford also included information on some IIEC work done in 1970
on base metal catalysts. This is not particularly relevant, since
base metal catalysts are not planned for use In 1975. These tests
indicate that a base metal catalyst run on fuel containing 0.5 grams
per gallon lead becomes poisoned much more readily than when it is
run on fuel with lead and scavengers. It seems unusual that the
vehicle using fuel containing only' lead would have more severe,
catalyst poisoning that the vehicle using the motor mix. Even .though
these results were not for 1975-type catalysts, they nevertheless
indicate that lead alone may came catalyst poisoning for base metal
catalysts,
Universal Oil Products (UOP) reported on some engine dynamometer
tests run in 1959 on a noble metal pelleted catalyst using fuel with
lead only. After 6000 miles at steady state conditions resulting
_ in catalyst temperatures of about 1200° F, the catalyst exhibited
severe degradation. In addition, lead deposits in the engine were
such that two engine overhauls were required. UOP concluded from
this work that lead is a serious catalyst poison.
In the Exxon 40 mph engine dynamometer tests with Englehard
IIB noble metal monolith catalysts, gasoline with 3.5'grama per gallon
lead was used, and a catalyst operating temperature of 1200° F was
reached. The tests showed that lead is a definite poison for this
catalyst, though not as serious a poison as lead with the scavengers.
However, the catalyst poisoning from lead alone appears to be
Irreversible. •
-------
- 5 -
DuPont has run tests on an experimental ?t-Pd catalyst they
have developed. A 200 hour single cylinder test shows this catalyst
is poisoned much mote by fuel containing lead and both scavengers
than fuel with lead alone, though the test with lead alone did exhibit
some deterioration.
The Ethyl Corporation reported results from a series of tests
on leaded gasolines without scavengers. An engine dynamometer test
equivalent to about 12,000 miles showed identical deterioration when
a noble metal monolith catalyst with an inlet temperature of 1500-
1600° F and 2 grams per gallon leaded fuel was compared with a control
catalyst where fuel without lead or scavengers was used. Again, the
very high catalyst temperature may have inhibited lead poisoning.
Ethyl also conducted some single cylinder engine tests in which
the catalyst temperature did not exceed 850° F, Englehard PTX catalysts
were run on indolene with 0.5 grams per gallon lead and on indolene
without additives. The catalyst on leaded fuel exhibited only slightly
greater deterioration than the unleaded. When this test was repeated
using 6 grams per gallon lead} the catalyst run with lead showed a much
greater deterioration. These Ethyl tests suggest that lead is a more
serious catalyst poison in higher concentration, at least for low
temperatures.
5. The effect of ethylene dibromide alone on catalyst activity,
Engine dynamometer tests conducted by Chrysler showed that
fuel containing ethylene dibronside without lead or other additives causes
rapid deactivation of Chrysler's catalysts. However, when fuel containing
no additives was then used, there was a major but not complete recovery
of activity, suggesting that ethylene dibromide poisoning is reversible.
Recovery is tnore complete for CO chan HC.
In a laboratory bench test employing synthetic exhaust gas,
GM reports that the HC conversion rate for a heated catalyst sample
dropped from 92% to 48% when small quantities of ethylene dibromide
were added to the exhaust mixture. The catalyst activity was restored
by passing the gas mixture without ethylene dibromide over the catalyst
for an hour. In engine dynamometer tests of noble metal pelleted
catalysts planned for 1975 usa by GM, HC conversion efficiency dropped
significantly when ethylene dibromide was added ,to the clear test
fuel, with good recovery on subsequent use of the indolene without
additives.
-------
- 6 -
In these tests, GM discovered that ethylene dibromlde in a fuel
with no lead can. scavenge lead iron engine deposits built up on previous
engine operation with leaded fuel. GM feels it is important to use an
engine never exposed to lead to ascertain the effect of scavengers as
catalyst poisons.
Ford used their pulse flame reactor to test the effect of ethylene
dibromide oh a monolith catalyst sample. KC and CO conversion dropped
over the 8,000 mile test, but when isooctane fuel without additives was
used on the same sample, almost complete recovery of catalytic
activity occurred. This strongly suggests that ethylene dibromide
is a temporary catalyst poison.
Ethylene dibromide was tested in the Exxon Research and
Engineering series on an engine dynamometer, using an Engelnard
IIB monolith catalyst at a temperature of about 1200° F. The fuel
with ethylene dibromide resulted in a very severe drop in HC and
CO conversion, but this loss was almost completely reversible. Exxon
feels that ethylene dibromide forms a noble metal halide which later
decomposes.
6. Thg^eff^ec^^f^ethylene dichloride jiloiie on catalyst activity..
Chrysler used a fuel containing only ethylene dichloride
in an engine dynamometer test. The engine was run under very mild
conditions for 10 hours, during which no poisoning of the catalyst
due to ethylene dichloride was detected,
GM used a laboratory bench set-up with synthetic exhaust gas, to
which a. small amount of ethylene dichloride was added. A significant
drop in HC activity of their catalyst sample was noted,-with twenty
minutes required for full recovery when passing the gas mixture without
ethylene dichloride through the catalyst. This indicates that ethylene
dichloride causes reversible catalyst poisoning.
Ford results with the pulse flame reactor indicate no detectable
loss in catalyst activity due to ethylene dichloride aver a period
equivalent to a 10,000 mile test. The tests were conducted on a
monolith catalyst sample over cyclic temperature variations from 700
to 1400° F. The same test, with activity measurements at 930° F,
had detected catalyst deterioration from ethylene dibrofiiide and lead
(separately). ~"
Engine dynamometer tests conducted by Exxon Research and
Engineering showed only a slight loss of HC conversion due to, ethylene
dichloride, most of which was reversible. Ethylene dichloride had no
discernable effect on the CO conversion efficiency.
MSAPC - December ]Q7i
-------
i-Jr. S. L. Terry, Vica
Chrysler Corporation
Post Office Bex 1919
Detroit, Michigan 43231
Gear iir» Terry:
Oa April 13, 1974, Dr. Mss»U Taagea of tba Chryalsr Corporation
presented a paper at t^g gy'p^lmt ''Health Coaagqcsaefts of Srsrtronaental
Controls: Lspact of Kabila Ea±3a±oa» Controls" held ia Darfaaa, Sorth
Carolina. The title of Dr. Teagae's pa&ex ^aa "SO^ Saiaaioea frca
ad i4o»-O3±datioa Catalyst-feprLpfed Veaicla*". Caa topic
In hfg preaantatica was tiie .ef f act on catalyst effltrlfncy of
tetraathyl lead and of the haliria sca^eagars (etirylzaa dibroaida asd
dlchlerdda) prasa&tl^ es«d with lead
In the preaentatioa of Ma papar,. Dr. Taagws reierred to data
In a &arias of eogise dTnaaoHsater catalyst efficiency testa
conducted with diffarsnt fuel and adoitlva crggalcacicga. Is particular,
&TI> Teagce'a work ccttsldarad ^g-^rata coabiaatiooa of lead sddltd^Tca acd
ethyLsne dlbrcmida and etiylana dicHlorld^ sea^e&^ers* Fros thasa data
it ^aa pogtnlatad by Dr. Tea^aa that it is the atbylaoa dlbrtraida
not lead antiinoei odditiveo, tjhieh is principally responsible for catalyst
deacti nation associated slth the 09 a of lea^ad gasoliaaa.
Such a caMielcaiaaa, if aabatautiatad by fortber
clearly has strung r&lawnca to the tinriroira«iital ?rotection Ageaey'a
tnd^r S^rtlnn 211 of tba Claan Air Act: as STtgarda the
regoLatioa of fnala and fsal addizlves gfaieh -aay ba fomaj to lapair tha
-cerf oramkc« of oxidation catalytic converters. 1^ order to facilitate
farther i:e.\i±mm aad jpTaBrlgatioo o£ this nattar by tha Sn^iroaaantal
Protaetiaa Agency, I aa hemby re^aeatins tbat tha Chrysler Corporation
: provide ua vith tha full details and resales of the
described by Dr. Teagoa la tha prssaBtaticn dascriiad above,
all othax data o? information gfrich Chrylsar way hava ^ileh am
to tba relativ* inportaaea of laad additlvea an^ organic
scavengers In caaains tba poiaonias of sctOHDt±T9 eahjjaiat catalytic
coiwertara* Re are also hereby requesting say, inforaatioa chieh thai
Chryalerr .Corporation say bava ca altamati-Te scavenger fcrsalatioos
uhicb raigirt peradt tha nae of tfaded gasollae la oxidation catalyst-equipped
autcmobilea without stiiatanti-al catalyst
-------
-2-
To perait a pTOliaiaary evaluation of this isstse vhich has b-ean
by Cirryslar, we ars nakdtig similar re^vnaats for Infor^atloo oa tfcega
subjects to a fnw othar an£o s»nufactarsr3, catalyse izaiiafaet
additive TTwEiuisetUTarg, aiid petrolaua coj3?ard23, Iks atta=!p£ is being
at ciis tiaa to solicit 9ueh iaforaaticsi £r-5a all poflalbla Interastarf parties,
ftather, siiould tola Drallrdnmrf rerisv ba.
-------
FACTS ABOUT METHANE GAS
FOR AUTOMOTIVE USE
1 • Wjiat is inethano gas?
At room temperature methane gas is an odorless, colorless, hydrocarbon
gas. Its chemical formula is CH^. Methane is the principal gaseous
constituent (90-95%) of natural gas which is commonly used for cooking
and home heating.
2. Hhere_is methane found?
Methane is found mainly in oil fields as gas pockets in upper parts
of oil wells or in gas wells. As a result, methane is usually the
first gas to appear when an oil well drilling is successful. It is
also the main constituent of sewage gas (2/3 CH^, 1/3 C02), and of
mar>h gas which is created by decomposition of organic material such
as vegetation and manure. Methane can also be produced from coal in
"high BTU" coal gasification systems now at the pilot stage.
3. Can methane gas be used as a fuel for a motor vehicle?
Methane, or more usually natural gas is employed in motor vehicles
either in its gaseous form (CNG; compressed natural gas) at high
pressure, or as a cryogenic liquid at - 26Q°F at low pressure (LNG:
liquefied natural gas). Either storage method results in considerable
complexity and cost relative to the conventional gasoline tank and
fuel system, and accordingly, additional expense. Also, the operating
range of the vehicle is more limited with methane due to its lower
density.
Experimental fleet programs using natural gas as a fuel have been conducted
by the Federal government General Services Administration (GSA) and various
-------
-2-
gas companies in the United States.
4. DoesjTiethane, ujed as a fuel by motor vehicles, provide low exhaust
emj s s j onj_?
Tests have shown that methane used in current Otto cycle automobiles
can meet the Federal 1972 emission standards. EPA data and other
readily available data on natural gas have not demonstrated the 1975
Federal standards. This testing, however, has been limited to dual-
fuel applications (gasoline and natural gas). In order for vehicles
to have the multi-fuel capability, compromises in engine calibrations
are required and the optimization of emissions is not possible. Data
are available, however, showing propane conversions (single fuel
conversions) that have met the 1975 standards. It is believed that
similar demonstrations could be made with natural gas if emission
optimization were performed.
5. How do the exhaust_g_a_s emissions from use of methane compare with thosj
from use of gasoline in the same engine?
The exhaust gas emissions are about the same except for carbon
monoxide which is one fifth of the amount produced by use of gasoline.
Available data on natural gas demonstrates major reduction in all three
regulated pollutants. It is also important to note that fuels whose
major component is methane, will have a high proportion of non-reactive
methane derivatives in the exhaust. Thus the reactivity (or photochemical
smog producing potential) of the hydrocarbon exhaust from a vehicle
operating on natural gas in significantly lower than comparable operation
*
on gasoline.
-------
-3-
6. Would the spark Ignition engine have to be modified to use methane
as a fuel?
A small modification in the carburetor and an additional pump, if the
gas is not pressurized, are necessary for metering the gas at proper
air fuel ratio. While on-board fuel storage is not directly related
to engine modifications for the presently used internal combustion
engine, it is a critical part of the modifications required for
gaseous fuel use.
7. Is anyone using methane gas from sewage?
Yes. It is used by some sewage disposal plants to supply heat and
power for their operation. The residue of the sewage sludge after
it has been processed has been used as a fertilizer, such as Milorganite,
a product of the city of Milwaukee sewage disposal system. It is often
the case that sewage disposal plants produce more methane than required to
operate their own equipment; the remainder is usually flared. Technical,
practical and jurisdictional barriers prevent this gas from being added
to the conventional natural gas system.
8. What is the amount of sewage gas obtainable from a city sewage system?
The amount is less than 1.0 cubic foot at normal temperature and
pressure per capita of population per day.
9. What amount of energyjcould be derived from city sewaje_gpmpared to
that obtajjied from_the total amount of natural gas burned annually
in the U.S.?
Ten billion cubic feet (10x 10^) per year of "substitute natural
gas" could presently be produced from sewage. This is a small amount
-------
-4-
1 o
compared to the 22 trillion cubic feet (22 x 10 ) of natural gas which
are consumed yearly in the United States.
10. What Is the total amount of organic waste matter generated in this
D3UjTtry_ jjgr year and what ampunt__of_ energy could be derived by
conversion to methane?
Stating the organic waste in terms of methane equivalency, there is
a total potential of 8.8 trillion cubic feet per year of methane which
could be theoretically obtained. The fundamental problem in using methane
from organic waste is its collection and handling because the waste must
be brought to a central location and left to decompose and then the resultant
methane transmitted into the natural gas supply line. It is difficult
to quote with precision the cost of methane derived from waste because
costs would vary appreciably depending on the collection scheme available
locally. The U.S. gas industry is well aware of the methane potential
of organic waste and when the cost to utilize methane from this source
becomes competitive with either methane or natural gas derived from other
sources it is reasonable to expect that this potential will be tapped.
11. Is._ anyone, using_,J|n_et^h_aiTig__g_a_s_f_roni_ jecompos ition of_ anijrial__manure?
No. The problem involves systematizing collection of organic waste-
matter. The big city sewage system is an example of an efficient
collection system.
12. What is the comparison in terms of energy content and volume between
methane jas an_d_ gasoline?
For methane gas at 3QOO psi pressure and a temperature of 80°F a volume
of 27 ft^ (methane gas plus container) would be required to provide
the energy equivalent of 2,7 ft of gasoline. (One hundred thirty-
two cubic feet of pure methane gas at normal temperature and pressure
has the energy equivalent of one gallon of gasoline).
-------
-5-
On a per pound basis, methane is slightly superior to gasoline in heatinq
value (21 ,500 vs. 18,000 RTU/lb, lower heatinq value). As a cryoqenic
liquid, its most dense state, methane has a specific gravity of 0,42, about
half that of gasoline.
13. VJhat js the j:omparisj)n in terms of energy content arid voTume__between_
sewage^ gas amd
One hundred eighty cubic feet of sewage gas at normal temperature and
pressure has the energy equivalent of one gallon of gasoline.
14. Is methane/natural gas a practical automotive fuel?
Although methane/natural gas fuels can provide lower emissions than
gasoline in current automobile power plants these gaseous fuels are
not recommended for national use based on limited fuel availability —
present and future. Additionally, vehicle volume constraints are a
physical handicap for practical use of gaseous fuels.
In limited fleet use where controlled conditions exist, gaseous fuels
are potentially practical.
EPA/OMSAPC
11-27-73
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C, 20460
OFFICE OF
AIR AND WASTE MANAGEMENT
FACT SHEET
KENDIG CARBURETOR
The Environmental Protection Agency has received many
inquiries about a device known as the Kendig Variable Venturi
Carburetor for which claims are made as regards improved fuel
economy and reductions in air pollution.
Early in 1973, the Kendig Variable Venturi Carburetor was
brought to the attention of EPA's technical staff. At EPA's
suggestion, the promoters of the Kendig carburetor arranged to
have a standard test made of a vehicle equipped with that
carburetor. The vehicle tested was a 1973 Toyota. The emission
and fuel economy data reported by the promoter of the Kendig
carburetor for his Toyota test vehicle were 1.53 gpm hydrocarbon,
15,69 gpm carbon monoxide, and 2.66 gpm oxides of nitrogen. The
fuel economy reported for the Kendig carburetor was 15.6 mpg.
These emission and fuel economy data were about equal to the
1975 Federal interim standards for unburned hydrocarbons, carbon
monoxide, and oxides of nitrogen, and were not materially different
from the standard 1973 Toyota. The fuel economy reported for the
vehicle equipped with the Kendig carburetor compared unfavorably
with a standard 1973 Toyota. EPA's technical staff advised the
promoters of the Kendig carburetor that on the basis of the data
provided no useful purpose would be served by confirming the Kendig
test results in the EPA's laboratory. However, the promoters were
invited to furnish additional data that might demonstrate significant
improvements over what had already been demonstrated.
In July of 1975 EPA was contacted concerning more recent
tests on the Kendig carburetor by an independent laboratory. Results
from these tests on a 1974 AMC Ambassador with a 401 CID V-8 engine
indicated substantial reductions in hydrocarbon and carbon monoxide
emissions with the Kendig carburetor installed, compared to a
baseline test on the same vehicle. Fuel economy was slightly
worsened. However, only one test each with and without the carburetor
were run, so the results were not conclusive.
FS-8
-------
- 2 -
On July 29, 1975, EPA invited the promoters to provide
either the vehicle with system attached, or the carburetor and
installation kit, for evaluation at the EPA laboratory. However,
the promoters informed EPA that they preferred to wait until
further development has been completed, at which time a pre-
production prototype would be made available for testing.
OMSAPC/December 1975
-------
* /
I
$ UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
Mobile Source Air Pollution Control
FACT SHEET
SUPPRESSED CARBURETORS THAT IMPROVE FUEL ECONOMY
We have frequently received inquiries that suggest that there are
available carburetors or other devices that, when Installed on automobiles,
would significantly increase fuel economy, and that are being suppressed
by either the automobile or the petroleum industries. In spite of diligent
efforts to do so, our technical staff has been unable to confirm such
suggestions. Furthermore, we are inclined to believe that because of
significant competitive advantages that would accrue to any company that
would be in a position to equip its vehicles with such fuel saving devices,
it is highly unlikely that any such devices are available and are being
suppressed.
However, if anyone should have available specific technical data
and test results on carburetors or other devices that substantially improve
fuel economy, we would be moat interested in reviewing such material. Such
information should be sent directly to the Director of the EPA Emission
Control Technology Division at 2565 Plymouth Road, Ann Arbor, Michigan 48105,
TS-9, ,
January 18, 1974
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
Hydro-Catalyst
The Environmental Protection Agency has received many inquiries
about a device known as Hydro-Catalyst, for which claims for significant
fuel economy and emission control benefits are being advocated. This
Fact Sheet has been prepared to answer those inquiries.
The Hydrocatalyst Corporation produces a bowl shaped screen-like
device which they claim exerts a catalytic effect on the fuel when the
device is suspended In the air/fuel flow stream at the base of the
carburetor. The alleged catalytic effect Is claimed to lower vehicle
cctane requirement and allow for leaner carburetion thus achieving a
reduction In emissions and an Improvement In fuel economy.
EPA tests on a 1970 Valiant with a 225 CID engine In June 1974
did not support the manufacturer's claims of lower emissions and improved
fuel economy. A test made on the vehicle immediately after the Hydro-
Catalyst device was installed showed a 26% Increase In hydrocarbons,
a 73% increase In carbon monoxide, no change In oxides of nitrogen, and
a 4% decrease In fuel economy when compared with a test of the car without
the device, A retest after the car was driven 1500 miles showed a 24%
increase in hydrocarbons, a 58% Increase in carbon monoxide, a slight
increase In NQx and an 8% decrease In fuel economy compared with the
baseline test. "•:'"'_
This limited test program tends to confirm an earlier test made
In July 1973 by EPA on the hydrocatalyst which concluded that no significant
control of hydrocarbons or oxides of nitrogen was demonstrated and that
a low level of carbon monoxide control demonstrated during the earlier
test was due to choke adjustment rather than to the Hydro-Catalyst device.
Although the quantitative results of these limited tests are not necessarily
applicable to all cars, EPA feels that the general conclusions drawn from
these tests are valid and that the Hydrocatalyst device is not effective
In either reducing automobile emissions or improving fuel economy.
OAWM/OMSAPC August 28, 1974
FS-10
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C, 20460
: FACT SHEET . . • • '
Fuel Economy of Mazda Rotary Engine -Vehicles
Early in January of 1974, United Press International carried a story
datelined Los Angeles which stated that 1fMazda Motors of America today
accused the Environmental Protection Agency of publishing misleading
figures about the fuel consumption of its Wankel-powered cars. Mazda
presented a report by J. D. Powers and Associates, a Los Angeles research
firm, indicating a majority of owners of the rotary engine Mazda were
getting 17 miles per gallon in city driving and 20 miles on the highway."
In response to inquiries on this matter from UPI, EPA explained the
basis of its fuel economy testing, and expressed the view that it is •
confident that the relative fuel economy results on all cars on which
EPA has published fuel economy data, including the Mazda rotary, are valid.
EPA has received many inquiries on these widely publicized stories.
To respond efficiently to these inquiries, this Fact Sheet has been developed,
Background on EPA Fuel Economy Data
The President's Energy Message of April 18, 1973, directed EPA, in
cooperation with the Department of Commerce and the Council on Environmental
Quality, to develop a voluntary auto fuel labeling program beginning with
1974 model year cars. EPA had already published the miles per gallon fuel
economy results that 1973 model year cars achieve when tested at the EPA
laboratory for the purpose of demonstrating that their air pollution
emissions are within Federal standards. Under Federal law, cars may not
•be sold in the U.S. unless they comply with air pollution standards, and
thus prototype models of all basic types of cars are ^tested by EPA each
year. The 1973 fuel economy data-were published in the Federaj. Registeir;
beginning with the 1974 model year, the data appear in dealers* showrooms,
and on the cars themselves.
The EPA test involves driving the vehicle, in a laboratory under
controlled temperature and other conditions that can affect fuel economy,
through a 7.5 mile driving cycle that .is typical of city driving common
to urban commuting. The test begins when the vehicle is cold, because
FS-11
-------
-2-
a cold start is typical of coTmnuting travel. This test procedure is
different from fuel economy test procedures typically used by automakers
since automakers test their cars, with engines that are already warmed up,
at more or less, steady speeds on a test track or on the highway. The
EPA test is far, more repeatable than a test track or highway fuel economy
test, and of course, more accurately represents the type of driving of
the typical commuter. ......
All fuel economy testing has its limitations, because fuel'economy
of any individual vehicle depends on many factors, one of the most
important being how the vehicle is driven. The EPA has clearly pointed
out in the,fuel economy data that it has published that individual drivers
can expect to get better or poorer fuel economy on their own cars of the
same type as tested by EPA, depending primarily on such factors as the
options on the car they buy, number of short and long trips, use in
city traffic or at steady speeds, and personal driving habits.
Nevertheless, the EPA published fuel economy data is the only data
available on so large a number of different cars that is obtained under
strictly controlled, entirely repeatable conditions, and for that reason
provides the best basis for comparing the relative fuel economy of cars
that are available for purchase by consumers. Although in the strictest
sense these, relative ratings apply only to a 7.5 mile city driving trip
of the type represented by the Federal Test Procedure, there are no
fundamental technical reasons why the relative fuel economy of cars should
not be about the same under different types of driving modes. For the 1975
model year, however, EPA will also develop and publish fuel economy data
under highway driving conditions.
Fuel Economy of the Mazda
The fuel economy results published by EPA are grouped by the weight
class into which each vehicle falls and at which it is tested, because
weight is the single most important factor that governs fuel economy for
most cars. In its weight class (2750 Ibs) the Mazda rotary engine car
demonstrated markedly lower fuel economy than did other cars. Excluding
the Mazda, the 1974 model year fuel economy results in the 2750 Ib class
ranged from about 15 to over 25 miles per gallon, with some vehicles at
each fuel economy-level in-between. The-Mazda rotary engine vehicle
achieved 10.7 miles per gallon, which was 30% less than the lowest other
vehicle in the 2750 Ib weight class, and almost 60% less than the best
performer in the weight class.
-------
-3-
Mazda Motors of' America disputed these results and 'offered in re"buttal
a variety of reports and statements from owners to the effect that the
fuel economy of its'vehicles is higher than that reported by the EPA.
EPA staff studied these materials, and concluded that they do not invalidate'
the fuel economy results measured by EPA on the Mazda rotary engine car
in city stop and go driving. In addition, even though different absolute
miles -per gallon results were reported in various other studies, as would -
he expected because of the differing test procedures used, several of
these studies commented specifically on the -relatively low fuel- economy • ;
performance of the Mazda rotary engine car. -. . . .
However, to fully investigate Mazda Motors of America's assertion
that the Federal Test Procedure, while an adequate, test for conventionally-
powered cars, may be inadequate to test rotary engine cars, the EPA conducted
a special test program to investigate whether in the case of the rotary
engine car the relationship of fuel economy between city driving and
highway driving may "be different from that relationship on conventionally
powered cars.
The results of1 this special, test program were announced "by EPA on
April 11, 1974. In summary, the results showed that the relationship of
fuel economy results in city driving and highway driving are the same for
Mazda rotary engine vehicles and for conventionally powered vehicles — each
type of vehicle gets about 50% better fuel economy on the highway than it
does in the city. The following tabulation presents the key data on the
Mazda cars tested and on the conventionally powered vehicles that were
included in the test program to provide a basis for comparison:
Vehicle Ratio of
. Weight City Fuel Highway Fuel . Highway IE
Vehicle (Ibs) Economy_ Economy to City
Saab 2750 21.0 30,6 • ' 1.46
Vega Automatic 3000 18.7 27.7 1.48
Gremlin 17.7... 27.2 .' 1.54
Vega Manual 3000 17.5 30.7 1.75
Mazda BX-2 2750 13.4 21.2 . 1.58
Mazda UX-3 2750 13.3 19.0 ~ 1.43
Mazda EX-4 3000 12.5 20.5 1.64
Ford Torino 4500 12.5 20.0 1.60
-------
-4-
It should be noted that the city-driving fuel economy results for
the Mazda vehicles in this special test program were about 20% better
than the comparable results measured earlier in certification testing;
the same phenomenon exists for the Ford Torino., This fuel economy
improvement is primarily attributable to the relative state of tune
of the vehicles in each test program. In this test program, each
manufacturer was.invited to provide his vehicles in optimum state of
tune, whereas in certification testing vehicles are tested after 4000
miles of mileage accumulation without a major t-uneup allowed to be
performed. Constraints of time and other factors made it impractical -
to request manufacturers to run new cars for 4000 miles prior to testing
in the special program; thus, allowing all cars to be provided to EPA In
a state of optimum txineup was the only fair way of comparing the fuel
economy results.of these cars.
Fuel economy comparisons are not possible for the other vehicles in
the two test programs (except for the Vegas, see below) because the other
vehicles differed in some material respect from their certified configurations;
manufacturers are allowed to make changes from the certified configurations
during the model year if they obtain approval of such changes from 1PA, In
the case of the Vegas, the fuel economy results in the two test programs
are about the same5 GM provided to EPA the very same vehicles that had been
tested for certification, and GM did not perform a major tuneup on those
vehicles between the two test- programs.
From these and other data described in detail in the full report on the
special test program, EPA estimates that the fuel economy of Mazda rotary
engine vehicles in cold-start city driving is about 11 to 13 miles per
gallon, depending on the state of tune of the engine. The complete test •
report can be obtained on request from EPA's Office of Public Affairs,
Public Inquiries Section, Washington, D.C, 20460.
MSAPC/April 15, 1974
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON. U.C. 20/160
OFFICE OF
AIR AND WASTE MANAGEMENT
Use of Alcohols as Motor Fuel
The Environmental Protection Agency has received many questions
and suggestions on the subject of alcohols as motor fuel. To respond
efficiently to these many inquiries, this Fact Sheet has been prepared.
Among the advantages claimed for alcohols are lower emissions of
air pollutants, improved fuel economy, and expanded fuel supplies.
Over the past several decades, a number of studies have been performed
to analyze the feasibility of alcohols as motor vehicle fuels. These
investigations, focusing on the use of ethyl and methyl alcohols, have
considered the alcohols as blending components with gasoline as well as
pure fuels for vehicles.
Alcohol Availability
Hethanol (methyl alcohol) can be produced from natural gas, coal,
wood, or organic wastes. Most of the raethanol manufactured is produced .
from natural gas, but the future availability of natural gas in the
United States is much too limited to support increased production of:
methanol to use as fuel — natural gas is far too valuable as a fuel, in
its own right.
Wood waste as a source of methanol is technically feasible,, but
methanol from this source could not be made available on a large scale
because wood waste is a limited resouce. The same is true for methanol
produced from municipal organic wastes. Neither source could supply a
significant fraction of U.S. motor fuel requirements. The production
of methanol from agricultural waste materials is also possible and is
being intensively studied, but it is too early to say whether collection
of the many diffuse sources of agricultural waste materials for sub-
sequent processing to make methanol is economically justifiable.
An entirely feasible and potentially abundant resource for expanded
methauol production is coal. The technology is known and several different
feasible processes have been identified. However, coal can also serve as
the raw material for other synthetic fuels, including gasoline. Also, methanol
produced from coal can be further processed to make synthetic gasoline. It
is not clear whether — when gasoline costs rise to a point that makes the use
FS-12
-------
of coal as a source for synthetic fuel economically feasible — it
would be better on a total system basis to use coal to (1) produce
gasoline directly, (2) produce mathanol for subsequent conversion to
gasoline, or (3) produce methanol for direct use in vehicles.
Ethanol (ethyl alcohol) is primarily produced from ethylene, a
petroleum derivative, and to a lesser extent from grain, sugar cane
and other fermentable crops or crop residues. For petroleum conser-
vation reasons, it is necessary to consider here only the non-petroleum
sources for potential expanded ethanol manufacture. In the United
States, the largest potential non-petroleum source of raw material
for ethanol production is grain. However, if all "United States grain
production were allocated to produce ethanol for vehicle fuel, the
total amount would be equivalent to only about 30 percent of current
gasoline usage. Grain production could not, of course, be diverted
on a large scale for this purpose. It is apparent that ethanol
could not be produced in significant amounts in the United States
in the reasonably near future, except possibly in limited, regional
areas in the grain producing states. Recent studies by the Department
of Agriculture have investigated this topic much more completely.*
Periodic grain surpluses along with off-specification or spoiled
grain which is not acceptable for food purposes could.potentially be
converted to ethanol. A program to encourage the usage of ethanol as a -
gasoline supplement has been actively pursued by the State of Nebraska
for a number of years. Here, a state law provides a three cent per
gallon reduction in the state gasoline tax on fuels containing 10 percent
agriculturally derived .ethanol and the balance unleaded gasoline. Financing
is being sought to permit the construction of one or more large ethyl
alcohol plants to enlarge this program, but .the prospects for successful
commercialization are unclear at this time. Such plants, once built,
must operate more or less continuously in order to have a chance of
paying for themselves, which might become a problem during periods of
grain shortages.
Other fermentable crops which are potential feedstocks for ethanol
production, such as sugar cane, sugar beets, and potatoes, are considered
even less economically attractive for motor fuel purposes than the cereal
grains, in the growing conditions characteristics of the continental
United States.
*Gasohol From Grain - The Economic Issues, U.S. Department of
. Agriculture, ESCS No. 11, January 19, 1978. (Prepared for
Task Force For special purposes, Committee of the Budget, U.S.
House of Representatives.)
-------
- 3 -
In Brazil, ethanol is currently being used as a fuel extender
(up to 30 percent mixed with gasolines at times in some localities)
in quantities amounting to a national average of 1-2 percent of the
gasoline supply. However, vehicles produced for sale in Brazil are
equipped with modified fuel systems designed to minimize any incompa-
tibility with the alcohol blends. Previous to these design changes,
vehicles experienced failure of certain fuel system materials which
are caused by the ethanol/gasoline blends. It is suspected that use
of gasahol blends in the U.S. without modifications to in-use vehicles
to minimize fuel system incompatibility may lead to accelerated failure
of certain fuel system materials that are susceptible to chemical and/or
physical attack by ethanol. Intensive .efforts in Brazil are under way
to increase the national average to 20 percent in the 1980's by the use
as a raw material of a root crop called manioc. Although it appears
potentially feasible to use manioc for ethanol production, the
chemical processing steps needed to convert the starch root (20-40 percent
starch) to fermentable sugar have not yet been fully proven. .Brazil's
potential to produce large quantities of ethanol stems from several
conditions. First, Brazil already has a surplus of sugar cane which
has been encouraged in the past few years by government policies. Sugar
cane can produce, in the proper soil and climate, approximately 300 gallons
per acre per year of ethanol. Second, in the long term, Brazil has vast
quantities of unused arable land for potential future production of
ethanol. This is not the case in the United States-, where most readily
cultivated land is already in full agricultural production.
Exhaust Emissions of Alcohol Fuels
The exhaust emissions of methanol and ethanol fuel, both in pure
form"and blended with gasoline, have been investigated by EPA and are
continuing to be evaluated by the U.S. Department of Energy. Most
testing has been done with methanol because it will probably have a
greater impact on the fuel situation in the United States than ethanol.
In the pure alcohol tests, modifications were made to the vehicles
(mainly carburetor changes) to allow proper operation.
Emission tests on methanol/gasoline blends on unadjusted vehicles
have shown comparable HC emissions, slightly reduced CO emissions, and
reduced NOx emissions when compared to vehicles operating on pure
gasoline. There are also varying amounts of unburned methanol, which
are only partly measured by the hydrocarbon analyzers and aldehydes,
which are not measured at all during most emissions testing. The
impact of increased aldehydes, emissions on 'air quality remains to be
determined. However, aldehydes are one of the species of highly
reactive oxygenated hydrocarbons that contribute to formation of
photochemical oxidants, so that some adverse air quality effect is .
likely if substantial increases in mobile source emissions of aldehydes
occur. Preliminary indications are that the emissions of methanol and
I/ Science, Vol. 195, February 11, 1977, pp. 564-566.
-------
aldehydes are reduced by catalytic exhaust system reactors, along with
the carbon monoxide and hydrocarbons.
The test results depend to a great extent on the test vehicle
operating conditions, especially when more than 10 percent methanol is
used. This is because the addition of significant amounts of methanol
to gasoline causes the resulting combustion mixture,to shift toward the
lean (excess air) side of the chemically correct proportions. However,
if a vehicle is adjusted to compensate for this effect no significant
gaseous emissions changes have been noted, except for a slight reduction
in NOx emissions, which is due to the lower temperature of combustion.
As a sidelight, this effect can be of some benefit, if used selectively
in high altitude, sections of the United States, since vehicles calibrated
for optimum emissions performance at low altitudes tend to operate excessively
rich at high altitudes and display correspondingly high HC and CO emissions.
The enleanment effect of operation with alcohol gasoline blends can then
work to the advantage of both emission control and fuel economy. An EPA
sponsored test program has been established to further evaluate the potential
benefits of the use of ethanol/gasoline blends (gasohol) as a high altitude
emissions reduction strategy.
In order to operate properly over a range of alcohol/gasoline blends,
a vehicle carburetion system should be calibrated to provide acceptable
driveability on the blend containing the highest concentration of alcohol
likely to be encountered in service. Such vehicles might then operate with
excessively rich mixtures (excess fuel) when they operate on pure
gasoline, with the probable result of increased HC and CO emissions. For
example, in Brazil where the ethanol level in gasoline is random (varying
from 0 to 30 percent in some localities), vehicles are designed to run at
rich mixtures to accommodate this wide range of blends. This results in
increased average HC and CO exhaust emissions, compared to vehicles designed
to meet U.S. emission standards. However, recent advances in automotive
emission control technology have led to the development of the-closed-
loop three-way catalyst emission control system which is in use on a small
number of cars currently and is expected to be used on more cars in the
future. This closed-loop three-way system uses an exhaust oxygen sensor
to control the fuel distribution system (fuel injection or carburetion)
so that a chemically correct combustion mixture is maintained. Recent
data have suggested that such a system may be capable of adjusting the
oxygen content of the exhaust gas so that the catalyst is effective for
a range of gasoline/alcohol blends. If this is true, such a vehicle
may achieve both effective emission control and good fuel economy with
a wide range of alcohol gasoline blends. More data are needed on the
compatibility of three-way catalyst systems with alcohol gasoline blends
to establish whether this generalization is true.
-------
Fuel Economy Characteristic^of Alcohol Fuel
Alcohols have lower heating values than gasoline. For example,
methanol has only 45 percent of the volumetric heat of combustion (BTU's
of heat energy per gallon of fuel) of isooctarie, a typical gasoline
component. Thus, more alcohol is needed to maintain an equivalent
engine power output. A vehicle with an unaltered fuel storage tank
will therefore have only about half .the operating range, when operated
on pure methanol with no other changes except to adjust the carburetor
metering so as to allow the vehicle to run properly. If an engine were
completely designed for best performance on methanol» through such measures
as increased compression ratio, and various intake system changes to
permit stable engine operation at very lean mixtures> this penalty'in
range could potentially be considerable reduced, but not eliminated..
Such basic design changes cannot realistically be retrofitted on existing
vehicles.
The penalty in range will be correspondingly less and perhaps
tolerable to the average motorist with methaneI/gasoline blends.
However, reduced fuel economy has been noted when vehicles are
operated over a wide range of alcohol/gasoline blends including more
than 5 percent alcohol. This is caused by the reduced energy content
of the methanol/gasoline blend. A contributing factor is that such
vehicles must be adjusted to operate -properly on the alcohol/gasoline .
blends that contain the highest expected concentration of alcohol, and
will thus tend to run too rich when operated on blends containing less
alcohol. However, recent tests sponsored by the Energy Research and
Development Administration (ERDA) indicate that if a 10 perecnt alcohol
blend were used regularly and appropriate engine adjustments were made
for this blend, motorists would not likely observe any significant
change in fuel economy.
Alcohol Fuel Costs .
Although no definite figures are available for estimating the cost
of producing large quantities of fuel grade alcohols, some rough estimates
can be made comparing alcohol fuel costs to gasoline. The following costs
for alcohol fuels are current estimates and would be modified by future
changes in technology such as improved large scale coal to methanol con-
version facilities. Table 1 persents rough cost estimates on alcohol
and gasoline fuels.
-------
- 6 -
Table 1 - Alcohol Fuel Costs I/
Fuel Type
Gasoline
Gasoline
Methanol
.Methanol
Methanol
Methanol
Ethanol
Source
Harmf^ctur/ing^ Cos t
$/GalIon $ / Equ iv. _Energy .2 /
$9 /barrel crude
$20/barrel crude
Natural Gas
Lignite Coal
Petroleum Residual
Municipal Waste
Grain 47
0.38 £'
0.72
0.22
0.36
0.43 .
0.60
.96
0.38
0.72
0.44
0.72
0.86
1.20
1.45
As can be seen from Table 1, on an equivalent energy basis methanol
costs (as currently estimated) are comparable to gasoline which might be
produced in the future from crude oil priced at $20.00 per barrel. It
is considerably more expensives on an equivalent energy basis, than
gasoline manufactured from crude oil at current prices (about $9.QO/
barrel). Ethanol is much more expensive than methanol. The cost
listed above is believed by the Department of Agriculture to be the
•lowest achievable.
Health and Saftey Hazards of Alcohol Fuel
As with gasoline, small quantities of methanol are toxic to humans.
Methanol differs from gasoline in two ways which make its widespread use
as a fuel a matter of special public health concern. First, unlike
gasoline (even the kind containing tetraethyl lead) methanol can be
more easily absorbed through the skin in toxic quantities. This would
create health risks beyond those experienced with gasoline during
normal fuel handling or spillage as well as from use of methanol as a
cleaner/solvent. However, methanol is soluble in water, unlike gasoline,
so that cleaning up a spill or washing off exposed skin is a relatively
simple matter. Second, also unlike gasoline, ingestion or inhalation
of relatively small amounts of methanol can result in irreparable damage
to human vision. Ingestion of small amounts of methanol can result in
blindness. Longer term exposure to small amounts may -result in reduced
visual capacity.
_!/ Stanford Research Institute data except for ethanol from grain,
2j Equivalent energy costs with, gasoline used as a. baseline and
alcohols adjust accordingly to account for tbeir lower energy
content.
_3_/ Corresponds roughly to gasoline selling for $0.64 per gallon at
the service station (which includes distribution and taxes).
'kl U.S. Department of Agriculture, ESCS No. 11, January 17, 1978.
-------
Thus, while gasoline and methanol are both toxic -to humans,
methanol has two properties different from gasoline—absorption through
the skin in toxic amounts and damage to vision in sublethal amounts—
which could result in an additional public health risk from general use
of methanol or methanol-gasoline blends. These additional risks are
amplified by the likelihood that people would tend to handle-methanol
in the same manner as gasoline, by syphoning or by use as a cleaner/
solvent. These and other health and safety factors are being investi-
gated in considerable detail by the Department of Energy.
Ethanol exhibits much less toxic effects than methanol but the
vapor is an eye and upper respiratory tract irritant.
The safety of met'hanol and ethanol relative to gasoline has yet to
be totally assessed. In open fires, alcohols appear to be less hazardous
than gasoline (except that alcohol fires are not readily visible) but in
ventilated containers it is more hazardous. Alcohol's solubility in water
makes fire suppression by water flooding relatively simple.
Other Tech.nic.al Considerations^
. The absolute solubility of methanol and ethanol in gasoline is a
function of the hydrocarbon make-up of the gasoline, temperature, and
quantity of water present. If solubility limits are exceeded, phase
separation will occur. Phase separation results in separate alcohol
and gasoline layers in the fuel tank. If this happens, the engine,
which is set to operate on mostly gasoline, may be fed a slug of alcohol
and water which has less energy content. As a result the engine may
miss, hesitate, stall, or otherwise operate in an undesirable way.
Test results indicate a significant separation problem with increasing
severity at low temperatures and water concentrations over 0.5 percent.
It may be possible to solve this by chemical formulation or by a separate
distribution system or special 'handling procedures if alcohol/gasoline
blends ever attain wide circulation as a vehicle fuel. In any event
special precautions are required to limit the introduction of water
into the alcohol fuel distribution chain.
Use of pure alcohols requires modifications to basic engine components.
Engine starting at temperatures below 50F is extremely difficult due to
the low volatility of alcohols. Thus, some form of starting aid, not
currently employed, would be required. Normal fuel vaporization under all
engine operating conditions requires addition of heat to the intake manifold.
Carburetors which supply Lhe correct air/fuel ratio for alcohol combustion
and other inlet system changes would also be needed.
-------
- Corrosion problems occur with certain materials in conventional
automobiles when these fuels are used. Materials which have exhibited
corrosion problems in the presence of methanol blends or straight
methanol are "aluminum, magnesium, lead (terneplated fuel tank lining)
and certain plastics. Severe corrosion in the fuel tank can occur at
the methanol-water/gasoline interface after phase separation. These
problems can be solved (at' extra costs) by -the substitution of corrosion
resistent materials of construction. While this can be done fairly
easily with new cars, it may require an expensive retrofit program for
unaltered in-use vehicles.
Alternative fuel studies, which .are in progress by the Department
of Energy to determine the most feasible non-petroleum automobile fuels
have shown that the most promising alternative fuels are synthetic
gasolines and distillates derived from coal and oil shale, followed by
methanol derived from coal. Criteria employed in making this choice
included a wide array of environmental, technical, economic and resources
considerations. The time period for which these conclusions apply is
from the mid-1980*s 'through the 1990fs, These studies are continually
being updated as more information becomes available.
Conclusions
Methyl alcohol has some potential for use as an automotive fuel
in the United States, but technical and economic problems associated
with the production, distribution, and use of pure methanol and
methanol-gasoline blends makes its use improbable for this purpose
during the next decade. In the longer term, however, methanol-gasoline
blends may become practical for general automotive fuel use. The
current information indicates that the use of pure methanol would
probably be limited to specially prepared fleet vehicles.
Ethyl alcohol is not as attractive as an alternative automotive
fuel for large scale usage in the United States, due to its limited
availability based on all processes known to have the potential for
large scale production capability in this country at this time.
However, there is a possibility of regional use of ethanol—gasoline
blends on a limited scale in locations where the costs of locally
produced ethanol from surplus grain stocks or wastes are low enough
to compete with the costs of gasoline shipped from distant supply
points. • • . .
There is no significant advantage for HC emission control
or fuel economy in the use of -alcohol or alcohol-gasoline blends
over .straight gasoline. The use of alcohol may reduce CO and NOx
emissions, but increase aldehyde emissions. The principal benefit
of alcohol as motor fuel would be the potential expansion of domestic
fuel resources which it represents.
MSAPC/45585
-------
\
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON. D.C. 20460
OFFICE OF
AIR AND WASTE MANAGEMENT
FACT SHEET
Automobile Fuel Economy
The Environmental Protection Agency (EPA) has received a -large
number, of inquiries from the public related to automotive fuel economy.
This fact sheet has been prepared to answer the most frequently asked
questions in this area..
It How does the EPA test and report fuel economy?
Approximately 500 prototype cars are tested each year by EPA to
determine emission compliance and fuel economy. An additional 235
prototype cars are tested by manufacturers for fuel economy and the
results.reviewed or confirmed, and approved, by EPA. The cars are
operated on a dynamometer by professional drivers. Use of dynamometers,
rather than driving cars out on the road, is much more economical for
such large scale testing, and also makes it possible for all tests to be
conducted the same way each time. This makes the results nore scienti-
fically valid and comparable than would road testing.
To determine fuel economy for each model, the EPA groups cars by
car line (e.g., Buick Skylark), engine size, number of cylinders,
catalyst usage and fuel system. Because the same engines and drive
trains are often used in a number of different car lines, it is not
necessary to test each individual combination of engine, drive train,
and car line to develop the fuel economy estimates that are listed
in the Gas Mileage Guide. In most cases, however, more than one car of
each model is actually tested. All relevant test results for each
model are sales weighted in arriving at an estimate of the fuel economy
of that model.
Fuel economy is calculated by dividing the miles driven during the
test by the amount of fuel used to drive those miles. The amount of fuel
used is determined from the measured values of hydrocarbons, carbon mon-
oxide, and carbon dioxide in the exhaust that is collected during the
test. This is an accurate, convenient, and generally accepted measure
of fuel consumption.
FS-13
-------
-2-
Beginning with the 1975 model year, the fuel economy of each car
was measured and published separately for city and highway driving.
The city fuel economy is measured during the Federal emissions test,
which simulates urban driving, The test represents the average results of
with an average speed of 20 miles per hour and an average of 2.4 stops
per mile. The highway test cycle, which is conducted only for fuel economy
purposes, is 10.2 miles long, with an average speed of 43.2 miles per
hour, a maximum speed of 60 mph, and 0.1 stops per mile and simulates
rural driving. Both city and highway fuel economy estimates are published
by EPA for each car so that the consumer can better estimate his expected
fuel economy for a particular vehicle based on the type of driving he does.
Beginning with the 1976 model year, a third number was added, Che
combined city/highway average.V The combined fuel economy is an average
of the city and highway fuel economy values weighted 55% and 45%
respectively. According to the Tederal Highway Adminstration, about 55%
of all driving is done in cities and 45% is done in non-urban areas,
2. Are EPA's fuel economy finures jrjpiresentativ'e of actual
driving, conditions?
No standardized test can ever represent each person's Individual
driving. (This is explained further in 3, below). Therefore, the user of
the EPA's fuel economy estimates must recognize that the EPA fuel economy
estimates primarily provide a useful comparison of different vehicles tested
under precisely the same conditions. EPA can not predict the exact
numerical results for each and every driver. However, any individual
driver can reasonably expect to get the same relative fuel economy
performance from different models as is reported in the EPA estimates.
In other words, if Car A is estimated by EPA at 20% better fuel economy
than Car B, any driver can reasonable expect Car A to give him 20% better
fuel economy than Car B, in his own type of driving.
The "city" and "highway" test cycles were designed to represent average
driving patterns in urban and rural driving. An independent survey
performed for the Tederal Energy Administration among 621 buyers of
new cars showed that car owner's reported fuel economy experience
compared with the EPA estimates as follows;
VThe formula used to calculate the combined mlles-per-gallon from
the individual city and highway fuel economy values is:
Combined MPG = 1
(0,55/city MPG) 4- (0.45/highway MPG)
This formula gives what is called a harmonic mean» which is the only
accurate way of relating total fuel consumed to the total distance driven.
-------
Comparison of New-Car Owners' Fuel Economy Experience with EPA Fuel
Economy Estimates
Fraction of Sample Fuel Economy Experience
6% 5 or more MPG better than EPA
estimate.
8% 3-4 MPG better than EPA estimate,
21%... .....1-2 MPG better than EPA estimate.
13%— .Equal to EPA estimate.
25%..- ....1-2 MPG less than EPA estimate,
16% 3-4 MPG less than EPA estima te.
11% 5 or more MPG Less than EPA estimate.
The study concludes that "Although there is considerable variation
from the EPA estimates, it appears that the EPA combined estimate ig an
accurate indication, on the whole, of what actual experience will be
like."
EPA and the Federal Trade Commission consider the fuel economy figures
EPA publishes to be the beat available estimate of fuel economy which
would be obtained by the average driver in typical urban an4 rural driving
under wind-free summer conditions,
3. Why is there such a wide_ ^variation in fuel economy, and why don't
I gee the EPA estimates?
Some of the factors which may be responsible for deviations from
the EPA estimate are che following:
a. Driver behavior/trip cjiarac_teristic_s.
Driving patterns such as quick acceleration, frequent stops and
starts, long periods of idling, short trips, and uneven speed decrease
fuel economy. Some of these relate to individual driving habits and some
depend on where you live. Individual driving habits have been shown to
to result in fuel economy differences as large as 30%.
b. Vehicle maintenance.
A properly maintained vehicle gets better mileage than a poorly
maintained vehicle. The average car that is in need of a tune-up
-------
-4-
eacperiences a 5-8% fuel economy improvement immediately after a
tuae-up. Deterioration between tune-ups depends on the frequency
of maintenance.
c. W_e_a_the_r conditions.
There ia about 1-2% loss In fuel economy for each 10"? drop in
temperature, (The EPA testa are made at about 75°F.) Driving into a
headwind also reduces fuel economy. Rain may reduce fuel economy
by 10% compared to dry roads. Typically, for any car, fuel economy is
paorer in winter thaa in summer, although the use of air conditioning in
the summer can obscure that effect,
d. Altitude and grades.
If a car ia driven at high altitudes with the carburetor and ignition
system calibrated for a range from sea level to about 1000 feet, a fuel
economy loss should be expected, (e.g., 15% at 4000 feet). Driving up
grades and on winding roads will also result ia lower fuel economy, for
a 3% grade, this penalty is about 33%. Curves and grades are not included
in the EPA test, which simulates straight and level driving.
e. Road conditions.
Poor road surfaces also reduce fuel economy. Badly broken and
patched asphalt causes a 15% penalty at 40 mpg compared to a. smooth
road. Gravel causes a 35% penalty; dry sand, a 45% penalty. The EPA
test corresponds to a well maintained, dry, smooth, paved road.
f• Vehicle Igading
The loading of a vehicle can make a considerable difference in
fuel economy. Each 100 pounds reduces a vehicles fuel economy by 1-3%,
depending on the size of car. The EPA test simulates two 150 pound
occupants.
£• Optional jaguigmept.
Optional equipment decreases fuel economy in two ways, the addition
of weight to the vehicle and the consumption of power used to operate
the equipment. These factors are more fully discussed under question 4,
h. Car to car_variability.
No two cars, like no two people, are exactly alike. Variations
associated with mass production give rise to variations ia vehicle per-
formance and fuel economy. Ordinarily, fuel economy"variations between
-------
two nominally identical cars do not exceed 10%, Therefore if the EPA
value for your model car is 20 opg, your own car might be measured at
between 18 and 22 mpg if the EPA test were made on it.
4. How joes vehicle equipment affect fuel economy?
a. Optional larger engines can decrease fuel economy significantly.
A 10% larger engine will result in a fuel economy penalty of 3 to 6%.
b. Air conditioning use typically will result in a 6% fuel economy
penalty, but it may result in a penalty as high as 20 to 30% on a hot,
humid day in slowly moving traffic,
c. Radial tires can improve fuel economy by 1 to 3% compared to bias-
ply tires made by the same manufacturer. However, some manufacturers*
bias-ply tires are more efficient than other manufacturers* radial tires.
d. Automatic transmissions generally are less efficient transmitters
of power than are manual transmissions, and typically give rise to a
penalty ranging from 2-6% compared to manual transmission cars driven
correctly. However, if manual transmission cars are not shifted properly,
they too can decrease fuel economy by causing inefficient operation of the
engine. The greater fuel economy advantage is seen for the manual trans-
mission in the lighter weight ranges. This may be due in part to the use
of less efficient automatic transmissions in smaller cars. Recently,
the use of spark retard on some cars with manual transmissions to
enable them to meet the emission standards has resulted in some manual
transmission-equipped cars having poorer fuel economy than their auto-
matic counterparts.
e. Axle ratio^ which is measured by the number of times the drive-
shaft turns for each time the rear wheels turn, affects fuel economy.
Generally, a numerically lower axle ratio will result in better fuel
economy because the engine runs slower for any given vehicle speed and,
therefore, has less internal friction to overcome. An axle ratio 10%
below the standard axle ratio for that car (such as from 3.0 to 2.7)
can increase fuel economy by about 2% to 5% for large cars and 5% to
10% for small cars.
5. How can I tell whether the cars listed in the Mileage Guide
were equipped with the same options _I am_interested in purchasing?
All vehicles tested by EPA are tested with the standard equipment
for that vehicle. Different axle ratios and transmissions are usually
tested if more than one are available. The options on the test car
are those which are bought by most vehicle purchasers. If more than a
third of a certain type of vehicle are expected to be sold with an
option such as air conditioning (and most domestically-manufactured cars
-------
have air conditioning), then the test car was equipped with air conditioning,
The same is crue for other power options, such as power steering and
power brakes.
6. What__can I do aboiit a car which gets poor fuel economy?
First, you should check the list of factors under question 3
which are responsible for most of the decreases In fuel economy observed
in actual customer use, to see if one or more of those factors account
for your low fuel economy. If you are then convinced that you are still
getting abnormally poor mileage, you. should bring your complaint to the
service department of your car dealer. If you are not satisfied with
the service you received at your dealers, you should contact the
manufacturer's area service representative in your area. Finally if
all of the above fail, many states have a consumer protection office
which may be of assistance. In some states this is a separate agency,
in many, it is within the state Attorney General's office.
7, What is the Federal Government fuel economy information^
program?
The EPA in 1973 established a voluntary fuel economy labeling
program in which participating auto manufacturers displayed the results
of EPA's fuel economy tests on their vehicles. The voluntary labeling
program was in effect from the 1974 model year to March 1976. At that
time, by act of Congress, fuel economy labeling of new cars became
mandatory. This program enables consumers to compare different models
and co take fuel economy into consideration when they purchase a
vehicle.
The information published on the vehicle labels is also available
in a booklet entitled 1976 Gas Mileage Guide that is prepared by the
Environmental Protection Agency and distributed by the Federal Energy
Administration. Separate editions of the booklet are published for
cars sold in California (since California cars are different, to meet
the more stringent emission requirements in that state) and for the
rest of the country. Single copies of this guide are available free
from any new car dealer, or by writing to: Fuel Economy, Pueblo,
Colorado 81009. Bulk copies are available by writing to Fuel Economy,
Federal Energy Administration, Washington, D. C. 20461,
8. Fuel economy standards.
The Energy Policy and Conservation Act passed by Congress in 1975
not only made fuel economy labeling mandatory on all passenger cars and
Light-duty trucks and requires dealers to make copies of the EPA/FEA Gas
Mileage Guide available to the public, but also requires that beginning in
1978 the average fuel economy of each manufacturer's new car fleet meet
the minimum fuel economy standards. The standards for 1978-1985 are:
-------
1978 18.0 m.p.g.
1979 19.0 m.p.g.
1980 20.0 m.p.g.
1981 22.0 m.p.g.
1982 24.0 m.p.g.
1983 26.0 m.p.g.
1984 27,0 m.p.g,
1985 27.5 m.p.g.
The Secretary of Transportation, on'3une~2?f 1977,promulgated-
the passenger car standards for 1981-1984 model years. Congress set
the 1978'. through 1980,- and. the 1985 standards,
9. What can I do to_get better fuel economy?
a. Proper Maintenance
Be sure that your automobile retains in a state*of good repair and
is properly tuned. The needed maintenance items and schedule are
described in the owner's manual and should be followed consistently.
Periodic maintenance items which especially affect fuel economy are the
air filter, the ignition system (spark plugs, distributor points, and
ignition timing), carburetor, cylinder compression, and lubrication.
A seriously defective vehicle, (e.g., spark plug misfiring, clogged
air filter, improper carburetor adjustment) can suffer a penalty of
20% or more. On the average, tuned-up cars get 5 to 8% better fuel
economy than the average car that is not kept in a good state of tune.
b. Combine or avoid short trips
How you use your vehicle can have as large an influence on fuel
economy as the design of the vehicle and engine, and is an aspect over
which the driver has control throughout the vehicle's life rather than
just at the time of purchase. Short trips made from a cold start
(engine not warmed up prior to use) result in much poorer fuel economy,
One experiment with a ear which delivered 11 m.p.g. in the IPA city test
got only 10 m.p.g. on a 5 mile cold start trip, 7 m.p.g. on a 2 mile
trip, and 5 m.p.g. on a 1 mile cold start trip under summer driving
conditions. In winter, the fuel consumed for short trips is even
greater due to the longer wanaup period. It is therefore important to
combine short trips to reduce the number of cold starts. And of course,
making shore trips by walking, public transportation, or a bicycle will
save even more fuel.
c. Avoid high speeds
The best fuel economy on most cars occurs at a steady speed near
40. m.p.h.. Cruising at 70 m.p.h. instead of 55 m.p.h. reduces fuel
economy by about 20%.
-------
d. Drive smoothly
Slow down gradually, well in advance of traffic lights, to avoid
stopping when possible. Accelerate gradually. If traffic lights in
your area are timed sequentially, try to drive at the constant gpeed
which will enable you to pass through the lights without stopping.
EPA/OMSAPC/Auguat 1977
-------
f A \ UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
^ is3HB&iif ^
I Sl^L " WASHINGTON. Q.C.
t '^•PHil^^JVi.
OFFICE OF
AIR AND WASTE MANAGEMENT
FACT SHEET
Automobile Fuel Economy
The Environmental Protection Agency (EPA) has received a large
number of inquiries related to automotive fuel economy. This fact
sheet has been prepared to respond efficiently to the most frequently
asked questions on this subject.
1. Mhat 1 s t h e__ IF e deral Government fue_I gc_qnomy_
mformation program?
The EPA in. 1973 established a voluntary fuel economy labeling
program in which participating auto manufacturers displayed
the results of EPA's fuel economy tests on their vehicles. The
voluntary labeling program was in effect from the 1974 model year
to March 1976. At that time, by act of Congress, fuel economy
labeling of new cars became mandatory. This program enables
consumers to compare different models and to take fuel economy
into consideration when they purchase a vehicle.
The information published on the vehicle labels is also
available in a booklet entitled 1978 Gas Hi 1ea ge Gu id e that
is prepared by the Environmental Protection Agency and distributed
by the Department of Energy. Separate editions of the booklet
are published for cars sold in California (since California cars
are different, to meet the more atingent emission requirements in
that state) and for the rest of Che country. Single copies of
this guide are1 available free from any new ear dealer, or by
writing to: Fuel Economy, U.S. Department of Energy, DPM Room
6500, Washington, D.C. 20461.
2» Fuel economy standards.
The Energy Policy and Conservation Act passed by Congress in
1975 not only made fuel economy labeling mandatory on all passenger
cars and light trucks and required dealers to make copies of
FS-13
-------
the EPA/DOE Gas Mileage Guide available to the public, but
also required that beginning in 1978 the average £uel economy of
each manufacturer's new car fleet (not individual cars) meet the
minimum fuel economy standards. The standards for 1978-1985
model year passenger cars are:
1978 18.0 m.p.g.
1979 19.0 m.p.g.
1980 20.0 m.p.g.
1981 22,0 m.p.g.
1982 24.0 m.p.g.
1983 26.0 m.p.g.
1984 27.0 m.p.g.
1985 27.5 m.p.g.
The Secretary of Transportation, on June 27, 1977, promulgated
the passenger car standards for 1981-1984 model years. Congress
set the 1978 through 1980, and the 1985 standards.
3. How does the EPA test and report fuel economy?
Approximately 600 prototype cars and trucks are tested each
year by EPA to determine emission compliance and fuel economy.
An additional 250 prototype cars and trucks are tested by manufac-
turers for fuel economy and the results reviewed or confirmed,
and approved, by EPA. The vehicles are operated on a dynamometer
by professional drivers. Use of dynamometers, rather than driving
cars out on the road, is much more economical for such large
scale testing, and also makes it easier to control test conditions.
Close control of test conditions insures that the test results
for the various models of cars can be compared to each other.
To report fuel economy for each model, the EPA groups
cars by car line (e.g., Buick Skylark), engine size, number of
cylinders, catalyst usage, fuel system, and type of transmission.
Because the same engines and drive trains are often used in
a number of different car lin
-------
Fuel economy is calculated by dividing the miles driven
during the test by the amount o£ fuel used to drive those
miles. The amount of fuel used is determined from the
measured values of hydrocarbons, carbon monoxide, and carbon
dioxide in the exhaust that is collected during the test.
This is an accurate, convenient, and scientifically accepted
measure of fuel consumption.
Beginning with the 1975 model year, the fuel economy
of each car was measured and published,separately for city and
highway driving. The city fuel economy is measured during the
Federal emissions test, which represents urban driving not just
congested, midtown driving. The test represents the average
results of hot and cold start operation with an average speed of
20 miles per hour and an average of 2.4 stops per mile. The
highway test cycle, which is conducted only for fuel economy
purposes, is 10.2 miles long, with an average speed of 48.2 miles
per hour, a maximum speed of 60 mph and 0*1 stops per mile and
represents the various types of rural driving. Both city and
highway fuel economy estimates are published by EPA for each
model of car and light truck.
Beginning with the 1976 model year, a th^td number
was added, the combined city/highway average.— The
combined fuel economy is an average of the city and highway
fuel economy values weighted 352 and 45%, respectively.
According to the Federal Highway Administration, about 552
of all driving is done in and around cities and 452 is done in
other areas.
*/
— The formula used to calculate the combined miles-per-
gallon from the individual city and highway fuel economy values is
Combined HPG = 1
(0.55/city MPG) + (0,45/highway MFC)
This formula gives what is called a harmonic mean, which is the
only accurate way .of relating' total fuel consumed to the total
distance driven.
-------
4 . Hov j?ood are EPA's numbers in helping me make a decision
about new car fuel economy?
The primary purpose of the fuel economy information program
is to provide a relative ranking of various new models of cars
and light trucks by fuel economy which can be used by the consumer
to select the models with the best fuel economy. However, not
every individual car or truck in a model type with a higher EPA
fuel economy value will always get better fuel economy than every
car or truck in a model type with a lower EPA fuel economy value.
This is due to a number of factors including the variability
inherent in the test procedure, the differences among cars that
are nominally identical, the rounding off of EPA fuel economy
measurements for the Gu ide , differences among vehicles in the same
model type due to options and tires and the like, etc. Thus, if
there is a difference of two miles per gallon between the combined
city/highway fuel economy of one model type and another, Che
ranking of the model types is right for the individual vehicles that
a consumer might purchase about 4 out of 5 times. As the mpg dif-
ference between two vehicles* model types increases, so does the
certainty that the ranking of individual vehicles will be the
same as the ranking of the model types of those vehicles.
5. How cj.ose can j expect to come to EPA' s fuel economy
estimates in my everyday driving?
It is not possible to predict how close anyone will come to
the EPA estimates without a great deal of knowledge about his
car and driving conditions. Actual average in-use fuel economy is
7% lower than the EPA city estimate and 16% lower than the EPA
highway estimate. In-use fuel economy, however, varies widely from
these averages. Data indicate that in-use fuel economy may range
from 40% to 140% of the EPA combined estimate, that is, the experience
of owners of vehicles rated at 20 mpg by EPA may vary between 8 and
28 mpg.
6. Why is there such a wide variation jn^ue^ gconomy?
Some of the factors which may be responsible for deviations
from the EPA estimate are the following:
-------
a. Trip characteristics/driver bejvavior
Two of the most important trip characteristics for fuel
economy are average speed and trip length. The EPA cicy estimate
is not representative of heavily congested downtown driving or o£
cold stare trips Less than 7.5 miles in length.
Congestion is reflected in low average speeds. The average
speed in a congested area such as downtown Manhattan may be only
7 mph. The following table shows the relative impact of congested
driving on a typical. 7.5 mile urban trip under mild weather
conditions. Use of air conditioning or cold weather or short
trips would result in lower mileage.
Change in Fuel Economy
Average Speed (mpg) Relative to EPA City Estimates
5 -57%
10 -30%
15 -12%
20 (EPA city test) 0
25 +10%
30 +16%
40 +25%
Urban driving under the conditions of the EPA city test,
but with shorter trip lengths, would also result in lower fuel economy.
Longer trips would result in slightly better fuel economy as
illustrated in the following table:
Change in Fuel Economy
Trip Length (miles) Relative to EPA City Estimates
1 -45%
3 -20%
5 - 7%
7.5 (EPA city tast) 0
10 +2%
15 + 8%
Probably the most prevalent cause of lower in-use highway
fuel economy than the EPA estimate is vehicle speeds in excess
of the 55 mph speed limit. The following data show the effect
of highway speed relative to 50 mph:
Cruise Spe'ed Change fron^ 50 mph
45 . +5%
50 (EPA highway test) 0%
55 (National speed Limit) -5%
60 -10%
70 -20%
80' -30%
-------
b. Weather conditions
There is about a 1-2% loss in fuel economy for each IO°F
drop in temperature. (The EPA teats are made at about 7-5°F.)
Driving into a headwind also reduces fuel economy. Rain may
reduce fuel economy by 10% compared to dry roads. Typically, for
any car, fuel economy is poorer in winter than in summer,
c. Altitude and grades
If a car is driven at high altitudes with the carburetor and
ignition system calibrated for a range from sea level to about
1000 feet, a fuel economy loss should be expected, {e.g., 15% at
4000 feet). Driving up grades and on winding road will also
result in lower fuel economy. For a 3% grade, this penalty is
about 33Z. Curves and grades are not included in the EPA test,
which simulates straight and level driving.
d. Road conditions
Poor road surfaces also reduce fuel economy. Badly broken
and patched asphalt causes a 15% penalty at 40 mph cruise compared
co a smooth road. Gravel causes a 35% penalty; dry sand, a
45% penalty. The EPA test corresponds to a well maintained, dry,
smooth, paved road.
e. Car to car variability
No two cars are exactly alike. Variations associated with
mass production give rise to variations in vehicle performance
and fuel economy. The fuel economy of 2/3 of all nominally identical
cars will be within 20% of each other when driven under the same
conditions. The fuel economy of the other third will be about
equally divided above and below this range. EPA found that when
tested on the EPA test procedures approximately 5% of tn-use
vehicles would not get better than 80% of the Guide values for their
models which indicates that the fuel economy potential of some
individual cars is considerably below average. The cause of the
poor fuel economy of these "lemons" was not determined.
f. Mileage effect
Mileage improves as cars are fully broken-in. The cars
which EPA tests typically get 5 to 6% better mileage than the
average brand new car in consumer use. Full break-in at about
15,000 to 20,000 miles tends to equalize the mileage of EPA test
cars and production cars.
-------
g. Optional equipment
The tires and axle ratio may be different on the vehicle that an
individual consumer may purchase than the vehicle that was tested by
EPA. Convenience options such as power steering, air conditioning,
etc., may decrease fuel economy in two ways, the addition of weight
to the vehicle and the consumption of power used to operate the
equipment. These factors are more fully discussed under question 8.
h. -Vehicle loading
The loading of a vehicle can make a considerable difference
in fuel economy. Each 100 pounds reduces a vehicle's fuel
economy by 1-3%, depending on the size of car. (Small cars are
more sensitive to weight changes than large cars.) The EPA test
simulates two 150 pound occupants.
i. Vehicle maintenance
A properly maintained vehicle gets better mileage than
a poorly maintained vehicle. The average car that is in need
of a tune-up experiences a 5-8% fuel economy improvement immediately
after a tune-up. The amound of deterioration between tune-ups
depends on the frequency of maintenance.
7. What is EPA doing to make its estimates more realistic/?
EPA is making changes to its fuel economy test procedures
wherever possible. For instance, EPA has determined that some
manufacturers were using and recommending to EPA the use of shift
point's for manual transmissions that the typical consumer would not
be likely to use but which gave substantial fuel economy benefits.
This problem has been corrected for the 1979 model year. Other
test procedure changes are being studied and will be implemented
Lf determined to be warranted and feasible.
8. How does vehicle equipment affect fuel economy?
a. Optional larger_engines^ can decrease fuel economy signifi-
cantly. A 10% larger engine will result in a fuel economy penalty
of 3 to 6%.
b.' Ait conditioning use typically will result in a 6% fuel
economy penalty, but it may result In a penalty as high as 20 to 30%
on a hoc, humid day in slowly moving traffic.
-------
c. Radial tires generally improve fuel economy by 41 compared
to bias-ply tires made by the same manufacturer. However, some
manufacturers' bias-ply tires are more efficient than other manufac-
turers' radial tires.
*** Automatic transmiss ions generally are less efficient
transmitters of power than are manual transmissions, and typically
give rise to a penalty ranging from 2-6% compared to manual trans-
mission cars driven correctly. However, if manual transmission cars
are not shif-ted properly, their advantage over automatics can be
eliminated by causing inefficient operation of th eingine. The
greater potential fuel economy advantage is seen for the manual
transmission in the lighter vehicle weight ranges. This may be due
in part to the use of less efficient automatic transmissions in
smaller cars. However, recently, the use of spark retard on some
cars with manual transmissions to enable them to meet the emission
standards has resulted in some manual transmission-equipped cars
having poorer fuel economy than their automatic counterparts
even when the former were driven properly,
a. Axle ratio, which is measured by the number of times
the drive-shaft turns for each time the rear wheels turn, affects
fuel economy. Generally, a numerically lower axle ratio will
result in better fuel economy because the engine runs'slower for
any given vehicle speed and, therefore, has less internal friction
to overcome. An axle ratio 10% below the standard axle ratio
for that car (such as from 3.0 to 2,7) can increase fuel economy
by about 2% to 51 for large cars and 51 to 10% for small cars-
9, How can I tell whether the cars listed in the Mileage
Guide were equipped with the same options I am interested
in purchasing?
All vehicles tersted by EPA are tested with the standard
equipment for that vehicle. Different axle ratios and trans-
missions are usually tested if more than one is available. It is
best to regard EPA test vehicles as base vehicles having no power
consuming options. As noted above, power steering, power brakes,
air conditioning, etc., may result in small to significant fuel
economy losses which would be reflected in lower fuel economy
than the EPA estimates.
-------
10. V)hat can I doabout a__c_ar which gets_ poor fuel
economy?
First, you should check the list of factors under question
6 which are responsible for most of the decreases in fuel economy
observed in actual customer use, to see if one or more of those
factors account for your low fuel economy. If you are then convinced
that you are still getting abnormally poor mileage, you should bring
your complaint to the service department of your car dealer. If you
are not satisfied with Che service you received ac your dealer's,
you should contact the manufacturer's area service representative in
your area. Finally if all of the above fail, many states have a
consumer protection office which may be of assistance. In some
states this is a separate agency; in many, it is within the state
Attorney General's office. EPA has no authority to take any action
on behalf of individuals who are not satisfied with the fuel economy
or any other feature of their ears.
You should also be aware that the law which requires EPA fuel
economy testing and mileage labels (15 U.S.C. 2006} states that
the mileage information does "not create an express or implied
warranty under State or Federal law that such fuel economy will
be achieved...under conditions of actual use."
11. Vh_a_t_can I do to _.get better _ fuel economy?
a. Proper maintenance
Be sure that your automobile remains in a state of good repair
and is properly tuned. The needed maintenance items and schedule
are described in the owner's manual and should be followed consistently.
Periodic maintenance items which especially affect fuel economy are
the air filter, the ignition system (spark plugs, distributor
points, and ignition timing), carburetor, cylinder compression, and
lubrication. A seriously defective vehicle, (e.g., spark plug
misfiring, clogged air filter, improper carburetor adjustment) can
suffer a penalty of 20X or mote. On the average, tuned-up cars get
5 to 81 better fuel economy than the average car that is not kept in
a good state of tune.
b. Combine or^ avoid short trips
How you use your vehicle can have as large an influence on fuel
economy as the design of the vehicle and engine, and is an aspect
over which the driver has no control throughout the vehicle's life
rather than just at the time of purchase. Short trips made from a
-------
cold start (engine not wanned up prior to use) result in much poorer
fuel economy. One experiment: with a car which delivered 11 nup.g.
in Che EPA cicy test got only 10 nup.g. on a 5 mile cold start trip,
7 trup.g. on a 2 mile trip, and 5 m«p«g. on a 1 mile cold start trip
under summer driving conditions. In winter, the fuel consumed for
short trips is even greater due to the longer uarmup period. It is
therefore important to combine short trips to reduce the number of
cold start trips. And of course, making short trips by walking,
public transportation, or a bicycle will save even more fuel.
c. Avoid higji speeds
The best fuel economy on most cars occurs at a steady
speed near 40 tn.p.h. Cruising at 70 m.p.h. instead of 55
m.p.h. reduces fuel economy by about 15 to 20%.
d. Drive smoothly
Slow down gradually, well in advance of traffic lights
to avoid stopping when possible. Accelerate gradually. If
traffic lights in your area are timed sequentially, try to
drive at the constant speed which will enable you to pass
through the lights without stopping.
EPA/OMSAtC/45582
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
' WASHINGTON, D.C. 2Q4SQ
OFFICE OF
AIR AND WASTE MANAGEMENT
FACT SHEET
Automobile 'Fuel Economy
The Environmental Protection Agency (EPA) has received a large
number of inquiries from the public related to automotive fuel economy
and the relationship between fuel economy and emissions control. This
fact sheet has been prepared to answer the most frequently asked
questions in this area,
1, How does the EPA tes_t___andL report .fuel jconomy?
Approximately 600 prototype cars are tested each year by EPA- to
determine emission compliance and fuel economy and an additional 200
prototype cars are tested by manufacturers for fuel economy and the
results reviewed or confirmed, and approved, by EPA, The cars are
operated by professional drivers on a dynamometer. Use of dynamometers,
rather than driving cars out on the road, is much more economical for
such large scale testing and also makes it possible for all tests to be
conducted the same way each time. This makes the results more
scientifically valid and comparable than would road testing.
To determine fuel economy for each model, -the EPA groups cars by
car line (e.g., Buick Skylark), engine size, number of cylinders,
catalyst usage and fuel system. Because the same engines and drive
trains are often used in a number of different car lines, it is not
necessary to test each individual combination of engine-, drive train,
and car line to develop the fuel economy estimates -that are listed
in the mileage guide. In most cases., however, more than one car of
each model is actually tested. All relevant test results for each
model are sales weighted to provide the best possible estimate of the
fuel economy of that model.
Fuel economy is calculated by dividing the miles driven during
the test by the amount of fuel used to drive those miles. The fuel used
is determined from the measured values of hydrocarbons, carbon monoxide,
and carbon dioxide in the exhaust that is collected during the test.
This is an.accurate, convenient, and generally accepted measure of fuel
consumption.
FS-13
-------
-2-
Eeglnriing with the 1975 model yerr, the fuel economy of. each' car
xjas measured and published separately for city and highway driving.
'The city fuel eeonopy value is measured during the Federal emissions
test, which simulates'urban driving. The test cycle is 7.5 miles long,
with an average speed of 20 miles per hour and an average of 2.4 stops
pet mile. , The highway test cycle, which is made only for fuel economy
.purposes, is 10.2 miles long, with-an average speed of 48,2 miles per
hour, a maximum speed of 60 mph, and 0,1 stops per mile and simulates
rural driving. Both values are -listed for each car so that the.
consumer can better .estimate his expected fuel economy for a particular
vehicle based on the type of driving he does.
Beginning with the 1976 model year, a third number was added, the
combined city/highway average.*/ The combined fuel economy is an average
of the city and highway fuel economy values weighted 55% and 45%
respectively. The Federal Highway Administration has reported that 55%
of all driving is done in cities and 45% .is done on highways.
jjYThe formula used Co calculate the combined miles-per -gallon from
the individual city and highway fuel economy values is:
Combined fuel economy = . _ 1
(0.55/city MPCT"" (0745? highway MFC)
This formula gives what is called a harmonic mean, which is the most
accurate way of expressing a car's fuel consumption, i.e., the amount
of fuel consumed for a given distance of driving, Miles-per-gallon is
the reciprocal of that fuel consumption value.
-------
—3—
2. Are EPA's fuel economy figure'.,_ r epr e sen ta t ive of actual
d r jiving cond it ions?
No standardized test can ever represent each person's individual
driving. (See 3, below). Therefore, the user of the EPA's fuel
economy estimates must recognize that the EPA fuel economy estimates
primarily .provide a useful comparison of different vehicles tested
under precisely the same conditions. EPA can not predict the,'exact
numerical results for each and every driver. However, any individual
driver can reasonably expect to get the same relative fuel economy
performance from different models as Is reported in the EPA estimates.
The city and highway driving cycles accurately represent driving
patterns in city and highway driving. A recent independent survey
performed for the Federal Energy Administration' among 621 buyers of
new cars showed that car owner's reported fuel economy experience
compared with the EPA estimates as follows:
Com par i s o n p f. N ew-_Ca r jjwners' Fuel Economy Experience, yith^ EPA Fuel
Economy Estima_tes_
Fraction of Sample Fuel Economy Experience
6% '. 5 or more MPG better than EPA
estimate.
8%.... , 3-4 MPG better than 'EPA estimate.
21% 1-2 MPG better than EPA estimate.
13% Equal to EPA estimate.
25%.... 1-2 MPG less than EPA estimate.
16% .3-4 MPG less than 1>PA estimate,
11%. ...5 or more MPG less than EPA estimate,
The study concludes that "Although there is considerable variation
from the EPA estimates, it appears .that the EPA combined estimate is an
accurate indication, on the whole, of what actual experience will be
like."
EPA and the Federal Trade Commission consider the fuel economy
figures EPA publishes to be the best available estimate of fuel
economy which would be obtained hy the average driver in the summertime
under city and highway conditions.
-------
-U-
i F ' R sucha w.de vari-r.ion In
I get the EPA estimates?
Some of the factors which may be responsible for reducing fuel
economy of any car below the EPA estimate are the following:
. a . Driver behavior/ trij> characteristics .
Driving patterns such as quick acceleration, frequent stops and
starts, long periods of Idling, short trips, and uneven speed decrease
fuel economy. Part of this is in individual driving habits and part
in driving conditions that depend on where you live.
b. Vehicle maintenance.
A properly maintained vehicle gets better mileage than a -poorly
maintained vehicle. The average car that is in need of a tune-up
experiences a 5-8% fuel economy improvement immediately after a
tune-up. Deterioration between tune-ups depends on how far the car is
allowed to get out of tune before the next tune-up.
c . " Weather conditions ,
There is about 1-2% loss in fuel economy for each 10°F drop in
temperature. (The KPA test is made at about 75°F.) Driving into a
headwind also reduces fuel economy. Rain may reduce fuel economy
by 10% compared t:o dry roads. Typically, for any car, fuel economy is
poorer in winter than in summer, although the use of air conditioning in
the summer can obscure thai effect.
d . AJjjj: u*^ and_gr adj
If a car is driven at high altitudes with the carburetor and
ignition system calibrated for sea level to 1000 feet, a fuel economy
loss should be expected, (e.g., 15% at 4000 feet). Driving up grades
and on winding roads will also result In lower fuel economy. For a 3%
grade, this penalty is about 33%. Curves and grades are not included
in the EPA test, which simulates level driving on dry roads with neither
a headwind or tail wind.
e. Road conditions.
Poor road surfaces also reduce fuel economy. Badly broken and
patched asphalt causes a 35% penalty at 40 mpg compared to a smooch
road. Gravel causes a 35% penalty; dry sand, a 45% penalty. The EPA
test corresponds to a well maintained, dry, smooth, paved road.
f, Vehicle loading
The loading of a vehicle may make a considerable difference in
-------
-5-
fuel economy. Each 100 pounds reduce:; a vehicles fuel economy by 1-3%,
depending on the size of car. The EPA Lest includes the weight of two
passengers but no luggage.
§'• Optional equipment.
Optional equipment decreases fuel economy in two ways, the addition
of weight to the vehicle and the consumption of power used to operate
the equipment. These factors are more fully discussed under question 4,
h. Car to car variability.
No two cars, like no two people, are exactly alike. Variations
associated with mass production give rise to variations in vehicle
performance and fuel economy. Ordinarily, fuel economy variations
between two nominally identical cars should not exceed 10%. Therefore
if the EPA value for your model car is 20 mpg,' your own car might be
measured between 18 and 22 mpg if the EPA test were made on it.
4, How do vehicle weight^ tires, and cpnvenienpe devices affect
fuel economy?
a. Vehicle weight and engine size are the most important factors
affecting automotive fuel economy. Each 100 pounds of added weight
decreases a vehicle's fuel economy by 1-3%, depending of course on
what fraction of total vehicle weight is represented by 100 pounds. In
addition to the weight which they add to an automobile, power accessories
cut fuel economy by increasing the load on the engine when they are in
operation. ' The fuel penalty for air conditioning in normal use is
typically 6% but may range as high as 20% in slowly moving traffic on
a hot humid summer day.
b. Automatic transmissions generally are less efficient transmitters
of power than are manual transmissions, and typically give rise to a
penalty ranging from 2-6% compared to manual transmission cars driven
correctly. However, if manual transmission cars are not shifted
properly, they too can decrease fuel economy by causing inefficient
operation of the engine. The greater fuel economy advantage is seen for
the manual transmission in the lighter weight ranges. This may be
due -in part to the use of less efficient automatic transmissions in light
weight cars. Recently, the use of more severe engine calibrations on
some cars with manual transmissions to enable them to meet the emission
standards has resulted in some manual transmission equipped cars having
poorer fuel economy than their automatic counterparts.
c. Axle ratio, which is measured by the number of times the drive-
shaft turns for each time the rear wheels turn, affects fuel economy.
Generally, a numerically lower axle ratio will result in better fuel
economy because the engine runs slower for any given vehicle speed and.
-------
-6-
therefore, has less internal friction to overcome. An axle ratio 101
below the standard axle ratio for Chat car (such as from 3.0 to 2,7)
can increase fuel economy by about 2% to 5%,
5. How can I tell whether the cars listed in the Mileage Guide
w_ere equipped; with t_h^__same^ ^p^ions I _a_in__i_nteresj:ed^ _i_n__ purchasing?
All vehicles tested by EPA are tested with the standard equipment
for that vehicle. Different axle ratios and transmissions are usually
tested if more than one are available. The options on the test car
are those which are bought by most vehicle purchasers. If more than a
third of a certain type of. vehicle are expected to be. sold with an
option such as air conditioning (and most domestically-manufactured cars
have air conditioning), then the car was equipped with air conditioning,
The same is true for other power options, such as power steering and
power brakes.
6. What can___I___do about a car^ which. gets_ pOor fuel econoni_yj_
First, you should check the list of factors in question 3
which are-responsible for most of the decreases in fuel economy observed
in actual customer use, to .see if one or more of those factors account
for you'r low fuel economy. If you are then convinced that you are still
getting abnormally poor mileage you should bring your complaint to the
service department of your car dealer. If you are not satisfied with
the service you received at your dealers, you should contact the
manufacturer's area service representative in your area. Finally if
all of the above fail, many states have a consumer protection office
which may be of assistance. In some states this is a separate agency,
in most it is within the state Attorney General's office.
7. What _is the Federal Government fuel economy information
grogram?
The EPA in 1973 established a voluntary fuel economy labeling
program in which participating auto manufacturers displayed the results
of EPA's fuel economy tests on their vehicles. The voluntary labeling
program was in effect from the 1974 model year to March 1976. At that
time, by act of Congress, fuel economy labeling of new cars became
mandatory. This program enables consumers to compare different models
and to take fuel economy into consideration when they purchase a
vehicle. ' . . • ; •
The information published -on the vehicle labels is also available
in a booklet entitled 1977 j^as Mileage Guide that is prepared by the
Environmental Protection Agency and distributed by the Federal Energy
Administration. Separate editions of the booklet are published for
cars sold in California (since California cars are different, to meet
the more stringent emission requirements in that state) and for the
-------
-7-
rest of the country. Single copies of this guide are available free
from any new car dealer, or by writing to: Fuel Economy, Pueblo,
Colorado 81009- Bulk copies are available by writing to Fuel Economy,
Federal Energy Administration, Washington, D. C. 20461.
8. Fuel economy standards.
The Energy Policy' and Conservation Act of 1975 (EPCA) not only
made fuel economy labeling mandatory on all passenger cars and light
duty trucks and required dealers to make copies of the EPA/FEA Mileage
Guide available to the public, but also required that beginning in
1978 the average fuel economy of each manufacturer's? new car fleet meet
the minimum fuel economy standards. The standards for 1978-1985 are:
1978 18.0 m.p.g.
1979 19.0 m.p.g.
. 1980 20.0 m.p.g.
1980-1981 (to be established by the U.S.
Department of Transportation)
1985 27.5 m.p.g.
9. What can I do to getjbetter fuel economy?
a. .Prop e r Ha in t e n a nc e
Be sure that your automobile remains in a state of good repair and
is properly tuned. The needed maintenance items and schedule are
described in the owner's manual and should be followed carefully.
Periodic maintenance items which especially affect fuel economy are the
air filter, the ignition system (spark plugs, distributor points, and
ignition timing), carburetor, cylinder compression, and lubrication.
A seriously defective vehicle, (e.g., spark plug misfiring, clogged
air filter, improper carburetor adjustment) can suffer a penalty of
20% or more. On the average, tuned-up cars get 5 to 8% better fuel
economy than the average- car that is not kept in a good state of tune.
b. Combine or avoid short trij)s
}]ow you use your vehicle can have as large an influence on fuel
economy as the design of the vehicle and engine, and is an aspect over
which the driver has control throughout the vehicle's life rather than
just at the time of purchase. Short trips made from a cold start
(engine not warmed up prior to use) result in much poorer fuel -economy.
One experiment with a car which delivered 11 m.p.g. in the EPA city test
got only 10 m.p.g. on a 5 mile cold start trip, 7 m.p.g. on a 2 mile
trip, and 5 m.p.g. on a 1 mile'cold start trip under summer driving
conditions-. In winter, the fuel consumed for short trips is even
greater due to the longer warmup period. It is therefore important to
-------
-8-
combine short trips to reduce the number of cold starts. And of course,
making short trips by walking, public transportation, or a bicycle will
save even more fuel.
c i Avoid high speeds
The best fuel economy on most cars occurs at a steady speed near
40. m.p.h.. Cruising at 55 m.p.h. instead of 70 m.p.h, reduces fuel
consumption by about 20%.
d. Drive
Slow down gradually, well in advance of traffic lights, to avoid
stopping when possible. Accelerate gradually. If traffic lights in
your area are timed sequentially, try to drive at the constant speed
which will enable you to pass through the lights without stopping.
OMSAPC/Nov. 1976
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
Mobile Source Air Pollution Control
FACT SHEET
FUEL ECONOMY DATA ON INDIVIDUAL CARS
QmcEOF
AIR AND WATER PROGRAMS
In the Fall of 1973, the U. S. Environmental Protection Agency published
fuel economy data on a large number of 1974 model year cars in a booklet
entitled 1974 Gas Mileage Guide for Gar Buyers. The list specified each
car by weight, manufacturer, model name, transmission, carburetor, cubic
inch displacement, and axle ratio.
Many people have written to EPA to ask for fuel economy data on cars
equipped with somewhat different transmission and axle ratio options from
the cars for which fuel economy data were published. Also, people have
asked whether other options, such as air conditioners and power steering,
were on the cars that EPA listed. To respond efficiently to these inquiries,
this Fact Sheet has been prepared.
Fuel economy data reported by EPA comes from vehicle testing that EPA
requires as a part of its emission control compliance program. Each year,
automakers must demonstrate, through tests of prototypes of the vehicles
that they intend to sell, that their cars are designed to comply with Federal
emission standards. EPA specifies which options must be on each vehicle
tested. Options such as air conditioners, power steering, and power brakes
are required on each car which the manufacturer estimates that 33% or more
will be sold with such an option.
However, EPA does not require the emission testing of a prototype
vehicle for every conceivable combination of options, for to do so would
make the testing workload wholly unmanageable for the government and industry,
as well as be unnecessary to assure that the basic car is designed to meet
emission standards.
The approximately 500 1974 model year cars tested by EPA represent a
careful sampling of the models and options that each manufacturer expects
to sell, and represent generally the other cars that are similar to the
prototype test cars. The fuel economy data published by EPA is intended
only to provide general guidance as to the types of cars that have shown
relatively better or poorer fuel economy results. The specific options
on the vehicle brought, the length and number of trips the vehicle usually
makes, and the personal driving habits of the operator may all cause the
car to demonstrate different fuel economy than that shown in the EPA list.
FS-14
-------
-2-
The fuel economy data published by EPA is all that Ig available
from EPA tests. It is not possible for EPA to provide specific fuel
economy data on cars with options different from those specifically
included in the booklet. EPA is considering including reference to
other optional equipment, such as air conditioners, in future model
year publications of fuel economy test results. Thus, fuel economy
data on the car in the booklet that is most like the car that may
be of particular Interest to any one individual represent EPA's best
estimate of the fuel economy of such a car.
February 11, 1974
-------
O vjt
? £5 \
t^SE ?, UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
\, ,c/ WASHINGTON, D.C. 20460
. . Fact Sheet
"Ring_of Power" Emission Control Device
The April 11, 1976, issue of The National Tattler carried a story
about a device known as "Ring of Power." Substantial claims have
been made for this device by its developers and promoters. The
promoters are quoted in the story as asserting that the only obstacle
to widespread general use of the device is a lack of government approval
of the device. The promoters are also quoted as asserting that the
Environmental Protection Agency has failed to approve the device because
it is protecting big business monopoly. This Fact Sheet has been
prepared to respond efficiently to inquiries that the EPA has received
on this subject.
As regards the maccer of government approval of such devices offered
for sale, there is neither a need for such approval nor a process of
providing it. Automakers are free to use any technology that they believe
best meets the requirements of the performance standards for emission
control that have been established to protect the public health.
Similarly, for add-on components for cars already in the hands of con- ,
sumers there is no Federal Government approval requirement, although, the
Federal Trade Commission is of course empowered to act against fraudulent
and misleading advertising claims.
The EPA does, however, receive a large number of proposals and
inventions for which claims for improved fuel economy and reduced
emissions are made. The EPA reviews all such proposals and inventions,
and as appropriate conducts confirmatory tests in its own technical
laboratories. Because of its limited laboratory facilities the EPA
requires inventors to provide a minimum of valid test data in support
of their claims before EPA confirmatory tests are scheduled.
. In the case of the "Ring of Power" EPA. technical staff first •
reviewed information provided by the developer in early 1974. On the
basis of information provided by the developer—which information did
not include data from valid testing of the performance of the device—
EPA staff concluded that the principles used in the "Ring of Power"
wer.e neither new nor novel. In the absence of valid test data that
would support the claims made by its developer for the device, EPA
confirmatory testing could not be justified.
EPA had further communication with the developer early in. 1975, and
again requested the submission of valid test data in support of the
claims made. The EPA has received no further data from the developer
since that time.
FS-14
-------
-2-
The EPA continues to stand ready to make eonfiraatory tests of
the "Ring of Power" if EPA is provided with valid test data that tend
to confirm the claims made for the device. However, on the basis of
the information currently available to EPA technical staff the claims
wa.de for the "ling of Power" cannot be confirmed by 1PA, On the bagis
of IPA's review of the principles of operation of the "ling of Power",
and in view of EPA's lack of success in getting the developer to provide
valid test data that support his claims of improvement in performance,
EPA technical staff believe - that the likelihood of the claims being
valid is low.
OMSAPC/April 1976
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
. WASHINGTON, D.C. 20460
Mobile Source Air Pollution Control
FACT SHEET '
Effect of Vehicle Weight on Automotive Emissions
The relationship between vehicle weight and automotive fuel economy
is quite pronounced and has recently received much attention. The
extent to which automotive emissions are related to a vehicle's weight
has received somewhat less attention, although there have been
proposals from ttae-to-time for restriction of vehicle size or weight:
as a means of reducing automotive air pollution.
The implementation of automobile emission standards (Federal
standards became effective with the 1968 model year), has provided a
strong pressure toward equalization of automobile emission levels
independent of vehicle weight, since for public policy reasons all
models, light and heavy, are required to meet the same emission
standard in terms of average grams emitted per vehicle mile over a
standard emission test procedure.* Thus, emission levels of current
vehicles can. not be expected to show any consistent relationship to
vehicle weight,
On the other hand, it is possible that such relationships between
automotive emission levels and vehicle weight would be observable for
vehicles built prior to the implementation of emission standards. The
reason is that the volume of exhaust gasses released by a vehicle per
mile of travel bears a close relationship to the work done to propel
the vehicle and thus, particularly in urban/surburban driving, to the
vehicle mass which mist be accelerated through the driving pattern. .
To evaluate the relationship between emissions and vehicle weight
for automobiles built before the implementation of emission standards,
EPA analyzed emissions data for approximately 600 pre-emlsslon control
automobiles which were tested as part of recent EPA emissions surveillance
programs. All vehicles were borrowed from private owners and were tested
in an "as received" condition. The vehicle sample covered the 1957
through 1967 model years and Included primarily U.S. manufactured vehicles •
. The test results; stratified according to vehicle weight, are
presented in Table 1 on the next page. , .,, .
* Since the 1972 model year, mass emissions have been measured directly.
Prior to that time, exhaust concentrations were measured, but vehicles
were required to meet different standards depending on the vehicle's
engine displacement (1968 and 1969 models) , or mass emissions were
calculated from exhaust concentrations' using a correlation between
exhaust volume and vehicle weight (1970 and 1971 models),
FS-15
-------
—2—
Table 1
Emission Levels as a Function of Vehicle Weight
for Uncontrolled (1957-67) Automobiles
Inertia
Weight Category
(Ibs.)
2000 or less
2000 - 2500
2500 - 3000
3000 - 3500
3500 - 4000
4000 - 4500
greater than 4500
Total/Average
Humber of
• Vehicles Tested
33
10
119
140
195
81
20
598
(go/mi
EC
10.2
6.5
8.1
8.2
9.4
7.6
8.5
"sTo"
Average Emissions
by 1975 Federal Test
CO
64.5
70.4 .
79.0
85.3
94.1
98.0
106.3
87.9
Procedure)
KOx
2.00
2,55
2.79
3.10
3.27
3.36
.' 3.61
3.08
-------
It can be seen from the data In Table 1 that for uncontrolled
vehicles a direct relationship exists between vehicle weight and
emissions of carbon monoxide (CO) and oxides of nitrogen (NOx), while -
no such relationship between vehicle weight and hydrocarbon (HC)
emission levels is apparent. These observations were verified by
statistical analysis. That analysis showed at the 1% level of significance
(99Z confidence) that the mean emission levels of CO and KOx of the
different weight groups are different. On the other hand for HC the
mean values for the groups are not different at the II level of -
significance,** . -_ ;
The reason for the different relationships to vehicle weight
observed on the one hand for CO and ISOx, and on the other hand for .
HC, can be found in the vehicle design characteristics which influence
the levels of"these emissions. The concentrations of CO and HOx found
in automobile exhaust depend principally (for pre-emission controlled
vehicles) on engine air/fuel ratio and combustion temperature. Since
these engines parameters showed no direct relationship to vehicle
weight for pre-controlled cars, the relationship between vehicle weight
and exhaust volume resulted in increasing mass emissions of CO and NOx
with increasing vehicle weight.
In the case of hydrocarbons, combustion chamber design, as well as
engine air/fuel ratio, plays a major role. The "quench layer" of
unburned or partially burned hydrocarbons which forms near the surfaces of
the engine*s combustion chambers contributes significantly to the engine's
hydrocarbon emissions. Small engines of the type typically used in
lighter weight cars have combustion chambers with a larger surface-to-
volume ratio than larger engines and result in higher hydrocarbon exhaust
cqnc.Tent_raitign3. The higher hydrocarbon concentrations in exhaust
from small cars tend to offset the smaller exhaust volumes from
those cars, resulting in no significant-trend with vehicle weight.
** It may also be noted that for all weight classes the HC and CO values,
and for all but the 4 lightest weight classes the NOx values, were
above current emission standards., 1973/74 cars are allowed to emit-at
levels equivalent to 3.0 gm/mi BC, 28 gm/mi CO, and 3.1 gm/ml NOx
as measured by the 1975 IT?': the" Federal standards for 1975 and
1976 are 1.5 gm/mi HC, 15 go/mi CO, and 3.1 gm/ml NQx; and the ... ""
original statutory emission standards called for by the Clean Air
Act are 0.41 gm/mi HC, 3.4 gm/mi CO, and 0.4 gm/mi NOx.
MSAPC/August 1974
-------
THE TWO-CAR STRATEGY
Many people have inquired about the need for automobile pollution
controls in communities where air pollution is not a severe problem.
This has been prepared to respond to such questions.
Since some areas of the country have far less of an automotive air
pollution jiroblem than large cities , why can 't there be two kinds of.
automobiles—one with air pollution controls for cities and another,, without
cojntrpls , for rural areas?
EPA believes
This concept has been called the "two-car" strategy.
that it would not be practical, for several reasons:
1. Cars are highly mobile. A car registered in a relatively clean
area will on occasion be driven to nearby cities. It would be almost
impossible to control where an automobile might be operated.
2. Even if it were possible to prohibit the sale and initial registra-
tion of uncontrolled cars in heavily polluted cities it probably would
be impossible to control the sale of used uncontrolled cars in such
cities. In fact, such uncontrolled cars are likely to be driven a
few miles and then "bootlegged" for resale in cities almost immediately,
thus circumventing the law.
3. Beginning with the 1975 model year, stringently controlled automobiles
will require unleaded gasoline to protect their catalytic converters.
Because of these requirements, they -night have serious problems being
refueled in those areas of the country in which such unleaded fuel — and
repair parts for stringently controlled cars--would not be readily
available. The average citizen's mobility would thus be unacceptably
impaired.
You say the two-car strategy won't work, yet what about California?
That sj^ate has for v_ears imposed more stringent emission standards on cars
than any other jurisdiction in the^ country.
A two-car system is feasible in an area 'which is geographically
separate from all other large metropolitan areas--in other words, In
California. Even there, all cars are subject to the same standards, even
though they may be registered and used most of the time in areas where
auto pollution is not a significant hazard.
In regard to the importation of used cars into California that do not
meet the more stringent California emission standards, not even California,
FS— #16
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY • WASHINGTON, D.C. 20480
-------
with its almost 10 years experience in imposing its own emission standards
on new cars has yet devised and implemented a way of prohibiting their
sale in California.
jjjnce automotive air pollution is not a problem where^ I live^ and
there is a fuel shortage^, why shouldn't I disconnect the air pollution
controls on my^ car?
Disconnecting the pollution controls on your car is not likely to
improve the fuel economy. EPA recently completed a technical study on the
effects of emission control removal on the fuel economy of 1973 and
1974 model year cars. The results of this study showed that when the average
mechanic worked on the automobiles, almost all cars showed a decrease in
fuel economy. The average decrease was 3.5%.
In addition, air pollution where you drive and live
would usually increase if you have the controls removed from your
automobile. Your area may not have an automotive air pollution
problem now: help keep it that way.
But what can I do to get the best mileage from my automobile?
Keep your car tuned to the manufacturers specifications. If you
donlt, you are likely to suffer an approximate 6% fuel penalty and maybe
more. Watch your driving habits—steady speeds, and avoiding sudden
starts and stops will -increase your car's fuel economy. Andj when you
are purchasing a new car—remember that the weight of the car greatly
affects the fuel economy. Power accessories, like automatic transmissions
and air conditioning, also require more fuel.
PS-Mobile-4 '
February 1974
*U»S, GOVERNMENT PRINTING OFFICE: 1974-733-415/10 3-1
-------
I UNETED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
FAPT SHFFT OFFICE OF
TALI OMtiJiJ. A!R AND WATER PROGRAMS
EMA Motor
The Environmental Protection Agency has received many inquiries
about an engine that can run without fuel that is said to have been
developed by a Mr, Edwin Gray* Stories about this engine have run in
a publication known as The Na t i o na1 Ta 111er.
This matter was brought to the attention of the Environmental
Protection Agency in the spring of 1973. At that time Mr. Gray was
invited by EPA's technical staff to provide data for a full evaluation
by EPA of the engine he claims to have developed. To date, the EPA
has received no communication from Mr. Gray and thus the EPA has no
information about the engine beyond that reported in The National
Tattler.
In the absence of technical data on the EMA "no fuel" engine,
the EPA is not in a position to comment substantively on the potential
merits of this development.
OKSAPC/February 1974
FS-17
-------
Removal of Emission Controls
The Environmental Protection Agency has made a study to
evaluate the feasibility of improving fuel economy on emission-
controlled cars by reversing or disconnecting emission control
features on the engines.
Late in 1973, the advent of the fuel shortage created exten-
sive public interest in whether the fuel economy of cars subject-
to emission controls could be improved by eliminating such
rontrols. The EPA made public its technical judgment that any
mass program to remove emission controls from cars would most
likely result in no net fuel economy gain, -and might even result
in a fuel economy loss.
To check out its technical judgment, the EPA, during December
and January, ran a test program on this question. Ten late-model
cars (1973/74 models) were obtained for this experiment. EPA
engineers tuned up most of these cars to obtain baseline emissions
and fuel economy values? some cars were not initially tuned up
but were baseline tested in as-received condition. EPA engineers
then made all feasible adjustments and disconnections that did
not require the use of redesigned carburetor or distributor
components {which are not realistically available to the service
industry or to EPA) for the purpose of maximizing fuel economy.
Emissions and fuel economy were then measured on each car, and
each car put back to manufacturers' specifications.
These tuned-up cars were then taken to -service stations and
' garages with a request that the emission control -systems be
removed. In most cases the service mechanics did not know that
they were participating in an EPA study. After being worked on
by the independent service industry, the-cars were returned to
the EPA laboratory, and the emissions and fuel economy were again
measured. ' _ -^
In three cases, the cars were delivered to the service
industry in as-received condition, to see .if materially different
results would be obtained. A total of 13'garage tampering episodes
were evaluated with the ten cars? some cars were used more than
once in the program.
In general terms, this test program found that highly-skilled
emission control technicians who are equipped with the best tools'
available (like the EPA technicians who worked on these cars},
IS—#18
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY » WASHINGTON, D.C, 20480
-------
were able to improve the fuel economy of the cars in most cases.
The increases found ranged from a low of 2.2% to a high of 17.8%,
with the average increase being 7%, Emissions of all regulated
pollutants increased substantially in most of these cases.
When worked on by service garages of various types, in most
cases the cars showed fuel economy losses; only one out of the 13
cars showed a significant fuel economy improvement, while three
showed negligible improvements. The range of results was from
a loss of 15.5% to a gain of 9.9%; the average" loss for these
cars was 3.5%. Again, emissions increased greatlyT
The numerical values cited above cannot be represented as
valid for the entire car population on the road today, for the
following reasons:
(1) The test cars were all 1973 and 1974 models, which
are the most stringently controlled cars on the
road today. Thus, if competently modified, these
cars would show the greatest fuel economy gains, and
older cars would have lower fuel economy gains;
(2) The sample of 13 tampering episodes on 10 cars
was too small to permit reliable quantitative ex-
trapolation to the vehicle population as a whole.
However, the study does identify the directipri
of the fuel economy changes likely to be experienced
at the hands of highly skilled emission control
specialists, and at the hands of ordinary source
industry personnel. -
From the data in this test program, as supplemented by
extensive other data available from other EPA and industry tests,
one can generalize that on the average the motorist could avoid
a fuel economy loss of about 6% through annual tune-ups; in other
words, about the same gain in fuel economy can be achieved through
keeping a car in proper tune as was experienced when experts
defeated the emission controls.
It is the EPA's view that this study confirms its earlier
technical conclusion on the impracticability of significantly
improving fuel economy of cars in the field by attempting to
remove emission controls. It is especially interesting that
two cars in this test program were modified by a large specialty
garage that widely advertises its emission control removal service?
in both cases their attempt to improve fuel economy was hot
successful.
In the interest of both fuel economy and clean air, the EPA
urges motorists to keep their cars in proper tune; such action
stands a much higher chance of improving fuel economy of cars
than does an effort to remove emission controls.
FS-Moblle-5
* U.S. GOVERNMENT PRINTING OFFICE: 1974-733-115/1! 3-1 FeDTUary 1974
-------
: 53^1 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
* ' WASHINGTON, D,C. 20460,
Electric Vehicles as a Solution
To Air Pollution and Fuel Shortages
The Environmental Protection Agency has received many inquiries
about the feasibility of using electrically-powered vehicles as a
solution to air pollution problems and fuel shortages. This Fact
Sheet has been prepared to respond efficiently to those inquiries,
Technical feasibility of Electric Cars
•Electric vehicles were in common use early in this century.
However, with the gradual improvement in internal combustion engines
electric vehicles could no longer compete in terms of range of
travel, ease of refueling, and acceleration and high speed character-
istics. Widespread use of electric cars was abandoned in this
country except for highly specialized and limited short range
applications.
The EPA has sponsored studies on the technological, energy,
environmental, and economic impacts associated with presently
available and projected future electric car technology and its
application. _ These studies are being continued by the Energy
Research and Development Administration.
Although there is room for some engineering advances to
improve performance and efficiencies of electric vehicles, the
basic technology required to build such vehicles is readily
available. However, the major obstacle standing in the way of
the widespread use of electric vehicles to meet urban transportation
needs is the unavailability of batteries of acceptable cost with
sufficiently high power and energy density to provide adequate
vehicle range and road performance, approaching that of conventional
gasoline-fueled vehicles of comparable utility. Unfortunately,
the lead-acid batteries in common use, and used in the few electric
vehicles on the market today, are inadequate to provide such operating
range and performance*
Batteries currently available limit electric vehicles to a
range of from 30 to 50 miles of low-speed urban driving before
needing electric recharge. Development programs are in progress
to develop higher performance batteries, but the technology needed
to produce practical versions of advanced batteries is not expected
to be available before 1980 at the earliest,
FS-19
-------
Relative efficiency of energy use by Electric Cars
Electric cars with advanced types of batteries could be of
comparable efficiency to their ICE counterparts; however the
major advantage of electric cars over the ICE is not improved
efficiency but their ability to utilize power generated from more
abundant energy sources. The electric car would still provide
reduced range. In addition, acceptance of electric cars would
necessitate some changes in the ways the general public uses their
cars, to accomodate the lessened capability to support accessory
and comfort subsystems such as heating, air conditioning and other
power consuming accessories, as well as inherently reduced range.
With lead acid type storage batteries of the types available
today, an electrically powered car with performance features that
approach as much as possible those of comparable utility internal
combustion engine powered cars would consume more energy, if it
is assumed that the energy in both cars is derived from petroleum.
However, if the energy were derived from coal, the comparison
would £avor electrically powered vehicles, because coal can be
burned directly to generate electrical power for charging the
batteries of the electrics, whereas it must undergo extensive chemical
conversions having relatively low efficiencies in order to be converted
into gasoline of a quality which can be utilized in internal combustion
engines. Thus, the real potential for widespread use of electrically
powered vehicles in future years lies in their inherent independence
on the type of fuel used to generate electricity, and thus their
ability to reduce petroleum consumption.
Until advanced batteries are developed, or until a shift is
made from petroleum to coal as a primary source of energy for both
electric power generation and for automotive transportation, it is
not realistic to expect a significant substitution of electric
cars for gasoline-powered cars, and thus not realistic to count on
environmental benefits in terms of reduced air pollution from the
use of electric cars.
Over the very long term, the ability of electric cars to
utilize energy generated by nuclear power plants and hence
be completely independent of fossil fuel reserves, would seem to
be a compelling reason to continue with research and development
on better batteries. However, the increasing public concerns
over safety of nuclear systems would appear to cast some doubt
on the prospects for rapid expansion in this direction.
OMSAPC/March 1976
-------
FLYWHEELS FOR MOTOR VEHICLES
The Environmental Protection Agency has received a number of
inquiries about the feasibility of motor vehicles powered in part
by flywheels. Claims for low pollution and fuel economy characteristics
are frequently made for such a system. To respond efficiently to
these inquiries, this Fact Sheet has been prepared.
1. What is a flywheel?
A flywheel is a heavy wheel for opposing and thus moderating
by its inertia fluctuations of speed in the machinery with which
it revolves. This definition applies to contemporary automotive
flywheels, which are used to damp the vibrations caused by the
non-uniform piston power strokes. In such applications, the flywheel
stores only a snail portion of the total system energy output to
perform.its function. However, flywheels also have the capability
of storing much more substantial amounts of vehicle kinetic energy.
2. Is the flywheel suitable for^autompbile applications?
Internal combustion engines used in contemporary motor vehicles
operate most efficiently and have their lowest exhaust emissions at
one ideal combination of load and speed; however, typical automobile
driving requires substantial changes in load and speed. Today's
engines cannot, therefore, operate all the time at their optimum
condition and still satisfy normal driving cycle requirements. A
flywheel used in conjunction with an engine run at a fixed speed would
store excess engine energy during periods of low power requirements and
discharge this energy to supplement the engine during periods of high
-------
-2-
power requirements. In this way, th-c engine would operate at essentially
constant load and speed, and could show an increase in fuel economy
and decrease In pollutant emissions compared to the case where the
engine alone acts as the prime mover.
Pure flywheel systems are also a possibility. Such systems are
"charged" at a central stationary location and therefore serve as the
only source of power In the vehicle. Such systems have very limited
*
range based upon current and projected technology (less than ten » - .
,.,'-, .......
miles* for a 4500 lb. automobile). •-.••' . ,
3. Are there any flywheel motor vehicle systems in use?
Several inventors in the United States have designed and
constructed heat engine/flywheel systems. Limited usage of the
.concept has been made by several foreign countries.!. Flywheel technology
is considered to be in the development and testing stage. There have
been several unsuccessful attempts to use flywheel systems in the past.
However, these were experimental and/or developmental systems with
limited performance capabilities. No flywheel motor vehicle system
has yet been mass-manufactured. " •
4. Are there any flywheel-motor vehicle jsv3jtem_a _ planned for the
n_ear _ future?
les. Two systems^ are, seriously being considered by the Federal
government. An Advanced Concept Train is being built by the Boeing
Vertol Company for the Department of Transportation.. It will contain
a flywheel system designed by Garrett Alresearch Manufacturing Company.
-------
-3-
The flywheel will act as a regenerative brake by absorbing the
kinetic energy of the movint train. This energy will then be
available for subsequent train accelerations. Additionally, the
Department of Transportation plans to contract to build two
trackless trolleys for use in San Francisco. The flywheels will
be recharged at convenient locations along the route. This will
allow the removal of overhead cables in congested areas. Subsequent
system development and use will depend strongly upon the results
observed with these prototypes,
5. Is there a^otential application fpr_flywheel systems in automobiles?
Studies conducted for the Environmental Protection Agency* by -the
Lockheed Missiles and Space Company (LHSC #D007905, 4/30/71) indicate .
'* , '
that the flywheel system is practical when used in conjunction with a
constant speed, spark-ignition, engine and can achieve substantial
reductions in emission levels. Increases In fuel economy are also
possible for automobiles which are used.in inner-city, atop and go
traffic, where acceleration and deceleration loads'represent a substantial
percentage of the total energy requirements.
6. What ar_e__the characteristics of a typical flywheel?
Flywheel characteristics are strongly dependent upon the application.
The characteristics given here are what would be expected for a typical -™
family car application: . ' • '-..-•-
*Several additional studies have also been performed for EPA which include:
"Feasibility Analysis of the Transmission for a Flywheel/Heat
Engine Hybrid Propulsion System," MTI-71TR75; "Heat-Engine/Mechanical-
Energy-Storage Hybrid Propulsion Systems for Vehicles, Final Report,"
APTD-1344, and "Hybrid Propulsion System Transmission Evaluations,
Phase 1 Final Report," AER 640.
-------
-4-
Maximum Rotational Speed - 20,000 to 30,000 RPM
Rotating Weight - 50 to 100 Ib.
Diameter 20 to 30 inches
Maximum Energy Storage - 10 to 20 watt-hr/lb. with
Capacity potential to 30 watt-hr/lb.
This-size flywheel is capable of providing more than enough energy to
accelerate a 500 Ib. automobile from 0 to 60 mph in 18 seconds.
7. How would a flywheel be integrated into _a_mgtor vehicle?
The flywheel can be mounted between the engine and drive train.
Two transmissions are required in order to convert engine speed to
flywheel speed and flywheel speed to drive train speed. The flywheel
may designed to be integral with the engine/transmission compartment
for front engine automobiles or integral with the transaxle for rear
engine automobiles.
Gyrodynamic forces are produced by the flywheel during normal
vehicle maneuvers. These forces are reduced by maximizing the flywheel
speed while minimizing the flywheel rotational moment of inertia. The
maximum gyrodynamic forces expected .for automobiles during rapid maneuvers
will be less than 100 Zb, •
It is not expected that such forces will cause a safety hazard,
but they may affect the "feel" of the vehicle. Slightly stiffer
suspension systems may have to be used to reduce the effect of such
forces.
The gyrodynamic forces are dependent upon the relative relationship
between rotational axis of the flywheel and the direction of any maneuver.
-------
-5-
i
There do not, however, appear to be any "forbidden" flywheel orientations,
Final flywheel position and orientation will be dependent only upon
vehicle, engine, and transmission design.
8. What problems remain before the flywheels can be used in
motor vehicles?
a. New power transmission systems are needed to efficiently
convert the low-spe,ed shaft engine power into high speed
shaft flywheel power. - ^
b. Electronic control systems are needed to provide smooth
power application and to allocate energy between the
engine, flywheel, and drive train.
c. Flywheel burst containment techniques must be perfected
in order to provide a level of safety commensurate with
conventional motor vehicles. . - ...
d. The development of techniques for the cost-effective
mass-production of high vacuum pumps and seals and high
speed, low friction bearings is required,
9. What is the EPA doing to solve these problems?
While EPA has conducted the basic studies referenced on page 3
of this fact sheet, currently the inovative efforts by private industry
are being relied upon to further extend the results of these basic
studies to consideration of practical automotive designs.
MSAPC
3-7-74
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C, 20460
FACT SHEET
Gasoline/Water Emulsions for Emission Control
The Environmental Protection Agency has received many
inquiries concerning the use of water-in-gasoline emulsions
to reduce vehicle emissions and improve fuel economy. This
fact sheet has been prepared to respond to these inquiries.
One such system that has received widespread public
attention is the "Vareb-10 Gasoline/Water Emulsion". This
substance contains, in addition to gasoline, 10 to 13 percent
water together with a proprietary emulsifing agent intended to
prevent separation of the water from the gasoline in the vehicle
storage tank.
In August of 1973 this particular emulsion was tested at the
EPA vehicle emissions laboratory in two vehicles provided by the
developer. The vehicles were tested by the procedure currently
being used for emissions certification of 1975 model automobiles.
Under these conditions, both vehicles exhibited stalling and
generally poor driveability. Fuel economy (miles per gallon of
gasoline used)* in both cases was approximately 10% poorer than
with gasoline alone, while hydrocarbon emissions were from
300 to 500% higher. On the other hand, nitrogen oxide emissions
were reduced by about 50%, which is consistent with other EPA test
data on vehicles employing water injection devices. Carbon monoxide
test results were inconsistent, with one vehicle showing lower and
the other higher CO emissions.
It was hypothesized that with 10% water in the fuel the
"leaning-out" of the air/fuel mixture may have caused these
vehicles, both of which were emission controlled 1973 models,
to approach lean misfire limits, which would account for the
higher hydrocarbon emissions and poorer fuel economy and still
be consistent with the reduced nitrogen oxide emissions. After
further discussions with the developer, EPA conducted additional
tests using two government owned vehicles, one a 1963, pre-emission
controlled model, and the other a 1970 model.
FS # 21
-------
-2-
The 1970 car performed like the developer's vehicles,
showing such severe driveability problems that the high emission
test results from this car were considered invalid. The 1963
model car, which operated at richer air/fuel ratios, did show
reductions in emissions of all three regulated pollutants, 39%
for hydrocarbons, 55% for carbon monoxide, and 24% for oxides of
nitrogen. The fuel economy, in terms of gasoline consumption
only* was unchanged.
It is believed that the favorable emissions behavior of the
older car reflected the fact that the car was designed to have
richer carburetor settings than do later models» and therefore
the enlearnnent effect of 10% water in the gasoline did not cause
this vehicle to encounter lean misfiring or driveability problems.
The hydrocarbon and carbon monoxide reductions on the 1963 car
appear simply to reflect enleanment which would also have been
achieved with a carburetor calibrated at leaner mixture settings.
In summary, the tests conducted on the Vareb-10 Gasoline/
Water Emulsion by EPA failed to corifim the claimed improvements
in fuel economy on any test vehicle, but rather showed results
ranging from no change to 10% fuel economy loss. Reduction in
emissions of all three pollutants was observed only on a 1963,
ore-emission controlled, teat car. From these data EPA concludes
that the gasoline/water emulsion approach has not been shown to
have large scale potential for reducing emissions or for Improving
fuel economy. At most, the application of this approach to pre-
emission controlled vehicles with..rich .carburetor .calibrations
may provide .some reduction, in emissions.with no fuel economy
penalty.
* Fuel economy calculations based on gasoline only, with
no attempt to consider any fuel contributed by the
trade-secret emulsifying agent.
EPA/OMSAPC—June 1974
-------
T;
I UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
y WASHINGTON, D.C, 20460
FACT SHEET
ALTERNATIVE ENGINES FOR CARS
The U.S. Environmental Protection Agency is charged by the 1970
Clean Air Act Amendments to reduce air pollution, A major source of
the total air pollution problem is the automobile. Many citizens have
inquired about the future of the conventional internal combustion engine
and the prospect for the alternative engines on which EPA is conducting
research'. This Fact Sheet has been prepared to respond to these inquiries.
What is EPA doing to develop new'types of engines that will not pollute,
not: require^external 'pollution 'controlequipment, and get good fuel
prnnrvnv?
1.
economy
Since 1970, at the EPA Ann Arbor Automotive Testing Facility, the
Alternative Automotive Power Systems Program (AAPS) has been conducting
research on possible engine systems, that are inherently clean. Three
systems have been under development because they are the most promising:
The gas turbine, the Rankine (steam) cycle, and stratified charge engines.
The gas turbine and Rankine cycle systems both employ continuous
combustion rather than the intermittent combustion process used in the
conventional engine. The gas 'turbine, in its simplest form, consists
of a compressor, a combustion chamber, and a turbine. Air is taken in
by the compressor, compressed to a higher pressure, and then delivered
to the combustion chamber where it is mixed with fuel and burned. The
resulting high-temperaCure, high-pressure gas runs the turbine. Part of
the shaft power developed by the turbine is used to drive the compressor;
the remainder is Che output used to drive the vehicle and the accessories.
The Rankine cycle system is an external combustion engine in which
high pressure steam or other:working fluid vapor is expanded in either
a turbine or a piston—type expander to produce work. A pump draws liquid
from a condenser and forces it under high pressure into the vapor generator
where it is converted to superheated vapor by the heat from combustion in
the burner. The hot, high-pressure vapor is.then metered into the expander
where it produces usable power. The vapor expands to a low pressure and
is then cooled and converted back to a liquid in the condenser. The
resulting low pressure liquid is then returned to the vapor generator by
the pump to repeat the cycle.
FS-22
-------
The sGratified charge engine is a refinement of the conventional
engine which features a more efficient combustion process. This engine
is a spark-ignition, gasoline-fueled, internal combustion engine with
riany of the hardware characteristics of the conventional engine, A
"layered" or "stratified" fuel mixture is used in the combustion chamber.
A characteristic of this process is air/fuel swirl, which occurs near
the top of the combustion chamber. After combustion is initiated in the
swirling mixture near the top of the cylinder, the burning mixture then
expands into the lower portion of the cylinder (which is oxygen—rich)
where burning continues. The overall result is that the combustion products
are similar to those obtained using a very lean mixture throughout the
entire burning period.
2. How is the rese^arcji progressing on these _sys terns?
The approach to the gas j:urbine_ has stressed problem—solving research
and demonstration of the results in practical test-bed engines, rather than
in the development of a completely new gas turbine configuration. The EPA
program has focused on the most significant problems impeding introduction
of the gas turbine:
nitrogen oxide emissions
relatively high fuel consumption under
typical driving conditions, and
costly materials and manufacturing processes
Intensive combustion research has determined premixed3 prevaporized low
emission cornbustor technology is the most promising for future'application.
Emission levels well below the statutory HC and CO emission standards have -
been achieved on combustor test rigs.
Problem solving efforts in the areas of fuel economy and manufacturing
costs have been directed towards automotive gas turbines with demonstrated
suitability for automobile propulsion.
Demonstration of an improved gas turbine in passenger cars is planned
for 1975.
The Kankine cycle engine development program was initially structured
around problem solving and component development. When significant progress
was made in these areas, preprototype systems development was initiated using
this latest component technology.
-------
— 3—
Solutions to Lhe basic technical problems have been demonstrated. The
results of combustion research on Rankine cycle combustors have consistently
shovm that the statutory Federal emission levels for HC, CO, and NOx may
be expected to be achieved with Rankine systems. The size and weight of
system components such as the condensor , burner-vapor generator, and
feed pump are now within goals originally set.
The overall goal in fuel economy is to obtain at least 12 miles per
gallon over the Federal Driving Cycle compared to approximately 10,3 miles
per gallon for a 1973 automobile of similar weight powered by a 'conventional
internal combustion engine.
Much of the initial work on the "stratified charge engine" was
sponsored by the U.S. Array Tank-Automotive Command starting in the mid-1960 's.
Several generations of development have been funded by the Army. In 1970
the potential of low emissions was shown and in 1971 this engine system
brought into the EPA program. Since that time the engine development work
has been jointly sponsored by the Army and EPA. EPA's work on this engine
has emphasized the reduction of emissions. The measured exhaust emission
levels, for several experimental stratified charge engines installed in
small military vehicles, employing oxidation catalytic exhaust after-treatment
and exhaust gas recirculation, are below all of the statutory emissions
standards. The controlled stratified charge engine tests on "jeep" versions
have not only met 1976 emission standards at low mileage but have consistently
shown fuel economy equivalent to or better than the uncontrolled conventional
engine that it can replace.
Due to the advanced state of stratified charge' engine technology, EPA's
role has been reduced to one of evaluation of available stratified charge
engines installed in passenger vehicle chassis. After the EPA passenger
car evaluations, recommendations will be made for resolution of current
design problems. The similarity of this engine configuration to the
conventional engine, coupled with its more efficient combustion process,
make it the most probable near term candidate as a low emission replacement
for the conventional engine .
3. How soon will J^he^jmaines being developed by EPA be available in cars
in the showroom?
That will depend on many factors. One, of course, is the success of
the development program itself. Another is the progress that the auto
industry will make in solving the environmental and fuel economy problems
of the conventional engines that it is currently building.
-------
The purpose of the EPA Alternative Engine Development Program is not
to build and market a car with an EPA engine, but rather Co assure that
the nation can make an intelligent choice among all reasonable alternatives,
If one of the engines being developed "by EPA proves to be significantly
better than the best that the auto industry can do with its conventional
engine, then it is reasonable to anticipate eventual adoption of the
better concept.
However, even if that happens, lead time in the auto industry is so
great that there,is no real chance» except'for the stratified charge engine,
that cars with alternative engines will be available for purchase before
the ISSQ's at the earliest. As regards the stratified charge, several
cospanies are expected to introduce their own version in the late 1970's.
Basically, the EPA engine development program is an insurance policy
against the contingency that the auto industry may not achieve the goals
that it is striving toward. If that should happen, there may be available
later in this decade proven engine concepts that can gradually become the
basis of an improved, cleaner automobile transportation system.
MSAPC/April 1974
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
' '
WASHINGTON. D.C. 20460
OFFICE OF
AIR AND WASTE MANAGEMENT
FACT SHEET
Introduction of Diesel Powered Passenger Automobiles
The Environmental Protection Agency has received numerous questions
about public statements made by certain domestic and overseas manufacturers
to the effect that they are considering the Introduction of dlesel powered
passenger cars, but that whether or not they will actually introduce
such vehicles into the market place will depend upon Congressional
action on pending amendments to the Clean Air Act. In some letters,
EPA has been urged to exempt diesel vehicles from certain air pollution
control requirements, to foster and promote the use of diesel engines
in cars. This Fact Sheet has been prepared to respond efficiently
to these inquiries.
Diesel engines have both advantages and disadvantages for use In
passenger cars. Among the advantages are better fuel economy and
lower emissions of unburned hydrocarbons and carbon monoxide. Among
the disadvantages, at least In. the past, have been higher noise levels,
lower acceleration performance, higher costs, and difficulty In starting
in very cold weather.
In the past, when there were ample supplies of low cost gasoline,
the disadvantages of diesel engines for passenger car use have tended
to keep most automakers from offering diesel powered cars. As fuel
has become more expensive the fuel economy advantages of diesel engines
has been receiving substantially greater attention. It Is for that
reason that manufacturers have been giving renewed consideration to
introducing diesel powered passenger cars.
Insofar as the question of emissions of air pollutants from
diesel powered automobiles Is concerned, the emissions of unburned
hydrocarbon and carbon monoxide from diesels Is In most cases so
very low that no special measures need to be taken to assure that
such vehicles meet Federal emission standards. Ho exhaust after-
treatment devices are necessary on diesel engines. However, as
regards the emission of oxides of nitrogen, the third automotive
pollutant currently subject to Federal control, diesel engines present
FS-22
-------
-2-
a different picture. Although at the level of current Federal oxides
of jiitrogen standards (3.1 grams per mile In 1976, and 2.0 grams per
mile in 1977) diesel engines have no particular problem complying,
diesel engines would have significantly difficulty meeting substantially
lower emission standards of oxides of nitrogen. Catalytic emission
control technology has a potential for permitting gasoline engines
to meet oxides of nitrogen emission standards substantially lower
than those in effect for today. Diesel engines cannot, for valid
technological reasons, utilize such technology.
In general those manufacturers who have announced that they
are considering the introduction of diesel engines have also stated
that they would not take that step if the oxides of nitrogen emission
standard for future years is set by the Congress at a level at which
diesel engines cannot comply, or could comply only at the cost of
significantly increasing fuel penalty.
The Congress is currently deliberating the level of auto ^mission
standards to be applicable to cars built in future years. All of the
technical issues related to this matter have been provided to the
Congress by the EPA and the Industry. EPA is not and will not be in
a position to exempt diesel pov?ered cars from air pollution control
requirements established by the Congress to be applicable to all
future models of new cars.
MSAPC/Hay 1976
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
OFFICE OF
AIR AND WASTE MANAGEMENT
MOTORCYCLE FACT SHEET
This Fact Sheet discusses the exhaust emission characteristics
of motorcycles and the activities of the U.S. Environmental Protection
Agency toward the control of these emissions.
Emissions from motorcycles vary significantly depending on their
engine size and type* The table below is a sample of average emission
test results from some current motorcycles:
Motorcycle Exhaust Emission Test Results
(1975 Federal Vehicle Test Procedure)
Nominal Engine Displacement (cc)
and Tyjie
50
100
125
250
350
650
750
Over
1974
Stati
2-stroke
4-stroke
2-stroke
2-stroke
4-stroke
4-stroke
2-stroke
800 4-stroke
Federal automobile standards
itory -Federal automobile
HC
grams/mile
8.1
2.0
13.8
18.6
3.5
5.4
28.5
5.2
3.0
0.41
CO
grams/mile
14
22
20
31
51
46
43
71
28.
3.4
NOx
grams /mile
0.03
0.33
0.07
0.04
0,08
0.11
0.10
0.31
3.1
0.40
standards
FS-23
-------
-2-
When considering the size of motorcycle engines and the quantities
of fuel used, it is difficult for many people to believe that motorcycle
HC and CO emissions are greater than automobile HC and CO emissions.
High motorcycle emissions can be explained by considering actual engine
performance. The motorcycle obtains relatively high fuel economy because
its small engine is required to do very little work when compared to the
larger and heavier automobile. Since NOx emission levels are generally
proportional to engine loading, the light engine loads characteristic of
a motorcycle produce the very low NOx levels seen in the previous table.
However, when comparing engine efficiencies, the automobile typically
produces substantially more work per gallon of fuel used than the motorcycle
engine, irrespective of engine size. Therefore, as might be expected, '
much of the fuel that does not produce useful work ends up as an exhaust
pollutant.
The high hydrocarbon concentrations in the exhaust of the two-stroke
engine motorcycle result primarily from the scavenging portion of the
engine operating cycle. When the fresh charge of air and fuel is forced
into the cylinder through the transfer port, there is a period when the
exhaust port is also open, and as much as 35% of the fresh fuel charge
passes through the cylinder and out the exhaust port before the port is
closed in the compression stroke. The near elimination of this short-circuiting
of intake air and fuel through the exhaust should not only reduce exhaust
emissions, but also significantly improve the fuel economy of the engine.
Hydrocarbon emissions from the four-stroke engine motorcycle are
substantially lower than the two-stroke, because valves are used to control
the flow of intake and exhaust gases, and the short-circuit scavenging
process does not occur to the same extent. However, hydrocarbon and
carbon monoxide emissions remain relatively high when considering the
size of the engine, A major contributor to these emissions is the
relatively simple carburetion system which results in poor fuel
atomization. Carburetor improvements to the four-stroke engine are
expected to provide a significant reduction in these emissions.
Another cause of high HC and CO emissions is the rich fuel-air mixture
used in air-cooled two and four-stroke motorcycle engines. Rich fuel-air
mixtures generally result in good driveability, high power, and cool
engine operation; however, emissions and fuel economy are greatly
compromised. Leaning out of the fuel-air mixture in motorcycle engines
can reduce the hydrocarbon and carbon monoxide emissions and improve
fuel economy to some extent. To achieve this reduction, means other
than excess fuel will have to be devised for engine cooling.
-------
-3-
The need to control emissions from motorcycles became important
when analysis of emission sources in certain regions experiencing high
pollutant levels revealed the significant contribution of motorcycles.
To achieve the emission reductions required to meet the EPA Ambient
Air Quality Standards in these critical regions, registration limitations
and a restriction on the operation of motorcycles during periods of
expected high pollutant concentration were considered. In response
to such limitation proposals, the major motorcycle manufacturers urged
as an alternative the establishment of national emission standards for
new motorcycles. The motorcycle manufacturers, in general, indicated
that emission reductions were feasible and could be implemented in a *
reasonable period of time.
Proposed standards for.new on-road motorcycles, to be implemented
in two stages, were published in the Federal Register on October 22, 1975
(40 CFR 49496). The initial stage is being proposed for promulgation
in the 1978 model year and to continue through 1979. The allowable
pollutants levels for this stage are based upon improvements in the
motorcycle engine that are considered feasible to implement in the short
term. The proposed near term standards for 1978 are: Hydrocarbons—a range
of 5.0 g/km to 14.0 g/km based on vehicle engine displacement; carbon
monoxide—17 g/km, which is comparable to the 1972 through 1974 passenger
car standards; and oxides of nitrogen—1.2 g/km, which is the same as
the 1977 passenger car NOx standard. A second stage is expected to
apply to the 1980 model year and beyond. For that period, the EPA
proposed that new motorcycle emissions should be limited to the same
standards in effect for passenger cars at that time, unless such
control is found to be infeasible due to technological or cost restraints.
Comments on these proposed standards are currently being reviewed,
and EPA expects to publish final emission control requirements for
motorcycles during calendar year 1976.
MSAPC/March 1976
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
' WASHINGTON, D.C,
OFFICE OF
AIR AND WASTE MANAGEMENT
MOTORCYCLE EMISSION CONTROL
FACT SHEET
On January 5, 1977, EPA issued final regulations for the control
of motorcycle emissions of hydrocarbons (HC) and carbon monoxide (CO)
beginning with motorcycles manufactured in 1978. This Fact Sheet has
been prepared to respond efficiently to frequently asked questions
about this EPA action.
Why control motorcycles?
From the standpoint of air pollution, motorcycles are dirtier
than cars. On a per-vehicle basis an uncontrolled motorcycle emits
more pounds of hydrocarbon and carbon monoxide pollutants than a 1971
car,
Emissions from uncontrolled motorcycles vary depending on the size
and type (two- or four-stroke) of engine. A large two-stroke motorcycle
without controls emits more than thirteen times the hydrocarbon that a
1977 car is allowed to emit, and more then twice the carbon monoxide.
Even a small two-stroke motorcycle emits over seven times more hydro-
carbon than a 1977 car. Though the average four-stroke motorcycle
emits even more carbon, monoxide than the average two-stroke, it emits
fewer hydrocarbons. Still, four-stroke motorcycle emissions exceed
the amount cars are permitted to emit.
Collectively motorcycles contribute to the air quality problems
encountered in many of our large cities. Even with the automobile
stringently controlled, reductions in air pollution from other sources
are necessary in order to meet the clean air goals set by Congress in
the Clean Mr Act. To meet the clean air goals, several States in 1972
and 1973 considered restrictions on the operation of motorcycles during
periods of high pollution concentration. In response to such proposals,
the major motorcycle manufacturers called for'the establishment of
national emission standards for new motorcycles. Throughout the
development of the regulations which were issued in January, 1977,
representatives of the industry worked closely with the EPA on develop-
ing regulations which vould achieve the goal of reducing the pollution
from motorcycles.
FS-23
-------
-2-
Control of motorcycle anisslons will not by itself result in air
quality Improvements aa large as those that are being obtained through
control of passenger cars simply because there are so many more cars
than motorcycles. However, motorcycle emission control is a relatively
low cost way to belp reduce pollution. In addition, as cars become
cleaner, the proportion of motorcycle emissions to total emissions will
increase. Indeed, analysis has confirmed that control of motorcycle
emissions is highly cost effective compared to other possible control
strategies!
Since'.motorcyclesare_ smaller and^ get^ better £uel economy than ears^
how can they be dirtier?
Motorcycles generally get better fuel economy than cars because
they are smaller and lighter.
The high emissions of HC and CO from motorcycles result from
the differences between car and motorcycle engine performance and
efficiency.
A motorcycle obtains relatively high fuel economy because its
small engine is required to do very little work compared to the
engines used to propel the larger and heavier automobile. The
automobile typically produces substantially more .work per gallon of
fuel than engines used in motorcycles, irrespective of engine size.
Therefore, much of the fuel used to power motorcycle engines does
not produce useful work and ends up as unburned or partially burned
fuel in the exhaust. This unburned fuel is the cause of air pollution.
The high hydrocarbon concentrations in the exhaust of the two-
stroke engine motorcycle are emitted primarily during the scavenging
portion of the engine operating cycle. When tae fresh charge of air
and fuel is forced into the cylinder through the transfer port, there
is a period of time during which the exhaust port is also open, and
as much as 35% of the fresh fuel charge passes through the cylinder
and out the exhaust port before the port Is closed In the compression
stroke. The reduction of this short-circuiting of intake air and fuel
through the exhaust will not only lower exhaust emissions, but will also
significantly improve the fuel economy of the engine.
Hydrocarbon emissions from the four-stroke engine motorcycle are
substantially lower than the two—stroke because valves are used to
control the flow of intake and exhaust gases, and the short-circuit
scavenging process does not occur to the same extent. However,
hydrocarbon and carbon monoxide emissions remain comparatively high
because of the relatively simple carburetion system used on four-
-------
-3-
stroke motorcycles. Carburetor improvements such as accelerator pumps
and better fuel metering to motorcycles are expected to provide a signi-
ficant reduction in these emissions, as well as improvement in fuel
economy.
Another cause of high EC and CO emissions is the rich fuel-air
mixture that is used in air-cooled two- and four-stroke motorcycle
engines. Rich fuel-air mixtures have been used to maintain good
driveability and cool engine operation, but they do so at the expense
of fuel economy and increased emissions. Leaning out the fuel-air
mixture in motorcycle engines can reduce the hydrocarbon and carbon
monoxide emissions and improve fuel economy. When used in conjunc-
tion with carburetor modifications and improved cooling, good
driveability and reliable engine operation can be accomplished.
How much will the new_rules reduce motorcycle emissions?
The 1978 and 1979 standards represent a 34 and 36 percent reduction
in hydrocarbon and carbon monoxide emissions respectively (from
uncontrolled levels). The 1980 standards represent a 54 and 49 percent
reduction for these pollutants respectively. By contrast, passenger car
standards for the 1977 model year represent an 83 percent reduction for
both hydrocarbons and carbon monoxide from uncontrolled cars.
What will thie_dp^p motorcycles and_ how jjuch__will it cost?
s
. t
Manufacturers of motorcycles generally hav? indicated agreement
with EPA that the standards now promulgated can be met in the time
allowed with available technology. While some two-stroke motorcycles
may have to be converted to four-stroke design to meet the 1978 or
1980 standards, improved carburetion and ignition systems will be
enough on most motorcycles. Based on data supplied to EPA by manu-
facturers, it is estimated that the costs incurred to comply with
the 1978 federal emission standards will increase the cost of a
motorcycle an average $47. Manufacturers1 data also indicate that
motorcycle fuel economy will improve 20 percent as a by-product to
meeting the standards. This will save the vehicle operator an average
of- $33 in fuel costs over the life of the vehicle. Thus the net cost
of meeting the 1978 and 1979 standards will be about $14 per motorcycle,
Meeting the 1980 standards is expected to increase the first cost to
the consumer by another $18 with additional fuel economy improvements
reducing the total costs to about $9 per vehicle on the average.
MSAPC/April 1977
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
. ^ OFFICE OF
AIR AND WASTE MANAGEMENT
Odors from Diesel-Powered Vehicles
The Environmental Protection Agency has received many
inquiries concerning causes and control of odors from diesel
powered vehicles. This fact sheet has been prepared to respond
to such inquiries.
1. What causes diesel exhaust odor?
No one single chemical compound is responsible for
diesel exhaust odor. Over 100 different complex compounds
produced during combustion, including unbumed and partially
burned fuel, have been found to contribute to diesel exhaust
odors.
2. Do many people, fjLnd_diesel_ exhaust odor objectionable^
Studies sponsored by EPA have shown that roughly 901 of
urban citizens find diesel exhaust odors of the type and intensity
produced by older city buses to be objectionable.
3. Is there any difference • in the exhaust odors produced "by
different types of diesel powered vehicles?
There are no inherent differences in the qualities of odors
and quantities of odorous compounds produced by similar engines,
whether .used in buses, trucks, or diesel powered automobiles.
However, buses tend to be more concentrated in the centers of
cities and operated In close proximity to large numbers of people
under prolonged engine idling conditions. Therefore, odors from
buses are more noticeable to.the average citizen. Moreover, diesel
trucks often have vertical exhaust stacks, resulting in both
greater dilution of the exhaust and less exposure to the public.
4. How can diesel exhaust odors be reduced?
Hewer diesel powered buses now come equipped with improved
fuel injection nozzles, which have'significantly reduced the
odor level. Use of vertical exhaust stacks in new buses also •"
has reduced the perception of odors because of greater atmospheric
dispersion or mixing of-the exhaust. Of course, vertical stacks
do not reduce the total amount of emitted odorous compounds.
The modified fuel nozzles can also be installed on older buses
and achieve odor reductions, and a retrofit kit for this purpose
is available from the manufacturer (GM) of the diesel engines
that are used in almost all buses.
FS-24
-------
-2-
With diesel engines other than those used in buses, it also
appears that fuel injection system design and timing is the most
attractive and coat/effective approach to odor reduction. While
catalyst exhaust reactors have shown modest odor, supression effects
in research testing, their installed cost at this time is too high,
in comparison to their demonstrated effectiveness, to justify
their use,
5. How can diesel exhaust odors be measured1^
The most basic measure of diesel odors is still the human nose.
For that reason trained human panels have been used in the past
to measure these odors.
In recent months, however, joint government/industry research
partially sponsored by EPA through the Coordinating Research Council
has resulted in an instrument which is capable of responding to
diesel exhaust odors to about the same degree as do the trained
human panelists. This instrument is now being used by both govern-
ment and industry laboratories in research on minimizing odors from
newly designed diesel engines, but requires more development before
being adopted as an odor control enforcement tool.
6. Is the EPA planning to establish standards to limit odors
from new diesel engines?
Some authorities believe that new diesel engines manufactured
which meet the current EPA hydrocarbon emissions standards will be
acceptable from the odor standpoint as well. However, If this
proves not to be the case, the EPA would attempt to develop separate
odor standards,
HSAPC/ July 9, 1974
-------
.
\ UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
" WASHINGTON, D,C. 20460
«
OFFICE OF
AIR AND WASTE MANAGEMENT
Odors from Diesel-Powered Vehicles
The Environmental Protection Agency has received many inquiries
concerning causes and control of odors from Diesel-powered vehicles.
This fact sheet has been prepared to respond to such inquiries.
1, What causes Diesel exhaust odor?
No one single chemical compound is responsible for Diesel exhaust
odor. Over 100 different complex compounds produced during combustionj
including unburned and partially burned fuel, have been found to contribute
to Diesel exhaust odors.
2. Do many people find Diesel exhaust odor objectionable?
Studies sponsored by EPA have shown that roughly 90 percent of
urban citizens find Diesel exhaust odors of the type and intensity
produced by older city buses and current types of Diesel-powered
passenger cars to be objectionable.
3. Is the.re'any difference in the exhaust odors produc_ed_ by different
types of.Diesel-powered vehicles?
There are no inherent differences in the qualities of odors and
quantities of odorous compounds produced by similar engines, whether
used in buses, trucks» or Diesel-powered automobiles. However, buses
tend to be more concentrated in the centers of cities and operated
in closer proximity to large numbers of people under prolonged engine
idling conditions. Therefore, odors from buses are more noticeable
to the average citizen. Diesel-powered trucks and newer city buses
often have vertical exhaust stacks, resulting in both greater dilution
of the exhaust and less exposure to the public. Diesel-powered
automobiles are as yet too few in number for their contribution to
urban odors to be noticed. This may, of course, change as they
become more popular because of their excellent fuel economy.
FS-24
-------
4. Hgw^ can Diesel exhaust odors be reduced?
New Diesel-powered buses now come equipped with improved fuel
injection nozzles which have significantly reduced the odor level,
Use of vertical exhaust stacks in new buses also has reduced the
perception of odors because of greater atmospheric dispersion or
mixing of the exhaust. Of course, vertical stacks do not reduce
the total amount of emitted odorous compounds. The modified
fuel nozzles can also be Installed on older buses and achieve odor
reductions, and a retrofit kit for this purpose is available from
the manufacturer (GM) of the Diesel engines that are used in almost
all buses operated in the United States.
With Diesel engines other than those used in buses, it also
appears that fuel injection system design and timing is the most
attractive and cost/effective approach to odor reduction. While
catalytic exhaust reactors have shown modest odor supression effects
in research testing, their installed cost at this time is too high,
in comparison to their demonstrated effectiveness, to justify
their use.
5. How can Diesel exhaust_odors be measured?
The best measure of Diesel odors is still the human nose. Trained
human panels have been used in the past to measure these odors. Joint
government/industry research partially sponsored by EPA through the
Coordinating Research Council has resulted in development of an
instrument which is capable of responding to Diesel exhaust odors in
a manner similar to trained human panelists. This instrument is now
being used in research on minimizing odors from newly-designed Diesel
engines, but requires more development before it can be used as a tool
for use either in odor control certification of new Diesel engines,
or in odor control enforcement with respect to in-service engines.
i
6. Is the EPA planning to establish standards to limit odors from
new diesel engines?
There is some reason to believe that new heavy-duty Diesel engines,
and Diesel-powered automobiles which meet the 1980 EPA hydrocarbon
emissions standards, will have sufficiently low odor emissions to be
acceptable from the odor standpoint as well. However, if this turns
out not to be the case, the EPA may consider development of a separate
odor standard.
MSAPC/45582
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHiNGTON, D.C, 20460
OFFICE OF
AIR AND WASTE MANAGEMENT
Fact Sheet
Comparison of the Japanese and U.S.
Automotive Emission Standards
The Environmental Protection Agency has received inquiries about the
relative stringency of the U.S. and Japanese automobile emission standards.
To respond efficiently to these questions this Fact Sheet has been prepared.
General Background
The Government of Japan hag established a program of automotive emission
standards for new cars that appear to be numerically equivalent to the 1978
U.S. emission standards required by the Clean Air Act as amended in 1974
(since changed by the Clean Air Act Amendments of 1977). However, che
test procedures by which compliance with the respective emission standards
is demonstrated are not the same. For that reason direct comparison of
the U.S. and Japanese auto emission standards in terms of their simple
numerical levels is misleading.
To explain this complex issue, it is necessary first to set forth some
basic principles for defining emissions, secondly to describe the way in
which emissions from cars are measured in the U.S. and in Japan, and
finally to discuss the differences between the measurement methods and
the resulting differences in the emissions levels.
BasicPrinciples for Defining Emissions
It is axiomatic that no meaningful statement can be made about exhaust
emissions from cars other than in terms of a specified test procedure. This
is true because one cannot count directly the units of emissions coming
from the tailpipe of a car. Emissions are whatever a test procedure says
they are—there is no other way of expressing emission levels.
An emission test procedure consists basically of two things:
(1) instruments that measure chemicals or analogs of chemicals, and (2) a
way of exercising the engine of the car while the chemicals are being
measured, i.e. , a driving cycle. Different instruments may give different
results; different driving cycles are almost certain to give different results,
FS-25
-------
In the case of the U.S. and Japanese emission test procedures, the
instruments used to measure the chemicals are basically the same, but the
driving cycles are totally different. For that reason, only the driving
cycle aspects of the two test procedures need to be discussed.
Descriptionof U.S. Test Procedures and Related Standards
The U.S. Federal Test Procedure consists of two 7.5-mile simulated
trips run in a laboratory on a chassis dynamometer. One trip starts with
a cold engine, the other with a warmed-up engine. A ten-minute waiting
period separates the two trips. The same driving cycle is used £or both
trips. Each trip has an average speed of 19.7 raph, a top speed of 57 mph,
and 2.4 stops per mile.
The measured emissions during these two trips are weighted in proportion
to the number of cold and hot starts per average vehicle day. The U.S.
emission standards in terms of this test procedure are as follows:
U.S. Emission Standards
H£ CO NOx
(grams per mile)
1976 Federal 1.5 15 3.1
1976 California 0.9 9 2.0
1977-79 Federal 1.5 15 2.0
1977-79 California 0.41 9.0 1.5
1980 Federal 0.41 7.0 2.0
1981 and later Federal 0.41 3.4 1.0
Description of Japanese Test Procedures and^Relate^ Standards
The Japanese test procedure is also run in a laboratory on a chassis
dynamometer. It uses two different driving cycles. The first cycle
starts with a warmed-up engine, is about 0.4 miles in length, has about
4.8 stops per mile, an average vehicle speed of 11.1 mph, and a top speed
of 25.0 mph. The driving cycle is repeated four times to establish an average
emissions level. The second cycle stares with a cold engine, is about
2.6 miles in length (four repetitions of a 0.65 mile basic cycle after
engine start), has abouc 1.6 stops per mile, an average vehicle speed of
19.1 mph, and a top speed of 37.5 mph.
The measured emissions during the cold and hot start tests are not
combined into a single value (as in the U.S. test procedure) but are
calculated as separate values for the cold start and hot start tests.
Separate sets of limits are established for the results of each test.
-------
One set of limits is a maximum value which must not be exceeded by any
individual vehicle produced. A second (and more stringent) set of limits
may not be exceeded by the mean emissions of all vehicles of a particular
type produced.
The standards summarized below apply to passenger vehicles carrying
10 persons or less, and weighing more than 2200 pounds (less stringent
standards are prescribed for lighter vehicles and those powered by two
cycle engines). The effective dates apply to all vehicles manufactured
in Japan; later dates are in some cases prescribed for vehicles imported
into Japan from other countries.
Japanese^ Emissions Standards
HC CO NOx
(grams per mile)*
1976-77 Models:
Hot Start Test
Maximum 0.6 4.3 1.9
Average 0.4 3,4 1.4
Cold Start Test*
Maximum 3.7 33.3 3.5
Average 2.7 23.5 2.8
1978 and Later Models:
Hot Start Test
Maximum 0.6 4.3 0.8
Average 0.4 3.4 0.4
Cold Start Test*
Maximum 3.7 33.3 2.4
Average 2.7 23.5 1.7
*Cold start test results are expressed as grams/test in Japanese
standards, but are converted here to grams/mile for ease of
comparison; in addition, the Japanese grams/kilometer values
have been converted into grams/mile for this analysis.
Comparison of _the.Relativejtringency of the U.S. and Japanese Standards,
As can be seen from the above table, only the Japanese standard for
hot start average emissions for production cars is numerically equivalent
to the U.S. 1978 standards that were required by the Clean Air Act Amendments
of 1974 (since changed by the Clean Air Act Amendments of 1977). Thus
-------
even in numerical terms, both the original 1978 and revised 1981 U.S.
standards are not comparable, since they are expressed in terms of a
test procedure which includes engine operation from both hot and cold
engine starts. Cold start operating conditions contribute substantially
higher levels of HC and CO, because of fuel-rich operation during cold
start, and because of higher internal engine friction.
Beyond the simple numerical comparisons, the large differences
between the U.S. and the Japanese driving cycles are vitally important.
The higher speeds in the U.S. cycle tend to stress the engine more
severely, which in turn tends to increase NOx emissions. The top speed
in the U.S. cycle is about 57 mph, compared to about 25 mph in the
Japanese hot cycle and 37.5 mph in the Japanese cold cycle; the average
speeds are 19.7 mph for the U.S. cycle, 11.1 raph for the Japanese hot
cycle, and 19.1 mph for the Japanese cold cycle.
Further, the maximum acceleration required by the U.S. cycle
(2.4 mph/second)* is more severe than that encountered .during either
the Japanese hot cycle (1.8 mph/second)* or cold cycle (1.6 mph/second).
The higher rate of acceleration tends to cause higher NOx emissions during
the U.S. test, especially with smaller, relatively underpowered cars.
Another point which tends to increase the effective stringency of the
U.S. standards is that the U.S. driving cycle is designed to reproduce
portions of an actual driving route, whereas the Japanese cycle is a smooth
modal operation. The U.S. driving cycle requires much more throttle move-
ment, for it is composed almost entirely of transient (or changing) speed
conditions. While the Japanese driving cycles do contain accelerations
and decelerations, the cycles are basically sequences of fixed operating
modes and do not include the random transients experienced in actual
driving conditions.
Comparison of Test Data on Cars Tested by U.S. Procedure and by Japanese
Hot Start Procedure
The EPA has reviewed emissions data obtained by automotive manufacturers
on over 60 vehicles, using both the U.S. and Japanese test procedures. The
vehicles tested included models designed for the 1976 Japanese market only,
models designed for the 1975-76 California market, and models designed for
the 1977 California market. In addition, data were available on a single
car which has achieved emissions levels below the requirements of the
*This means that at the end of each second of acceleration the vehicle
is travelling 2.4 mph faster than it travelled at the beginning of
the same second.
-------
1978 Japanese standards in terms of the hot start test procedure. The
test results for these cars are summarized in the tabulation below, in
terms of the U.S. federal test procedure and in terms of the Japanese
hot start test. The Japanese hot start test is an important basis
for comparison because it produces the lowest numerical results and
because comparisons of U.S. and Japanese emission standards are usually
expressed in terms of the Japanese hot start test:
Vehicle Emissions by the U.S. Federal Test
and Japanese Hot Start Test Procedures
Average of 4 small car models designed
to meet 1976 Japanese standards
U.S. Federal Test
Japanese Hot Test
Average of 5 small car models designed
to meet 1975-76 California standards
U.S. Federal Test
Japanese Hot Test
Average of 14 medium-large car models
designed to meet 1975-76 California
standards
U.S. Federal Test
Japanese Hot Test
Average of 11 medium-large car models
designed to meet 1977 California
standards
U.S. Federal Test
Japanese Hot Test
Single small car designed to meet
1978 Japanese standards
U.S. Federal Test
Japanese Hot Test
HC
CO
NOx
(grams per mile)
0.45
0.16
0.24
0.16
3.66
1.39
2.35
0.74
0.46
0.25
4.66
1.23
0.27
0.25
0.32
0.08
3.46
0.13
8.00
2.29
1.77
0.93
1.64
1.32
1.29
1,39
1.18
1.21
0.98
0.35
-------
The above data suggest that for individual cars that are tested on
both the U.S» and Japanese procedures, numerical values of the Japanese
hot start emission levels for HC and CO are in most cases significantly
below those resulting from the Federal Test Procedure. The ratio is In
the range of two to four times lower for the 1975-76 models. This indicates
that emission standards of the same nominal numerical levels for the two
different procedures would differ in stringency by roughly these amounts,
i.e. the U.S. 1981 standards are about two to four times more stringent
than the Japanese hot start 1978 standards for HC and CO,
The vehicles calibrated to meet the more stringent HC level required
by the 1977 California standards produced exceedingly low CO emissions in
terms of the Japanese hot start test, about 27 times lower than during the
U.S. Federal Test Procedure. This simply reflects the fact that essentially
all the CO for these cars is produced during the cold start and warm-up
operating modes of the U.S. test procedure. Limited testing with
non-catalyst equipped cars has shown that the catalyst is primarily
responsible for these large differences in relative stringency of the
U.S. and the Japanese hot start standards (with the U.S. standards being
much more stringent), since catalysts are extremely effective in consuming
HC and CO in fully warmed-up cars.
For NOx, the small cars tended to produce slightly higher levels
on the U.S. Federal Test Procedure, probably because of the higher top
and average speeds and more severe accelerations, while the larger
cars showed little difference between the two test procedures. The
single car tested which met the 1978 Japanese hot start standards
(including NOx) produced from three to four times as much of all
three pollutants on the U.S. Federal Test Procedure, and thus would
have slightly exceeded the CO requirements of the new U.S. 1980
standards, and been over double the U.S. 1981 CO requirements.
It should be noted that, even at the same approximate level
of stringency for NOx after 1981, the cars designed exclusively for the
Japanese market could take advantage of the significantly less stringent
HC requirements, which permits them to achieve a given NOx level with a
less complex emissions control system. This occurs because techniques
which are effective in reducing NOx tend to cause increases in HC emissions.
Comparison of Test Data on Cars_ Tested by U.S. Procedure and by Japanese
Cold__Start Procedure
The relationship between the U.S. and Japanese cold start emissions
test results are compared in similar fashion in the following tabulation:
-------
Vehicle Emissions by the U'.S. Federal Test and
Japanese Cold _Start ...Tegt Procedures
HC CO ROx
(grans per mile)
Average of 4 small car models designed
to meet 1976 Japanese standards
U.S. Federal Test 0.45 3.66 1,77
Japanese Cold Test 1.82 9.72 1,95
Average of 5 small car models designed
to meet 1975-76 California standards
U.S. Federal Test 0,24 2.35 1.64
Japanese Cold Test 0,87 11.94 1.97
Average of 14 medium-large car models
designed to meet 1975-76 California
standards
U.S. Federal Test 0.46 4.66 1.29
Japanese Cold Test 0.89 9.19 1.40
Average of 5 medium-large car models
designed to meet 1977 California
standards*
U.S. Federal Test 0.27 3.46 1.18
Japanese Cold Test 1.07 6.65 1,93
*For six of the eleven 1977 California cars shotm on the previous table
of hot scare test results no data were available for tests by the
cold start procedure, nor were such data available for the single small
car designed to meet 1978 Japanese standards.
The Japanese cold start test produced from two to five times as
much CO as the U.S. Federal Test Procedure, and about two to four times
as much HC. However, since the numerical levels for the Japanese average
1978 cold start standards in terras of this test are about seven times
higher than the 1981 U.S. standards in grama per mile, the Japanese cold
start test in conjunction with the Japanese standard is somewhat less
stringent than-the U.S. standard. While no car tested came at all close
to failing the Japanese cold start standard, the margin of compliance was
not as great as with the hot test, especially for the 1977 California
models. This is no doubt due to the catalyst warm up period inherent in any
cold start test. In contrast, only one group of cars, the 5 small car
models designed to the 1975-76 California standards, would have complied
with the U.S. 1981 HC and CO standards, which therefore are clearly more
stringent than the 1978 Japanese cold start standard.
-------
For NOx, the absolute values shown by the Japanese test are slightly
higher than the U.S. Federal Test Procedure, but the numerical levels
required by the Japanese standards are also higher than those required
by the U.S. 1981 standards, so as to make their respective NQx requirements
of roughly the same stringency. All the vehicles tested would have passed
the U.S. 1977-79 NOx limit of two grams/mile by at least a 10 percent margin
and the 1976-77 Japanese cold start standard by at least a 25 percent margin.
Some of the vehicles tested by the Japanese cold start procedure would
also have passed the average Japanese 1978 cold start NOx requirement of
1.7 grams/mile as well.
Conclusions
The tabulation below indicates very roughly the relative stringency
of Japanese and U.S. standards, based on tests with 1976, 1977, and a
single 1978 Japanese standards prototype vehicle(s).
U_.S. Standard
1977-79 Federal
1976 California
1977-79 California
Original U.S. 1978*
1980 Federal
1981 Federal
1978 Japanese Standards
HC and CO NOx
Japan more stringent
U.S. and Japan equal
U.S. more stringent
U.S. more stringent
U.S. more stringent
U.S. more stringent
Japan more stringent
Japan more stringent
Japan more stringent
U.S. more stringent
Japan more stringent
U.S. and Japan equal
*Changed by 1977 Clean Air Act Amendments. Original 1978 standards included
values of 0.41 HC, 3.4 CO, 0.4 NOx; revised in 1977 to 0.41/3.4/1.0 for 1981,
All of the foregoing conclusions must be understood to be of limited
applicability. In the absence of comparable driving cycles, and with
limited back-to-back test data on individual cars that were tested on
both the U.S. and the Japanese test procedures, it is simply not
possible to make quantitative comparisons that can be demonstrated to have
general applicability with a high degree of precision. Nevertheless, the
foregoing conclusions are helpful in answering the often-asked question
of why Japanese emission standards for 1978 and later are more stringent
than the 1981 U.S. emission standards. The answer, as best it can be
given, is that the 1978 Japanese standards are not more stringent for UOx,
and that chey are substantially less stringent for HC and CO,
OMSAPC 455711
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
OFPICE OF
AIR AND WASTE MANAGEMENT
Fact Sheet
Comparison of the Japanese and U.S.
Automotive Emission Standards
The Environmental Protection, Agency has received inquiries about the
relative'stringency of the U.S. and Japanese automobile emission standards.
To respond efficiently to these questions this Fact Sheet has been prepared.
General Background
The Government of Japan has established a program of automotive emission
standards for new cars that appear to be numerically equivalent to the 1978
U.S. emission standards required by the Clean Air Act as amended in 1974
(since changed by the Clean Air Act Amendments of 1977). However, the
test procedures by which compliance with the respective emission standards
is demonstrated are not the same. For that reason direct comparison of
the U.S. and Japanese auto emission standards in terms of their simple
numerical levels is misleading..
To explain this complex issue, if is necessary first to set forth some
basic principles for defining emissions, secondly to describe the way in
which emissions from cars are measured in the U.S. and in Japan, and
finally to discuss the differences between the measurement methods and
the resulting differences in the emissions levels.
Basic Principles for Defin in gJSm lesions?
It is axiomatic that no meaningful statement can be made about exhaust
emissions from cars other than in terms of a specified test procedure. This
is true because one cannot count directly the units of emissions coming
from the tailpipe of a car. Emissions are whatever a test procedure says
they are—there is no other way of expressing emission levels.
An emission test procedure consists basically of two things:
(1) instruments that measure chemicals or analogs of chemicals, and (2) a
way of exercising the engine of the car while the chemicals are being
measured, i.e., a driving cycle. Different Instruments may give different
results; different driving cycles are almost certain to give different results.
FS-25
-------
In the case of the U.S. and Japanese emission test procedures, the
instruments used to measure the chemicals are basically the same, but the
driving cycles are totally different. For thac reason, only the driving
cycle aspects of the two test procedures need to be discussed.
Description of' U.S. Test Procedures and Related Standards
The U.S. Federal Test Procedure consists of two 7,5-mile simulated
trips run in a laboratory on a chassis dynamometer. One trip starts with
a cold engine, the other with a warmed-up engine. A, ten-minute waiting
period separates the two trips. The same driving cycle is used for both
trips. Each trip has an average speed of 19.7 mph, a top speed of 57 mph,
and 2.4 stops per mile.
The measured emissions during these two trips are weighted in proportion
to the number of cold and hot starts per average vehicle day. The U.S.
emission standards in terms of this test procedure are as follows:
U.S. Emission Standards
HC CO HOx
(grams per- mile)
1976 Federal 1.5 15 3.1
1976 California 0.9 9 2.0
1977-79 federal 1.5 15 2.0
1977-79 California 0.41 9.0 1.5
1980 Federal 0.41 7.0 2.0
1981 and later Federal 0.41 3.4 1.0
Description of Japanese Test Procedures and RejLated Standards
The Japanese test procedure is also run in a laboratory on a chassis
dynamometer. It uses two different driving cycles. The first cycle
starts with a warmed-up engine, is about 0.4 miles in length, has about
4.8 stops per mile, an average vehicle speed of 11.1 mph, and a top speed
of 25.0 mph. The driving cycle is repeated four times to establish an average
emissions level. The second cycle starts with a cold engine, is about
2.6 miles in length (four repetitions of a 0.65 mile basic cycle after
engine start), has about 1.6 stops per mile, an average vehicle speed of
19.1 mph, and a top speed of 37.5 mph.
The measured emissions during the cold and hot start tests are not
combined into a single value (as in the U.S. test procedure) but are
calculated as separate values for the cold start and hot start tests.
Separate sets of limits are established for the results of each test.
-------
One set of limits is a maximum value which must not be exceeded by any
individual vehicle produced. A second (and more stringent) set of limics
may not be exceeded by the mean emissions of all vehicles of a particular
type produced.,vf
The standards summarized below apply to passenger vehicles carrying
10 persons or less, and weighing more than 2200 pounds (less stringent
standards are prescribed for lighter vehicles and those powered by two
cycle engines). The effective dates apply to all vehicles manufactured
in Japan; later dates are in some cases prescribed for vehicles imported
into Japan from other countries.
Japanese^JEmissions Standards
H£ C£ NOx
(grams per mile)*
1976-77 Models:
Hot Start Test
Maximum 0.6 4.3 1,9
Average 0.4 3.4 1.4
Cold Start Test*
Maximum 3.7 33.3 3.5
Average 2,7 23.5 2.8
1978 and Later Models:
Hot Start Test
Maximum 0.6 4.3 0.8
Average • 0.4 3.4 0.4
Cold Start Test*
Maximum 3.7 33,3 2.4
Average 2.7 23.5 1.7
*Cold start test results are expressed as grams/test in Japanese
standards, but are converted here to grams/mile for ease of
comparison; in addition, the Japanese grams/kilometer values
have been converted into grams/mile for this analysis.
Comparison jjf the Relative Stringency of the U.S. and Japanese Standards
As can be seen from the above table, only the Japanese standard for
hot start average emissions for production cars is numerically equivalent
to the U.S. 1978 standards that were required by the Clean Air Act Anendoents
of 1974 (since changed by the Clean Air Act Amendments of 1977). Thus
-------
even In numerical terms, both the original 1978 and revised 1981 U.S.
standards are .not comparable, since they are expressed in terms of a
test procedure which includes engine operation from both hot and cold
engine starts. Cold start operating conditions contribute substantially
higher levels of HC and CO, because of fuel-rich operation during cold
start, and because of higher Internal engine friction,
Beyond the simple numerical comparisons, the large differences
between the U.S. and the Japanese driving cycles are vitally important,
The higher speeds in the U.S. cycle tend to stress the engine more
severely, which In turn tends to increase NOx emissions. The top speed
In the U.S. cycle is about 57 mph, compared to about 25 raph in the
Japanese hot cycle and 37.5 mph in the Japanese cold cycle; the average
speeds are 19.7 mph for the U.S. cycle, 11.1 mph for the Japanese hot
cycle, and 19.1 mph for- the Japanese cold cycle.
Further, the maximum acceleration required by the U.S. cycle
(3.3 mph/second)* Is more severe than that encountered during either
the Japanese hot cycle (1.8 mph/second), or cold cycle (1.6 mph/second).
The higher rate of acceleration tends to cause higher NOx emissions during
the U.S. test,, especially with smaller, relatively underpowered cars.
Another point which tends to Increase the effective stringency of the
U.S. standards is that the U.S. driving cycle is designed to reproduce
portions of an actual driving route, whereas the Japanese cycle is a smooth
modal operation. The U.S. driving cycle requires much more throttle move-
ment, for it is composed almost entirely of transient (or changing) speed
conditions. While the Japanese driving cycles do contain accelerations
and decelerations, the cycles are basically sequences 'of fixed operating
modes and do not include the random transients experienced In actual
driving conditions.
Comparison of Test Data en Cars Tested by U.S. Procedure and by Japanese
Hot Start Procedure
The EPA has reviewed emissions data obtained by automotive manufacturers
on over 60 vehicles, using both the U.S. and Japanese test procedures. The
vehicles tested Included models designed for the 1976 Japanese market only,
models designed for the 1975-76 California market, and models designed for
the 1977 California market. In addition, data were available on a single
car which has achieved emissions levels below the requirements of the
*This means that at the end of each second of acceleration the vehicle
is travelling 3.-3 mph faster than. It travelled at the beginning of
the same second.
-------
1978 Japanese.standards in terms of the hot start test procedure. The
test results fo*r these cars are summarized in the tabulation below, in
terms of the U.S.. federal test procedure and in terms of the Japanese
hot start test. The Japanese hot start test is an important basis
for comparison because it produces the lowest numerical results and
because comparisons of U.S. and Japanese emission standards are usually
expressed in terms of the Japanese hoc start test:
Vehicle Emissions by the U.S. federal Test
__and. Japanese Hot Start Test Procedures
HC
CO
NOx
Average of 4 small car models designed
to meet 1976 Japanese standards
U.S. Federal Test
Japanese Hot Test
Average of 5 small car models designed
to meet 1975-76-California standards
U.S. Federal Test
Japanese Hot Test
Average of 14 medium-large car models
designed Co meet 1975-76 California
standards
U.S. Federal Test
Japanese Hot Test
Average of 11 medium-large car models
designed to meet 1977 California
standards
U.S. Federal Test
Japanese Hot Test
Single small car designed to meet
1978 Japanese standards
U.S. Federal Test
Japanese Hot Test
(grams per mile)
0.45
0.16
0.24
0.16
0.46
0.25
0.27
0.25
0.32
0.08
3.66
1.39
2.35
0.74
4.66
1.23
3.46
0.13
8.00
2.29
1.77
0.93
1.64
1.32
1.29
1.39
1.18
1.21
0.98
0.35
-------
The above >{Jata suggest'that for individual cars that are tested on
both the U.S. 'and Japanese procedures, numerical values of the Japanese
hot start emission levels for HC and CO are in most cases significantly
below those resulting from the Federal Test Procedure. The ratio is in
the range of two to four times lower for the 1975-76 models. This indicates
that emission standards of the same nominal numerical levels for the two
different procedures would differ in stringency by roughly these amounts,
i.e. the U.S. 1981 standards are about two to four times more stringent
than the Japanese hot start 1978 standards for HC and CO.
The vehicles calibrated to meet the more stringent RC level required
by the 1977 California standards produced exceedingly low CO emissions in
terms of the Japanese hot start test, about 27 times lower than during the
U.S. Federal Test Procedure. This simply reflects the fact that essentially
all the CO for these cars is produced during the cold start and warm-up
operating modes of the U.S. test procedure. Limited testing with
non-catalyst equipped cars has shown that the catalyst is primarily
responsible for these large differences in relative stringency of the
U.S. and the Japanese hot start standards (with the U.S. standards being
much more stringent), since catalysts are extremely effective in consuming
HC and CO in fully warmed-up cars.
For NOx, the small cars tended to produce slightly higher levels
on the U.S. Federal Test Procedure, probably because of the higher top
and average speeds and more severe accelerations, while the larger
cars showed little difference between the two test procedures. The
single car tested which met the 1978 Japanese hot start standards
(including NOx) produced from three to four times as much of all
three pollutants on the U.S. Federal Test Procedure, and thus would
have slightly exceeded the CO requirements of the new U.S. 1980
standards, and been over double the U.S. 1981 CO requirements.
It should be noted that, even at the same approximate level
of stringency for NOx after 1981, the cars designed exclusively for the
Japanese market could take advantage of the significantly less stringent
HC requirements, which permits them to achieve a given NOx level with a
less complex emissions control system. This occurs because techniques
which are effective in reducing NOx tend to cause increases in HC emissions,
Comparison of Test Data on Cars Tested by U.S. Procedure and by Japanese
Cold Start Procedure
The relationship between the U.S. and Japanese cold start emissions
test results are compared in similar fashion in the following tabulation:
-------
Vehicle Emissions by the U.S. Federal Test and
':._]_i__i_i Japanese Cold Start Test Procedures
HC CO NOx
(grams par mile)
Average of 4 small car models designed
to meet 1976 Japanese standards
U.S. Federal Test 0.45 3.66 1.77
Japanese Cold Test 1.82 9.72 1.95
Average af 5 small car models designed
to meet 1975-76 California standards
U.S. Federal Test 0.24 2.35 1.64
Japanese Cold Test 0.87 11.94 1.97
Average of 14 medium-large car models
designed to meet 1975-76 California
standards
U.S. Federal Test 0.46 4.66 1.29
Japanese Cold Test 0.89 9.19 1.40
Average of 5 medium-large car models
designed to meet 1977 California
standards*
U.S. Federal Test 0.27 3.46 1.18
Japanese Cold Test 1.07 6.65 1.93
*For six of the eleven 1977 California cars shown on the previous table
of hot start test results no data were available for tests by the
cold start procedure, nor were such data available for the single small
car designed to meet 1978 Japanese standards.
The Japanese cold start test produced from two to five times as
much CO as the U.S. Federal Test Procedure, and about two to four times
as much HC. However, since the numerical levels for the Japanese average
1978 cold start standards in terms of this test are about seven times
higher than the 1981 U.S. standards in grams per mile, the Japanese cold
start test in conjunction with the Japanese standard is somewhat less
stringent than the U.S. standard. While no car tested came at all close
to failing the Japanese cold start standard, the margin of compliance was
not as great as with the hot test, especially for the 1977 California
models. This is no doubt due to the catalyst warm up period inherent in any
cold start test. In contrast, only one group of cars, the 5 small car
models designed to the 1975-76 California standards,-would have complied
with the U.S. 1981 HC and CO standards, which therefore are clearly more
stringent than the 1978 Japanese cold start standard.
-------
For NOx, the absolute values shown by the Japanese teat are slightly
higher than the>TT.S. Federal Test Procedure, but the numerical levels
required by the Japanese standards are also higher Chan those required
by che U.S. 1981 standards, so as to make their respective NOx requirements
of roughly che same stringency. All the vehicles tested would have passed
the U.S. 1977-79 NOx limit of two grams/mile by at least a 10 percent margin
and the 1976-77 Japanese cold start standard by at least a 25 percent margin,
Some of che vehicles tested by the Japanese cold start procedure would
also have passed the average Japanese 1978 cold scare NOx requirement of
1.7 grams/mile as well.
Conclusions
The tabulation below indicaces very roughly the relative stringency
of Japanese and U.S. standards,, based on tests with 1976, 1977, and a
single 1978 Japanese standards prototype vehicle(s).
U..S.__ Standard
1977-79 Federal
1976 California
1977-79 California
Original U.S. 1978*
1980 Federal
1981 Federal
1978 Japanese Standards
HC and CO NOx
Japan more stringent
U.S. and Japan equal
U.S. more scringenc
U.S. more stringent
U.S, more stringent
U.S. more stringent
Japan more stringent
Japan more stringent
Japan more stringent
U.S. more stringent
Japan more stringent
U.S. and Japan equal
*Changed by 1977 Clean Air Act Amendments. Original 1978 standards included
values of 0.41 HC, 3.4 CO, 0.4 NOx; revised in 1977 to 0.41/3.4/1.0 for 1981.
All of the foregoing conclusions must be understood co be of limited
applicability. In the absence of comparable driving cycles, and with
limited back-to-back test data on individual cars that were tested on
both the U.S. and the Japanese test procedures, ic is simply not
possible co make quantitative comparisons that can be demonstrated co have
general applicability with a high degree of precision. Nevertheless, the
foregoing conclusions are helpful in answering the often-asked question
of why Japanese emission standards for 1978 and later are more stringent
than the 1981 U.S. emission standards. The answer, as best it can be
given, is thac the 1978 Japanese standards are not more stringent for NOx,
and that they are substantially less stringent for HC and CO.
OMSAPC 455711
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
Hydrogen Fuel for Automobiles
The Environmental Protection Agency has received many
inquiries as to the possibility of using hydrogen as an
automobile fuel, both to reduce pollutant emissions and to
supplement diminishing fossil fuel supplies. This fact sheet
has been prepared to respond to such inquiries,
1. What_are the air pollution advantages of hydrogen fuel?
Since hydrogen Itself contains no carbon, neither carbon
monoxide or hydrocarbons would be emitted by an engine burning
hydrogen. This would eliminate two of the motor vehicle pollutants
which EPA is attempting to control. If hydrogen were burned with
pure oxygen instead of air, as some proponents suggest, there
would be no nitrogen oxide emissions either because these are
formed by "fixation" of the nitrogen in air wnen exposed to flame
temperatures.
2. Can hydrogen be successfully burned in Automobile engines?
Laboratory tests have shown that with careful attention to
mixing, spark timing, and other factors, Internal combustion engines
can be designed to burn hydrogen fuel without major modifications.
Moreover, if gas turbines or steam engines come into the picture
for motor vehicle propulsion, use of hydrogen fuel would allow
simplified combustors to be used with these engines.
3. How would hydrogen fuel be dispensed and stored in
passenger cars?
This is one of the more difficult problems which must be
solved before hydrogen could be used as a vehicle fuel. In
principle hydrogen could be stored as compressed gas, much as
it is when used for laboratory purposes or welding. Practically
speaking, however, the storage pressures would have to be tremendous
(60(JO-8tiOO PSI) for enough hydrogen to be carried in the vehicle
to permit reasonable vehicle range. It appears impractical at
this time for fuel tanks to be constructed from known materials
which would be both strong enough to insure against the possibility
of bursting under such pressures and yet light enough to mount
in a passenger car.
FS-26
-------
-2-
Hydrogen night also be liquified by refrigeration to very low
temperature (-425°F) and stored as a cryogenic liquid in a heavily
insulated container. However, one then has the problem of how to
safety vent off the vapors from hydrogen evaporating during extended
vehicle storage in garages and other enclosed locations, since no
such container could be constructed strongly enough or insulated
perfectly enough to contain liquid hydrogen indefinitely,without
provisions for venting. If a vehicle were used everyday, there
would be little or no hydrogen lost by venting. However, if a
vehicle were stored for a period of several days the losses of
hydrogen by venting would gradually rise to about 1% per day. The
refueling system for liquid hydrogen would have to be much more
complex than-ordinary filling station equipment, since all fittings,
hoses, nozzles, etc., would have to be both leak proof during the
refueling operation and resistant to extremely low temperatures -
yet any practical system must be simple enough to be used safely
by non-technical personnel. Other approaches are being considered
which would involve storing the hydrogen in a weak chemically bonded
state with certain metals such as aluminum, since the metal hydride
can be easily handled and stored. This research is in a very
preliminary stage at this time, but some authorities believe that ,
in the long run (post-2000) this type of approach will turn out
to be far more attractive than either pressurized gas or cryogenic
liquid storage.
Use of pure oxygen instead of air would compound the above
problems since it too would have to be carried aboard the vehicle
or manufactured through air liquefaction on the vehicle, as some
researchers have proposed.
4. How would hydrogen be manufactured if used for vehicle
propulsion?
Hydrogen could potentially .be manufactured by a variety of
different processes, of which the two most practical today are
steam reforming of hydrocarbons and electrolysis of water. The
latter process is economically competitive at the present time
only in locations where costs of electricity are unusually low.
If hydrogen were to be introduced as a vehicle fuel as a measure
towards conserving petroleum resources, it would be counter productive
to manufacture it from petroleum. Therefore other sources for hydro-
carbons would have to be used if hydrogen were to be manufactured on
a large scale by steam reforming. Coal, which is be far the nation's
largest source of hydrocarbons, would be the logical source to use.
In this case the manufacture of hydrogen would have to compete with
the manufacture of conventional gasoline or dlesel fuel from coal.
-------
-3-
In making an economic comparison between hydrogen and other fuels
derived from coal it is important to consider the stored form of
the hydrogen. For example, if the comparison is based on liquid
hydrogen, the costs of liquefaction at the plant and transporting
it under this condition are actually much greater than the manu-
facturing cost. In this case, current estimates are that hydrogen
produced from coal would cost the consumer at least 50% more per
unit of energy than would gasoline or diesel fuel manufactured from
coal. No cost estimates will be attempted on the compressed gas
approach, since this is considered to be the least attractive
manner of utilizing hydrogen in vehicles. , Further, not enough is
.known yet about the metal hydride approach to hydrogen storage to
permit a meaningful cost estimate.
If hydrogen were to be manufactured by electrolysis of water,
present costs on a nationwide basis would be roughly 25% higher than
with coal. However, in the long term (post-2000), hydrogen is
potentially available in very large quantities if the large amounts
of electrical energy required by water electrolysis were supplied
by nuclear power generating plants. This would represent an energy
source completely free of dependence on fossil fuel reserves and
Is believed to be the most likely source for the use of hydrogen
as a fuel. . . • .
5. How does hydrogen^ compare; as a fuel to electric_battery
poured vehicles?
Since the major energy source for making hydrogen in large
quantities is electricity, it is also of interest to compare the
energy production and distribution efficiencies for liquid hydrogen
as a vehicle fuel against electrical energy transmitted for
charging the batteries of electric cars. On "this basis,,the
energy efficiency for all processes up to the vehicle storage tanks
or battery is about 15-20% for liquid hydrogen against 25-29% for
electrically driven vehicles. A choice between these two potential
power systems will depend on development of better electric storage
batteries on the one hand versus solution of hydrogen handling and
storage problems on the other.
MSAPC/July 15, 1974
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, O.C. 20460
OFFICE OF
AIR AND WASTE MANAGEMENT
OCTANE REQUIREMENTS FOR 1975 MODEL YEAR CARS
OPERATING ON UNLEADED GASOLINE
The Environmental Protection Agency has received many inquiries
concerning the likelihood of 1975 model cars encountering engine knocking
after 10,000 miles or more when operated on the available unleaded
gasoline. This Fact Sheet has been prepared to respond to such inquiries.
1Jhat_ is Gasoline_0ctaneL_Rating?
The octane ratings used in specifications for gasoline refer to
its resistance to knock as measured in a variable compression ratio
laboratory test engine. The higher the octane number, the greater the
resistance to knock. The "octane number" compares the knocking behavior
of the test gasoline to the performance of a blend of two pure hydrocarbon
reference fuels (isooctane as "100" and pure normal heptane as "0").
What causes _a_n engine to knock?
The "knocking" or "pinging" sound which sometimes occurs with
automobile engines is caused by premature spontaneous ignition of the
gasoline-air mixture in one or more cylinders. With a brand new engine,
the degree of knocking depends on the composition of the gasoline, the
compression ratio, ignition timing, combustion chamber design and engine
load. Knocking is also influenced by climatic conditions such as
temperature, humidity, and barometric pressure (or altitude).
Engine design and climate can not be controlled by the motorist,
but engine load, ignition timing, and fuel composition can be altered to
some extent. A knock problem can be reduced or eliminated by a "light
foot" on the accelerator, by having the spark timing retarded, or by
using higher octane fuel,
What is meant by Octane Requirement Increase?
With motor vehicle engines, there has always been a phenomenon
known as Octane Requirement Increase (ORI). As a new vehicle goes
through its normal break-in process, deposits accumulate in the
combustion chamber and eventually reach a stabilized level. The
occurence of knock is enhanced with engines which have accumulated
deposits in service. Deposits tend to Insulate the combustion chamber
walls and thus increase the combustion zone temperature, and to reduce
FS-27
-------
Che combustion chamber volume and thus increase the compression ratio.
Both effects tend to raise the octane requirement. Engine oil consumption,
fuel and fuel additive composition also have some influence on ORI. In
addition, Che deposits sometimes tend to form local "hoc spots", which
can cause pre-ignition and knocking independently of the spark plug.
For all of these reasons, the gasoline octane number required by the
engine for maintenance of knock free operation increases uncil all
such effecCs stabilize. To compensate for this, auto makers design
their vehicles so that, when new, they have lower octane requirements
that they would be expected to have after stabilization.
Individual manufacturers vary in the conservatism of the design
targets which chey use to assure that excessive customer complaints
will not be received concerning knocking. The information provided
to the EPA by the automotive manufacturers indicates that their targets
vary from 85-95% customers satisfied as to knocking behavior throughout
the industry,
Will 1975-1976 model vehicles operate satisfactorily cm available
unleaded gasoline?
The EPA has been in close contact with the automobile manufacturers
with respect to the ORI behavior of 1975 vehicles. At this time it
appears that the majority of 1975 vehicles marketed in this country are
operating on the available unleaded gasoline supplies, without unusual
incidence of customer complaints about knocking compared to past model
years. This is based on reports to EPA by both vehicle manufacturers
and petroleum companies.
What can be done if a vehicle encounters knocking problems in
cjusjEpmer service?
A slight knock which occurs only under full acceleration depression
at low speed is not an indicator of malfunction and does not cause engine
damage. However, heavy, frequent, or prolonged knocking can cause
damage and should be corrected. Such correction can be achieved either
by the purchase of suitable higher octane fuel, or by a slight retard-
ation of spark timing (which is a simple adjustment). All of the U.S.
manufacturers have agreed to adjust ignition timing under warranty,
if required under these circumstances-.
In many parts of the country, unleaded gasoline of octane quality
adequate to "satisfy" the more critical cars without spark retardation
is available - thus some customers can shop around for their gasoline
in the traditional manner, instead of returning the cars to the dealer
for ignition adjustment.
-------
What are the effects of retarded ignition timing on fuel economy?
Auto manufacturers have estimated that each degree of spark
retardation from the recommended basic setting will cause about one
percent loss in fuel economy. At this time, the information available
to EPA indicates that in the most extreme cases a five percent spark
retard should eliminate knock due to ORI, and that in most cases less
spark retard will be needed. It must be emphasized again that the
experience through the 1975 model year, has indicated that few
vehicles have encountered knock problems and thus most vehicle owners
need not be concerned at all. A few degrees of spark retard cm a
small percentage of vehicles will have a negligible effect on national
gasoline consumption.
QMSAPC/November 1975
-------
\m.
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D,C. 20460
Fire Hazards With Catalyst-Equipped Cars
Many 1975 and later model year automobiles are equipped with cata-
lytic converters which serve as a primary means for reducing the
emissions of air pollutants from these cars. The Environmental
Protection Agency has received reports concerning over-temperature
problems or fire hazards from catalytic converters. This Fact Sheet
has been prepared to respond efficiently to such inquiries.
1. Why do catalytic converters get hot?
Catalysts reduce emissions by accelerating the combustion of
pollutants leaving the engine. In doing the job they were designed
to do, they get hot. The outside metal temperatures of some types
of converters may approach 800-1000° F under conditions of extremely
high engine loading. However, measurements by the United States
Forest Service has shown surface temperatures just as high as this
In the exhaust systems of pre 1975 cars at extreme engine load
conditions, so that catalytic converter surface temperatures do not
present a new type of problem for automobile manufacturers.and users
as long as the engine is running properly.
The EPA has also made measurements of catalyst surface
temperatures on vehicles. The temperatures at 30 mph and 60 mph
steady speed conditions respectively appear to be well under 500° F,
a level which is not likely to result In vegetation fires or excessive
heat transferred to the occupants of the cars.
However, if there is a partial ignition system failure, such
as one or more misfiring spark plugs or defective Ignition wires, the
temperatures of the catalytic converter surfaces and the exhaust system
downstream from the converter may reach 1200°F-1400aF. This Is because
of the abnormal amount of unburned fuel delivered by the nonflring
cylinders. Further, once hot, the converter will take longer to cool
off than other parts of the exhaust system, because of Its greater mass.
This points out the need for careful attention to vehicle maintenance
and alertness by vehicle owners to any signs of abnormal engine operation.
FS-28
-------
-2-
2. What precautions, have been ^aken to make sure that catalytic
converters,do not cause undue fire hazards in service?
EPA regulations require that any emission control system used
by vehicle manufacturers "shall not in its operation, function, or
malfunction result in any unsafe conditions endangering the motor
vehicle, its occupants, or persons or property in close proximity
to the vehicle".
The vehicle manufacturers are of course aware of the need to
provide protection to the occupants of the vehicle and to other
vehicle components from possible hazards or even discomfort that
could be associated with high catalyst temperatures, as well as
to avoid possible fire hazards associated with driving vehicles
through tall grass or other vegetation. The exact means taken by
the different manufacturers to provide high temperature protection
vary, and include such approaches as insulating the entire catalytic
reactor so that the outside surfaces are not hotter than mufflers,
installing protective metal shields between the converter shell and
vegetation, and using thicker carpeting materials inside the car
so as to protect the occupants from experiencing high floor-board
temperatures. In addition,, some cars have temperature sensing
devices to deactivate the catalytic reactor or alert the driver to
abnormally high temperatures, such as might be caused by misfiring
spark plugs, etc.
The United States Air Force has determined, following indepen-
dent testing of catalytic converter equipped light trucks, that such
vehicles can and will be operated using the same safety restrictions
that apply to other vehicles. In addition, the ignition timing is
checked on all new vehicles received and periodically at each
scheduledlnspectlon, to assure that it is in accordance with manu-
facturers specifications. The operation of catalytic converters Is
Included in Air Force driver training courses and vehicle control
officer programs. Decals are installed inside Air Force vehicles
notifying the operator to take the vehicle out of service and turn
it in for repairs if the engine is not running properly.
3* ln_ spite^ of;_these precautions, have there been any^ documented
instances j)f fires caused by catalysts?
The EPA has received reports of vehicle and vegetation fires
in which catalysts have involved, both from vehicle owners and
from the National Highway Traffic Safety Administration (NHTSA), who
have been monitoring the frequency of such incidents with individual
manufacturers. In some cases it appears that combustible under-
coating material had been applied to the catalyst and other exhaust
system hardware. In most cases so far reported, vehicles were also
reported to have been running badly, with evidence of non-firing
spark plugs, or other ignition system defects. If an abnormal
amount of unburned fuel is fed to any catalyst, such as when the
engine is misfiring In one or more cylinders, the catalyst will
-------
—3—
attempt to "do its Job" by burning this fuel, instead of simply
expelling it out the exhaust pipe as would older cars. In so
doing the surface temperatures of the catalyst container and the
exhaust pipe can become abnormally hot, possibly leading to charring
or burning of undercoating that may have been inadvertently sprayed
on the catalyst or the exhaust system, charring of floor mats in
the car, or ignition of dry vegetation if the vehicle is operated
off the road. Vehicle service manuals caution against applying
undercoating on the catalyst of exhaust system.
It should be pointed out that vegetation fires caused by
hot automobile exhaust systems have occured in the past, before
the advent of catalyst equipped cars, and no doubt will occur in
the future. The Forest Service has periodically conducted tests of
cars for fire hazards since 1967 because of the long standing concern
by that agency over vehicle-Induced fires in National Forest recre-
ational areas.
4. What will be done in the future to assure that catalysts do not
create fire hazards?
The EPA and the National Highway Traffic Safety Administration
(NHTSA) have been monitoring closely the frequency and type of such
incidents. The NHTSA, on the basis of a review completed in
December 1976, has concluded that "the rate and nature of catalytic
converter incidents do not present an unreasonable risk of health or
injury to the public," EPA will continue to monitor such incidents
of catalyst fires as they are reported, and will continue to require
manufacturers to design their vehicles so that when such vehicles are
properly operated and maintained they pose no hazard to either life
or property.
5. What can a Vehicle Owner^do _tpAvgid^Cajalyst_ Overheating Problems?
If you keep your car properly maintained as recommended in your
Owners Manual, you should normally have no problems. If you notice
the engine running rough, you may have a misfiring spark plug; be
sure to have that checked promptly, not only to avoid catalyst over-
heating but also to restore good performance and to save fuel.
You should not park a catalyst-equipped car — or for that matter,
any car — on a pile of dry leaves or other dry vegetation after having
run that car hard enough to have caused the exhaust system to become
very hot. The phenomenon of cars setting fire to dry leaves or other
dry vegetation is not new. Normal caution in how you use your car
is all that is needed to avoid catalyst fires.
OMSAPC/January 1977
-------
4
r I UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
St -^ WASHINGTON. D.C, 20460
Fire Hazards With 1975 Catalyst-EquippedL Cars
Many 1975 model year automobiles are equipped with catalytic
converters which serve as a primary means for reducing the emissions
of air pollutants from these cars. The Environmental Protection
Agency has received reports concerning over-temperature problems
or fire hazards from catalytic converters. This fact sheet has been
prepared to respond efficiently to such inquiries.
1, Why do catalytic_converters get hot?
Catalysts reduce emissions by accelerating the combustion of
pollutants leaving the engine. In doing the job they were designed
to do, they get hot. The outside metal temperatures of some types
of converters may approach 800-1000* F under conditions of extremely
high engine loading. However, Measurements' by the United States
Forest Service has shown surface temperatures just as high as this
in the exhaust systems of pre 1975 cars at extreme engine load
conditions, so that catalytic converter surface temperatures do not
present a new type of problem for automobile manufacturers and users
as long as the engine is running properly.
The EPA has also made measurements of catalyet surface
temperatures on vehicles. The temperatures at 30 mph and 60 mph
steady speed conditions respectively appear to be well under 500° I»
a level which is not likely to result in vegetation fires or excessive
heat transferred to the occupants of the cars.
However, if there la a partial Ignition system failure, such
as one or more misfiring spark plugs or defective Ignition wires, the
temperatures of the catalytic -converter surfaces and the exhaust system
downstream from the converter may reach 12QQeF-1400°F. This is because
of the abnormal amount of unburned fuel delivered by the nonflring
cylinders. This points out the need for careful attention to vehicle
maintenance and alertness by vehicle owners to any signs to abnormal
engine operation.
FS-28
-------
-2-
2. What, Sre5Au.tA°JlS_Jiav'e keen taken to make sure that
catalytic converter^ do_ no_t_ _cause undue f ire_jia.za_rd_s_ in
service?
EPA regulations require that any emission control system used
by vehicle manufacturers "shall not in its operation, function, or
malfunction result in any unsafe conditions endangering the motor
vehicle, its occupants, or persons or property in close proximity
to the vehicle".
The vehicle manufacturers are of course aware of the need
to provide protection to the occupants of the vehicle and to other
vehicle components from possible hazards or even discomfort that
could be associated with high catalyst temperatures, as well as to
avoid possible fire hazards associated with driving vehicles
through tall grass or other vegetation. The exact means taken by
the different manufacturers to provide high temperature protection
vary, and include such approaches as insulating the entire catalytic
reactor so that the outside surfaces are no hotter than mufflers,
installing protective metal shields between the converter shell
and vegetation, and using thicker carpeting materials Inside the
car so as to protect the occupants from experiencing high floor-
board temperatures. In addition, some cars have temperature
sensing devices to deactivate tha catalytic reactor or alert the
driver to abnormally high temperatures, such as might be caused
by misfiring spark plugs, etc.
3. Inj5gite_ _of these .precautions^ have there, .been any
documented instances of fires caused by catalysts!
The EPA has received reports of vehicle and vegetation fires
in which catalysts have heen involved, both from vehicle owners
and from the National Highway Traffic Safety Administration (NHTSA),
who have heen monitoring the frequency of such incidents with
individual manufacturers. In some cases it appears that combustible
undercoating material had been applied to the catalyst and other
exhaust systems hardware. In most cases so far reported, vehicles
were also reported to have been running badly, with evidence of
non-firing spark plugs, or other Ignition system defects. If an
abnormal amount of unburned fuel is fed to any catalyst, such as
when the engine is misfiring in one or more cylinders, the catalyst
will attempt to "do its job" by burning this fuel, instead of
simply expelling it out the exhaust pipe as would older cars. In
so doing the surface temperatures of the catalyst container and the
exhaust pipe can become abnormally hot, possibly leading to charring
-------
—3—
or burning of undercoating that may have been Inadverently sprayed
on the catalyst or the exhaust system, charring of floor mats In
the car, or ignition of dry vegetation if the vehicle is operated
off the road. Vehicle service manuals caution against applying
undercoating on the catalyst or exhaust system.
It should be pointed out that vegetation fires caused by
hot automobile exhaust systems have occurred in the past, before
the advent of catalyst equipped cars, and no doubt will occur in
the future. The Forest Service has conducted tests of cars for
fire hazards since 1967 because of the long standing concern by
that agency over vehicle-Induced fires in National Forest
recreational areas.
4. What will be done in the future to assure that catalysts
do not create fire hazards?
The EPA and the National Highway Traffic Safety Administration
(NTHSA) are monitoring closely the frequency and type of such
incidents and the measures which are being taken by the manufacturers
to eliminate any possible problems. If significant problems are
Identified, the EPA in coordination with NHTSA will make as certain
as possible that vehicles equipped with catalytic emission control
systems will not inadvertently result in Increased fire hazards.
The EPA has already urged automakers to take voluntary action to
install some form of warning device In vehicles to alert drivers
to an overheated catalyst.
MSAPC/July 1975
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
. WASHINGTON. D,C, 20460
OFFICE OF
AIR AND WASTE MANAGEMENT
Unregulated Pollutants from Catalysts Used for Automotive
Emission Control
The Environmental Protection Agency has received many inquiries
regarding the catalyst emission control systems used on many 1975 and
later model cars. Many of these questions have concerned reports that
cars equipped with catalysts may emit new, dangerous pollutants in
place of the pollutants the catalysts are intended to control. This
Fact Sheet has been prepared to respond efficiently to such questions.
Summary
It has been suggested that catalysts, now being used on many cars
as highly effective emission control devices, may result in the emission
of new pollutant substances which could pose a health hazard. However,
with the exception of sulfuric acid, and in some cases hydrogen sulfide
and hydrogen cyanide, significant emissions of such new pollutants from
catalyst-equipped cars have not been found.
Under certain circumstances, some oxidation catalyst-equipped cars
have been found to produce exhaust with a "rotten-egg" odor, probably
caused by the presence of hydrogen sulfide and other compounds. Such
problems are generally caused by improper adjustment or malfunction of
the vehicle. While.this odor is annoying, and vehicles producing such
an odor should be repaired, the levels of such emissions do not pose a
serious public health risk.
Under certain malfunction conditions, some cars equipped with
three-way catalysts have been found to emit hydrogen cyanide in the
exhaust. However, the levels of hydrogen cyanide emissions from a
malfunctioning.three-way catalystrequipped car are too low, when
compared with carbon monoxide emissions, to cause adverse healch effects.
Again, this problem is caused primarily by a malfunction condition which
should be repaired.
Properly functioning oxidation catalyst-equipped cars have been
found, in general, to emit greater amounts of sulfuric acid than do non-
catalyst cars, although the absolute levels emitted are still quite
small on a mass basis in comparison to those of automotive pollutants
FS-29
-------
-2-
which are already regulated. Automotive emissions of sulfuric acid are
not currently considered to pose a health hazard. However, concern has
been expressed that in the future, if nearly all cars were to be equipped
with oxidation catalysts, elevated concentrations of sulfuric acid might
occur near heavily travelled roadways from time to time.
EPA has concluded that current data on automotive sulfuric acid
emissions and their possible adverse health impact do not warrant EPA
action to control sulfuric acid emissions from cars. Studies are
underway to continually monitor roadway and roadside levels of sulfuric
acid. If found to be necessary in the future, action could be taken by
EPA to establish a sulfuric acid emission standard for cars, to require
that the sulfur levels of gasoline be lowered, or even to prohibit the
use of certain technologies related to catalytic emission controls which
lead to increased sulfuric acid emissions.
What are__c_atal_y_st_s_?_ _Why^ is EPA requiring that they be put on
cars?
In general, the term catalyst is used to describe a substance which
speeds up a chemical reaction without itself being consumed in that
reaction. Since the 1975 model year, most new cars are being equipped
with a type of emission control device known as an oxidation catalyst.
This device is installed in the vehicle's exhaust system, and is intended
to achieve more complete oxidation of hydrocarbons and carbon monoxide,
two pollutants in engine exhaust, into harmless water and carbon dioxide.
The active materials in the oxidation catalyst which accomplish this are
noble metals (typically platinum and/or palladium) deposited on a high
surface area support.
As emission standards become more stringent, some future cars will
use a different type of catalystj called a three-way catalyst. This
other catalyst differs from an oxidation catalyst, in that it controls
all three regulated pollutants, HC, CO, and NOx, instead of controlling
only HC and CO. Control of the third regulated pollutant, NOx, is
achieved in a three-way catalyse by chemically reducing oxides of nitrogen
to elemental nitrogen. The active materials in chese catalysts are
similar to those in oxidation catalysts, although in most cases rhodium
is expected to be used instead of palladium as a catalytically active
material.
-------
-3-
Strictly speaking, the EPA does not require that catalysts be
installed on cars. EPA establishes performance requirements, in the
form of emission standards, which simply require that vehicle emissions
not exceed specified levels. It is up to the individual auto manu-
facturers to decide what control hardware they will use on vehicles
to meet such standards.
Oxidation catalysts were first considered for use on automobiles
in the early 196Q's when California began to regulate automobile emissions.
Although California approved some catalysts for use, triggering a require-
ment for cars to meet certain standards under their law, the auto manu-
facturers found it possible to meet those early standards by changes in
engine adjustments and chose not to use catalysts. The lack of general
availability of unleaded gasoline at that tine (lead poisons catalysts
and thus makes them ineffective for their intended purpose) also made
catalysts impractical. Non-catalyst techniques were used exclusively
by the manufacturers to meet Federal emission requirements from their
initial implementation with the 1968 models through the 1974 models,
and are still being used on some new cars. In general, however, auto
manufacturers have found that at the more stringent levels of emission
control required today and for future cars, catalysts are an important
ingredient in designing cars with good'fuel economy and performance as
well as satisfactory emission levels.
Hasn't it been shown that catalysts emit.__da_ng_g_rp_us...pollutants.?.
lf^ so, what are they, and what adverse health effects will they
cause?
While the principal effect on auto emissions of using catalysts
is the desired reduction in hydrocarbon, carbon monoxide, and (for
chree-way catalysts) oxides of nitrogen emissions, tests by EPA scientists
and others have shown that catalysts also result in emissions of other
substances with a potential for adversely impacting upon public health.
The high level of public awareness of this issue was generated in large
part as a result of the investigations by EPA scientists of emissions
from catalyst-equipped cars.
A number of studies have shown that use of oxidation catalysts
can result in emissions of sulfuric acid aerosols* Sulfuric acid, whose
adverse health effects are discussed in a later paragraph, is present in
the exhaust of non-catalyst cars only in trace quantities, if at all.
Other substances could be emitted from catalyst-equipped cars, such as
platinum, palladium, hydrogen sulfide, ammonia, hydrogen cyanide, and
trace metals, but such substances have not been detected at levels high
enough to warrant a public health concern.
-------
-4-
On the other hand, some earlier studies found that the use of
catalysts substantially decreases emissions of polynuclear aromatic
hydrocarbons, aldehydes and phenols, all of which are currently not
regulated in auto exhaust but are nevertheless undersirable emissions
from a health standpoint. Additional testing of current and future
catalyst-equipped cars is being done to measure their levels of these
emissions.
Automotive emissions of sulfur oxide pollutants originate
principally from sulfur-containing impurities which occur naturally
in petroleum. A small portion of the sulfur in crude oil ends up
in che gasoline after refining (typical gasoline sulfur levels
range from 0.01% to 0.07% with a national average of about 0.03%).
The sulfur compounds in gasoline are burned (oxidized) during the
engine's combustion process and emitted in the exhaust. For non-cacalyst
carst tests show that nearly all of the sulfur compounds in the gasoline
are emitted in the form of sulfur dioxide (502) §as- The S02 disperses
in the air and a portion of the S02 slowly reacts to form particulate
sulfates, such as sulfuric acid or other acid sulfates. The S02 emitted
from motor vehicles constitutes only about 1% of the total U.S. manmade
S02 emissions. In a few urban areas, however, such as the Los Angeles
basin, vehicles contribute a substantially greater percentage to total
S02 emissions due to high vehicle density and relatively low sulfur
emissions from stationary sources.
Oxidation catalysts can cause the rapid conversion of some of
the S02 in the exhaust to sulfuric acid. The potential for adverse
health effects associated with the emission of sulfuric acid from
oxidation catalyst-equipped vehicles is one of localized exposure
in and near major concentrations of motor vehicles before significant
dilution can occur in the air.
Since the discovery in 1972-73 of sulfuric acid as an exhaust
pollutant from certain catalyst-equipped prototype cars, EPA and
others have extensively investigated these emissions. It has been
found that a number of factors, including the amount of sulfur in
the gasoline, the amount of oxygen in the exhaust passing over the
catalyst, the catalyst's operating temperature, the type and, extent
of previous driving, and the catalyst's composition, can all signi-
ficantly affect the amount of sulfuric acid produced. It has been
found that some catalyst-equipped cars, particularly those with low
levels of exhaust oxygen, emit about the same amount of sulfuric
acid as non-catalyst cars, while those with higher oxygen levels"
produce much more sulfuric acid.
-------
-5-
The EPA is also conducting a program to assess the potential public
health impacts of the use of platinum and palladium in catalysts, A
continuing public health assessment program was initiated in 1973 to
augment the very limited knowledge then available on the health effects
of these metals in low concentrations. At present, exhaustive emissions
testing of catalyst-equipped vehicles by the EPA and by the auto industry
has shown only minute levels of platinum or palladium in the exhaust
particulate from current catalysts, unlike results from some of the
earlier prototype devices. The EPA, now believes that platinum and palladium
compounds at the levels emitted do not pose a risk to the public through
exposure to those metals from normal operation of catalyst devices. The
potential for emission of these metals during unusual catalyst operating
conditions is being further investigated,
Emissions of hydrogen sulfide and hydrogen cyanide from catalyst-
equipped cars have been, reported by industry laboratories. These emissions
occurred during cold start operation of the vehicle. In addition, EPA
has received some reports from the public of a hydrogen, sulfide-type odor
being produced by catalyst-equipped cars. Such odor problems have been
found to result from improper adjustment or malfunction of the vehicle
and appear to be eliminated when the vehicles are repaired. While the
EPA is further investigating the emission of these pollutants, and
others which may be unique to catalysts, che EPA does not currently see
automotive emissions of these pollutants as posing a public health risk.
Is sulfuric acid a new environmental pollutant? Is it a health
hazard? If so, how sure are__yo_u about its potential health risk?
Sulfuric acid is not a new environmental pollutant. It is emitted
from sulfuric acid plants and is one of the sulfates generated in ambient
air by the oxidation of sulfur dioxide gas which is emitted from all com-
bustion sources burning coal or oil. Sulfuric acid is thought to comprise
a major portion of the ambient air particulate sulfates in some areas,
while in other areas it is a minor constituent.
Sulfuric acid can be a health hazard at relatively low concentrations
compared to some other pollutants. A number of studies have been carried
out in which human volunteers were exposed to sulfuric acid aerosols.
Other studies have been conducted using various laboratory animals. In
addition, the EPA has been conducting major epidemiologic'al studies in
several urban areas which include particulate sulfates as one parameter
being examined. All of these studies agree that particulate sulfates
(including sulfuric acid) at significant concentrations of exposure are
respiratory irritants.
-------
-6-
EPA has underway human exposure studies for the purpose of
evaluating the effect of sulfuric acid at the low concentrations
expected to result from emissions from oxidation catalyst-equipped cars.
Preliminary exposures of healthy adults to 100 ug/m3 of sulfuric acid,
thought to be the most potent sulfate irritant, produced no detectable
significant responses. This level of exposure to sulfuric acid is much
higher than the maximum level projected to result in localized areas of
high vehicle traffic, or in areas of worst case sulfuric acid exposures.
Thus, although EPA is continuing to perform health studies on the effect
of sulfuric acid exposure, there does not at this time appear to be a
need to regulate automotive sulfuric acid emissions to protect the
public health.
What is EPA doing to avoid adverse health effects from catalyst-
produced sulfuric acid emissions?
Since early 1973, when sulfuric acid emissions from catalyst-
equipped cars were first identified, EPA has been studying the various
aspects of this potential health problem to assess its magnitude and
determine if regulatory action is required. Vehicle test procedures and
emission rates, air quality and exposure impact modeling, and possible
control techniques have been studied as well as health effects. Ambient
monitoring alongside a major Los Angeles freeway has also been implemented
to identify trends in sulfate levels as the usage of catalyst-equipped
cars increases. In March, 197b, effort? f.o develop a sulfuric acid
emission standard for new automobiles were begun, and improved vehicle
test procedures and more extensive data on sulfuric acid emissions have
resulted.
After extensively reviewing the currently available data, EPA
has concluded that there is no current need to adopt a sulfuric acid
emission standard to assure protection of the public health. EPA is
continuing to measure the various pollutants that are associated with
usage of new emission control systems, and will continually assess the
need for regulatory action to protect the public health should it be
determined that catalyst-equipped vehicles emit harmful pollutants.
OMSAPC/EPA
45584
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
OFFICE OF
AIR AND WASTE MANAGEMENT
FACT SHEET
Mew_. Ppllut_an_t_s_ from_ Oxidation .Catalysts for Automotive Emission^ Control^
The Environmental Protection Agency has received many inquiries
regarding the oxidation catalyst emission control systems used on
many 1975 and later model cars. Many of these questions have
concerned reports that cars equipped with catalysts may emit new,
dangerous pollutants in place of the pollutants the catalysts are
intended to control* This Fact Sheet has been prepared to respond
efficiently to such questions.
Summary/
It .has been suggested that oxidation catalysts, now being used on
many new cars as highly effective emission control devices, may result
in the emission new pollutant substances which could pose a health
hazard. .However, with the exception of sulfuric acid, and in some
cases hydrogen sulfide, significant emissions of such new pollutants
from catalyst-equipped cars have not been found,
Under certain circumstances, some catalyst-equipped cars have been
found to produce exhaust with a "rotten-egg" odor, probably caused by
the presence of hydrogen sulfide. Such problems are almost always •
caused by improper adjustment or malfunction of the vehicle. While
hydrogen sulfide odor is annoying, and vehicles producing such an odor
should be repaired, such emissions do not pose a public health risk.
Properly functioning catalyst-equipped cars have been found, in
general, to emit substantially greater amounts of sulfuric acid than
do non-catalyst cars, although the absolute levels emitted are still '
quite snail in comparison to those of automotive pollutants which are
already regulated. Automotive emissions of sulfuric acid are not
currently considered to pose a health hazard. However, concern has
been expressed that in the future, when nearly all cars might be
equipped with catalysts, excessive concentrations of eulfuric acid
might occur near heavily travelled roadways from time to time.
FS - 29
-------
EPA has concluded that current data on automotive sulfuric acid
emissions and their possible adverse health impact are too uncertain to
determine at this time whether, and to what degree, sulfuric acid
emissions from cars need to be restricted in the future. Studies are
-underway to help resolve this question. It found to be necessary in- the
future, action could be taken by EPA to establish a sulfuric acid emission
standard for cars, to require that the sulfur levels of gasoline be lowered,
or even to prohibit the use of certain technologies related to catalytic
emission controls which .lead to increased sulfuric acid etaissions. In the
meantime, EPA will continue to closely monitor these emissions and their
effect on air quality in the vicinity of roadways, so as to identify any
need for preventative action before a real danger to public health could
develop,
What are catalysts? Why j.s EPA requiring that they be put on cars?
In general, the term catalyst is used to describe a substance
which speeds up a chemical reaction without itself being consumed in
that reaction. Since the 1975 model year» most new cars are being
equipped with a type of emission control device known as an oxidation
catalyst. This device is installed in the vehicle's exhaust system
between the exhaust manifold and the tailpipe, and is intended to
achieve raore complete oxidation of hydrocarbons and carbon monoxide,
two pollutants in engine exhaust, into harmless water and carbon
dioxide. The active materials in the oxidation catalyat which
accomplish this are noble netals (typically platinum and/or
palladium) deposited on, an inert ceramic substrate.
Strictly speaking, the EPA does not require that catalysts be
installed on cars. EPA establishes performance requirements, in the
form of emission standards, which simply require that vehicle emissions
not exceed specified levels. It is up to the individual auto
manufacturers to decide what control hardware they will use on vehicles
to meet such standards.
Oxidation catalysts were first considered for use on automobiles
In the early 1960's when California began to regulate automobile
emissions. Although California approved some catalysts for use,
triggering a requirement for cars to meet certain standards under their
law, "the auto manufacturers found it possible to meet those early
-------
-3-
standarda by changes In engine adjustments and chose not to use catalysts.
The lack of general availability of unleaded gasoline at that time (lead
poisons catalysts and thus makes them ineffective for their intended
purpose) also made catalysts impractical. Non-catalyst techniques were
used exclusively by the manufacturers to meet Federal emission requirements
from their initial Implementation with the 1968 models through the 1974
models, and are still being used on some new cars. In general, however,
auto manufacturers have found that at the more stringent levels of emission
control required today oxidation catalysts are an Important Ingredient In
designing cars with good fuel economy and performance as well as
satisfactory emission levels.
Hasn* t it been__s_hown that catalys.ts. emit dangerous_ jiollutants?
If so, what, are they, and what adversj^ health ejifect^ will they
c_aus_e_?
While the principal effect on auto emissions of using catalysts
is the desired reduction in hydrocarbon and carbon monoxide emissions,
tests by EPA scientists and others have shown that the catalyst also
results in emissions of other substances with a potental for
adversely Impacting upon public health. The current high level of
public awareness of this issue was generated in large part as a
result of the investigations by EPA scientists of emissions from
catalyst-equipped cars.
A number of studies have shown that use of catalyts can result
in emissions of sulfuric acid aerosols. Sulfuric acid,, whose
adverse health effects are discussed in more detail In a later
paragraph, Is present In the exhaust of non-catalyst cars only in
trace quantities, 'if at all. The possibility of emissions of other
substances from catalyst-equipped cars, such as platinum, palladium,
hydrogen sulfide, and phosphine, has been suggested hy some
investigators buC, except for hydrogen sulfide, has not been confirmed
in tests of 1975-type cars by the EPA.
On the other hand, some earlier studies found that the use of
catalysts substantially decreases emissions of polynuclear aromatic
hydrocarbons, aldehydes and phenols, all of which are currently not
regulated in auto exhaust but are nevertheless undesirable emissions
from a health standpoint. Additional testing of current cacalyst-equipped
cars is being done to measure their levels of these emissions.
-------
-4-
Automotlve emissions of sulfur oxide pollutants originate
principally from sulfur-containing impurities which occur naturally
in petroleum. A small portion of the sulfur in crude oil ends up in
the gasoline after refining (typical gasoline sulfur levels range from
-100 to 700 parts per million with a national average of about 300), In
addition, some gasolines may contain sulfur compound additives. The
sulfur compounds in gasoline are burned (oxidized) during the engine's
combustion process and emitted in the exhaust. For non-catalyst cars, tests
show chat nearly all of the sulfur compounds in the gasoline are emitted in
the form of sulfur dioxide (SO ) gas. The SO disperses in the air and
slowly reacts to form particulate sulfateg, such as sulfuric acid or
other acid sulfates. The S0» emitted from motor vehicles constitutes
only about 1% of the total U.S. manmade SO emissions. In a few urban
areas, however, such as the Los Angeles basin, vehicles contribute a
substantially greater percentage to total SO emissions due to high
vehicle density, high sulfur gasolines, and relatively low sulfur
emissions from stationary sources.
Catalysts can cause the rapid conversion of some of the SO2 in the
exhaust to sulfuric acid. The potential for adverse health
effects associated with the emission of sulfuric acid fr.ora catalyst
vehicles is one of localized exposure in and near major concentrations
of motor vehicles before significant dilution can occur in the air.
Since the discovery in 1972-73 of sulfuric acid as an exhaust
pollutant from certain catalyst-equipped prototype cars, EPA and
others have extensively investigated these emissions. It has been
found that a number of factors, including the amount of sulfur in
the gasoline, the amount of oxygen in the exhaust passing over the
catalyst, the catalyst's operating temperature, the type and extent
of previous driving, and the catalyst's composition, can all
significantly affect the amount of sulfuric acid produced.
It has been found that some catalyst-equipped cars, particularly
those with low levels of exhaust oxygen, emit about the same
amount of sulfuric acid as non-catalyst cars, while those with
higher oxygen levels produce much more sulfuric acid.
The EPA ia also conducting a program to assess the potential
public health impacts of the use of platinum and palladium in
catalysts. A continuing public health assessment program was
initiated in 1973 to augment the very limited knowledge then
-------
-5-
available on the health effects of these metals In low concentrations.
At present, exhaustive emissions testing of catalyst-equipped
vehicles by the EPA has not shown detectable levels of platinum or
palladium in the exhaust particulate from current catalysts, unlike
-results frora some of the earlier prototype devices. This result is
confirmed by a number of industry studies. The EPA now
believes that platinum and palladium do not pose a risk to the
public through exposure to those metals from normal operation of
catalytic devices. The potential for emission of these metals during
unusual catalyst operating conditions is being further investigated.
Emissions of hydrogen sulfide and possibly phosphine from catalyst-
equipped cars have been reported by industry laboratories. These emissions
occurred during cold start operation of the vehicle. In addition,
EPA has received some reports from the public of hydrogen sulfide
odor being produced by catalyst-equipped cars. Such odor problems
have been found to result from improper adjustment or malfunction
of the vehicle and appear to be eliminated when the vehicles are
repaired. While the EPA is further investigating the emission of
these pollutants, and others which may be unique to catalysts, the
EPA does not currently see automotive emissions of these pollutants
as posing a public health risk.
Is sulfuric acid a new environmental pollutant? Is it a health hazard?
If so, how surg^ a_r_G_ you about its potential health_ rl_sk_?
Sulfuric acid is not a new environmental pollutant. It.is emitted
from sulfuric acid plants and is one of the sulfates generated in
ambient air by the oxidation of sulfur dioxide gas which is emitted
from all fossil fuel combustion sources. Sulfuric acid is thought to
comprise a major portion of the ambient air particulate sulfates in
some areas, while in other areas it is a minor constituent,
Sulfuric _acid can be a health hazard at relatively low concentrations
compared to some other pollutants. A number of studies have been carried
out in which human volunteers were exposed to sulfuric acid aerosols.
Other studies have been conducted using various laboratory animals.
In addition, the EPA has been conducting major epidemiological studies
in several urban areas which include particulate sulfates as one
parameter being examined. All of these studies agree that particulate
sulfates (including sulfuric acid) are respiratory Irritants.
-------
-6-
While' a number of studies have been performed on the health
effects of sulfuric acid and other sulfates, currently available data
do not provide a basis to clearly assess the health impact of the
relatively low concentrations of small particle size gulfurlc acid
expected to be produced on and near roadways by catalyst-equipped cars.
Thus, automotive sulfuric acid emissions must continue to be considered
a potential source of health risk. Further studies are being performed
to better quantify their effects.
Whatis EPA doing to avoid adverse health effects from catalyst-
_p_rgduced sulfuric acid emissions?
Since early 1973, when sulfuric acid emissions from catalyst-
equipped cars were first identified, EPA has been studying the
various aspects of this potential health problem to assess its
magnitude and determine if regulatory action is required. Vehicle
teet procedures and emission rates, air quality and exposure impact
modeling, and possible control techniques have.been studied as well
as health effects. Ambient monitoring alongside a major Los Angeles
freeway has also been implemented to identify trends in sulfate
levels as the usage of catalyst-equipped cars increases.
In March, 1975, efforts to develop a sulfuric acid emission
standard for new automobiles were begun, and improved vehicle
test procedures and more extensive data on sulfuric acid emissions
have resulted. After extensively reviewing the currently available
data, EPA has concluded that additional study is needed before a
sulfuric acid emission standard could be meaningfully adopted.
In particular, additonal data are needed in two areas to determine
whether, and if so how stringent, a sulfuric acid standard for
automobiles is necessary. One of these areas is the health effects
which may be associated with exposures to sulfuric acid in the
particle size range, and at the concentrations, which may'in the
future result from widespread usage of catalysts. The other area
is the degree to which sulfuric acid emissions from a given car will
change as that vehicle's catalyst ages. Some preliminary studies
have shown a substantial and rapid decline in sulfuric acid emissions
from catalyst-equipped cars over their lifetimes. If further
studies validate this finding, automotive sulfuric acid emissions
would have much less impact than has been previously estimated.
EPA is continuing to explore these and other aspects of the
automotive sulfates question and will continue to reassess the need to
take action to reduce sulfuric acid emissions so as to avoid any real
danger to public health from such emissions.
OMSAPC/May 1976
-------
Oxidation Catalysts for Automotive Emission Control
The Environmental Protection Agency has received many inquiries
regarding the oxidation catalyst emission control systems used on
many 1975 model cars. Many of these questions have concerned reports
that cars equipped with catalysts will emit new, dangerous pollutants
in place of the pollutants the catalysts are intended to control.
Other questions have concerned costs, or other aspects of the use of
catalysts on cars. This Fact Sheet has been prepared to respond
efficiently to such questions.
FS-29
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY ° WASHINGTON, D.C, 20460'
-------
What are catalysts'? Why is EPA_jreqjjirinj* that they be put on 1975^ model
cars?
In general, the term catalyst is used to describe a substance which speeds
up a chemical reaction without itself being consumed In that reaction. As
many as 85 percent of all 1975 model cars sold nationwide, and nearly 100 percent
of 1975 models sold in California, are expected to be equipped with a new type
of emission control device known as an oxidation catalyst. This device is
installed in the vehicle's exhaust system between the exhaust manifold and the
tailpipe, and is intended to achieve more complete oxidation of hydrocarbons and
carbon monoxide, two pollutants in engine exhaust, into harmless water
and carbon dioxide. The active materials in the oxidation catalyst which
accomplish this are noble metals (typically platinum and/or palladium)
deposited on an inert ceramic substrate of aluminum oxide.
Strictly speaking, the EPA is not requiring that catalysts be installed on
1975 model cars. EPA establishes performance requirements, in the form of
emission standards, which simply require that vehicle emissions not exceed
specified levels. It is up to the individual auto manufacturers to decide
what control hardware they will use on vehicles to meet such standards.
Oxidation catalysts were first considered for use on automobiles in the
early 1960's when California began to regulate automobile emissions. Although
California approved some catalysts for use, triggering a requirement for cars
to meet certain standards under their law, the auto manufacturers found it
possible to meet those early standards by changes in engine adjustments and
chose not to use catalysts. The lack of general availability of unleaded
gasoline at that time also made catalysts impractical. Non-catalyst
techniques have been used by the manufacturers to meet Federal emission
requirements from their initial implementation with the 1968 models through
the 1974 models.
In 1970, the Congress adopted legislation requiring that much more
stringent levels of automotive emission control be achieved nationwide by the
1975 model year. Shortly thereafter the auto manufacturers concluded that
oxidation catalysts provided their best option for meeting those standards by
the required time and focused their efforts on the further development of
catalytic devices. In 1972 and 1973, when the EPA held hearings on auto industry
requests for a delay in the implementation of the statutory standards, it was
evident that the only technology then available to permit achievement of
the standards in the Congressionally-mandated timeframe was the oxidation
catalyst. In seeking the delay the manufacturers argued that, while the
catalysts would permit substantial emission reductions, an attempt to install
such newly-developed technology on all cars produced in the 1975 model year,
-------
and a requirement that those cars meet the very stringent statutory standards,
would lead to a high risk of major production delays, causing economic and
social disruption of national scope. It was also argued by some manufacturers
that the durability of catalysts In the hands of the public was as yet unproven.
On the basis of that testimony and the EPA's own technical studies,
the EPA Administrator concluded that the risk of economic and social
disruption through across-the-board implementation of the new technology in
a single model year outweighed the air quality cost of delaying implementation
of the standards. Therefore, he granted a one-year delay of the statutory
standards and established two sets of interim standards for the 1975 model
year. One set, applicable nationwide except to cars sold in California,
was set at levels about one-half the 1974 model year standards. These
nationwide interim standards are considered to be achievable on most
cars without the use of oxidation catalysts. The second set of Interim
standards, applicable to 1975 model cars sold in California, was set
at levels about one-third the 1974 standards. These California interim
standards were expected to be met by using catalysts on nearly all cars.
The purpose of the two levels of interim standards was to provide for
a phasing-in of catalyst technology, as the auto industry had strongly
urged be done. Subsequent to that decision, however, when auto
manufacturers were faced with the decision of what technology to employ
on their various models to meet the two sets of interim standards, many
elected to use catalysts for both sets. Thus, while in EPA's judgment
most of the 1975 non-California cars could have been designed to meet
the Federal standards without using catalysts, the manufacturers, have
chosen to use catalysts on those care, generally to achieve
Improvements in vehicle performance and fuel economy.
Hasn't it been shown ^that Catalysts einit dangerous pollutants?
If so, what are they, and__what adverse health effects will they
cause?
While the principal effect on auto emissions of uaing catalysts
is the desired reduction in hydrocarbon and carbon monoxide emissions,
tests by EPA scientists and others have shown that the catalyst also
results in emissions of other substances with a potential for adversely
Impacting upon public health. The current high level of public
awareness of this issue was generated in large part as a result of the
investigations by EPA scientists of emissions from catalyst-equipped cars.
A number of studies have shown that use of catalysts will result
in emissions of sulfuric acid aerosols. Sulfurlc acid, whose adver.se
health effects are discussed in more detail in a later paragraph, is
present in the exhaust of non-catalyst cars only in trace quantities,
-------
if at all. Emissions of other substances from catalyst-equipped cars,
such as platinum, palladium, hydrogen sulfide, and phosphine, have been
reported by some investigators but have not been confirmed in tests of
1975-type cars by the EPA and others.
On the other hand, the use of catalysts IB also expected to substantially
decrease emissions of polynuclear aromatic hydrocarbons, aldehydes and
phenols, all of which are currently not regulated in auto exhaust but are
nevertheless underslrable emissions from a health standpoint.
Automotive emissions of sulfur oxide pollutants originate principally
from sulfur-containing impurities which occur naturally in petroleum. A
small portion of the sulfur in crude oil ends up in the gasoline after .
refining (typical gasoline sulfur levels are 100 to 700 parts per million
with a national average of about 300). In addition, some gasolines may
contain sulfur compound additives. The sulfur compounds in gasoline
are oxidized during the engine's combustion process and emitted in the
exhaust. For non-catalyst cars, tests show that nearly all of the sulfur
compounds in the gasoline are emitted in the form of sulfur dioxide (802) gas.
This S02 disperses in the air and slowly reacts to form particulate sulfates,
such as sulfuric acid or other acid sulfates. The S0£ emitted from motor
vehicles constitutes only about 1% of the total U.S. manmade 502 emissions.
In a few urban areas, however, such as the Los Angeles basin, vehicles
contribute a substantially greater percentage to total SCb emissions due to
high vehicle density, high sulfur gasolines, and relatively low sulfur emissions
from stationary sources.
Catalysts cause the rapid conversion of some of the SO? 1R tne
exhaust to sulfuric acid. Thus, the potential for adverse health effects
associated with the emission of sulfuric acid from catalyst vehicles is
one of localized exposure In and near major concentrations of motor vehicles
before significant dilution of the sulfate can occur in the air.
Using available data on sulfuric acid emissions from catalyst-
equipped cars and anticipated fuel sulfur levels, the EPA has employed
several predictive models to estimate the Increase in exposure to acid
sulfates likely to result under various assumptions of traffic,
meteorology, and extent of use of catalysts on cars. These studies,
whose results were presented by the EPA to the Senate Public Works
Committee early this year, show that when catalyst-equipped cars account
for about 25% of miles driven (roughly two model years equipped with
catalysts) the additional exposure of commuters on our busiest expressways
to acid sulfates during periods of low atmospheric dispersion
would exceed levels associated with adverse health effects in susceptible
segments (about 10%) of the population. In less busy areas, such levels
-------
would be anticipated after perhaps six model years were catalyst^equipped,
It should be emphasized that while these projections have been based
on preliminary information, they indicate a need for close study of this
potential adverse side effect of catalyst usage. Additional studies of
automotive sulfate emissions which the EPA is conducting are discussed later.
The EPA Is also conducting a program to assess the potential public
health impacts of the use of platinum snd palladium in catalysts.
A continuing public health assessment program was Initiated about
a year ago to augment the very limited knowledge then, available on
the health effects of these metals in low concentrations. At present,
exhaustive emissions testing of prototype catalyst-equipped vehicles
by the EPA has not shown detectable levels of platinum or palladium in
the exhaust particulate from current catalysts, unlike results from
some of the earlier prototype devices. This result is confirmed
by a number of industry studies also. The EPA now believes that
platinum and palladium do not pose a risk to the public through
exposure to those metals from normal operation of catalytic devices.
The potential for emission of these metals during unusual catalyst
operating conditions is being investigated.
The emission of hydrogen sulfide and phosphine have been
reported by industry laboratories. These emissions occurred during cold
start operation of the vehicle. While the EPA is investigating the
potential for the emission of these pollutants, and others which may be
unique to catalysts, the EPA does not currently see automotive emissions
of these pollutants as posing a public health risk.
Is sulfurlc acid a new environmental pollutant? Is it a healtj^liazard?
If ao^ how sure are you about its potential health risk?
Sulfuric acid is not a new environmental pollutant. It is emitted from
sulfuric acid plants and is one of the sulfates generated in ambient air by
the oxidation of sulfur dioxide gas which is emitted from all fossil fuel
combustion sources. Sulfuric acid is thought to comprise a major portion
of the ambient air particulate sulfates in some areas, while in other areas
it is a minor constituent.
Sulfuric acid can be health hazard at relatively low concentrations
compared to some other pollutants. 'A number of studies have been carried
out in which human volunteers were exposed to sulfuric acid aerosols.
Other studies have been conducted using various laboratory animals. In
addition, the EPA has been conducting'major epidemiological .studies in several
urban areas which include particulate sulfates as"one parameter being
examined. All of these studies agree that particulate sulfates (including
eulfuric acid) are potent respiratory Irritants at sufficiently high levels.
-------
The exposure level required In order to detect respiratory effects in
healthy people is quite high compared to the levels which
appear to adversely affect individuals with preexisting heart or respiratory
diseases. While there are difficulties in establishing a precise exposure
level which truly constitutes an adverse health effects threshold, present
data suggest that at a level of about 10 micrograms per cubic meter
(24 hour average) the roost susceptible segment of the population will
experience measurable adverse health effects such as Increased frequency
and severity of asthmatic attacks.
If EPA doesn't yet have adequate information on the side effects of
catalyst_s_>_wh^_wasn/'t their,jise postponed until they had been thoroughly
studied?
Obviously, postponement was considered* but such an action would have
slowed ongoing efforts to control auto emissions for the rest of the decade.
As discussed earlier, use of oxidation catalysts was the only technologi-
cal alternative available to permit timely achievement of the stringent
emission standards mandated by the Congress in 1970, standards which were
adopted to substantially reduce a significant threat to public health
from carbon monoxide and photochemical oxidant pollution. By the time
preliminary data on automotive sulfate emissions were sufficiently
developed to permit a decision, in late 1973» a coordinated effort to
manufacture and install catalysts, and to provide the unleaded gasoline
required by catalysts, was well underway. Early achievement of the
statutory emission levels, necessitating catalyst .use, was also an integral
assumption of State air pollution control plans which would have been
disrupted by an extended delay.
r Any effort to discourage or prohibit the use of catalysts on 1975
mo.dels at that late point in the vehicle design process would have
necessitated holding the emission requirements for the 1975 cars at the
19.74 levels, foregoing the anticipated 1975 emission reductions. While
standards somewhat more stringent than the 1974 levels would have been
achievable In subsequent model years without catalyst usage, the only
apparent alternative for meeting the statutory standards without
catalysts was, and is, adoption of alternative engines such as the
stratified charge engine. Conversion of all models to such an alternative
engine was considered to be impossible until at least the end of the
decade, and probably much longer. In addition, it was felt that any
e-ffort to delay catalyst implementation after so much coordinated effort
had been expended would likely cause such disruption as to make any
attempt to reinstate catalyst useage a few years later fruitless.
-------
Thus, a temporary delay In catalyst Introduction pending further study
did not appear a viable option In late 1973 when the EPA was faced with
making'a decision on this Issue. Rather, the choice was whether or not,
on the basis,of the limited data then available on catalyst side effects,
to substantially delay the auto emissions control effort set Into motion by
the Congress through the 1970 Clean Air Amendments. The Administrator's
decision was to permit the"initial introduction of catalysts accompanied by
a high priority program to further quantify the aide effects and identify
alternative means to prevent or counteract them.
What Is EPA doing to find out more about these side effects? When
will you have the answers?
As a result of the Administrator's concern about the potential
health risk from catalyst-generated sulfates, which he discussed
before the Senate Public Works Committee in November, 1973, the
EPA accelerated its existing research program and expanded it to
cover all major scientific aspects of catalyst-related pollutants*
The current program Includes emissions studies, pollutant measurement
methods development, refinement of meteorological, models used to estimate
exposure levels near roads and complex sources, toxicological, biological,
and human studies to more precisely define potential adverse health
effects, a highway monitoring program to measure actual emission
concentrations in the real-world environment, and studies to determine
how to control sulfate emissions from catalysts-equipped vehicles.
Certain studies, principally those related to emissions measurement
and the toxicological/biological aspects of platinum and palladium were
initiated in July 1973. The highway monitoring program was Initiated in
'April 1974, while the bulk of Che- expanded program was begun in July 1974.
Some results from this multi-disciplinary program have already
become available, principally measurements of sulfate emissions from
current generations of catalytic converters. These results tend to
confirm the emission estimates developed earlier, although they
demonstrate that the emission -levels vary considerably depending on the
catalyst design and the type of driving the vehicle is exposed to. Most
new results on health effects, air quality estimation procedures, sulfate
emissions from In-use vehicles, and possible sulfate control approaches
will not be available until early-to-mid 1975. Some studies Inherently
requiring longer study periods, such as chronic health effects and long
term air quality trends, are scheduled to continue until at least mid-
1977. . ' " '
-------
What willISAdoif the dangerous side effects of the catalysts are
confirmed?
EPA Is certainly concerned that efforts to solve one setlous environmental
problem should not produce another one. If It Is confirmed that continued
use of oxidation catalysts would result in dangerous levels of sulfates or
other pollutants, EPA will take regulatory action to prevent such a
condition from occurring.
With respect to sulfate emissions in particular, EPA would have basically
two options. One would be to restrict the amount of sulfur that can be
in the unleaded gasoline used by catalyst-equipped cars. Removing the sulfur-
containing impurities from the gasoline would eliminate the sulfate emissions.
The technology for doing this in the refining process is known, but implementation
of this approach would be expensive and it would take some time for all refiners
to build up the required capacity. EPA is studying this further, as well as
possible interim steps to maximize the use of low sulfur refinery products
in the unleaded gasoline.
The other alternative would be to adopt an emission standard limiting
the auto manufacturer in terms of the amount of sulfates his cars may emit.
The manufacturer would have two possible ways of responding to such a standard.
One would be to drop the catalyst and change over to an alternative engine.
As mentioned earlier, thia. would take a number of years to fully implement
since the lead-time for manufacturers to obtain the new tooling needed to
manufacture an alternative engine is quite long. Alternatively, the
manufacturers might be able to change the design of their catalyst systems to
minimize the formation of sulfates or install devices to trap or neutralize
the sulfates and prevent their emission. Such devices are theoretically
possible, but proven technology to accomplish this doesn't exist st this time.
A major concern in evaluating these alternative strategies will be
the timing with which they could be implemented. Each of the possible
approaches being studied would take time to Implement, even after a
decision is made on the course of action to be followed.
•of
What will catalyst systems cost the consumer? Won't they require
sp ecial, expensive gaaolines?
;a
:*The total increase in cost of standard sized catalyst-equipped
1975 models over that of comparable 1974 models is estimated to be from
about $130 to possibly $225 for the additional emission control equip-
ment. Of this, $60 to $100 would be for the catalyst Itself. The
remainder would be for other emission control changes, which may include
-------
Improved chokes and carburetors and advanced ignition systems. Some
catalyst systems have been designed to require catalyst replacement after
about 25,000 miles of use, although most cars have been designed not to
require any catalyst change before 50,000 miles. Costs for replacing a
catalyst could range from $40 to $100 depending on the manufacturer's
design.
All catalyst-equipped 1975 models and many non^catalyst 1975 models will
be designed to use unleaded gasoline exclusively, and will be equipped with
special restrictors in the gasoline inlet pipe to prevent refueling except
with the smaller nozzles on pumps that dispense unleaded gasoline. While
unleaded gasoline is currently priced at one cent more per gallon than the
leaded regular grade, the average operating costs of catalyst-equipped
cars using unleaded gasoline can be expected to be sufficiently lower than
those for current cars which use leaded gasoline to more than offset the
extra cost of the unleaded fuel. The reason is the improved fuel
economy expected from many catalyst-equipped cars, and the longer life
of such components as spark plugs and exhaust pipes which occurs when
unleaded gasoline is used.
There have been reports thatafter a short period of use carswith catalysts
will ne_ed high octane _ gasoline which will not ;be generally_available_in_the_
unleaded grade required by catalysts. What is the EPA going to do about this?
The EPA is aware of a number of reports suggesting that a greater than
normal percentage of the 1975 vehicles will not operate with the typical
unleaded grade gasoline without knocking. In order to better assess the
expected magnitude of any such problems, the EPA wrote to auto
manufacturers asking for their estimates of the percentage of their
vehicles which would require corrective adjustments to avoid spark
knock with unleaded fuel. The major U.S. manufacturers have responded
that they anticipate that only a small portion of their vehicles (from
less than 20% to less than 5% depending on manufacturer and assumptions
made) will exhibit noticeable knock when set to factory specifications
and operated on 91 octane fuel (the minimum permitted for unleaded fuel
under EPA regulations). They indicated that they expect far fewer than
these percentages to actually require adjustment (spark retard) since "-"many
drivers may have access to higher octane unleaded fuel or will not drive
their cars under conditions where the knock would be noticeable.
Thus, the manufacturers do not appear to anticipate a serious
problem in this regard. Should it turn out that 1975 model cars do
exhibit this problem to a greater extent than the manufacturers now
anticipate, it may be expected that the automotive and petroleum companies
will mutually take steps to bring engine requirements and fuel
capabilities into line as they have done in the past.
-------
How does the EPA know that the jiatjilysts^wl 11 _ really work in the hands of
the public? What: will happen T if catalyses cip fall in use? Wil3^ this
the motorist:, or those ngar by?
Before manufacturers are permitted to introduce and sell their various
models of cars, each model must be tested over 50,000 miles to demonstrate
compliance with Federal emission standards. In addition to this testing,
many of the manufacturers have carried out independent tests of catalyst-
equipped fleets over extended mileage to assure themselves that with
appropriate maintenance the emission control systems will function
properly over the 50,000 mile lifetime as required by the Clean Air Act.
EPA regulations limit the maintenance during compliance testing to. items
considered likely to be done by owners. For example, tuneups may not
be performed more often than every 12,500 miles; a maximum of one
servicing of the catalyst is permitted during the 50,000 miles, and then
only if a warning light or buzzer is provided to remind the driver
when service is needed.
It is possible, of course, chat aome catalysts will fail in use,
In all mass-produced goods defective items are occasionally found, even
with strong quality control efforts by the manufacturers. The Clean
Air Act authorizes the EPA to take various actions to ensure that vehicles
are produced which comply with Federal standards over 50,000 miles of
use if properly maintained and used by their owners. Such actions
include testing of vehicles at the time of production, which EPA is
currently investigating, and the possible recall of non-complying classes
of vehicles. A number of States are developing emission Inspection
programs to help ensure that vehicles receive adequate maintenance
b. No danger to vehicle occupants or those nearby is anticipated in the
event of a catalyst failure. If a catalyst were to be inadvertently
poisoned by use of leaded gasoline, or If through some malfunction
it were to fail through overheating, no change in the vehicle performance
or operating characteristics other than increased emissions of HC and CO
would be expected. Depending on the manufacturer's design, emission
levels could be increased by 100 to 300 percent in the event of total
catalyst failure, but they would probably still be well below emission
levels for uncontrolled cars.
-------
10
What_are the alternatives to catalysts? Are catalysts likely to
be a .long-range measure, or simply an interim solution?
As has been mentioned earlier,, catalysts present the only real
possibility for meeting the statutory hydrocarbon and carbon monoxide
emission standards on all cars during this decade, fhe principal
alternatives would be other types of engine designs such as the
stratified charge or diesel engine. More extensive changes such as
the gas turbine, steam engine, and Stirling engine are also being
investigated. .
Whether or not any of these alternatives Is ultimately phased-in
by auto manufacturers to replace the oxidation catalyst will depend -
upon a number of questions whose ultimate resolution is still uncertain.
One of these, of course, will be what is determined about the significance
of sulfuric acid emissions from catalysts and the feasibility of
reducing those emissions to .acceptable levels. Another factor will
be the extent to which catalysts are found to provide satisfactory
emission control performance during extended consumer use. The
growing emphasis on fuel economy as a vehicle design goal will
undoubtedly also influence auto manufacturers* decisions on which
engine and emission control alternatives they pursue.
Another factor which will influence manufacturers* decisions on
whether or not to introduce alternative engine types will be the level
of future automotive emission standards for oxides of nitrogen (NOx).
Some engine types, such as the diesel and certain stratified charge
engines, can meet statutory hydrocarbon and carbon monoxide require-
ments without catalysts, but there is great uncertainty as to their
ability to meet the statutory T3QX standard of 0.4 grains per mile.
Some manufacturers have Indicated that they will not convert to such
alternative engines unless it Is clear that less stringent KOX
requirements will be in effect for an extended period so as to justify
the investment in changes in production tooling. The EPA .has recommended
to the Congress that the stringency of the statutory NOx standard be
reduced. •
In any case, It can reasonably be expected that manufacturers
would wish to use catalysts on at least several model years of new
cars before any alternative approach would be generally adopted.
11/74
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
Dresserator Fuel Induction. System
To respond efficiently to the many inquiries about the
Bresserator Fuel Induction System the Environmental Protection
Agency has prepared this fact sheet,
The Dresserator system has been developed by Dresser Industries,
Inc., of Dallas, Texas, for application to gasoline fueled spark
Ignited Internal combustion engines. It is basically a new type of
sir and fuel Induction system embodying a "critical-flow" venturi in
which mixture flows .are said to achieve sonic velocity, causing
extremely effective atomization and mixing as the mixture passes
through a compression shock wave downstream from the venturi throat.
The design Is such that the venturi throat can be varied In size
so as to maintain sonic flow conditions over a wide range of engine
speeds. Close control of the air/fuel ratio Is achieved by matching
the fuel delivery rate to the venturi throat area.
The Dresserator system Is designed to allow extremely lean air/fuel
ratios (about 18.5 : 1) over a wide range of engine speeds with, little
fuel wetting of the intake manifold. It provides excellent cylinder
to eylinder distribution while avoiding lean mixture misfiring. These
features lead to low pollutant emissions, good fuel economy, along
with maintenance of good driveability.
After reviewing the technical information, including exhaust
emissions and fuel economy data, supplied by Dresser Industries, EPA
technical staff determined that a series of tests at the Agency's
Motor "Vehicle Emissions Laboratory were Justified. Such tests are
conducted regularly as a part of the Agency's on-going effort to stay
abreast of development In vehicle exhaust emissions control.
Two vehicles equipped with the Dresser system were tested, a
1973 Chevrolet having a 350 cubic Inch displacement engine and a.
1973 Capri having a 159 cubic inch displacement engine. In addition
to induction system changes, the Capri was also fitted with an
enlarged and Insulated exhaust manifold to help promote oxidation
of pollutants.
The results of the EPA tests on these two cars showed that both had
emission characteristics substantially lower than the allowable 1975
levels of 1.5 g/m hydrocarbons and 15.0 g/m carbon monoxide. The Capri
met the more stringent California requirements of 0.9 g/m hydrocarbons
and 9.0 g/m carbon monoxide while nitrogen oxide emissions with both
cars were well below the allowable 1977 level of 2.0 g/m. These results
were achieved without using catalytic converters or exhaust gas recir-
culation. With each car, the fuel economy was better than the 1973
certification test results for its counterpart. The test program and
results are described in more detail in EPA Technology Assessment and
FS-3Q
-------
- 2
Evaluation Report # 75-7, "Evaluation of the. Dresserator Emission
Control System". A limited number of copies of this report are
available from the Test and Evaluation Branch, Emission .Control
Technology Division, Environmental Protection Agency, 2565 Plymouth
Road, Ann Arbor, Michigan 48105.
On the basis of these test data and engineering evaluation,
EPA concludes that the use of the Dresserator-system (perhaps with
the addition of. an oxidation catalyst) has potential for achieving
the 1977 emission standards of 0,41 hydrocarbon, 3.4 carbon monoxide,
and 2.0 nitrogen oxide, while at the same time achieving excellent
fuel economy.
OMSAPC/November 20, 1974
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
Summary of Responses to EPA Request for Information on Octane
Requirement Increases for 1975 Model Automobiles
INTRODUCTION
Automobile engine knock is the sound produced by improper firing
of the gasoline in the combustion chamber. Excessive deposits alter the
compression ratio and form "hot spots" which can cause premature ignition
and very rapid combustion (detonation.) which result in the knocking sound.
The degree to which an engine will knock depends on the accumulation of
deposits, the composition of the gasoline, the basic design of the engine
combustion chamber, the compression ratio, the engine operating conditions
especially spark timing and load (or throttle position), along with such
ambient parameters as temperature, altitude, and humidity,
In designing an engine, the automobile manufacturer will specify an
octane number or range of octane numbers for the gasolines which the engine
should satisfactorily operate on without knocking. The Octane rating
of gasolina is the measure of its resistance to knock. Octane levels are
designated by two methods, the Research Octane Number (RQH) and the Motor
Octane Number (MON). Because it is measured under more severe engine
operating conditions which produce a greater tendency for knocking, the
Motor Octane Number is typically the lower of the two. The difference
between the ROM and MON is known as 'the sensitivity; a high sensitivity
gasoline will perform well under mild conditions but is much more
susceptible to knock at higher speeds. .
Engine designers have long recognized the phenomenon known as Octane
Requirement Increase (ORI). When an engine is brand new, it can operate
satisfactorily on a lower octane gasoline. After it is broken in and
combustion chamber deposits have begun to form, the octane requiremsat starts
to increase. The manufacturer's recommended octane level is meant to
accomodate this increase. However, some few vehicles will increase in .
octane requirement beyond the level of the-gasoline recommended by the
manufacturer. Spark retard can eliminate knock caused by excessive ORI
(and will tend to also reduce the emission of hydrocarbons and nitrogen
oxides), but spark retardation reduces fuel economy. Because spark retard
is likely to be needed on only a few automobiles, its impact on overall
fuel economy would be slight.
Some concern has been voiced that with the introduction of unleaded
91 RON gasoline for 1975 model vehicles and the gradual elimination of
premium high octane gasoline, new cars that develop knock problems might
FS-31
-------
- 2 -
find it difficult to locate higher octane unleaded gasolines, and that
many'of them would have to resort to spark retard adjustments, with the
resultant loss of fuel economy. To obtain nore information on this subject,
EPA wrote on August 16, 1974, to several automobile manufacturers, A copy
of that letter is attached. The responses of the four domestic automobile
manufacturers have been reviewed, and a surcaary of their replies appears
below. Copies of the responses are available for inspection by the public
at the Freedom, of Information Center at EPA headquarters in Washington,
B.C.
SUMMARY OP RESPONSES
The letter to the manufacturers listed five questions related to -
ORI and the possible impact of 91 RON gasoline on 1975 production automobiles,
The following is a summary of the responses to each of the five questions:
1. On the basis of data available to you, what percentage
of your 1975 model year vehicles do you expect to require
such adjustment (spark retard)?
The manufacturers generally cited the lack of the field data on
1975 model year vehicles, but were able to cake sose conclusions based on
the performance of 1973 and 1974 cars. General Motors refers to the
Coordinating Research Council (CRC) study of 1973 vehicles, which found
satisfaction levels with 91 RON unleaded gasoline of 64% based on borderline
knock, 77% based on customer (light) knock. Borderline knock is -measured
by trained observers; light knocking is the level which usually can. be
detected by the public. GM does not consider short duration light knocking
harmful to the engine, though it may be objectionable to some drivers.
More prolonged heavy knocking can cause engine damage.
Based on the CRC results, GH estimates that a maximum of 20% of 1975
GM vehicles meeting specifications might, have borderline knock. However,
GM feels that only a few of these cars will require spark retard. Even if
higher octane unleaded gasoline is generally unavailable, some customers
never drive their cars under conditions as severe as the CRC tests. .Some
drivers will have access to higher octane fuels, and others will simply
drive in a way that avoids the problem.
The Ford responses states that their 1975 model engines have been
designed to operate with 87 ROM gasoline during rigorous dynamometer testing
after 3000 miles of engine break-in. . Ford concludes that 95% of their
engines will provide customer satisfaction even under "the most severe
operating conditions," with 91 RON unleaded gasoline. Under more normal
operating conditions, Ford expects a customer satisfaction level of much
greater than 95%. : . •
-------
Chrysler Corporation emphasized that they have no way of knowing
precisely bow many of their 1975 cars will need adjustment when run on
91 RON unleaded gasoline. However, they believe that over 9J3% of their
vehicles will operate properly on the available fuel. They expect that
any problems in the field will be minor and easily correctable.
American Motors Corporation was unable to estimate the percentage
of their 1975 model year cars which might require spark retard adjustment.
They state that more information on the characteristics of the gasoline •
which will be marketed in 1975, especially motor octane ratings, is
necessary. •
2. . Are you actively arranging to obtain approval from
EPA, through the running change/field fix procedures
of the certification process, for the modified calibrations
that might be used in such cases?
'GM filed a running change request (RC #11), for modified spark
timing calibrations with the Certification and Surveillance Division of
EPA on August 22, 1974. Ford explains that they are in the process of
arranging for approval of modified calibrations for the particular engine-
emission system combinations which have the greatest potential for an octane
limitation problem. Approval of modified calibrations for other engine-eoission.
system combinations will be sought if problems v?ith them are identified from
field studies or from Ford's continuing test program. ' •
Chrysler states that they have insufficient information at the present
time to ask EPA for any kind of ORI field adjustments. American Motors is
riot currently seeking a running change for modified spark calibrations, but
intends to do so in the near future.
. 3. Will your company be willing to adjust, without charge
to the vehicle owner, any of your 1975 model year vehicles . ,:
that cannot operate without spark knock on 91 RON gasoline
when such vehicles are adjusted to your, specifications?
The expense of the timing adjustment will be assumed by CM "as a ' .
matter of policy" if the engine has received recommended maintenance, there
is no evidence of tampering, 91 RON fuel has been used, and EPA approves the
spark retard modification. . .- . •
Ford will adjust the spark retard for any octane requirement problem
identified upon customer complaint once during the first twelve months or
12,000 miles, free of charge. Chrysler states that any problem occuring during
the warranty period will, be dealt, with.
-------
American Motors explains that it is standard practice under their
Buyer Protection Plan to resolve any custoner problem resulting froa
factory defect during the first twelve months or 12,000 miles without
charge. Presumably, this includes spark retard adjustments necessitated
by octane requirement increases.
A. Since an increase in octane requirement is not likely to
appear at low mileage, for how many miles or years of the
vehicle's life will you be willing to make such adjustments
without cost to the vehicle owner?
Assuming that the requirements stated in the responses to Question 3
are net, GM will make such adjustments for five years,-or 50,000 miles.
Ford's policy is for one adjustment during the first twelve months or
12j000 miles. Ford test data, indicates that this will adequately satisfy
the customer's needs.
Chrysler points out that octane requirement increase can be caused
•by many factors, including the method of operation, ambient conditions,
engine maintenance, and other factors possibly not completely understood.
Chrysler says that each case will be examined on its own merits, and
corrections will be made by "the petroleum companies, the antifreeze
suppliers, or ourselves, if any of these parties is at fault, or if none
is at fault, by the owner."
American Motors will make adjustments covered by, their Buyer
Protection Plan during the first twelve months or 12,000 miles without
charge. • Customers with the extended Protection Plan are covered for .24
months, or 24,000 miles, whichever comes first. • .
5. Are you planning to advise purchasers of your vehicles
of your policy on this matter? Row will you notify them?
Since the number of vehicles affected is expected to be quite small,
GM is not planning to issue a general announcement of their policy, in
fear of creating unjustified consumer confusion. They believe that most
owners will recognize knocking as a need for higher.octane gasoline, and
that owners vlll consult with the dealer on any particular knock problem.
To handle complaints to the dealer, GM will issue a dealer bulletin outlining
their policies, including spark retard modifications if approved by EPA.
A similar plan will be employed by Ford. They will Issue Technical
Service Bulletins to their dealers informing them of the details o£ the
Ford policy. Both the Chrysler and the American Motors responses state
that their warranty policies are Included in the Owner's Manuals.
December 1974 - MSAPC
-------
^ UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
' . : WASHINGTON. D.C. 20450
' . . RUG 1 S 1974
THE AD,M!f*iSTRATOa
Daar ilr. Starknart: . . .,..:.••
As you are wall aware,' in recent.weeks :public attention,
has bean" directed to', the possibility", that SOES -1975- model .year
cars may not be. able tcr operate', without spark knock on. the7 91 '
RON ualeailajd gasalias for .which they are designed*. VHiila/we" ~,
•fully appreciate', that the' phenbsEandu of- Octane Reqiiizeneji
(ORI) ~h^5 long "bj***rt' Vpf-hgpiT gpa."j-n<^ largely.compensated' for.in, tha'
design of-autacDoilas,-it is.also- tme that ia tha'past1 sonia'scaJJ. •
fraction of vehicles' have—-because1 of a stack-up of tolerances,* .
aciong othar'. factors—-beec' imable after" deposit stabilization •'•'• -.-
to' oparate. withciit spark loiack except "by', utilizing gasoline b£
a higher octane rating than specif iei for the* vehicle." ...
. In the" pasf,. this problem'has bean" minor inasmuch'as laotorists',
could .readily buy gasoline of somewhat higher'octane." However,
beginning .in the" 1S75' tnadsl' year :such higher" octane unleaded gas-
oline may not be' generally available in all parts;, of, the* country, •
and some iaotorlsts'.Eay thus encounter' spark knock p rob lams, that --.
iri.ll require'adjustcent of engine calibrationa,• in .particular
spark retardation. Concern has "been, expressed that it appears '•• - -
: unfair to:burdsn'an indii?ldual motorist- with: the' cosf of haying
such adjustments* Bade to-his car since his inability: to: satis—•
: factorily operate' his car on the' gasoline recbrsnended' for.it by*-, v "*.
. tha' Eianufactnrer' is in. no way a condition to..which, ha-hiasalf ,"
. has contrihuted. It has beeh':sugge3ted that in those- occasional •
cases in which raadjustnsnt of a vehicle is necessary,- the vehicle
nanufacturer' should ba' willing to.sake such adjustmeatsiwithotit : "
. cost to: the'vehi'cle owner. .The", purpose'.of this .letter'is to1 seek," "•'
infonaation from your- coEpany as to'.-tha' policy;on. this n-atter" that,
.it vill follow;^ . ' .•-•..:•. ••:.'• •••.. ..." ... -'...,- . . .
. 1. " On the" basis of data:.available to-you, what .:
: .percentage of your 1975* model-year vehicles" do
you expect to', require such adj.ustap.ant?'. .
-------
2. Are you actively arranging to obtain approval
" f ccra EPA, through, the running change /field fis
procedures of tha certification process, for the -
iied calibrations that night he used in such
Will your cqsuacy be willing to adjust, without
charge to the TaM.de owner, any of your 1975
codal yaar vehicles that cannot operate without •
spark, "knock an 91 EON gasoline when, such vahiclaa
, 'ace adjusted to your specifications?
Sine.* an increase- in octaae-requirsassnt is not
' lijcely t° appsar' at lew cdleaga, for, how. many
isxlea or years of ths vald.de Ts life will you .
• Tbe williisg to mate ,suii"-adjua,t3Msits without cost'.-
-"to the Tehicla' o-^naz? .'•• :'; — .•'.• .•;':.• .
5. • ; "Arc 'yon planning to adirisa .purcliaaera of your
Tahielas of your policy on this matter? Hoi*
will you-notify thzmt ' -., , •' ••; ': •.'. : •' , ..'
I will appreciate receiving your response to the eiova
questions t>y August 30, .1974'. Pleasa direct you respoaaa to
ths attention of our Deputy Assistant AoiairiistiratQE' for Motile. -
Source Air Pollution Control at our Washington headquarters offices.
• "• '•••'" • . • • ' " '. '-Sincerely yours, -
' ''' Jpnn.Quarlea
Russell. E. Train
•/Mr. Ernest S* Stazinasi • , .'
Vice Preaidairt ' ' \ . . ; "_.'•' ' "'•'/•"•^
Environ!2satal.: Activities' Staff-
General ttotora Corporation
Warrea, Micaisaa, 48090
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON. D.C. 20460
Comparison of Union Oil Company
and EPA Fuel Economy Tests
The Environmental Protection Agency has received a number of
inquiries about a fuel economy testing program that was carried
out by the Union Oil Company, the results of which were widely
publicized. The inquiries have expressed particular interest in
the reason for differences between the EPA'a fuel economy data and
the Union Oil fuel economy data for specific cars. This Fact Sheet
has been prepared to respond efficiently to these inquiries.
The test procedures use.d by the Union Oil Company were developed
by the Society of Automotive Engineers. Three driving cycles are used
in the test: urban, suburban, and interstate. The SAE urban fuel
economy test is similar to the EPA city test cycle; it has a lower
average speed (16 miles per hour for the SAE urban cycle, vs. 20 mph
for the EPA city cycle) and has more stops per mile (4 stops per mile
vs. 2.4 stops per mile). Because of these differences, the fuel
economy measured on the EPA. city cycle would be expected to be higher
than on the SAE test used by Union Oil; in fact, the EPA city
cycle fuel economy data averaged 17% higher than did Union Oil urban
fuel economy data for comparable cars.
A similar situation exists with regard to highway fuel economy
as measured by Union Oil and EPA, respectively. In that case, the
combined suburban and interstate SAE test cycle used, by Union Oil has
a higher average speed, and a greater number of stops per mile, than
does the EPA highway test cycle. One would expect lower fuel economy
on the Union Oil test cycle than on the highway cycle used by EPA; in
fact, the fuel economy measured by Union Oil in highway driving was
12% lower than that measured by EPA on similar cars.
These differences in test cycles and in fuel economy results
naturally raise the question of which of these test procedures is the
more valid. There can be no categorical answer to that question, for
it is impossible for any single set of test cycles to fully reflect
all of the diverse driving conditions encountered in the United States
in actual use, To have any meaning at all, comparative fuel economy
data must be based on a single, repeatable driving cycle chat is as
representative of actual driving conditions as possible. The EPA
test procedures are fully repeatable, are conducted in the laboratory
under controlled conditions, and have been carefully designed to reflect
FS-32
-------
-2-
average vehicle operating conditions. The SAE test procedures, which
are conducted on a test track or a public road, are based on a com-
bination of driving cycles that have in the past been used by the
automobile companies, and also have validity. Neither test procedure
Is right or wrong, although EPA feels its driving cycles are a better
representation of real world driving patterns. Even though the absolute
fuel economy values generated by the different test procedures are
different, on the whole the relative performance of the cars under each
test is quite similar, and It is the relative fuel economy for cars that
is of greatest importance to potential car buyers.
In considering the differences in fuel economy results, it
should be noted that the EPA results were in most cases the
average results from more than one car, whereas the Union Oil Company
tested only one car of each type.
However, even if the Union Oil Company had undertaken to re-run
the same testing program completed by EPA, using exactly the same
'driving cycles, test procedures and vehicle selection, there would
still have been some differences in test results due to car to car,
test to test, and test facility to test facility differences.
Therefore, considering all the factors which were not the same,
the comparative similarity in fuel economy ranking in the Union Oil
test and the EPA tests Is striking. The maximuni difference between
the 82 cars tested by Union Oil and their relative ranking in EPA's
city driving mileage derby was 23 places, and 82% of all cars tested
were within 10 positions of their EPA rank. Twelve percent of the
cars ranked exactly the same in both tests.
The ranking of cars is even closer in the highway tests. The
EPA.fuel economy values were higher than either the SAE suburban-
or SAE interstate fuel economy values in all but one case. Taking into
consideration that the combined SAE suburban and interstate test
results are 12% lower than the EPA highway test, 82% of the cars tested
by Union Oil scored fuel economy results within 10% of the values
published by EPA.
The only vehicle which scored significantly different results
In the Union Oil tests as conipared to the EPA tests was one Pinto,
with a 140 cubic inch engine. Other Pintos tested by Union Oil
compared well to the results obtained by EPA. The difference for
the one car Is apparently the result of random test to test or car
to car variability. Since the other tests conducted by Union Oil
and all the test conducted by EPA indicated fuel economy around 15
-------
miles per gallon on the SA.E test and 18 miles per gallon on the EPA
test, the 19.6 miles per gallon city test result on the SAE test is
probably not representative.
OAWN/OMSAPC December 1974
-------
UNITED STATES ENVIRONMENTAL PROTECTiON AGENCY
WASHINGTON. D.C. 20460
FACT SHEET
EPA Evaluation of the LaForce Car
-The Environmental Protection Agency, at the request of the U.S.
Senate Public Works Committee, carried out an extensive test program to
evaluate the validity of widely publicized claims that had been made for
an American Motors Hornet vehicle equipped with an engine that had been .
modified by Messrs. Robert and Edward LaForce. The claims made for the
engine included better fuel economy, lower emissions of air pollutants,
and increased power.
Single copies of the test report are available from the EPA Public
Affairs Office, Washington, D.C. 20460. In summary, the report concludes
as follows:
1. When compared ,to a standard car of the same type and same
basic engine, the LaForce car had about 30% better fuel economy. However,
it achieved that improved fuel economy at the cost of substantially
reduced power output and substantially increased emission of air pollutants,
2. Compared to the stock Hornet provided by LaForce, both unburned
.hydrocarbons and carbon monoxide emissions were about four times higher.
3. Acceleration tests and full load steady state tests indicated
that the modifications made to the standard engine by LaForce resulted in
a power loss of approximately 20%.
4. On an equal performance basis the fuel economy of the LaForce
car would not be significantly different from the economy available with
conventional engines.
FS-33 EPA/OMSAPC 12/20/74
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON. D.C. 20460
Diesel-Powered Au tpmobiles
Many recent publications have pointed out the inherently superior
emissions and fuel economy characteristics of diesel powered automobiles.
The Environmental Protection Agency has received numerous questions
asking why diesel powered automobiles are not manufactured and distrib-
uted on a large scale by United States automotive manufacturers. This
Fact Sheet has been .prepared to respond efficiently to such questions.
What is a diesel^ engine^
A diesel engine physically resembles a conventional automobile
engine except that there is no spark ignition system nor carburetor.
The fuel is sprayed directly into the combustion chamber and ignition
is caused by the heat developed during the, compression stroke. To
accomplish this, diesel engines must operate at very high compression
ratios (15 or 20 to 1) and the injection must be precisely timed to
occur at a time when the temperature has risen high enough to cause
ignition and when the combustion process will be most effective in
pushing the piston down for the power stroke. Relatively non-volatile
hydrocarbon fuels (fuel oils or kerosenes) must be used, because they
have the preferred compression ignition, characteristics which gasoline
does not have.
What are the pollutant emission characteristics of diesel•engines?
Because the overall air/fuel ratio used in diesel engines is
extremely lean (that is, a lot of excess air)s the emissions of carbon
monoxide and hydrocarbons are inherently low. Through careful combus-
tion chamber design, the emissions of nitrogen oxides can also be
controlled to relatively low levels, though not low enough at present
to meet the statutory (0.4 g/mi.) Federal Emission Standards for this
pollutant. Some diesel engines emit visible smoke and others tend to
cause offensive odors. Both of the latter characteristics have been
responsible for many complaints to EPA regarding diesel powered trucks
and buses operating in urban environments; however, both of these
can be overcome by careful attention to engine design and, above all,
through proper prcventative maintenance.
Why dp diesel engines have such at tractive^ fuel conjBumgticm
eha ra c t e r is t i cs?
The high compression ratios required by the diesel cycle result in
superior thermal efficiency, but the principal advantage results from
the fact that most diesel engines are not controlled in power output by
varying the position of a throttle valve as in conventional carbureted
spark ignited engines. The air charge is usually unthrottled and the
FS 34
-------
power output is controlled directly by the amount of fuel that Is
injected into the cylinder. For unthrc t,l:led diesels, the large pressure
drop which is characteristic of throttled engines at low power outputs
does not exist. This means that diesel fuel consumption characteristics,
while good at all operating conditions, are especially superior to
gasoline engines at low power conditions. This is the reason why
diesel-powered taxi cabs are so popular in Western Europe. Both gasoline
and diesel fuels cost a great deal more In European countries, so that
fuel economy considerations have been important to purchasers and
users of vehicles in those countries.
Why are diesel engines not used in United States manufactured automobiles?.
The advantages of diesels are offset by. the fact that diesel engines
cost more to manufacture because of the requirements for high compression
ratio and precision fuel injection systems. Diesel engines, in addition,
tend to be heavier and larger for the same, performance characteristics,
which means that for a given vehicle size and weight the acceleration
and overall driveability of the diesel is poorer than a gasoline powered
vehicle. Further, available diesel engines tend to be noisier and
"rougher" in their operating characteristics, and, in some instances,
difficult to start in cold weather. A more recently recognized problem
is that diesel engines, which can easily meet the carbon monoxide and
hydrocarbon emission standards, would require considerable development in
order' to meet extremely low nitrogen oxide emission standards required by
the Clean Air Act. These disadvantages of the diesel engine, combined
with the fact that fuel economy has, until recently, been of minor concern
to the auto buyer in this country, may explain the lack of attention given
to the diesel engine by domestic automakers who generally have said that
they do not believe that a sufficiently large market exists in the U.S.
for diesel powered cars to merit their production.
Could^ diesel, engines_be manufactured for passenger cars which would
offer all round acceptible performance?
A recent study sponsored by the EPA concluded that a diesel engine
could be designed to offer performance typical of a small American V-8
engine. It would cost about $100 more than a gasoline engine of the
same capability and would be about 150 pounds heavier. It would have
acceptable noise and driveability, 50% better fuel economy and would
meet the 1977 CO and HC emission standards. This engine could be
brought down to nitrogen oxide levels of approximately 1.0 g/mi. using
known technology. To meet the 0.4 g/mi. KO level required in 1978 by
the Clean Air Act would require research toxdevelop new technology for
reducing nitrogen oxide emissions without compromising the other-
attractive features which diesel engines offer.
OMEAPC/August 1976
-------
>
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
- WASHINGTON, D.C, 20460
Office of Air and Waste Management
OBJECTIONABLE ODORS FROM CATALYST-
EQUIPPED VEHICLES
The Environmental Protection Agency has received inquiries
from purchasers of catalyst-equipped cars regarding objectionable
odors being emitted from the exhaust under certain types of
operation. In particular, concern has been expressed about the
cause of a "rotten egg" odor, and about possible means of
eliminating that odor. This fact sheet has been prepared to
respond to such inquiries.
What is the objectionable exhaust odor?
Data available to EPA indicates that occurrence of the
"rotten egg" odor coincides with the formation of hydrogen
sulfide. Hydrogen sulfide can be formed in emission control
catalysts under certain vehicle operating conditions when not
enough oxygen is present in the vehicle's exhaust to react with
all of the combustible products. Although little is presently
known about the chemical reaction which produces hydrogen sulfide,
it appears that the gas oxidizes and disappears in a relatively
short time after it has been emitted into the atmosphere.
How is the odor produced?
Catalyst-equipped vehicles are designed to operate so
that unwanted pollutants in the exhaust are oxidized in the
presence of excess air to form carbon dioxide and water vapor.
Any engine maladjustment or operating condition which causes
insufficient oxygen in the exhaust gases leaving the engine and
entering the catalyst, can result in the sulfur in the exhaust
being converted by the catalyst to form small quantities of
hydrogen sulfide. For air pump equipped vehicles, malfunctions
causing inadequate supplementary air delivery at particular
operating conditions can have the same effect. The Information
available to the EPA indicates that the number of vehicles producing
such odors is relatively small.
FS-35
-------
—2—
What__can_^be^_dg_n_e to j3J.imin.ate the odor?
Since the odor is the result of insufficient excess air
in the exhaust mixture entering the catalyst, the cause can
conceivably be either an overrich air/fuel mixture going
into the engine or insufficient air pump delivery for those
vehicles equipped with air pumps. Both of these abnormalities
would be expected to raise emissions levels as well as to cause
odors. From the information available to EPA, it appears that
the greatest single cause of the "rotten egg" type odor is an
overrich idle air/fuel mixture setting. Dealers should be able
to eliminate the odors in most cases by making sure that carburetor
idle air/fuel mixtures are adjusted correctly, as well as that
no other source of excessive mixture richness exists, such as a
clogged air cleaner or sticking choke. In stubborn cases it may
be necessary to exchange the carburetor, or dismantle it and
check internal adjustments and clearances. If a dealer does
not have available the service instructions provided by the
manufacturers to deal with this type of problem, or if a dealer
claims that the odor can not be eliminated, the vehicle owner
should contact a higher level in the manufacturer's dealer
organization to insist that the problem be corrected. Another
approach for getting satisfaction is to write the manufacturer
for the Service Bulletin for the car in question and show this
Bulletin, to the dealer.
Do t_h_ese_^emissions_ pose a health problem?
At high concentrations, exposure to hydrogen sulfide represents
a serious health risk. However, hydrogen sulfide Is detectable
by its odor at levels far below those which have been found to
cause a health risk. With normal sulfur levels, hydrogen sulfide
concentrations, even in undiluted auto exhaust, would not be
expected to exceed the limits which have been set for continued
occupational exposure to this substance. Thus, while automotive
hydrogen sulfide emissions are objectionable because of their
odor, they are not currently anticipated to pose a health risk.
OMSAPC/February 1976
-------
? f* \ UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
*" "* ^ WASHINGTON. D.C. 20460
OFFICE OF
AIR AND WASTE MANAGEMENT
Mobile Source Air_PoIlution Control
FACT SHEET
LaPan Carburetor ("Gizmo")
The Environmental Protection Agency has received many inquiries
about a carburetor developed by LaPan Fuel Systems, Inc., of Fort
Wayne, Indiana, which reportedly will greatly increase gas mileage.
Our staff have invited LaPan officials to provide needed technical
data to our laboratory so that an evaluation of this device, and possible
confirmatory testing, could be undertaken by the EPA. LaPan in 1975
indicated they planned to continue their testing program at the Indiana
Institute of Technology and would perhaps contact EPA at a later date.
No such contacts have been made since then.
In the absence of technical data on the LaPan carburetor, the
EPA is hot in a position to comment substantively on the potential
merits of this device.
O^ISAPC/June 1977
FS-36
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
.po,^' WASHINGTON, n C. 20460
1
Emissions from Heavy j^ut^^rucks^^and Buses
The Environmental Protection Agency has received numerous inquiries
about whether emission control requirements apply to trucks and buses.
Most of these inquiries arise from public concern about visible smoke
emissions from diesel-powered vehicles. To respond efficiently to these
inquiries this Fact Sheet has been prepared.
Heavy duty engines used in trucks and buses have been subject to
Federal emission control requirements, including smoke limitation require-
ments, since the 1970 model year. Effective with the 1974 model year,
these requirements were made more stringent. Particularly as regards
smoke, there is no reason today for a well-maintained and properly operated
post-1970 model truck or bus to emit significant quantities of visible
smoke. The key phrase in the foregoing is "well maintained and properly
operated."
As regards maintenance, when an engine in a heavy duty vehicle is
not properly maintained, it is very likely that vehicle will emit visible
smoke. Common service or adjustment errors which cause high smoke are
failure to clean or replace a dirty air cleaner and "over-fuel" adjustment
of thfe fuel injection system. Both of these errors result in black smoke
caused by too much fuel for the available air for combustion. The black
smoke is composed of particles of unhurned carbon from the fuel. Thus,
excessive or prolonged black smoke is a sign of improper pollution control
and energy waste.
The driver of a properly adjusted and serviced truck can minimize
smoke by selecting the proper transmission gear to keep the engine operating
at most efficient speeds (which are usually midway between the torque peak
and rated speeds). Moderate truck start-up accelerations arid highway
cruising speed changes and reduced speed hill climbing will also minimize
smoke. Truck operating and servicing problems as described in the preceding
paragraphs can be improved by education.
In addition to emission control standards for the properly adjusted
diesel engine, that have already been imposed on trucks and buses, the
Environmental Protection Agency is at work on the development of new and
more valid emission test procedures, and on the evaluation of the feasibility
of more stringent emission control for heavy duty engines. EPA plans on
the basis of this work to propose even more stringent standards for heavy
duty engines than apply currently.
FS-37 OMSAPC/August 1976
-------
\ UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
"
WASHINGTON. D.C. 20460
OFFICE OF
AIR AND WASTE MANAGEMENT
FACT SHEET
EMISSIONS FROM HEAVY-DUTY TRUCKS AND BUSES
The Environmental Protection Agency has received numerous inquiries
about whether emission control requirements apply to trucks and buses.
Many of these inquiries arise from public concern about visable smoke
emissions from Diesel-powered vehicles. To respond to these, and other
inquiries concerning emissions of heavy-duty vehicles, this Fact Sheet
has been prepared.
Federal emission control requirements for engines used in heavy—duty
trucks and buses were first imposed in the 1970 model year. Since that
year the emission standards have been revised twice to stake them more
stringent, once applicable in 1974 and again for the 1979 model year.
The 1979 standards were based on the most stringent emission levels
believed to be achievable using best available non-catalyst emission
control technology. For gasoline-fueled engines, the 1979 emission
standards are estimated to represent approximately a 70 percent re-
duction of hydrocarbon (HC) emissions and a 50 percent reduction of
carbon monoxide (CO) emissions from uncontrolled levels, although
no decrease in oxides of nitrogen (KOx) emissions from uncontrolled
levels is required, Diesel engines inherently have low HC and CO
emissions (at or below the levels represented by the 1979 standards).
NOx emissions from these engines will be reduced by about 7 percent from
uncontrolled levels.
Smoke emissions from Diesel engines have been regulated since
1970. Smoke is composed primarily of unburned carbon particles from
the fuel which results when there is poor and excessive distribution of
fuel under heavy engine load conditions causing incomplete combustion
of a portion of the fuel. Thus, smoke emissions from Diesels are
usually observed under acceleration and engine lugging conditions.
Since smoke is created by unburned fuel it is a sign of both poor
pollution control and energy waste. If a post 1970 Diesel-powered truck
or bus is properly maintained and operated there is no reason for it to
emit objectionable quantities of smoke. The important factor for smoke
control is proper maintenance. Two common service adjustment errors can
FS-37
-------
-2-
resulc in high smoke emissions. They are 1) failure to clean or replace
a dirty air cleaner, and 2) over-adjustment of the fuel injection system
to allow more fuel to be injected under heavy power conditions than is
allowed or recommended by the service instructions. This latter adjust-
ment is often made by service mechanics in the belief that the engine
will develop more power. Both service errors result in an excess
amount of fuel being available for combustion, the condition that
causes smoke.
Vehicle operation can also affect the amount of smoke produced by
Diesel engines. Smoke emissions from properly adjusted and maintained
Diesels are minimized by selection of the proper transmission gear to
keep the engine operating at the most efficient speeds. Moderate vehicle
start-up accelerations and highway cruising speed changes, and reduced
speed for hill climbing, also minimize smoke emissions. The federal
government has no jurisdiction regarding improper vehicle operation;
assuring that vehicles are operated in a manner in which they do not
smoke is a responsibility of state and local jurisdictions.
EPA is currently working on several changes to the existing heavy-
duty vehicle emissions regulations* A new procedure for measuring exhaust
emissions of heavy-duty vehicles is under development to improve the
test's representativeness of in-u.se operation. The Agency is also working
on the establishment of more stringent exhaust emission standards
required by the Clean Air Act Amendments of 1977. The Act specifies
that beginning in the 1983 model year HC and CO emissions for heavy-duty
Diesel and gasoline engines must be reduced by 90 percent from the level
of emissions as measured from 1969 model year gasoline-fueled engines.
An oxides of nitrogen standard is required for the 1985 model year which
will represent a 75 percent reduction of emissions from 1973 model year
gasoline-fueled engines. Particulate emissions from heavy-duty engines
(mostly carbonaceous material) are also being studied, and it is expected
that a particulate standard'will be promulgated. Finally, the
Agency is developing a test procedure and emission standard for fuel
evaporative HC emissions from gasoline-powered heavy-duty vehicles.
OMSAPC 45581
-------
a
I UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
^
WASHINGTON, D.C. 20460
Pogue Carburetor
The Environmental Protection Agency has received a number
of inquiries about a device known as the Pogue Carburetor. The
inquiries suggest that the Pogue Carburetor Is capable of improving
the fuel economy of automobiles by five times or more, and that
the use of the carburetor has been suppressed by oil or auto
companies.
The EPA has not conducted an evaluation of the Pogue
Carburetor. EPA would be interested in making such an evaluation,
"but has been unable to identify anyone who claims to have the device
so that it could be evaluated.
Research into this matter carried out several years ago by
the Congressional Research Service indicates that from 1931-1936
several U.S. patents for carburetors were granted to Hr. Charles
M. Pogue of Winnipeg, Canada. No further information on the Pogue
carburetor is available. In the absence of being able to obtain
the Pogue Carburetor for evaluation, we are inclined to believe
that because of the significant competitive advantages that would
accrue to any auto manufacturers who could equip his vehicle with
a carburetor that provides such significant fuel economy improvement,
it is highly unlikely that a device that performs as the Pogue
Carburetor is claimed to perform, could—if it actually exists—be
successfully suppressed.
MSAPC/Harch 1975
FS-38
-------
&*\
' ™ UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
1 WASHINGTON. D.C. 20460
Fuel Economy, Emissions, and Safety of Small & ;Large.Carg
In response to many questions that have been received on the
emissions, safety, and fuel economy aspect! of Che large vs. snail
car issue, the Environmental Protection Agency and the National
Highway traffic Safety Administration of the Department of fransportatIon
have Jointly prepared this Fact Sheet.
1» Howdoes vehicle size affect fuel economy?
Large cars weigh more and have larger frontal areas than small
cars. This leans it takes more energy (i.e., fuel) to drive a large
car than a small car, because of greater inertia, aerodynamic, and
rolling friction drag.
Vehicle weight and performance are two of the most Important
design factors influencing automotive fuel economy. Weight, while
increasing fuel consumption, is a factor in the direction of occupant
safety in accidents. The effects of vehicle weight and performance
are most important in stop and go driving typical of city driving
conditions. Each 100 pounds of added weight decreases a vehicle's
fuel economy by 1 to 2 percent. 1975 models in the 2,500-pound
inertia weight class (typical for subcompact cars) averaged 24.7 ndles
per gallon on the composite IF A fuel economy test which simulates
city and highway driving. This is about twice the 12.9 miles per
gallon average of cars in the 5,000-pound class. (Standard size
domestic autos fall in the 4,500 and 5,000-pound inertia weight classes.)
However, about 15 percent of this difference can be attributed to the
higher performance level of the large cars which are not operating in
an efficient mode in city traffic.
Unlike vehicle weight, which is significant in all types of
driving, aerodynamic drag is significant mainly at highway speeds.
Drag Is a function not only of vehicle speed but also vehicle shape
and frontal area. Since heavy cars usually have larger frontal areas
than small cars, they experience greater aerodynamic drag and require
more fuel to maintain a steady cruise than smaller vehicles. Rolling
friction drag is important at all speeds and depends on roadway,
weight, tires, and driveline components.
FS-39
-------
- 2 -
2, What other factors influence fuel economy?
Fuel economy is also Influenced by a large number of factors,
including driving habits, road and traffic conditions, weather,
the use of power accessories, and type of emission control systems.
Driving in heavy city traffic, compared to normal freeway
driving, can reduce fuel economy by 45 percent. Rapid accelerations
as opposed to moderate ones can reduce fuel economy by 30 percent.
Short trips made from a cold start reduce fuel economy significantly.
According to one manufacturer's test results, a car which has a
warmed-up fuel economy of 13.5 mpg got only about 10 aspg on a 5-mile
cold start trip, 7 mpg on a 2-mile trip, and 5 mpg on a 1-mile cold
start trip, all under summer driving conditions. In the winter,
cold start fuel economy is poorer than in the sunnier, due to the
longer warm-up requirement.
Power accessories and convenience options also reduce fuel
economy. The fuel economy penalty for the constant use of air
conditioners averages 6 percent; the actual penalty depends upon
air-conditioner design, temperature, and driving conditions, and
may reach 20 percent at lower speeds. Automatic transmissions
transmit power less efficiently than manual transmissions and result
in a 2-15 percent loss in fuel economy, depending upon the efficiency
of their design.
The major factors influencing automobile fuel economy are
compared below:
Fuejjconomy Loss . .
Added weight to meet safety standards 2 to 5 %
Emission control (1974 models) 0 to 18 %
Air conditioner (when in constant use) 6 to 20%
Air conditioner (normal usage) 2 to 10%
Automatic transmission 2 to 15%
Type of driving (city vs. highway) 25 to 45%
Vehicle weight 1 to 2% per 100 pounds
-------
- 3 -
3. How do emission controls affect fuel egongmyj?
Emission control standards that have applied to all cars
since the 1968 year have brought about significant changes in
engine and vehicle design. These changes have included extensive
redesign of the combustion chambers, compression ratio, valve
timing, and fuel and ignition systems, as well as the installation
of additional specific emission control devices such as.air pumps,
EGR valves, and complicated interrelated switches, solenoid, and
modulating devices. In addition, a. complete evaporative control
syatem has Tbeen added, . •
The results of this redesign have been a substantial reduction
in the emission of air pollutants from those cars-, as- well as
changes in vehicle performance, Including fuel economy* While
heavy cars through the 1974 model year (4P000 pounds and higher)
deteriorated in fuel economy from uncontrolled cars by 14 to
21 percent, lighter cars (under 4,000 pounds) have shown smaller
penalties for the reasons described below. Most of these fuel
economy losses, however, were repaired in the 1975 model year because
of improvements in emission control technology.
Since nitrogen oxide (NOx) and carbon monoxide (CO) emissions
are to some degree a function of engine size and the emission
standards are the same for all cars, these emissions have been
somewhat-ssore easily controlled from small cars than fron large
ones. The need to use more exhaust recireulation and spark retard
on the larger cars to control these emissions has been largely
responsible for the proportionally greater fuel economy losses due
to emission controls on those cars. The sales weighted average loss
in fuel economy .has been 10.1 -percent for 1973 'and. 12.4 percent
for 1974 cars compared to uncontrolled cars.
4. Hov_dp_es vehicle size affect emissions!
Since 1970, the Federal Government has applied the same
emission standards to all cars regardless of vehicle weight. Hence, '•
no relationship between emissions and weight is evident on models to
which these emission standards-apply, A study of 600 pre-emission
control vehicles covering the years 1957-67, however, shows that a
direct relationship between vehicle weight and emissions of carbon
monoxide (CO) and oxides of nitrogen (NOx), whereas, mo such
relationship between hydrocarbon (HC) emission levels and weight
was apparent.
-------
The concentrations of CO and NOx found In auto exhaust on
pre-emlsslon controlled vehicles depended principally on engine
air/fuel ratio and combustion temperature. These parameters did
not vary in any consistent way with weight. The Increased emissions
of these pollutants in large cars was due to the greater exhaust
volume of larger, heavier cars.
Hydrocarbon emission, on the other hand, was largely due to
the quenching of the combustion processes on the walls of the
cylinder, which Is related to the surface-to-volurae ratio inside
the cylinder. Since small engines have higher surface-to-volume
ratios than larger ones, the smaller exhaust volume of smaller
cars was offset by the higher concentration of hydrocarbons, and
therefore no pattern of emissions as a function of car size was
found.
5. How much of the increase in the w_eight_pf cars over the
past^ several years^ ^s due to vehicle modifications to
meet Federal Standards?
The weight added for emission control systems is estimated
to be less than 25 pounds. Weight added to meet safety standards
varies according to the size of the vehicle hut averages about 250
pounds.
Passenger cars in all market classes have shown a steady
Increase in weight over the past 15 years. The intermediate car
(i.e., Chevrolet Chevelle, Ford Torino) of 1975 weighs, on the
average, about the same as the standard size car (i.e. Chevrolet
Impala, Ford Galaxie) of 1962, an increase of 800 pounds. Similarly,
the compact car of 1975 has increased in weight by 700 pounds on the
average and weighs the same as the intermediate car of 1962. The
standard car has Increased by 500 pounds on the average in the same
time period, although the Increase in some models has been douhle
that.
The increase in weight due to meeting emission control and
safety standards thus represents less than half of the increase in
weight in the past 15 years. Increases In vehicle size and more
accessories accounted for most of the increases in weight. U.S.
autos increased an average of 8 Inches in length in the last 10
years. The use of air conditioners has grown from 10 percent in
1962 to 70 percent in 1972.
-------
- 5 -
6. How doea vehicle size affect safety?
Two factors Involved In reducing occupant injury In automobile
accidents which place small cars at a disadvantage relative to large
cars. These are vehicle weight and the distance between the
occupants and the vehicle*! exterior required to control crash
forces. .
In the head-on collision of two Vehicles of unequal weights,
the lighter vehicle will he subject to a greater change In Its
velocity, subjecting Its occupants to greater forces than the
occupant of the heavier car*
Distance is required to control crash forces and slow the
occupants from the speed of the moving vehicle to a complete stop.
This distance Includes the Interior as well as exterior dimensions
of the vehicles. In head-on collisions, this distance is composed
of the exterior bumper to firewall distance and of the interior
oeeupanta to dashboard distance. In a typical standard size car,
this distance totals about 78 inches (60 inches exterior, 18 inches
Interior). This compares with 52 inches in the typical subcompact.
The lesser distance in the subcompact limits the level of protection
which can be provided. In these ways, a large car has Inherent safety
advantages over small cars.
7. What other factors affect occupant safety?
Among the other factors, the most significant is the restraint
system «sed» Safety belts reduce the chance of being killed In a
crash by about 30 percent for lap belt only or by about 50 percent
for 'lap and shoulder belt use. .
Vehicle speeds also have a significant effect on occupant
safety. One recent study estimated that with respect to vehicle
occupant death rates, the positive effect of lowering speed limits
to 55 mph would offset an average reduction in vehicle weight of
about 400 pounds.
The other factors which significantly affect occupant safety
ares (1) the driver's knowledge, experience, ability, and attitude;
and (2) the driving environment, which includes the design of the
highway, weather conditions, and other factors.
-------
- 6 -
8, Can _ca_rs b_e__safie>_have low emissions, and get good fuel
economy all at the same time?
Yes, but they will probably cost more. According to a recent
report submitted to Congress by DOT and EPA, weight reduction of
500 pounds on standard size automobiles of 4,500 pounds can be
achieved. Coupled with design changes and improved restraint systems,
it is possible to build lighter vehicles that are safer than today*i
larger cars. The city fuel economy Improvement due to such weight
reduction would be about B percent. Since CO and NOx increase with
vehicle weight, control of theie pollutants from lighter weight cars
would be easier.
It will take time to produce such cars. Within 10 years,
however, efficiency Improvements In conventional engines and other
technological changes could produce new cars having fuel economy
almost 50 percent greater than those of today. The result would
be safer, leas polluting, and fuel efficient cars. It will be a
challenge to industry to produce such cars at a reasonable price.
EPA/DOT June 2, 1975
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
Emissions and Fuel Economy Characteristics of the Honda CVCC Engine
The Environmental Protection Agency has received many requests
for information concerning the future promise of the Honda CVCC
stratified charge engine for meeting stringent emission standards
with good fuel economy. Some of these Inquiries have been stimulated
by a recent article appearing in the Reader's Pigest magazine. This
fact sheet has been prepared to respond to such inquiries.
1. How does the Honda Compound Vortex Control Combustion (CVCC)
differ from_ordinary automobile engines?
The basic combustion chamber of a conventional engine is augmented
in the CVCC engine by the addition of a small prechamber into which is
introduced a rich air/fuel mixture delivered by a special small carburetor
through an auxiliary intake valve. The spark plug ignites the mixture
in this prechamber. The burning mixture then expands through an opening
into the main combustion chamber where it acts as a torch to ignite
a very lean air/fuel mixture delivered through the standard carburetor
and intake valve. By this means, mixtures which are too lean for reliable
ignition in conventional engines can be burned. The excess air in
a lean mixture provides more oxygen. This helps to achieve more
complete combustion of the fuel and thereby reduces carbon monoxide
and hydrocarbon pollutants. The lean mixture also results in a lower
peak combustion chamber temperature. This in turn reduces nitrogen
oxide formation.
An engine in which the air/fuel mixture ratio is not uniform but
varies from rich to lean in the two parts of the combustion chamber,
is referred to as a "stratified charge" engine. There are a number
of different types of stratified charge engines which have been considered
for use in automobiles, but the Honda CVCC is the first to reach
production status.
2. What are the pollutant emissions and fuel economy characteristics
of the CVCC engine? '
The CVCC engine is currently meeting the 1975 California standards
of 0.9 grams per mile for hydrocarbons (HC, 9 grams per mile for carbon
monoxide (CO), and 2 grams per mile for nitrogen oxides (NOx), withouc
a catalyst. It has been tested successfully through 50,000 miles at the
FS-40
-------
- 2 -
.statutory HC and CO levels of .41 and 3.4 grams ,per mile respectively.
A fuel economy penalty -of 10% -was introduced "by achieving these more . -
stringent standards. In these tests NOx was well below, the 2.0 grams
per mile level presently required by 'the"State of California. This
specific capability applies only to the approximately 2000 Ib. weight
vehicles which this, manufacturer markets.
However, in late 1973 the EPA tested a larger (5000 Ib.) 1973
inode'l Chevrolet Impala' which had been converted to the CVCC configuration
by the Honda laboratory. Results at 3000 miles showed that the 0.4
g/mile HC and 3.4 g/mile CO standard were met, while the NOx level
was slightly below 2.0 g/mile. Fuel economy was equivalent or
slightly better than stock vehicles powered by the same basic engine.
Honda has also reported to EPA on tests which demonstrated the
capability to meet the 0.4 gram per mile statutory NOx standard on a
2000 Ib. vehicle, but to do'this a fuel economy penalty of about 251
was incuredi because of the large amount .of exhaust gas recirculation
and ignition timing retard which ia needed,
United States manufacturers investigating the Honda system for
application to larger vehicles have reported test results-to EPA,
showing HC and CO levels below .41 and" 3".4 grams per mile, but NOx
levels ranged between 1.5 and 2.0 grams per mile.
Therefore, available information at this time confirms that
the Honda system has the excellent- emission control potential described .
by the recent Reader's Digest article, but'does not offer equally
excellent fuel economy at the nitrogen oxidt emissions level required
by the Clean Air Act in 1978.
'3- What is the cost of the CVCC system compared to other
emissioncontrol approaches?
Increased customer costs based on National Academy of Sciences
estimates, are about $210 for a hypothetical 6 cylinder engine in
an Intermediate size vehicle equipped with the CVCC engine. By
comparison, the increased customer cost for a comparable vehicle
equipped with a conventional engine and a catalyst is about $167.
fhase cost increases are compared to a,1970 model as. a baseline.
4. Will the CVCC type of engine bejised.by U.S. .automakera? , •
The U.S. automakers are actively investigating stratified
charge engines with varying degrees of intensity but are not expected
to seriously consider their use until the current uncertainty about
-------
3 -
level of emission requirements for the longer-term future, and especially
the required emission control of oxides of nitrogen, is resolved.
5. Can conventional engines in existing vehicles be converted
to CVCC?
This type of conversion has been done for research purposes
by both U.S. automakers and by Honda, in experimental programs.
The conversion involves a new cylinder head with provisions for the
extra valve, new intake and exhaust manifolds, new carburetors, and
a new camshaft to provide for opening and closing the extra valve.
This conversion is much too complicated and expensive to be a practical
method of reducing emissions from older vehicles.
MSAPC/April 1975
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
Health Hazards Associated With 1975 Catalyst
Equipped Gars Operating In Confined Areas
Many 1975 automobiles are equipped with catalytic converters
which serve as a primary means .for reducing emissions of air pollutants
from the cars. - The Environmental Protection -Agency has received
inquiries concerning possible symptoms of illness in mechanics
and other -shop personnel operating -such cars inside shop areas. This
Fact Sheet has been prepared to respond efficiently to such inquiries.
1 . C_an^aut.o_ exhaust ' make roechanj.es.. .sick?
The danger of auto exhaust in inclosed, .poorly ventilated areas
has long been recognized. The danger has been associated primarily
with carbon monoxide (CO) concentration, although lead compounds which
are also emitted by non-catalyst vehicles using leaded gasoline, can
damage health in sufficient concentrations,
The catalytic converter greatly reduces the emissions of CO. Lead
compounds are not emitted by catalyst equipped 'vehicles because they •
roust use laad free gasoline to 'avoid ralMng"-fche -catalyst. However,
catalyst equipped, vehicles do emit more sulfuric acid (H^SO^) and hydro-
gen sulficle (l-^S) than non-catalyst vehicles, 'The ^SO^arises • from
the oxidation of some of the small amount of sulfur in gasoline, to
sulfur trioxlde (803) , and the combination of the SGj with the water
vapor present in the exhaust. Hydrogen sulfide is formed when there
is insufficient oxygen in the exhaust entering the converter. This is
an abnormal situation caused by an overly rich mixture (too much
gasoline added to the intake air in the carburetor) .
Sulfuric acid in sufficient concentrations can irritate the nose,
throat and lungs and with prolonged inhalation can cause severe
lung damage. Hydrogen sulfide has a disagreeable odor, similar
to rotten eggs, which is detectable at very low concentrations.
However, at concentrations much higher than the threshold of odor
detectabillty, 1US has serious adverse health effects. It is
important to point out that human beings "adapt" to the l^S odor
as concentrations rise, so that the first detection of odor should
be followed immediately with some form of corrective action.
2 . Are the concentrations of CO, lead^gmpounds, thSO/ and
existing inside shop; areas high enough to cause _concern?
In brief summary terms, any shop that maintains safe levels
of carbon monoxide will automatically have far lower than safe
•levels of other pollutants,
-------
- 2 -
The Occupational Safety and Health Administration (OSHA), Depart-
ment of Labor, who have the basic federal responsibility for investigat-
ing and controlling these kinds c£ hazards, has promulgated standards(l)
governing the maximum exposure to various chemicals in occupational
situations. Hie standards of interest are:
Chemical Concentration Limit Ayeraging Time
Carbon monoxide 55 reg/m . 8 hours
Lead compounds 0.2 mg/m 8 hours
*>
Sulfuric acid 1 mg/m 8 hours
*>
Hydrogen sulfide 27 mg/m . . 8 hours
o
68 mg/m 10 minute maximum,
once only
An out-of-adjustment, idling, 1975 automobile engine could emit these
pollutants in the following concentrations, as measured at -the tailpipe
exit: (2)
Chemical Concentration Minimum dilution Comments
needed to -bring
to QSHA standard
Carbon monoxide 33,000 mg/m3 600/1
Lead compounds 58 rag/m^ 290/1 3 gm lead
per gallon
of gasoline
Sulfuric acid 3 mg/m 10/1 catalyst equipped
vehicle with
air pump
3
Hydrogen sulfide 0.0015 mg/m none threshold odor
detection level
(1) Federal Register, Vol. 39, No. 125, June 27, 1974, page 23540,
"Occupational Health and Environmental Control".
(2) It should be recognized that the same engine would not produce
all pollutants at these levels at the same time. For example,
the H2.S and CO emissions result from overrich air/fuel mixtures
while sulfuric acid emissions occur under lean mixture
conditions. Lead emissions occur only when leaded gasoline is
used. Catalyst equipped automobiles must use unleaded fuel.
-------
.Need for Warning Devices for.Catalyst Overtemperature
Remarks of
Eric 0. Stork
Deputy Assistant Administrator
for Mobile Source Air Pollution Control
U.S. Environmental Protection Agency
Washington, D.C,
at
1975 Automotive Electronics Conference
Cobo Hall
Detroit, Michigan
.June 10, 1975
Mr. Stork served as luncheon speaker on the opening day of the 1975 Automotive
Electronics Conference. He spoke extemporaneously on the status of Federal
requirements relating to emission controls and fuel economy. No transcript
of his extemporaneous remarks is available. However, Mr. Stork concluded
his remarks with the following prepared text on the issue of warning devices
for catalyst overtemperatures.
FS-42
June 1975
-------
Proposing a new standard—establishing a regulation—is the way
in which the government normally deals with possible problems. But
establishing a regulation is a long and tedious process—it takes a lot
of time—and when the regulation is finally on the books it by its own very
existence creates new problems, for regulations tend to be inflexible and
they are hard to change.
'It would be much better if it were possible to deal with emerging
problems without always having the EPA or whatever agency of government
pass a new regulation. I think that this not only should be possible, but
also that it is possible—but only if the industry that would otherwise
be subjected to a new law or regulation is sufficiently forward looking so
as to voluntarily take reasonable action to protect against a possible hazard
from its product.
There is growing concern about the fact that under certain operating
conditions like long periods of idling, and certainly if the engine has a
couple of fouled spark plugs, catalysts get very hot. While the auto
industry seems to have done a good job of designing their catalytic systems
to function properly under normal operating conditions, no one can deny that
in certain failure modes catalysts can get very, very hot—as hot aa 1200
degrees F. or more. That kind of heat is of course enough to start
fires in combustible materials near the hot catalyst—materials in the car
itself—or near the car, like dry grass. Just last week, I understand, an
official of Los Angeles county put -on a demonstration for the press in which
he showed how an idling catalyst car can get hot enough to set dry grass
on fire, and how with a couple of plugs disconnected the catalyst glowed
cherry red. The Forest Service is much concern about this phenomenon—we
-------
2
are working with them to evaluate this potential problem. Some refineries
are reported to have banned catalyst cars from certain refinery areas. I know
that much of what has so, far been said, and published about this problem is
probably greatly exaggerated—there have been relatively few reports of
catalyst-induced fire—but the increased potential of a problem cannot be
denied.
What to do about it? Well, it seems to us that one of the most important
things to do is to warn the driver of the car if his catalyst is getting too
hot, so that he can take appropriate action to avoid risk of a fire. While some
may argue that drivers will ignore such warnings, I don't buy that point of view.
Sure, some people ace irresponsible, and always will be—some people drive
while drunk, or speed through a school zone—but most people are responsible
and try to do whatSs right if only they are given adequate information.
It seems to me that the auto companies should—as promptly as possible-
provide to a vehicle driver an adequate warning of catalyst overheating.
That would not be a tought technical problem. All it would require is a
temperature sensor on or near the catalyst, and something like a flashing
light or a buzzer on the dashboard that unmistakably alerts the driver to
an overheated catalyst. The technology for doing that is simple compared
to the complex technologies with which this group here Is dealing today—•
it is available and it can work. It needs only to be used.
How does this relate to what I Just said about regulations? Well, of
course one way of making sure that the driver of a catalyst car is given
adequate warning of possible hazard is for the EPA to issue a new regulation.
But another way, and I think a better way, is for the auto industry to not
-------
3.
watt for the ponderous regulation making process, but to go ahead on its
own—at least as a first step^—and do what quite clearly should be done.
I know that you have leadtime problems in implementing such a sensor and
warning device—and I do not presume to suggest that it would be easy for you to
do that on 1976 model cars which will soon come off the assembly lines. But
I cannot believe that it would be impossible to do this promptly—if not with
Job One then a few weeks later. I am always impressed by the difference
in leadtime requirements for something that the EPA might want to see done and
for some product improvement that the companies decide hy themselves they
want to Install. Our work with industry for quite a few years now has
made that difference quite clear to us.
So 1 hope that when you go back to your companies from this
meeting—or perhaps even by telephone before you get back—you suggest
to your companies that they take seriously the concerns about fire hazards
from catalysts that are increasingly being expressed by responsible public
officials and others, and that you do whatever is possible to reduce the
potential catalyst overheating problem without waiting to be required to do so
by a new regulation. Maybe such voluntary action would set a new trend—a
trend in which there may be less need to have the government spell out to
the auto industry each and every socially necessary requirement.
-------
„ *«
<•<>*
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
The Clean Air Coalition "Clean Air Car"
The National Clean Air Coalition (NCAC), a non-profit environ-
mental organization, contacted the Environmental Protection Agency
about a prototype emission control system they had developed and
had operating on a 1974 lord Pinto• The system was aimed at emission
levels of .41 grams per mile hydrocarbons (HC), 3.4 grams per mile
carbon monoxide (CO), and .4 grams per mile oxides of nitrogen (NOx),
Confirmatory testing at the EPA laboratory was requested by the
developers of the car, and conducted by EPA as part of its continual
technology assessment function. The average result of 2 tests at
the EPA lab was 0.28 HC, 2.20 CO, and 0.35 NOx.
Subsequent to these tests, misleading statementa appeared in
the press which are alleged to be conclusions drawn from EPA data.
This Fact Sheet has been prepared to answer questions regarding those
statements. Several statements attributed to NCAC and EPA's comments
follow:
1. Technology is already here to meet the J.JJ8 s^tandards and
to protect public health.
The control aystern used on the NCAC Pinto includes an early model
reduction catalyst produced by Gould Inc. This type of catalyst
has experienced poor durability to date. Since the NCAC vehicle when
tested by EPA had accumulated only 7,000 miles, the durability of
the system was not adequately demonstrated by the NCAC test program.
While Gould has improved the reduction catalyst design with the
result that durability now shows promise in prototype tests of up to
about 25,000 miles, there are unresolved questions regarding the
emission of nickel and other unregulated emissions from dual catalyst
systems. Only when the durability problems and other questions about
the dual catalyst are resolved, and the prototype design translated
into production hardware (a process that takes-at least two years)
can dual catalysts be considered to be available for use. Dual
catalyst control technology may thus be practical by 1979 or 1980,
if work on It continues and la successful.
FS-43
-------
2. Testa conducted by the EPA showed that the dual catalyst
Pinto met the statutory 1978 emission standardawith a
gain in fuel economy over a 1975 Pinto. This would result
in a consumer savings of $330 in gasoline costs over a
100,000 roile useful life of the vehicle.
The above statement is misleading because the cars being
compared are not the same. The 1975 Pinto was tested In the 3000
pound weight class, whereas the 1974 Pinto Is In the 2750 pound class,
The 1975 Pinto also has a larger engine than the 1974 model. A
comparison of the NCAC Pinto with the standard 1974 model shows
that a fuel economy loss of 15% was incurred, not a gain as reported
by NCAC,
3. A dual catalystsystem would mean^a$jO increase in
the sti eker price over the 1975 mode1.
The cost increment of dual catalyst systems has been estimated
by EPA, the National Academy of Sciences, and the auto manufacturers
at approximately S250.
MSAPC/July 1975
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
SUBJECT: Validity of EPA Highway Fuel Economy Data DATE:
FROM: Eric 0, Stork, Deputy Assistant Administrator
for Mobile Source Air Pollution Control (AW-455)
'I'D: Roger Strelow, Assistant Administrator
for Air and Waste Management (AW-443)
ISSUE . ' •
There has been public criticism that the fuel economy numbers
EPA has published for automobiles in the 1975 model year are
unrealistically high. , Questions have been raised mostly about
highway fuel economy. This memorandum provides recent test data
from EPA and others which indicate that EPA-published mileage
figures can be achieved and even surpassed in actual road driving.
SUMMARY. :
The limited data available tend to refute the claim that EPA
highway fuel economy values are not achievable in actual driving
conditions. .The probable reasons for some individual consumers -not
achieving EPA-published fuel economy values are differences among
driver habits, and driving at speeds higher than those used in the
EPA fuel economy test program. Also, the inclusion of even very
limited city driving or a cold start can significantly lower the
highway trip type fuel economy computations on the basis of one tank
of fuel .
DISCUSSION
EPA has consistently pointed out that the fuel economy numbers
it publishes can never match precisely what each consumer will get
becsuse of differences in driving patterns and habits, and that the
EPA numbers are intended primarily to allow a purchsser to compare
the relative fuel economy of many different cars. Critics have
responded that comparative validity is insufficient, that they want
to know exactly what the car will get, and that EPA is not telling
them.
Some data have recently become available which indicate that the
EPA dynamometer test for highway driving gives results that can be
obtained on. the road, and thus that the driving cycle used for highway
fuel economy is representative of fuel economy which- can be achieved
if consumers stay within the 55 mph speed limit.
FS-45
EPA K>™ 1320-4 (Rsv. 4-72)
-------
-2-
a. EPA Tests
This month EPA completed testing 6 cars on the dynamometer, on a test
track, and on the open road. The.results were as follows:
Prototype Same Production1 Car
Car
Mileage Guide Dynamometer test Track Test Road Tesl
Ford Granada 18 19 17 19
Pontiac Firebird 21 25 24. 25
Chevrolet Chevelle 18 19 18 19
Ford Pinto 26 28 26 " 27
Lincoln Continental .15 16 16 16
Volkswagen Rabbit 38 35 34 38 •
The results of the road, track, and dynamometer tests are essentially
similar. The mileage guide figures, of course, are only generally
applicable to the cars tested in this 6-car program because they represent
the average of automatic and manual transmissions, different axle ratios,
and different weights. Yet the average numbers published in the guide-
were quite similar to the actual results on those particular cars.
b. Volkswagen Tests
Volkswagen sponsored a test in January, 1975 of 21 vehicles,—all
Sciroccos and Rabbits—on 42 miles of Florida highways. All drivers were
local Journalists. The average mileage for all cars was 40 miles per
gallon, which is two miles per gallon higher than the EPA Mileage Guide
figure of 38 miles per gallon, The average speed used in the test program
is not known.
»
c, Ford Mptpr Coinpany Tests
The Ford Motor Company ran a series of tests in a number of cities,
similar to the Volkswagen test, to publicize the fuel economy of Ford's
new UPC cars. Only the results from tests conducted in Beltsvllle, Md.
last month have so far been provided to EPA by Ford. In that test program,
4 essentially identical cars with manual transmissions were driven by a
total of 32 local journalists. The EPA highway fuel economy estimate for
the manual transmission car is 34 inpg; the results of the tests ranged from
26 to 38, and averaged 34. It must be noted that the cars were driven as
nearly as possible at a steady speed of 40 mph. The average speed in the
EPA highway fuel economy test is 48 mph but includes speeds as low as 28
and as high as 59, with transients in the driving cycle that make the EPA
test other than steady speed. The Ford results thus are not directly
comparable to the EPA-predicted performance of these vehicles, but do
suggest a general similarity of EPA results and road results.
-------
-3-
d. WWJ-TV Tests
WWJ-TV in Detroit is in the midst of a test program in Detroit to
test various dealer showroom vehicles on Detroit streets and publish
average fuel economy figures for those vehicles. Each car was tested
three times on a 60-mile test route on Detroit freeways, secondary roads,
and two-lane streets. Of the thirteen cars tested so far, three are
reported to have obtained the same average fuel economy as the harmonic
average of EPA's city and highway fuel economy estimates for the car,
eight obtained results within one to three miles per gallon above^ the EPA
city and highway average, and one car obtained one mile per gallon below
the EPA city and highway average. The thirteenth car, a Dodge Colt with
a 5-speed manual transmission, got nine miles per gallon better than the
harmonic average of the EPA-published city and highway number; however,
the car was driven in fifth gear (overdrive) much of the time which could
increase fuel economy significantly over EPA results. While WWJ-TV test
results indicate that a different pattern of driving may yield higher
average fuel economy numbers than those measured by EPA, these results are
also generally consistent with EPA's estimates.
ANALYSIS
From the limited data presently available, it appears that the EPA
mileage guide fuel economy estimates are valid and achievable. The
Volkswagen data seem to confirm what EPA has all along tried to point out,
i.e. that there can be significant variation in fuel economy results as a
function of individual driver habits, as well as that there can be
differences in fuel economy results among nominally identical cars. The 21
cars in the Volkswagen test program were all driven on the same test -
route with the same instructions given to all drivers, and the
results ranged from 28 to 49 miles per gallon. The "Ford Beltsville
data suggest even more strongly that differences in driver habits are
important. Ford used only 4 cars, each of which was driven 6 to 9
times, each time by a different driver. On one car the results of 7
tests ranged from 27 to 35 mpg; on another car, the results of 9 tests
ranged from 26 to 37 mpg. In the other two cases, the differences in
results were 2 and 4 mpg, respectively.
The effect of highway speed on fuel economy Is extremely important.
EPA tested the cars in, its road test program at different speeds to
determine the sensitivity of fuel economy to speed variations. The
Volkswagen Rabbit got 46 miles per gallon at 30 miles per hour, 39 mpg
at 45, 33 mpg at 55, 25 mpg at 70, and 22 mpg at 80 miles per hour. The
drop in fuel economy of the Rabbit between 55 and 70 mph was 24%. While
heavier cars have poorer fuel economy at all speeds, the change in fuel
-------
-4-
economy at different highway speeds Is much less pronounced for large
cars than for smaller cars. In comparsion to the 24% drop for the
Rabbit (from 33 to 25 raph), the fuel economy of the much bigger
Chevrolet Chevelle dropped only 11% from 55 to 70 mph (from, 18 to 16 mph)
More study would be needed to determine precisely why there is a
proportionally greater drop in the fuel economy of small cars as highway
speeds are Increased. In part this may be due to the fact that
aerodynamic drag does not vary in direct proportion with weight, for the
frontal area of a 2500 Ib". car is more than half of the the frontal area
of a 5000 Ib. car; and in some part because most smaller cars have-a
lower power to weight ratio than do larger cars, which means that at
higher speeds the smaller cars are operating in the less fuel efficient
power-enrichment range of their carburetor calibrations, whereas larger
cars do not get into this less fuel-efficient carburetor range until
substantially higher speeds are achievedi
This phenomenon may explain why complaints about high EPA highway
numbers were particularly severe from owners of small cars; they
probably were driving their cars on interstate highways at speeds higher
than the 55 mph national speed limit.
Another factor of potential importance to the'fuel economy
experienced by ordinary drivers in what they may generally consider
to be highway driving is that in most cases people really do not do
only warmed-up highway driving between fill-ups. The ordinary driver
has no way of calculating his fuel economy except by dividing his
total mileage by the total gallons consumed. Even if he is careful
to have his gas tanked topped-up before he starts his trip, and topped-
up at the end of his trip, he is likely to include at least some city
driving in his overall trip, and likely to include aC least one cold
start In his total trip. The significantly lower fuel economy of city
driving, and of cold starts, will tend to reduce the calculated fuel
economy for the total trip. For example, one cold start and 20 miles
of city driving In a 100-mile total trip in a Volkswagen Rabbit, which
EPA estimates at 24 mpg in city driving and 38 mpg in the highway, would
reduce the overall fuel economy for the 100 mile trip to 34 tnpg; such a
combination of city and highway driving is quite common in inter-city
driving (e.g., Washington to Philadelphia), in which it takes a cold
start and some city driving to get out of town, and some city driving
to get to one's final destination.
-------
^E
; fc» «j
? UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
^ WASHINGTON. D.C. 20460
Fact Sheet
Future Emission Standards
On September 3, 1975, most daily newspapers in the U.S, carried
a full-page advertisement entitled "You'll be paying the bill, so
let Congress know your choice." The ad was sponsored by the four
major- U.S. automakers, and discussed a revision of the Clean Air Act
that is currently being considered by the Congress. The ad urged
readers to write to their Senators and Representatives on this issue.
The U.S. Environmental Protection Agency has received many
inquiries about this advertisement. To respond efficiently to
these inquiries, this Fact Sheet has been prepared.
Background .
To fully evaluate this extremely complex and important Issue
some additional background is needed.
In 1970 the Congress amended the Clean Air Act. Among the
changes in that law made at that time was a requirement that by the
1975 model year newly-produced automobiles meet very stringent emission
standards for the three major automotive pollutants — unburned
hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NOx).
The emission of these pollutants from the tailpipes, of automobiles
contributes significantly to polluted air in our cities where most
Americans live. Polluted air is harmful to health, damages materials,
and reduces visibility. Last year the National Academy of Sciences,
in a report to the Congress, estimated that automotive air pollution
each year causes 4,000 premature deaths, and 4,000,000 hospital days.
As a safety valve against the possibility that the auto Industry
might not be able to meet the schedule of emission reductions required
by the 1970 amendments to the Clean Air Act the Congress authorized
the Administrator of the EPA to grant a limited number of one-year
extensions of the deadline for meeting the statutory emission
standards. As a result of applications for such extensions by the
auto industry three such extensions have been granted. Current law
provides no further authority for extensions of the deadline.
Thus, unless current law is changed, the statutory emission standards
will go into effect with the 1978 model year.
FS-46
-------
_ 2 —
Since the 1970 amendments were enacted there has been much
additional study of these issues. These studies have confirmed
the need for the stringent control of HC and CO that Is called
for by the law, but have raised some question about the need for
extremely stringent control of NOx from automobiles. Over two
years ago the EPA recommended to the Congress that the statutory
NOx standard be substantially eased because the data on which
that standard had been based had been found to be of questionable
accuracy and because more study was needed to resolve these
issues.
In addition, more recently it has become apparent that
there Is a possibility that the principal emission control
technique so far used by the auto Industry to control the emissions
of HC and CO has the potential of causing other health hazards.
The catalyst accelerates the conversion of the small amounts of
sulfur dioxide that has always come from the tailpipes of cars to
sulfur trioxide which, when mixed with water vapor in the exhaust,
is emitted as sulfuric acid. Whether or not these extremely low
levels of sulfuric acid emissions will ever turn out to be a real
health hazard is yet to be determined; however, because of concern
about this possibility the Administrator of the EPA early this year
suggested a five-year program of less stringent emission control
than is currently called for by the law. Such a delay would avoid
Increasing emissions of sulfuric acid while further studies are
made of the significance of these emissions, and while control
technology for such emissions is being developed. This suggestion
was made in spite of the fact that the Administrator of the EPA
had determined that technology for meeting the statutory HC and
CO standards is available; if It had not been for the need for
caution about the possibility of adverse health effects from
sulfuric acid, the EPA Administrator would have denied the request
of the automakers for yet another extension of the deadline for
meeting the statutory HC and CO standards,
Subsequent to the EPA Administrator's decision on the extension
and his suggestions for a five-year program, the President — on the
basis of broader considerations than the EPA Administrator could
under the law take into account in his decision — recommended to the
Congress that a somewhat less stringent schedule for emission controls
be required through the 1981 model year. The Congress is currently
considering these and other alternative emission control schedules.
-------
— 3 —
SpecificComment on the September 3rd Advertisement^
The advertisement tends — as Is perhaps Inevitable in such
communications — to oversimplify the issues involved. In the
following commentary there are first presented the relevant state-
ments from the advertisement followed by EPA's comment on the point
raised:
1. You*11 be paying the bill...
Of course the car buyer will pay the bill for the cost of
emission controls an the car that he buys, just as he pays the
bill for the air conditioner, chrome trim, carpeting, and vinyl
roof that may be installed on his new car. But in another sense
each citizen is and will continue to be "paying the bill" for the
damage to the public health that is caused by automotive air
pollution — in terms of his own and his family's degraded health,
in terms of tax dollars to help care for those who must receive
medical treatment at public expense, or to help support those
who because of degraded health cannot' support themselves. The
bill for emission control on a new car is low compared to the
cost of the many luxury items on new cars that are sold as options,
and represents a far tetter bargin for the Nation than do many of
such items of optional equipment.
2. There will be continuedimprovement of air quality
as new cars replace old cars.
Yes there will be, but at a lesser rate than the improvement
that would be achieved at emission standards more stringent than
the current standards. This will be particularly important in
future years if the entire fleet of cars is controlled to today's
emission standards instead of to more stringent levels.
3. Compared to pre-controlled cars, today's standards
result in reductions of over80% for hydrocarbon and
carbon monoxide and about 40% for oxides of nitrogen.
The 80% reduction estimate for HC and CO is consistent with
EPA's data» but the 50% reduction estimate for NOx is not. Today's
reduction of NOx from pre-controlled cars is only about 11%. The
industry's 40% reduction estimate appears not to be based on NOx
emissions from pre-controlled cars, but rather on the substantially
-------
higher level of NOx emitted from earlier models of cars that were
controlled for HC and CO but were not required to be controlled
for NOx. Prior to Imposition of a NOx control requirement
beginning with the 1973 model year the industry allowed NOx
emissions to rise sharply from what they had been on uncontrolled
cars.
4. With current standards automakers can improve
industry-wide gas^ mileage, between. 1974 and 1980
by an average of at least 40%.
That is true, but a Joint study made last year by the
Department of Transportation and the EPA at the request of the
Congress concluded that better than a 40% fuel economy improvement
by 1980 could also be achieved at the statutory emission standards
for HC and CO, and that only the NOx standard needs to be relaxed
to achieve this goal.
5. Stricter^_sj_an_d_ar_d_s_w_Quld add only marginal improvemetvt
to aj.r quality_.
The improvement in air quality from stricter standards would
be greater in future years than in the near term, simply because
most of the auto air pollution today still comes from older, lees-
controlled or uncontrolled cars. In the long run the statutory
emission standards for HC and CO, and possibly for NOx, .continue
to be needed, according not only to EPA estimates but also estimates
from the National Academy of Sciences.
6. No auto manufacturer yet knows how to meet the 1978
standards on ^ mass production basis.
That is true only if all the 1978 standards are referred
to, including the stringent 0.4 grams per mile 1978 statutory
emission standard for NOx. The statutory emission standards for
HC and CO can be met, although as noted above a deferral of these
standards is in order to allow time for further study of, and if
needed development of control technology for, the sulfuric acid
emissions that can result from the use of catalytic HC and CO
emission controls. The cost estimates in the advertisement are
also for meeting all three emission standards. The costs of
meeting only the statutory HC anc CO standards at an NOx control
level of 2.0 grams per mile would not be so high; instead of from
$150 to $400, as stated in the ad, the increase in costs would range
from $50 to $100.
•MSAPC 9/75
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
OFFSCE OF
AIR AND WASTE MANAGEMENT
Fuel Penalty caused by Emission Controls
On January 22, 1973 an article appeared in Barren's Magazine authored by
Shirley Scheibla. The article covered a broad range of subjects related to
energy shortages, and included two short paragraphs in which General George
Lincoln, at that time Director of the Office of Emergency Preparedness, was
quoted as saying that "cleaning up auto exhausts already has cost 300,000 bar-
rels a day of extra gasoline and will cost about two million barrels a day by
1980," and in which an official of the U.S. Department of the Interior was
quoted as claiming that taking lead out of gasoline would bring about a 15% to
20% energy penalty.
The U.S. Environmental Protection Agency has recently received a substantial
number of inquiries about this two-and-one-half year old article. To respond
efficiently to these inquiries, this Fact Sheet has been prepared.<
At the time at which the article was written there was relatively little
publicly available data on the impact of emission controls on fuel economy.
Subsequent studies showed that the fuel economy of 1973/74 cars was, on the
average, about 10 to 12% lower than the fuel economy of comparable weight
vehicles built prior to the imposition of emission controls. However, with
the introduction of catalytic emission control technology (which requires the
use of unleaded gasoline) in the 1975 model year the auto industry succeeded
in regaining, on the average, all of the fuel economy that had been lost due
to the use of less efficient emission control technology through the 1974 model
year. The industry at the same time succeeded in reducing by about one-half
the emissions of unburned hydrocarbon and carbon monoxide from the level of
emission of these pollutants from 1973/74 model year cars. With further industry
experience it is expected that average 1976 model year fuel economy will be
even better than in 1975, and thus it can not now be validly asserted that the
national effort to clean up automobile exhausts is in conflict with energy
conservation needs.
The estimates for 1980 fuel economy were based on the state of the art
of emission control systems in 1972, which indicated a fuel economy penalty of
30% to meet the statutory emission standards. Many improvements have been
made in these technologies, and the implementation date for the imposition of
the statutory standards has been postponed from 1976 to 1978 with a further
delay possible through current Congressional consideration of amendment of the
Clean Air Act. The current state of the art of emission control technologies
has reduced the estimate of a fuel economy penalty to meet the statutory
standards, to about 7%, with further reductions in this penalty as technology
continue to advance.
FS-47 QMSAPC/September 1975
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
OFFICE OF
AIR AND WASTE MANAGEMENT
Mobile Source Air Pollution Control
FACT SHEET
REPLACEMENT OF OXIDATION CATALYSTS
The Environmental Protection Agency has received inquiries relating
to the need for scheduled replacement of the oxidation catalyst emission
control device during the first 50,000 miles or five years of vehicle
operation* Such inquiries have generally concerned whether manufac-
turers are within the law in requiring or recommending catalyst replace-
ment during the first five years or 50,000 miles, and who should pay for
such maintenance. This Fact Sheet has been prepared to respond efficiently
to these Inquiries.
1. Are manufacturers permitted to equip their automobiles with oxidation
catalysts whichL must^ be_repl_aced during the first 50.,OOP miles or five
yeartr of vehicle use?
In order to be legally sold in the United States, new automobiles
must be covered by an EPA Certificate of Conformity. EPA issues a
Certificate of Conformity when the manufacturer has demonstrated
successfully that a vehicle has been designed so that, when properly
built, maintained, and operated, it will meet emission standards through-
out a statutorily defined useful life of five years or 50,000 miles,
whichever comes first.
During the 50,000 mile durability test that is a part of the
demonstration of compliance, manufacturers are allowed to perform such
maintenance on their cars as is reasonable and necessary to assure
the proper functioning of the engine and emission control system,
provided that such maintenance approximates the maintenance which
would reasonably be expected to be done on a vehicle in actual use
during the initial five year or 50,000 mile period. Thus the amount
of maintenance permitted during the 50,000 mile durability test Is
quite limited and closely controlled.
During the 50,000 mile test manufacturers are allowed to perform
scheduled maintenance on the catalytic converter only once. This
maintenance may Include replacement of the catalyst Itself. Manufacturers
who elect to schedule catalyst replacement or servicing during the
durability test must Inform vehicle owners of the necessity of performing
FS-48
-------
-2-
thla maintenance by listing It, along with the appropriate mileage at
which the maintenance must be performed. in the maintenance Instructions
which accompany the vehicle at Its sale. There Is also a requirement
to alert the driver by an audible or visual signal In the vehicle when
the mileage at which catalyst service Is needed has been reached.
2. Why does EPA permit the use of catalysts which do not last for
five years or 50,000 miles?
The decision to permit one catalyst replacement during the 50,000-
mile durability testing was made In early 1973, shortly before 1975
cars were to start their durability testing. Manufacturers had announced
that they Intended to rely heavily on the use of these devices to meet
the stringent Federal emission standards In the 1975 model year.
j
Catalysts were a relatively new technology In 1973t., In the absence
of real world experience with these devices, EPA had to rely on assess-
ment a by the Industry, the National Academy of Sciences, and Its own
technical staff which Indicated that advanced emission control systems,
such as the catalyst, were likely to be less durable than required to
function adequately, without any maintenance, for 50,000 miles. -Conse-
quently, If manufacturers were not to be permitted to perform any catalyst
maintenance operation during the 50,000 mile durability test, the
likelihood of cars being able to meet the 1975 standards would have been
significantly reduced.
As It turned out, less stringent final 1975 emission standards than
had originally been contemplated for 1975 model cars were adopted. At
those levels very few manufacturers found It necessary to schedule
maintenance on catalysts during the 50,000 mile test. However, accord-
Ing to statements by the auto companies, as emission standards become
more stringent the catalyst will have to work harder and thus may not
last as long. Thus, on future cars, it Is possible that more catalyst
maintenance will be required than is currently needed on 1975 and 1976
cars.
3. Hov can the driver of a catalysj^-equipped vehicle^ jtell when the
catalyst needs to be serviced or replaced?
A catalyst which no longer cleans up pollutants usually does not
adversely effect the driveabillty of the vehicle. That is why it was
made a condition of allowing catalyst maintenance that manufacturers
Install audible or visual warning devices which will alert the vehicle
operator to the need for catalyst maintenance. All cars that require
scheduled catalyst maintenance during the first 50,000 miles are equip-
ped with such warning devices.
-------
Of course, even when the catalyst is designed to laft for at least
50,000 miles, It is possible that an occasional unit will fail in service,
either through a defect in workmanship, or through abuse of the vehicle,
or due to failure to perform needed engine tune-up a. In those Jurisdic-
tions in which periodic emission inspection programs are carried out,
such catalyst failures will be identified when the car's emissions are
tested.
4. When scheduled replacement of a catalyst is necessary within
th^Jfirst 50,000 miles or five years, doea the vejiicle owner
or the^ manufacturer have to pay for the repairs?
EPA does not require manufacturers to perform scheduled catalyst
maintenance without charge to the vehicle owner. Each manufacturer
is free to decide whether to perform such maintenance without additional
charge, or to charge for the maintenance at the time the catalyst is
replaced. Most manufacturers do not provide p re-paid catalyst replacement.
When EPA initially considered the terms and conditions under which
catalyst replacement should be allowed in the SO, 000-mile durability test,
much thought was given to requiring performance of scheduled catalyst
replacement at no additional charge to the vehicle owner, which would
of course mean that manufacturers would in one way or another include
the cost of catalyst replacement in the initial purchase price of the
automobile. The reasoning was that with the replacement already paid
for, car owners would be more likely to actually have the work done.
However, other government agencies and some public groups argued
strongly that such a pre-payment requirement had significant shortcomings.
There was much concern that pre-pald catalyst replacement would tend to
require cars to be repaired at the manufacturers' dealers' service
facilities, thereby .excluding independent parts producers and repair
shops from competition with the manufacturers. While some schemes for
avoiding such anti-competitive situations were explored, none appeared
feasible.
For example, if a coupon good for one catalyst replacement were
included in the owners manuals, there would be a new problem: The
coupons would be worth money, and would be likely to be stolen from
glove compartments. If the coupon were provided separate from the
owners manuals, the likelihood of the coupon being handy two or three
years later, when catalyst replacement came due, appeared rather low.
On top of that, it would be difficult to put a value on the coupons,
for labor rates vary widely throughout the United States. It also appeared
likely that a coupon system could simply create a new racket, in
which coupons for catalyst replacement that was performed in areas where
labor costs were low would be sent to high-labor cost cities for redemption.
-------
-4-
Other schemes, including the use of vehicle identification numbers
and computers were also considered, but all created large complexities
for little apparent gain. Thus the final decision was not to require
pre-payment of catalyst replacement in the initial purchase price of the
car. Since in one way or another the vehicle owner would have to pay
for the maintenance, forcing him to pre-pay the maintenance would have
created so many problems and additional administrative costs, that this
became a less than desirable way of handling the matter,
5. How much jri.ll It cost to replace a. catalyst?
The types of catalytic converters used in passenger cars vary
from company to company and from vehicle to vehicle, so it is Impossible
to say exactly how much it will cost to replace a single catalyst.
In general, however, catalyst replacement may cost from lees than $100
to about $250, depending upon the vehicle and the type and number of
catalysts used.
6. How many manufacturers currently require replacement of catalysts
on their vehicles prior to 50,000 miles?
No domestic manufacturers of automobiles require scheduled catalyst
replacement for any of their 1975 or 1976 vehicles. Some foreign
manufacturers have required catalyst replacement on 1975 and/or 1976
vehicles sold in California where more stringent emission standards
are In effect, and on a limited number of vehicles sold nationally.
These manufacturers are British Leyland (Jaguar, Triumph and KG), Flat,
Volkswagen (VW, Porsche, Audi) and Mercedes Benz. Not all models made
by these manufacturers require a catalyst change. Those that do are
estimated to make up 3.4% of all 1976 model year cars expected to be
sold in California, and only 0.2% of cars sold in the other 49 states.
Thue only a total of 0.6% of all 1976 model year light duty vehicles
expected .to be sold in the U.S. will require their owners to replace
catalysts prior to 50,000 miles.
You can readily find out if a vehicle you are considering purchasing Is
equipped with a catalyst which must be replaced prior to 50,000 miles.
The EPA/FEA Mileage Guide for New Car Buyers, in the 1976 Model Year
edition, indicates whether or not a car available In the showroom has
a catalyst, and whether replacement of the catalyst at less than 50,000
miles Is needed. You can get this publication by writing to: Fuel
Economy, Pueblo, Colorado, 81009. You can also ask the car dealer to
provide you with a copy of the owners manual for the car you are consider-
ing buying and read the maintenance section of that document to see if
the manufacturer calls for catalyst replacement!
MSAPC/October 1975
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON. D.C, 20460
OFFICE OF
AIR AND WASTE MANAGEMENT
Hydrogen Cyanide from Catalyst Cars
The Environmental Protection Agency has received a number of
questions about a report published by Bell Laboratories that suggests
that catalyst equipped cars may emit hydrogen cyanide (HCN) gas. This
Fact Sheet has been prepared to respond efficiently to such inquiries.
Bell Laboratories passed a mixture of nitric oxide (NO),
carbon monoxide (CO), hydrogen (H ), and varying amounts o£ water
and sulfur dioxide (SO ) over a heated platinum catalyst in the
laboratory. Under these conditions HCH was formed. With the larger
amounts of water and SO , HCN production was greatly reduced.
These results are not novel. These conditions are similar
to commercial synthesis of HCN (the Andrussow process), Methane
(carbon and hydrogen), ammonia (a source of nitrogen), and air are
passed over a heated platinum/rhodium catalyst in the Andrussow
synthesis. Another method for making HCN is reaction of NO and
hydrocarbons at high temperatures without catalysts.
From their work, Bell labs raised the possibility that
significant HCN formation is possible in auto exhausts on catalyst
cars. While the data suggest that further investigation is
warranted, the data by themselves do not support a concern that
catalyst-equipped cars present a health hazard by emitting HCN,
because:
a. The Bell lab work suggests that HCN is formed in
significant amounts only if the sulfur content of gasoline
is extremely low — much lower even than anyone has seriously
suggested as a desulfurization strategy.
b. For every pound of gasoline burned, over a pound of
water comes out of the engine. Hence in a car there is
always plenty of water, which, the Bell lab work demonstrates,
inhibits HCH formation.
FS-49
-------
2 -
c. The only way in which HCN could be formed in
catalysts on cars is under rich fuel/air mixture running
conditions. Under these conditions catalyst cars would
also emit hydrogen sulfids (FLS). Hydrogen sulfide smells
like rotten eggs and can be detected by humans at low
concentrations. The odor of hydrogen sulfide thus serves
as an indicator of rich operation, and because of its
disagreeable nature prompts most customers to return their
cars to the dealer to correct the problem.
EPA has preliminary data on HCN emissions from both
catalyst and non-catalyst cars. These preliminary results
indicate that HCN is produced on the order of 0.005 g/mi. from
both catalyst and non^catalyst cars, but that there is no
difference in the level of HCN emissions produced by each.
Another way of expressing it is that the concentration of HCN
in the exhaust is so low that even someone who were to breathe
undiluted vehicle exhaust would be exposed to only about l/5Qth
of the HCN level permitted under occupational health standards.
Of course, no one would or could breathe undiluted exhaust from
a car for very long without being subject to carbon monoxide
poisoning. Thus, from an over-all standpoint, the current levels
of HCN emitted from cars do not appear to constitute a health
hazard about which one needs to be concerned.
OMSAPC/January 1976
-------
< UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
^ WASHINGTON, D.C. 20460
Fact Sheet
Mobile Source Air Pollution Control Programs
On November 3, 1975, Barron's published an article entitled "Non-
Working Model, Yet EPA Is Moving Auto Certification to the Assembly
Line." The article was generally critical of the various programs
EPA has initiated in its efforts to assure that automobiles meet the
emissions standards mandated in the Clean Air Act, as amended June
1974, The article claimed that EPA is conducting, or is planning to
conduct, several control activities which are costly to industry and
consumers without knowing if they have achieved, or will achieve,
any benefits.
The U.S. Environmental Protection Agency has received many inquiries
about this article. To respond efficiently to these inquiries, this
Fact Sheet has been prepared.
Background
The goals that EPA seeks to achieve in the control of automobiles
have not been set by EPA. Rather, the Congress has mandated in the
Clean Air Act (CAA) that emission standards be applied to automobiles.
EPA is charged with the responsibility of carrying out programs to
assure that automobiles meet such standards.
The provisions of the CAA recognize that control of automobile
emissions requires attention to the design, construction, and use of
vehicles. Section 206(a) of the CAA requires EPA to establish a
Certification Program to ascertain whether or not vehicles have been
designed so as to comply with existing federal emissions standards.
Thig program tests prototype vehicles to assure that cars are designed
to meet the emissions standards for their full useful life, as defined
in the CAA.
While the Certification Program helps to assure that cars are
properly designed, the Congress recognized that proper design is
not by itself sufficient to assure that vehicles will in all cases
be properly built. For this reason Congress called upon EPA to establish
assembly line testing in Section 206(b) of the CAA, Regulations have
been proposed to implement this section under the title of Selective
Enforcement Audit (SEA).
FS-50
-------
-2-
Even when a car is designed and built so as to meet emissions
standards, vehicles in-use may not meet these standards if they are
not properly operated or maintained. For that reason Congress provided
in Sections 110(a)(2)(G) 'and 207(b) for the establishment of programs
to promote the proper maintenance and use of vehicles through periodic
emission inspection. Congress also provided, in Section 207(c), for
the recall and repair at the manufacturer's expense of classes or
categories of vehicles found to be exceeding the emission standards
in spite of their being properly maintained. The EPA is working with
states and localities on the implementation of inspection and mainte-
nance programs (.I/M), and the EPA is using a variety of means for
identifying classes of vehicles that should be recalled and repaired
because they do not meet the.standards in actual use.
By a combination of these control strategies vehicles will meet
the appropriate emissions standards. No one program alone can do the
whole job that must be done if automobile emissions are to be reduced
so that the air in our cities can again be clean.
The following comments are directed toward specific assertions
contained In the Barren's article:
1. The certification procedures are complicated and the costs
are high.
It is correct that the procedures followed to make certain
that manufacturers design vehicles that meet applicable emissions
standards are complex. However, they are not unnecessarily so.
Measuring and controlling automobile pollution is not a simple task.
EPA's test procedures are designed to duplicate the actual operating
conditions typically encountered by ih-use vehicles. EPA is always
receptive to considering improvement in its test procedures whenever a
good case, substantiated by technical data, is presented. Over the
years EPA has adopted a number of changes, including changes recommended
by manufacturers.
It is also true that in absolute terms a lot of money is spent
by manufacturers to certify their vehicles. GM .estimated expenditures
of $24 million for certifying 1975 model year vehicles. These costs,
it is understood, covered more than just the certification of passenger
vehicles; they include light duty and heavy duty truck certification.
EPA has not seen a detailed analysis of the $24 million, and thus cannot
know how the estimate was complied. Nevertheless, even if all of this
cost were assigned to only passenger cars it would work out to about
$7 per passenger car produced by GM.. Seven dollars per car does
not appear an unreasonable amount to pay for the assurance the
vehicles bought by consumers are designed so that they will meet
the Clean Air Act's standards.
-------
-3-
2. The complexity of the JTviles makes it necessary to test more cars.
The article states that GM tested only 160 cars in 1974 and
then had to test 284 in 1975, implying that it was the complexity of EPA
regulations that caused this dramatic increase. Several factors caused
the increase in testing requirements. First, in 1974 only one class of
light duty vehicles and one corresponding federal emissions test existed,
In 1975, as a result of a U.S. Circuit Court decision, EPA was required
to establish a separate light duty truck class. Secondly, in 1975 all
of the standards were different from 1974, whereas in 1974 (and in 1976)
the standards did not change from the previous year and manufacturers
could "carry—over" the certificates for cars that did not change in
those years. Finally, in 1975, there was a class of vehicles intended
for sale in California (where emission standards in 1975 were stricter
than federal standards) that was different from vehicles intended for
sale in the other 49 states. Manufacturers had the option of certifying
a vehicle only to the more stringent California standards and not
repeating the test to meet the less stringent federal standards. Since
few manufacturers choose to use the same control equipment on both types
of vehicles, one can surmise that they deemed it more beneficial to
incur the costs of designing and certifying two different vehicles.
3. Tests similar to jhose ir^jcertif ication will be conducted
gn jjjroductiUm models rolling off the assemblyline^
The article is referring in this case to the Selective
Enforcement Audit (SEA) program EPA plans to implement. While generally
the test procedures to be used in SEA are similar to certification tests,
SEA and certification differ in purpose and in terms of the specific
test procedures to be followed.
As noted earlier, the purpose of certification is to evaluate
whether a vehicle is properly designed to meet the emissions standards.
SEA is intended to assure that manufacturers actually produce their vehicles
so that they meet the emission standards when they come off the assembly
line. The two programs complement rather than duplicate one another.
The test to be used in SEA. is a somewhat shortened version of
the full Federal Test Procedure that is used during certification, SEA
testing differs from certification testing in that the former does not
include the running of a car for 50,000 miles to prove its durability.
Furthermore, Certification tests only a very few vehicles with each
type of engine. SEA will, on a sampling basis, test batches of up
to 25 cars with the same engine, thus providing greater statistical
confidence in the results.
-------
-4-
4. SEA would mean more stringent, standards, closing of assembly
lines, cost increases of $500 to $600 per car^ and may
exact a 13% fuel economy penalty.
SEA is an enforcement tool, provided for in the Clean Air Act,
which will be used to make sure that production cars are meeting the
standards appropriate for that model year. If a manufacturer fails an
SEA test it is because he is not building cars that meet emission
standards. This would indicate that his quality control program is too
lax and needs to be improved, or it would indicate that the manufacturer
has failed to translate a certified design into production.
It is possible that a manufacturer may fail an SEA. test.
Therefore it is possible that production of that vehicle may have to be
temporarily halted until the problem is solved, for the Clean Air Act
requires vehicles to comply with the standards. This will not happen,
however, if manufacturers have designed their cars properly and exercise
proper quality control when building vehicles for sale.
The cost of conducting one emissions test for SEA is estimated
to be from $280 to $600 per car tested, depending upon whether testing
is done at the plant or at some central test location. Current estimates
are that 700 tests may be required in the first year the SEA program is
implemented. Total testing costs, assuming no retesting, could be
$420,000 at most. If 8 million vehicles are sold in that first year,
SEA testing costs would add only 5 1/4 cents to the cost of each
vehicle sold, a very reasonable cost to assure that cars meet standards
when they leave the assembly line.
Audit procedures currently anticipated for SEA would allow up to
40% of the cars in a -test batch to be above the standards before the
batch is failed. Such an Acceptable Quality Level (AQL) would leave
manufacturers sufficient flexibility to build cars without running a
large risk of failing an SEA test. An AQL of 10% was proposed as the
ultimate goal for SEA. However, the implementation of this more stringent
level will not occur until experience with the 40% AQL shows a need for
it. There is no good reason why SEA at a 40% AQL would reduce fuel
economy, for at an AQL of 40% SEA does not impose a more stringent
performance requirement than already is imposed through Certification.
-------
<—*}-*
5. EPA has had trouble with the long emissions tests to be given
It is correct that problems were encountered during the conduct
of the 1972 In Use Compliance Program (IUCP) which caused EPA to question
the adequacy of the data, in a legal sense, for ordering of recalls
under Section 207 (c). These problems were not due to the overall approach
but rather to the manner in which the testing contractors did the work
[e.g., occasional failure to check calibration of the test equipment
before a specific test] and the maintenance performed on the vehicles
[e.g., occasional failure to change the fuel filter at the specified
mileage] . EPA has learned from the difficulties encountered during
the 1972 IUCP tests, and these problems can be avoided in future
IUCP programs, if such future programs are carried out,
6. State inspection tests jfould be headed by garages that lack
both dynamometers and trained personnel.
State governments will have overall responsibility for the
supervision of their inspection and maintenance programs. There are
several methods through which the states can discharge the responsibility
of performing the emissions tests. In some states, New Jersey for
example, state operated inspection stations will be used. Other states
will contract with independent testing firms which will conduct the
inspections. Still other states may elect to have private garages that .
are licensed by the state conduct the tests. Regardless of who performs
the tests, any vehicle maintenance required as a result of a failed
emissions test will be performed by mechanics in privately owned and
operated service stations or repair shops.
7. No reliable short tes_t_ has beery found which will correlate
to a full _sc_ale_ test .
The accuracy needed of a short test depends on the intended
use of the test. The Federal Test Procedure (FTP), which lasts 23
minutes and, must be preceded by a 12 hour storage period under controlled
temperature conditions, is intended to provide a precise measurement of
emissions. The test to be used for state emission inspection must be
short (1-3 minutes) and cannot require elaborate preconditioning,
but it needs only to distinguish between high and low emitting vehicles.
It is not necessary that a short test accurately predict the results
of the FTP, nor is .it reasonable to expect such accuracy from a short,
simple test,
Several short tests have already been tentatively identified which
can correctly fail high emitters with very little chance of failing a
car which actually meets the standards. EPA believes that with some
-------
-6-
further work it will be possible to formally establish one or more short
tests which fully meet the requirements of Section 207(b) of the Clean
Air Act, under which auto makers are responsible for repairing (during
the first 5 years or 50,000 miles) any vehicle which fails to pass a
state operated I/M program and which was properly operated and main-
tained.
MSAPC/January 1976
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, O.C, 20460
OFFICE OF
AIR AND WASTE MANAGEMENT
FACT SHEET
The Office of Mobile Source Air Pollution Control
We frequently receive inquiries about the programs of the Office
of Mobile Source Air Pollution Control (OMSAPC). This Fact Sheet has
been prepared in order to respond to those inquiries.
The primary purpose of the MSAPC program is to reduce the levels of
harmful pollutants emitted from motor vehicles. In the course of this
work, as a by-product of emission testing, there is also carried out testing
of motor vehicles for fuel economy and calculation of the resulting
fuel economy levels for categories of cars, and a fuel economy labeling
program for new cars.
* .
These efforts are carried out through several major types of
activities:
1. Technology A s s e s s men t
MSAPC keeps abreast of technological developments within the
auto industry so as to be able to advise the Administrator and other
EPA officials, other Federal agencies, and the Congress as to the ability
of the industry to meet emission standards and fuel economy goals.
Periodic reports on the status of technology are prepared, as well as
special reports related to specific issues on which technical information
is needed as a part of the decision making process.
2. Pollutant Characterization
This work involves measuring levels of currently unregulated
.vehicle pollutants that have the potential of being health hazards. To
enable measurement of these levels, there must often first be
developed special test procedures whereby these new pollutants may be
measured. Under investigation are pollutants from both presently-used
technologies and from advanced technologies likely to be implemented in
the near term. This information is needed to determine whether these
potential health hazards are emitted in sufficient quantities to
require their control.
FS-51
-------
3. Standards and Test Procedure^ JDevejLojjment
Once a need for control is determined, MSAPC is responsible for
developing routine test procedures which are reliable and repeatable,
and to specify these procedures in sufficient detail so as to
enable many laboratories to conduct identical tests. These test
procedures include a driving cycle which is representative of actual
use of the vehicles under the conditions of concern, so that the emission
levels measured from the test are representative of emission levels from
those vehicles when in actual use. The emission standards are set by
the EPA Administrator at levels which are technically and economically
feasible, to provide maximum health protection achievable.
4 . Regulation Pr^^os^l jjmj^nactment
After the standards and an associated test procedure have been
developed, MSAPC is responsible for managing the process by which
regulations to implement such standards are proposed and eventually
promulgated. Included in this process are the preparation and issuance
of Environmental and Inflationary Impact Statements, and the review of
the regulatory package by other elements of EPA, other agencies, and the
public. MSAPC regulations currently address passenger vehicles, trucks,
buses, motorcycles, and aircraft.
5. Certification pf^ Vehicles to Applicable Emission jtandards
Each year the MSAPC program must review applications submitted
by manufacturers for the purpose of obtaining certification of their
compliance with emission standards prior to the introduction of motor
vehicles for sale in this country. This process includes testing of
prototype motor vehicles to assure compliance with applicable standards.
The purpose of this process is to assure that each new model of vehicles
is designed in a way that will allow it to meet emission standards for
its useful life.
6. Fuel Economy Testing, Data Calculation, and Data Publication •
Concurrent with its emission testing for certification, ^fSAPC
conducts testing of new models of cars to determine their fuel economy.
These data are made available to the public through an annual Mileage Guide
published in cooperation with the Federal Energy Administration. These
data will also be used by the Department of Transportation in administering
the fuel economy standards program.
-------
7. Surveillance of In—Use Vehicles
There is a continuing need to test vehicles in actual use to
determine their emission levels after they have been purchased and
driven by their owners. The results of this testing are used to estimate
emission rates for air quality planning purposes. The results may also
be used to determine whether a particular class of vehicles, even though
properly maintained, still does not meet applicable emission standards; In
such cases, EPA's Office of Enforcement may order the recall of those
vehicles by the manufacturer to bring them into compliance with the
standards.
8. Technical Support of Inspection/Maintenance Programs-
The MSAPC program is the focal point within EPA for developing
the technological base for the operation of emission inspection/maintenance
•programs required by many transportation control plans, and for the
conduct of evaluations of such programs to provide data on their
effectiveness in reducing vehicle emissions. Other elements of EPA
headquarters, and the EPA regions, work with States and localities on
the actual implementation of I/M programs.
9. Organization of the Program
The Office of Mobile Source Air Pollution Control Is headed by
a Deputy Assistant Administrator who is located together with a small
staff at EPA headquarters in Washington, D.C. The technical staff of
the program is located in the Motor Vehicle Emissions Testing Laboratory
in Ann Arbor, Michigan. The Ann Arbor group is comprised of three
divisions: the Emission Control Technology Division, the Certification
Division, and the Program Management Division.
OMSAPC/EPA/January 1976
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
OFFICE OF
AIR AND WASTE MANAGEMENT
Mobile Source Air Pollution Control
FACT SHEET
The Portland Study: Control of Air Pollution
from Motor Vehicle Emissions
The Environmental Protection Agency has received many questions
about an evaluation of the motor vehicle inspection program being
carried out by the State of Oregon in the Portland Metropolitan area.
This Fact Sheet has been prepared to respond efficiently to the most
frequently asked questions.
1. What ia the Portland motor vehicle inspection program?
Motor vehicle emission inspection and maintenance programs (I/M
programs), such as the program conducted in the Portland area, are a key
element in controlling air pollution from automobiles. The major
function of such I/M programs is to help ensure that owners maintain
their cars properly, so that exhaust emissions from cars in use remain
as low as the car is designed to achieve. Proper maintenance is necessary
to achieve that goal. Since the 1968 model year, all cars sold in. the
U.S. have had the design potential to meet increasingly more stringent
Federal auto emission standards for their useful life, if such cars are
properly maintained. However, studies have shovn that many cars In use
have emissions well above their design potential. A major reason for
'that is that many car owners do not maintain their cars properly.
To reduce this unnecessary pollution, and thus to help provide health-
ful air for its citizens, Oregon and other States and Jurisdictions have
established motor vehicle inspection programs in which car owners are
encouraged to have their cars tested periodically for emissions and
serviced if necessary to reduce the emission levels,
2. How does the State of Oregjm get Portland residents to
participate in the inspection program?
Before a resident of the Portland area can renew hia motor
vehicle registration, the vehicle must pass a short emissions test. The
test is conducted by State personnel at a State operated inspection
FS-52
-------
-2-
station. The short emission test identifies those vehicles which would
exceed the Federal emission standards by a significant amount if the
vehicle were tested using the more time-consuming and costly full EPA
emission test procedure.
3. Why is £PA_8tudyln^ the_Por_tland program? What use will be made
of the results?
EPA ia studying the Portland Program to determine how to get the
most out of an I/M program. A number of more limited studies that were
performed in the past have shown that the periodic Inspection and mainte-
nance of autos can be effective in reducing auto emissions at a reasonable
cost. The earlier studies, however, were somewhat limited in the number
and variety of vehicles tested, were made using experimental or pilot
I/M programs, and were aimed primarily at learning whether an I/M
program would be cost effective. The full-scale Portland study will
quantify the emission reduction and fuel economy Improvements that are
achieved by an operating I/M program, and will help to identify Improve-
ments which can maximize the benefits and minimize the cost of I/M
programs. The study will also examine the effects of such real life
conditions as waiting time for inspection, the weather, the skill of the
mechanic who services cars which fail, and the precision with which the
short test is made on a high frequency basis, and will provide data to
help determine the optimum frequency of inspection. Finally, the data
provided by the study will be used to help develop the short test
performance standards for different types of vehicles.
4. Why evaluate Portland, since other jurisdictions also have
emissions Inspection programs?
Although there are some differences among existing I/M programs
that may affect their effectiveness, it would not be possible to conduct
an in depth evaluation of all existing emission inspection programs,
since evaluations of this type cost both time and money. EPA considered
all existing emission inspections programs, for the purpose of selecting
one for this evaluation. The major reasons for selecting Portland were:
(1) The program, in effect since 1975, is well
established but is still new enough to permit
learning about public reaction to a relatively
new I/M program.
(2) The program requires mandatory testing of all vehicles,
and mandatory repair of failing vehicles;
(3) Portland is a relatively small area (i.e., a city
rather than a state) and is located near cities which
do not require emission inspections. This allows
achievements of the Portland program to be readily
assessed by comparing Portland vehicle emission levels
to those of a nearby city;
-------
-3-
(4) The State of Oregon was enthusiastic about the
EPA evaluation because it too wants the sort of
data the study will provide.
5. How will EPA conduct its evaluation?
The basic study involves the conduct of several different series of
emissions tests. The tests will be performed on vehicles from the
Portland area whose owners normally participate in the Portland inspec-
tion program, and on vehicles from a nearby Oregon city where emissions
inspections are not required. In that way emission levels from cars
in the Portland area can be compared to those of a city which does not
make such inspections. Several thousand emission tests will be made.
for one of the test series, a group of cars will be tested every three
months for one year, first at the Portland inspection center and then by
EPA, In addition, the owners of the participating cars will be asked to
provide information about their vehicle usage and maintenance practices.
The attached Data Sheet contains additional information on the test
fleet and the test procedures which ZPA will use.
6. Are individual vehicle owners required t o_ j?articip a_te_
in the EPA evaluation?
. Ho. EPA will aek for volunteers. People who allow EPA to test
their cars will be offered leaner cars for the period during which their
cars are being tested and given a U.S. Savings bond as an incentive to
participate in the program.
7. How long will the_ evaluation take? How auch will it coetl
When wjLjLj.__the_ r_e_su_lt_a_ be__available?
Testing is scheduled to begin by May, 1977. The final results
should be available by Fall, 1978. Interim analyses will be made as
data come In. The cost of the study to EPA will be about $2.8 million.
Most of this money will be used to make the needed emission tests,
8. Isn't that rather expensive for such a study?
It la expensive, yes, but it is well worth the money. With about
10 million cars sold in the U.S. each year, and each of these cars
having about $200 worth of air pollution control equipment on them» our
country is already spending about $2 billion each year on new cars to
control air pollution. It is important that we as a nation get full
value for that money. Inspection programs will be needed in many
American cities. The cost of the study to improve these programs is
about l/10th of 1% of our total current annual expenditure on new car
auto emission control and, as such, the information that the Portland
Study will provide is well worth the cost.
Attachment
-------
DATA SHEET
The following chare shows the size and composition of the
fleet which will be used to develop the data base for the Portland Study.
The test fleet size and the distribution of model years within the fleet
were chosen, to provide statistically valid samples.
Test
Series I
Test
Series II
No. of
Test Vehicles
2,400
from Portland
200 from
Test Series I
Model
Year
1975 -
1976
1975 -
1976
Oregon short
test (Idle Test)
State and EPA
State and EPA
Federal
Short Cycle
Federal
3-Mode Test
State and EPA
State and EPA
1975
FTP
EPA
EPA
Highway
Fuel
Economy
"
EPA
200 from 1972 -
Portland Area) 1974 EPA
200 in a 1972 -
nearby city 1976 EPA
that has no I/M
EPA
EPA
EPA
EPA
EPA
EPA
Series I begins with the short test (idle test) used by the State of
Oregon for inspections. For the purpose of the EPA study, State personnel will
also conduct two additional short emissions tests, specifically the Federal
short cycle and the Federal 3-mode test. Unlike the idle test, however, both the
Federal short cycle and the Federal three mode test are conducted on a chassis
dynamometer. EPA will equip a State Inspection Center with a chassis dynamometer
and train State personnel in its use so that State personnel will be able to perform
the additional short tests in Test Series I. From the results of these tests, EPA
will develop appropriate short test performance standards for different types of
vehicles that may be useful in improving inspection programs. Series I continues
-------
-2-
with repetition of the three short tests by EPA at the contractor's facility. EPA
will also test the Series I vehicles using the longer, more complex Federal Test
Procedure (FTP). Comparison of the data from the short tests and the FTP will
help EPA to develop the short test performance standards for- different types of
vehicles. Each vehicle in. Series I will run through the entire test series once.
For Series II, the test fleet will include equal numbers of vehicles
that pass and fall the initial State short test at the State Inspection Center.
Cars which fail the Initial state Inspection will be repaired by a local mechanic
and tested again. After the Initial repairs, owners will follow their usual car
maintenance routine. The cars will be tested by EPA every three months for one
year after the initial set of tests to measure the emission levels, the fuel
economy, and the engine settings which change with";time that are important
to a carfs performance. The tests will Include the State idle test, the FTP,
* X.
the EPA highway fuel economy test, and an engine diagnostic check. From these data,
EPA will determine what types of engine maladjustments will cause a car to fall
the State short test, how soon the emissions from a repaired vehicle go up again,
how much an average repair will cost, and the effect of various engine maladjustments
on emission levels and fuel economy.
EPA/MSAPC/March 1977
-------
? A \ UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
I ^||^- .° WASHINGTON. D,C. 20460
OFFICE OF
AIR AND WASTE MANAGEMENT
Mobile Source Air Pollution Control
FACT SHEET
INTERCHANGE OP ENGINES ON GENERAL MOTORS CARS
The Environmental Protection Agency has received many questions
about the utilization by the General Motors Corporation of 350 CID
engines manufactured by the Chevrolet Division in Oldsmobile vehicles.
This Fact Sheet has been prepared to respond efficiently to these
inquiries.
Why did EPA allow General Motors to use Chevrolet engines in.
Oldsmoblies?
EPA's emission control certification program deals with engines and
associated powertrains. EPA evaluates the emission performance of these
for use in vehicles of varying weight classes. EPA's certificate of
conformity is Issued for an engine family. Thus, the General Motors
Corporation is not constrained by EPA regulations from using certified
engines and their associated powertrains in vehicles of any GM nameplate
designation (e.g., Chevrolet, Oldsmobile, etc.) so long as the weight of
the vehicle in which the engine is used is no higher than the weight for
which the engine Is certified.
Do other manufacturers interchange engines between cars with
different nameplates?
Most other manufacturers build their engines centrally for use by
all of their car divisions. General Motors is unique in that In many
cases GM specifically associates engine lines with car divisions.
However, GM does not always install in its cars an engine that was
manufactured by the Division that also manufactured the cars; in some
cases one car Division builds^ engines for use by another car Division.
FS-53
-------
-2-
What difference does it make whether my Oldsmobile has an
Oldsmobile or a Chevrolet engine?
There are some differences between the 350 cubic inch displacement
engines built by the Oldsmobile and Chevrolet Divisions. As a result of
these differences, the recommended maintenance schedules for the engines
are not identical. Also, the fuel economy estimated from EPA's fuel
economy tests is not the same for a vehicle equipped with an Oldsmobile
engine and drivetrain as for a vehicle of equivalent weight equipped
with a Chevrolet engine and drivetrain. For example, a 4,000 pound
vehicle equipped with an Oldsmobile engine is estimated to have a
combined city/highway fuel economy of 18 mpg., and a vehicle of the
same weight equipped with a Chevrolet engine and drivetrain Is estimated
to have a fuel economy of 17 mpg.
How do I knov_the fuel economy estimate for my car?
Federal law requires each vehicle to be labeled with the EPA fuel
economy data applicable to it. Thus Oldsmoblles equipped with Chevrolet
engines are required to be labeled with a fuel economy applicable to the
.Chevrolet engine. The EPA has no evidence that the General Motors
Corporation has failed to comply with this requirement.
What recourse do I have if I purchased an_QIdsTnobile_ with a
Chevrolet engine?
Inasmuch as there is no violation of EPA regulations involved in
the Interchange of engines and drivetrains among vehicles bearing
different divisional nameplates, the EPA cannot offer any assistance to
the purchaser of an Oldsmobile who is dissatisfied because his vehicle
is equipped with a Chevrolet engine. However, a number of States, as
well as the Federal Trade Commission, are reviewing this matter; the EPA
is not in a position to predict the outcome of those reviews.
OMSAPC/EPA
4/19/77
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 204SO
OFFICE OF
AiR AND WASTE MANAGEMENT
Motile Source Air Pollution Control
FACT
EPA's Process for Evaluation of Inventions for which Claims
of Improved Emission Control and Fuel Economy are Made
The Environmental Protection Agency each year receives several
hundred proposals or requests related to inventions for'improved
emission control or fuel economy. Between five to ten such requests
are received each week. This Fact Sheet has been prepared to respond
to inquiries about how EPA handles sueh requests.'
In the majority of cases the first contact is directly from the
inventor himself, usually by letter but sometimes by•telephone or in
person. Occasionally, we will be contacted by an inventor's attorney,
or by a member of Congress on. an inventor's behalf. Usually the
inventor has heard that EPA tests devices', and requests that we test
his concept or device. It is also very common for the inventor to
ask for developmental funds in addition to an evaluation of the potential
of his concept.
If the device for which development funds are sought is of a
conceptual nature (i.e. not reduced to hardware that can be tested)
it is referred by EPA to the Office of Energy Related Inventions,
Institute of Applied Technology, ia the National Bureau of Standards,
The inventor is advised of this referral. If the'invention is in
hardware that is capable of being tested, the inventor is advised to
contact EPA's Emission Control Technology Division in Ann Arbor, Michigan,
in a letter that also explains that:
a) EPA is interested in all potential improvements to conventional
•engines that may increase fuel economy or decrease emissions. EPA
conducts confirmatory tests of significant devices, at no cost to
inventors, for the purpose'of keeping the Government and the public
abreast of technical developments in automotive emission control
and fuel economy improvement.
FS-54
-------
-2-
b) EPA tests are confirmatory In nature. That means that they
are made only to confirm tests performed by or for the Inventor
that have shown significant potential for improvements. Because
of severely limited staffing and test facility resources, we
cannot test devices that have not demonstrated significant
improvements.
c) EPA does not financially support the development of
technology for improving emission and fuel economy.
If the inventor upon receipt of our response contacts EPA
technical staff in Ann Arbor he is provided information explaining
in detail the test procedures, and a list of laboratories which will
conduct tests for the inventor by the proper procedures. The cost
of generating the needed test data is about a $800-$900 at a commercial
laboratory.
EPA engineers explain to the inventor that, the Federal Emissions
and Fuel Economy Test Procedures must be used in order for his device
to be accurately evaluated and compared with other approaches to
emission control or fuel economy improvement. EPA engineers also
explain that idle exhaust concentration tests, on-the-road fuel economy
measurements, and customer testimonials are not an adequate basis for
undertaking EPA confirmatory tests. If on the basis of valid data
EPA confirmatory tests are subsequently scheduled, EPA engineers
prepare a formal test plan, in cooperation with the inventor.
If the inventor requests an evaluation (not testing or funds)
of his invention, we do provide an evaluation drawing on the technical
expertise on our staff. As may be appropriate, the evaluation compares
the inventor's concept with similar or existing concepts, and points
out advantages, disadvantages, and probable effects on emissions and
fuel economy. Test reports from our files on similar concepts are
often provided to the inventor with the evaluation to include data
illustrating a point that has been made.
Of the hundreds of proposals received every year, relatively few
inventors actually provide test data. When test data are submitted
that have potential for showing low emissions or improved fuel economy,
a confirmatory test plan is worked out with the inventor and the device
is tested at EPA. The EPA testing will normally consist of a series
of tests (the 1975 Federal Test Procedure, fuel economy highway cycle,
-------
-3-
and steady state tests) on a baseline car followed by the same series
of tests with the developer's system installed on the car. Selected
devices are tested on short tests and for sulfates, aldehydes, and
reactive hydrocarbons. Driveability evaluations are made on all
devices tested. In most cases EPA-owned test cars are used, but
rented or leased cars are used for certain evaluations. A complete
report on the testing and engineering evaluation of the results is
prepared and published.
EPA/MSAPC/May 1977
-------
.^ — >
2. ^* -o UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
OFFICE OF
AIR AND WASTE MANAGEMENT
Lead Anti-Knock Compounds Continue to be
Utilized in Gasoline to Conserve Fuel
The Environmental Protection Agency has received a number of
communications urging the continued use of lead anti-knock compounds in
gasoline to conserve fuel, and the use of lead traps to control tailpipe
emissions of lead.
The issues involved in this matter are complex and have a long
history. The Congress has consistently established emission control
standards in terms of performance requirements that, leave to the automakers
the choice of technology to meet those requirements. We believe that
continuation of that strategy is far wiser than would be the imposition
of a requirement for use of a particular type of technology, or conversely
the prohibition of use of a technology.
As regards lead anti-knock compounds, their use in gasoline was
subject to extensive deliberation not only in rule-making but also in a
number of court cases, including final consideration by the Supreme
Court. All of the arguments pro and con were thoroughly aired during
the years that it took to reach a decision on this matter. We believe
that che final decision arrived at is sound.
FS-55
EFA/OMSAPC/July 1977
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
OFFICE OP
AIR AND WASTE MANAGEMENT
Fact Sheet
Claimed Health Hazards from Palladium Content of Catalysts
The Environmental Protection Agency has received a number of inquiries
and expressions of concern about the possibility of health hazards from
palladium. Palladium Is used in small amounts in automotive catalysts.
To respond efficiently to these inquiries, this Fact Sheet has been prepared.
On September 2, 1977 a paper presented at the annual meeting of the
American Chemical Society expressed the view that palladium sulfates and
palladium nitrates were hazardous to health. In discussion of the report,
the author expressed his view that such substances may be emitted from
cars equipped with catalysts, or may be leached from discarded catalysts
from junked cars. This story was widely reported by the press.
EPA has closely reviewed the issues involved in this matter.
On the basis of limited data available it is estimated that the
rate of emissions of palladium from new catalyst-equipped cars is
in the range of two millionths of a gram per mile. This is a
negligible amount.
Based on this level of palladium emissions, estimates have been
made of palladium concentrations in the atmosphere assuming the most
adverse meteorological and traffic conditions. These estimates
indicate that the highest one hour concentration which might be
expected is about 0.0004 millionths of a gram per cubic neter of
air. In contrast, to compare this with levels associated with health
effects, the occupational threshold level value, for platinum is
2.0 millionths of a gram per cubic meter of air.* It is currently
believed, based on medical information from workplace environments,
that the worker can be exposed to higher levels of palladium than for
platinum compounds without developing similar adverse effects. As
a general rule, dividing the occupational threshold levels by 20
gives one a rough measure of a reasonable upper bound for general
population exposure (i.e., 2/20 = 0.1 millionths of a gram per cubic
meter of air). By this analysis, the "worst case" ambient concentra-
tion noted earlier is over two orders of magnitude lower than the
above calculated "safe" value for general population exposure.
* Time weighted average concentration for a normal eight hour
workday or 40 hour workweek, to which nearly all workers may
be repeatedly exposed, day after day, without adverse effects.
FS-56
-------
-2-
Moreover, only about 10-15% of the emissions of the palladium
that have been identified in tests of cars are in a water soluble
form which has the potential to be considered hazardous. Further,
an experiment with a used catalyst has identified no palladium in
a water soluble form.
Based on the limited information currently available, there
does not appear to be significant observed health effects from
human exposure to palladium in Che non-water soluble form. In
view of the extremely low measured emissions and predicted ambient
concentrations of palladium from cars in any form, EPA has con-
cluded chat there is no present basis for concern about adverse
health effects to the general public from the emissions of palladium
from automotive catalysts.
OMSAPC/EPA
October 1977
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON. D.C, 20460
OFFICE OF
AIR AND WASTE MANAGEMENT
FACT SHEET
Claimed Health jjazards from Palladium Content of Catalysts
The Environmental Protection Agency has received a number of inquiries
and expressions of concern about the possibility of health hazards from
palladium. Palladium is used in small amounts in automotive catalysts.
To respond efficiently to these Inquiries, this Fact Sheet has been
prepared.
On September 2, 1977 a paper presented at the annual meeting of
the American Chemical Society expressed the view that palladium sulfates
and palladium nitrates were hazardous to health. In discussion of the
report, the author expressed his view that such substances may be
emitted from cars equipped with catalysts, or may be leached from
discarded catalysts from junked cars. This story was widely reported
by the press.
EPA has closely reviewed the issues involved in this matter.
On the basis of limited data available it is estimated that the rate
of emissions of palladium from new catalyst-equipped cars is in the
range of two millionths of a gram per mile. This is a negligible
amount,
Based on this level of palladium emissions, estimates have been
made of palladium concentrations in the atmosphere assuming the most
adverse meteorological and .traffic conditions. These estimates
indicate that the highest one hour concentration which might be
expected is about 0.0004 millionths of a gram per cubic meter of
air. In contrast, to compare this with levels associated with health
effects, the occupational threshold level value for platinum is
2.0 millionths of a gram per cubic meter of air.* It is currently
believed, based on.medical information from workplace environments,
that the worker can be exposed to higher levels of palladium than for
platinum compounds without developing similar adverse effects. As
a general rule, dividing the occupational threshold levels by 20
gives one a rough measure of a reasonable upper bound for general
*Time weighted average concentration for a normal eight hour workday
or 40 hour workweek, to which nearly all workers may be repeatedly
exposed, day after day, without adverse effects.
FS-56
-------
population exposure (i.e., 2/20 =0.1 millionths of a gram per cubic
meter of air). By this analysis, the "worst case" ambient concentra-
tion noted earlier is over two orders of magnitude lower than the
above calculated "safe" value for general population exposure.
Moreover, only about 10-15 percent of the emissions of palladium
which have been identified in tests of cars are in a water soluble
form which has the potential to be considered hazardous.
Based on the limited information currently available, there
does not appear to be significant observed health effects from
human exposure to palladium in the non-water soluble forra. In
view of the extremely low measured emissions and predicted ambient
concentrations of palladium from cars in any form, EP& has concluded
that there is no present basis for concern about adverse health effects
to the general public from the emissions of palladium from automotive
catalysts.
OMSAPC/EPA.
45581
-------
\ UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
I WASHINGTON, D.C, 20460
OFFICE OF
AIR AND WASTE MANAGEMENT
FACT SHEET
Emissions From Motorized Bicycles (Mopeds)
The EPA has received many inquiries concerning the
emissions of motorized bicycles (mopeds} and the applica-
bility of federal emission standards to these vehicles.
This fact sheet has been prepared to efficiently respond
to these questions*
Currently, moat mopeds are not subject to federal
emission, regulations* EPA promulgated in January 1977
emission controls applicable to 1978 and later model
year motorcycles. However, these regulations define motor-
cycles so that most mopeds are not covered by emission
standards, for motorcycles with engine displaceaents less
than 50 cubic centimeters (cc) are excluded from the pro-
visions of the regulations* In addition* any motorcycles
that can sot with an 80 kilogram (176 pound) driver a) start
from a dead stop using only the engine, or b) exceed a
maximum speed of 40 kilometers per hour (24.9 miles per
hour) on a level paved surface also are not covered.
Thus most mopeds are exempt from the current motorcycle
emission control requirements*
Mopeds were excluded from the motorcycle regulation for
two reasons* First, mopeds did not at the time represent a
large enough population of vehicles in the United States to
contribute significantly to the problems of urban air
pollution. Secondly, during the development of federal
exhaust emission regulations for motorcycles, it appeared
that moped emissions would be relatively low — about the
same as the level of emissions from small two-stroke motor-
cycles. Small two-stroke motorcycles Just about meet,
without any special control efforts, the most stringent
emission standards currently promulgated for motorcycles.
FS-57
-------
As part of its continuing effort to accurately charac-
terize emissions from motor vehicles, EFA completed in late
1977 the testing of nine mopeds over various steady state
operating cycles* The results of this testing are summarized
in Table I. For comparison purposes, this table also
presents the results of similar tests conducted on seven
pre-emission control two and four-stroke motorcycles. It
can be seen from the table that mopeds generally have lower
emission levels than the average of the seven motorcycles
tested. Further, in most cases the results of the steady
state tests for mopeds were below the most stringent allowable
emission levels promulgated for motorcycles (when tested
over a transient test cycle)' A more direct comparison
is not possible because mopeds can not keep up with
the speeds and accelerations required to run the
federal motorcycle emission test.
Conclusion: Currently available data do not provide a
basis for imposing emission control requirements on
mopeds. However, the EPA will continue to monitor
the contribution of mopeds to urban pollution. If
data in the future indicate that aopeds may become
a significant source of air pollution, it may be
necessary to reconsider the appropriateness of the
exemption of these vehicles from emission control
regula tions *
-------
Table I
Comparative Average Steady State Emissions (grams per kilometer)
Mode
Idle I/
5 mph
Steady State
10 mph
Steady State
20 mph
Steady State
30 mph
Steady State
Vehicle Type
Moped £/
Motorcycle —
HC
1.07
1.91
Emissions (g/km)
CO KOx
1.55
6.62
0.00
0.01
Moped
Motorcycle
Moped
Motorcycle
Moped
Motorcycle
Moped
Motorcycle
7.4
3.64
2.78
5.62
3.33
4.23
16.66
8.64
9.36
37.88
10.1
30.0
0.00
0.00
0.00
0.04
0.01
0.05
Motorcycle Emission Standards (1980 Model Year)
Transient
Test
Motorcycles
8.0 g/km 12,0 g/km No Standard
a/ Emissions expressed in grams per minute.
b_/ Average of 9 njopeds tested. (1977)
c/ Average of 7 1971-1972 model year motorcycles tested. Four
were two-stroke and 3 were four-stroke. Engine displacements
ranged from 125-1,200 cc. (1972)
EPA/OMSAPC 45582
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
OFFICE OF
AIR AfJO WASTE MANAGEMENT
FACT SHEET
Proposed Ruleraaking on Fuel Economy Labeling
Procedures for 1979 and Later Model Year Automobiles
This fact sheet has been prepared to respond efficiently to
questions regarding EPA's- plans to improve the fuel economy
estimates which -it provides 'to the public through the fuel
economy Mileage Guide, and through labels on new cars.
EPA measures fuel economy by driving cars on dynamometers
and dividing the miles driven during the test by the amount of fuel
used -to drive those mi'les. The amount of fuel used is determined
from the measured values of hydrocarbons, carbon monoxide., and
carbon dioxide in the exhaust that is collected during the test.
The fuel economy of each car is determined separately
for city and highway driving. The city test represents the
average results of trips made from a cold start and from a hot
start with an average speed of 20 miles per hour and an average
of 2,4 stops per mile. .The highway test is 10.2 miles long with
an average speed of 48.2 miles per hour, a maximum speed of 60
miles per hour and 0.1 stops per mile and simulates non-urban
driving. Model year 1978 labels and the Guide show these values,
and also a third value, the combined number, which is an average
of the city and highway estimates weighted 55/45 respectively.
On February 16, 1978, EPA proposed in the. .Fedgjral i_egi_ste_r
(43 FR 6817), several alternative means for publishing the fuel
economy estimates that are printed on the fuel economy labels
attached to new cars and light trucks and in the Gas Mileage
Guide_.
Option 1: Publish only a single value
miles-per-gallon fuel economy rating rather
than the city, highway and combined ratings
now .given.
FS-58
-------
The current city miles-per-gallon value
is one value under consideration since
studies indicate that it corresponds fairly
closely to the mileage that most drivers are
experiencing. This alternative would eliminate
the highway value for which studies have
shown a greater disparity between EPA ratings
and actual performance, and it eliminates the
problem of the car buyer who focuses only on
the optimum number.
Option 2: Publish three miles-per-galion
values but adjust the measured values
obtained from the EPA fuel economy test to
account for driving conditions more adverse
to fuel economy than those included in the
EPA tests, so that the published values would
represent low, mid-range and high fuel
economy for the car. Adverse conditions that
are not included in the EPA tests include
cold weather, poor roads, higher-than-legal
speeds, and less-than-optimum maintenance of
cars.
For example, the low value could represent
a combination, of city driving with shorter
average trip length than the current 7-1/2 mile
test (e.g. , 3 miles) under cold temperature
conditions (e.g., 33 degrees F.) rather than warm
(c. 75 degrees F.) weather. This could result in
a 25 percent fuel loss fcom the current city
estimate,
The mid-range value would represent the mean
fuel economy for all in-use driving. According
to several surveys, it appears that the measured
EPA city fuel economy, without adjustment, is
already close to that mean.
The high value would represent a level that
could reasonably be achieved by a. typical
driver, in a mix of city and highway driving
in a properly maintained and fully broken-in
car. It might be derived by averaging the
city and highway test values weighted 30% and
70% respectively.
-------
Option 3: Publish only a relative fuel
economy performance index in which the cars
are compared to a common base number, without
providing miles-per-gallon values as such.
The current combined value, which gives
credit for both city and highway fuel economy
performance, would be compared to a base
value, for example, the 1985 passenger
automobile fuel economy standard of 27.5 mpg.
Thus, for 1979 the combined value for each car
would be divided by 27.5 and multiplied by 100.
For example, an automobile achieving a combined
rating of 20 mpg would receive an index
rating (relative to this 1985 standard)
of 73, whereas a car with a combined rating
of 15 mpg would get an index rating of only
55. A car achieving 30 mpg would have an.
index rating of 109*
In addition to the changes discussed above, EPA has made
minor but important technical changes in the test procedure
for the 1979 model year. There will be no change in the driving
cycle, that is, the speed versus time relationship or pattern in
which the cars are driven. Changes in the driving cycle are in
effect precluded by the Energy Policy and Conservation Act. The
changes that have been made for model year 1979 make use of
a more realistic estimate for aerodynamic drag, which is simulated
during the test, the requirement that manual transmission cars
are shifted realistically, and the separate testing and reporting
of overdrive and non-overdrive transmissions and those with a
different number of forward speeds.
In addition to written comments on the Notice of Proposed
Rulemaking to be submitted to EPA by April 3, 1978, opportunity
for oral comments on these proposals have been provided in public
meetings in Chicago, Boston, and Atlanta,
MSAPC/45582
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON. D,C. 20460
OFFICE OF
AiR AND WASTE MANAGEMENT
Mobile Source Air Pollution Control
FACT SHEET
Limited Adjustments on Future Cars
EPA has received many inquiries about a proposed change in the
emission control regulations that would authorize EPA to set adjust-
ments on cars anywhere within their physically adjustable range
before making the emission test to determine if the car complies with
Federal emission standards. This Fact Sheet has been prepared to
respond efficiently to those inquiries.
1. What has EPA proposed?
To reduce excess emissions- due to maladjustment of vehicles^ EPA
has proposed a change in the regulations to provide that, before a
vehicle is tested to determine if it complies with emission standards,
adjustable engine or emission control parameters may be set to
any selected setting within the physical limits permitted for the
adjustment. As a matter of practice, it is anticipated that even
after this regulation is promulgated the adjustable settings on test
vehicles will still in most cases be set within the limits specified by
the manufacturer, since it is expected that the manufacturer will
physically limit or preclude the adjustability of these parameters to
settings other than those recommended. Thus, making it difficult to
maladjust vehicles is the intended purpose of the proposed regulations.
2. Why has EPA made such a proposal?
EPA has collected data on the emissions of in-use vehicles. These
data indicate that a substantial number of vehicles failed to meet the
emission standards to which they were certified. The largest percentage
of failures in use were due to excessive CO emissions, but many failed
to meet the HC or NOx standard as well, even though they had accumulated
relatively little mileage. The reasons for these high failure rates
were mostly due to maladjustment of the idle mixture control* Maladjust-
ment of other adjustable parameters, such as the choke and the spark
timing, also contributed to these failures.
FS-59
-------
-2-
3. Are there data that prove that maladjustment is a serious problem?
In a major survey EPA found that 63% of the 1975 model year vehicles
that were tested failed to meet the standards for one or more pollutants.
Of 587 1975 model year vehicles tested, 49% failed because of high CO
levels only or in combination with other pollutants. Another study,
called the Restorative Maintenance project, was initiated to better
evaluate why such a large percentage of these vehicles had excessive
emissions and to determine if normal emissions performance could be
restored. The results from this study provide more definitive
information about the frequency of occurrence of maladjustment and
disabling. About 47% of the one hundred vehicles tested in Chicago
had broken or missing idle limiter caps, and 33% were considered to
have had a maladjusted idle mixture (greater than 0.5% CO at
idle). Approximately 21% of the vehicles tested in Chicago exhibited
exhaust gas recirculation (EGR) system problems, 21% had problems with
the spark advance system, 12% had problems with the air induction system
and 23% had problems with the choke system* The idle mixture problems
and most of the spark advance system and choke problems are in the
category of maladjustment, whereas EGR and air induction system problems
are considered disabling problems. The significant result of these
findings is that most of those vehicles initially failing to meet the
emission standards because of maladjustment were in compliance after
the vehicles were properly adjusted.
4. What would the auto industry do to comply^ with the proposed regulation?
To avoid having a vehicle fail to meet emission standards when
EPA tests it, the auto industry under the proposed regulation would either
eliminate certain emission-sensitive adjustments from the engine, or would
limit the degree to which the adjustments can be changed*
For example, some cars already have sealed idle mixture adjustments,
and those cars whose idle mixture adjustments are easily accessible would
be redesigned so that the idle mixture would be sealed at the factory,
or so that the range of adjustment would be limited to settings at which
the car would meet emission standards. That does not mean that it would
be impossible to adjust the idle mixture if such adjustment were really
needed; however, it would require special skills and tools to make such
adjustments. As a result the maladjustments of idle mixture that have
been found to be so common on cars in use, and that cause excess emissions,
would be far less frequent.
Similary, the choke calibration would be fixed at the factory, and
possibly ignition timing or other emission-sensitive adjustments.
-------
-4-
10. When will this new regulation go into effect?
EPA has proposed that the new regulations go into effect with Che 1980
model year. However, it is possible that the automobile industry may need
additional time to comply with this requirement. Many persons, including
auto companies and service industry representatives, have commented on
the proposed regulation. The comments are currently being studied, and
EPA technical staff will prepare a final proposal for the consideration
of the EPA Administrator from the information obtained through the proposed
rulemaking process. EPA still hopes to make this important change, which
will greatly contribute to reducing vehicle emissions and thus help clean
up the air in our cities, for the 1980 model year, and will certainly be
able to decide how and whether to make this change in time for the
1981 model year.
EPA/OMSAPC/45583
-------
-3-
5. Would cars undgr this regulation be complejej.y majjrtenanee free?
No. There are numerous important maintenance operations that every
car needs. These would continue to be needed. For example, regular
oil, filter, and spark plug changes would not be affected by this
regulation.
6. Will it cost more to buy cars with fixed or limited adjustments?
EPA has estimated that at the most the cost of limiting adjustments
on cars may increase the price of a car by about $3.00, and that in
most cases the additional cost would be lower.
7. Will cars with limited or fixed_adjustments run properly?
Will fuel economy suffer?
If a car is properly designed and built, and if fuel filters are
changed as recommended by the manufacturer, there should be no
need to change most adjustments after a car is adjusted at the
factory. Modern detergent gasolines don't clog up carburetors as
older fuels used to do; therefore, it is not necessary to adjust the
idle mixture to compensate for changes in carburetion caused by
fuel deposits accumulating in the carburetor.
Fuel economy is expected to be better on cars with fixed or limited
adjustments, for in most cases a change from the manufacturer's speci-
fication tends to reduce fuel economy.
8* Will fixed or limited adjustments put mechanics out of work?
Mechanics do much more than simply adjust idle mixtures and chokes.
There is in the United States a significant shortage of competent
mechanics, and many people complain about having to wait long periods
to get their cars fixed. There is no reason to believe that this
minor change on cars would adversely affect employment opportunities
for mechanics.
9. Will the individual car owner still be able to maintain his car himself?
To the degree that he has the needed skills and tools, yes. Of course,
modern cars are much more complex machines than were cars in earlier
years. The man who was able to fix his own Model A Ford with little
more than a screwdriver and a pair of pliers would not get very far with
such tools on a modern car. But even where today there is an idle screw
to adjust, properly adjusting the idle mixture on a modern car is not
possible for most people without special tools and considerable training
and experience. Thus the average home mechanic will not be handicapped
by this change.
------- |