EPA/AA/CTAB/8 9 -0 8
Technical Report
Options For Controlling
the Global Warming Impact
From Motor Vehicles
by
Robert M. Heavenrich
J. D. Murrell
Karl H. Hellman
December 1989
NOTICE
Technical Reports do not necessarily represent final EPA
decisions or positions. They are intended to present technical
analysis of issues using data which are currently available.
The purpose in the release of such reports is to facilitate the
exchange of technical information and to inform the public of
•technical developments which may form the basis for a final EPA
decision, position or regulatory action.
U. S. Environmental Protection Agency
Office of Air and Radiation
Office of Mobile Sources
Emission Control Technology Division
Control Technology and Applications Branch
2565 Plymouth Road
Ann Arbor, Michigan 48105
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
ANN ARBOR. MICHIGAN 48105
OFFICE OF
AIR AND RADIATION
JAN 23 1990
MEMORANDUM
SUBJECT: Exemption From Peer and Administrative Review
FROM;
TO:
Karl H. Hellman, Chief
Control Technology and Applications Branch
Charles L. Gray, Jr., Director
Emission Control Technology Division
The attached report entitled "Options for Controlling the
Global Warming Impact From Motor Vehicles" (EPA/AA/CTAB/89-08),
discusses ways to form control approaches that could be
involved in a regulatory program for control of carbon dioxide
emissions from cars and light trucks.
Since this report is concerned only with the presentation
of data and its analysis and does not involve matters of policy
or regulations, your concurrence is requested to waive
administrative review according to the policy outlined in your
directive of April 22, 1982.
Concurrence:
Charles L. Gray, J
Date
ECTD
Nonconcurrence:
Date:
Charles L. Gray, Jr., Dir., ECTD
cc: E. Burger, ECTD
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Table of Contents
Page
Number
I. Abstract 1
II. Introduction 1
III. Carbon Dioxide As the Example Pollutant 1
IV. Basic Approach 2
V. Banking and Selling C02 10
VI. References 11
VII. Acknowledgment 11
APPENDIX A - A GLOBAL WARMING INDEX FOR LIGHT-DUTY
VEHICLES 12
APPENDIX B - C02 AND FUEL ECONOMY ' 14
APPENDIX C - TABULAR DATA 15
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I. Abstract
There is a great deal of interest in the subject of global
warming and potential ways to mitigate the impacts of emissions
that contribute to global warming. This paper discusses ways
to formulate approaches that could be involved in a regulatory
program for control of carbon dioxide emissions from cars and
light trucks.
II. Introduction
The worldwide problem of global warming has been the
subject of a substantial amount of interest for several years
now. Recent publications [1-4]* provide an overview of the
subject that indicates the magnitude and complexity of the
problem. EPA is currently studying the overall problem and
investigating the various routes toward mitigation of the
problem, as are others.[5,6]
In all the studies that have looked at the potential for
reducing the emissions that contribute to global warming, the
transportation sector has been identified as a key sector for
any future reductions, if reductions are necessary.
If control of global warming emissions is necessary for
the transportation sector, it is of interest to investigate
ways in which the requirements for controls could be structured.
This paper concentrates on the passenger car and light
truck sectors of transportation and presents ways in which
regulatory programs for them could be constructed.
III. Carbon Dioxide As the Example Pollutant
v
Cars and light trucks emit four primary gases of concern
with respect to global warming: carbon dioxide (C02),
methane (CH4), nitrous oxide (N2O), and chloroflourocarbons
(CFCs). In the general case, a global warming index could be
constructed for each vehicle as the basic building block for
control purposes. This index would be the sum of the mass of
each of the four pollutants multiplied by their respective
global warming potential per unit mass.
Numbers in brackets denote references listed at the end of
the paper.
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Chloroflourocarbons (CFCs) are not treated in this paper
because it appears that their contribution to global warming
from vehicles will be approached by the material substitution
route. Since all practical near-term fuels for vehicles
contain carbon, material substitution as an approach to the
problem is not practical and a reduction in the amount of C02
emitted is the major route toward mitigating the impact of
vehicle emissions on global warming.
We have chosen to use C02 as the example for this paper
for three reasons: 1) C02 accounts for nearly half of the
global warming effects of all greenhouse gases, 2) by far the
bulk of the emissions generated by cars and light trucks is
C02, and 3) if the refinement of adding the other pollutants
is necessary, their impacts can be taken care of by computing
the global warming index in terms of CO2 equivalents.
Therefore, the use of C02 as an example in this paper could
serve to explore the control concepts and those concepts can be
extended to include the other pollutants, if necessary.
Appendix A provides an example of an approach that could be
used.
IV. Basic Approach
There are three aspects of any sort of regulatory
requirement that are key to determining the overall stringency
of the requirement. They are: 1) the baseline year, 2) the
form of the requirement, and 3) value of quantitative
improvement required. For this paper two baseline years were
studied: 1978 and 1988. Since we wanted to include the
possibility of combining cars and light trucks into the same
fleet, we chose 1978 as one illustrative baseline year because
it was the. first year in which cars and light trucks were both
subject to fuel economy standards. In some legislation that
has been proposed, for example H.R.1078 of the 101st Congress,
1988 is selected- as the base year from which to require
improvements, so 1988 was also selected as a base year for this
study. Although 1974 has not been considered a base year, it
is worth noting that the U.S. Domestic carmakers have
approximately doubled their 1974 MPG.
Two possible forms of the requirement were studied: the
option of combining cars and light trucks into one fleet was
considered, along with keeping the fleets separate as they are
now. Considering the sales-weighted grams of C02 per vehicle
mile provided a logical starting point since the requirement
applies more to the emission of vehicles in the aggregate
rather than to specific vehicles.
Considering cars and trucks together or separately and
considering the measure of C02 in sales-weighted grams per
vehicle mile gives the cases to study as shown in Table l.
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o
Table l
Approaches Considered
Vehicles
Grams Per Vehicle Mile
Cars + trucks
combined
Cars only
Trucks only
fc(C02)c + ft(C02)t
(C02)c
(C02)t
Where:
nc
nt
(C02)c
(C02)t
fc
ft
Numbers of cars
Numbers of trucks
Sales-weighted grams per mile of C02 for cars
Sales-weighted grams per mile of C02 for trucks
nc/(nc + nt)
nt/(nc + nt)
For the methods studied, a reduction in C02 emissions is-
an ^improvement.
The C02 emissions per vehicle are calculated from known
MPG values using the relationship discussed in Appendix B:
C0:
8777
MPG
The database used to generate the data in this paper is
described in detail in reference 7, as are the methods used to
classify vehicles as Domestic, European, or Asian passenger
cars or as Domestic or Imported light trucks.
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-4-
The data used to generate the figures in this report are
tabulated in Appendix C. Figures 1 and 2 show trends in C02
for cars and trucks together since 1978, on an absolute basis
in Figure 1 and on a relative basis in Figure 2. Figure 1
indicates that reductions in overall C02 emissions have taken
place since 1978. Figures l and 2 can be read to indicate that
the Domestic passenger car class is the only one that has
reduced its C02 emissions both on an absolute and on a
percentage basis.
Figures 3, 4, and 5 show some of the details behind the
overall trends. In terms of C02 per vehicle per mile, Figure
3 shows the Domestics making the largest improvements (over 25
percent), the Asians improving less than 10 percent, and the
Europeans making essentially no change.
Figures 4 and 5 show that the car and truck trends taken
separately lead to the same conclusions as the combined car and
truck fleet.
Figures 6 through 10 show trends in C02 and values of
possible future standards in various Bills being considered by
Congress: H.R. 1078, S.1224, and S.1630. The values used for
H.R. 1078 and S.1224 both use 1988 as the base so the figures
are normalized to (divided by) the 1988 value. The miles per
gallon improvements in the two Bills were converted to CO2
reductions. For S.1630, the values in the Bill of 242 and 170
grams per mile are plotted along with the trend in C02
emissions in grams per mile.
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TeraGrams CO2 per Year
1980
1982 1984 1986
Model Year
1988
Figure 1 - Total CO2 per Year
by Vehicle Type & Origin
Domestic Trucks
Domestic Cars
Asian Cars
European Cars
Imported Trucks
100%
80%
60%
40%
20%
1980
1982 1984 1986
Model Year
1988
Domestic Trucks
Domestic Cars
Asian Cars
European Cars
Imported Trucks
Figure 2 - Percent of CO2 per Year
by Vehicle Type & Origin
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10%
Change since 1978, CO2/Mile/Vehicle
-40%-
-50%
1978
Domestic Cars/Trucks
Asian Cars/Trucks
European Cars/Trucks
All Cars/Trucks
1980
1982
1984
Model Year
1986
1988
1990
Figure 3 - Trend in CO2,
Cars & Trucks Combined
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-7-
10%
Change since 1978, CO2/Mile/Vehicle
-10%
-20%
-30%
-40%
-50%
Domestic Cars
Asian Cars
European Cars
All Cars
1978 1980 1982 1984 1986
Model Year
Figure 4 - Trend in CO2,
Passenger Cars
1988
1990
10%
Change since 1978, CO2/Mile/Vehicle
1980
1982
1984
Model Year
1986
1988
1990
Figure 5 - Trend in CO2,
Light Trucks
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Relative CO2/Mile/Vehicle
1.50-
1.25-
1.00-
0.75 -
0.50-
0.25-
0.00
H.R. 1078
Asian Cars
European Cars
Domestic Cars
i i i i r
1975
1980 1985
1990 1995 2000
Model Year
2005 2010
Figure 6 - CO2/Mile/Car, and H.R. 1078
Requirements (1.00 « All 1988 Cars)
Relative CO2/Mile/Vehicle
1.50-
1.25-
1.00-
0.75-
0.50-
0.25-
0.00
H.R. 1078
Imported Trucks
Domestic Trucks
-i—i—i—I—i—r
~\—i—r
1975 1980
1985 1990 1995
Model Year
2000
2005 2010
Figure 7 - CO2/Mile/Truck, and H.R. 1078
Requirements (1.00 - All 1988 Trucks)
-------
Relative CO2/Mile/Vehicle
1.50-
1.25-
1.00-
0.75-
0.50-
0.25-
0.00
S. 1224
Asian Cars
European Cars
Domestic Cars
1975 1980 1985 1990 1995
Model Year
Figure 8 - CO2/Mile/Car, and S.1224
Requirements (1.00 - All 1988 Cars)
2000 2005 2010
Relative CO2/Mile/Vehicle
1.50-
1.25-
1.00-
0.75-
0.50-
0.25-
0.00
S. 1224
Imported Trucks
Domestic Trucks
1975 1980 1985 1990 1995
Model Year
2000 2005
Figure 9 - CO2/Mile/Truck, and S.1224
Requirements (1.00 = All 1988 Trucks)
2010
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-10-
500
Grams CO2/Mile/Vehicle
400 -
300 -
200 -
100
Domestic Cars
European Cars
Asian Cars
S. 1630
V
I i I j I I I I 1 I I I I I
1975 1980 1985 1990 1995 2000
Model Year
Figure 10 - CO2/Mile/Car,
and S.1630 Requirements
2005
2010
V. - Banking and Selling C02
As approaches toward regulatory controls become more
flexible and market-oriented, issues such as banking and
trading (selling) become of greater interest. All the options
discussed in this paper are averaging approaches. It is of
some interest to discuss how banking and selling could be
utilized in the C02 control approaches discussed here.
Banking is defined as being able to store up credits from
performance better than required, and use them when performance
does not meet required levels. Both regulatory approaches
could utilize banking as part of the increased flexibility that
market-based regulatory mechanisms allow. Selling is another
issue. If selling of credits is to be contemplated, it would
have to somehow account for the number of vehicles involved,
not merely their average emissions. Modifying the regulatory
measure from average grams per mile to an average gram per mile
per vehicle basis would account for fleet size and result in a
sellable unit.
Converting the current statutory penalty for falling below
the fuel economy standards into dollars per vehicle gram of
C02 yields a value of slightly less than $5.00 per vehicle
gram, if the fuel economy level chosen is-about 27.5 mpg. Of
course the value of a credit would depend on the market, but as
long as the regulatory program included the possibility of a
fine for noncompliance, the value of the fine would set an
upper cap on what the credits were worth.
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VI. References
1. The Challenge of Global Warming, Abrahamson, Dean
Edward, Editor, Island Press, Washington, DC, 1989.
2. The Greenhouse Effect, Climate Change and
Ecosystems, Bolin, B., B. R. Doos, J. Jager and R. A. Warrich,
John Wiley & Sons, Chichester, 1986.
3. National Academy of Science, Current Issues in
Atomospheric Change, National Ac ademy gjf Science Press,
Washington, D.C., 1987.
4. "Global Trends in Motor Vehicles and Their
Implications For Climate Modification," Walsh, Michael P.,
World Resources Institute, December 1988.
5. "Policy Options For Stabilizing Global Climate,"
U.S. EPA Draft Report to Congress, February 1989.
6. "The Transportation Sector and Global Warming,"
Parson, Edward A., OTA, May 1989.
7. "Light-Duty Automotive and Technology Trends Through
1989," Heavenrich, R. M. and J. D. Murrell, U.S. EPA,
EPA/AA/CTAB/89-04, May 1989.
VII. Acknowledgment
The authors wish to express their sincere appreciation for
the word processing, editing, and manuscript preparation
provided by Jennifer Criss in the preparation of this report.
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APPENDIX A
A GLOBAL WARMING INDEX
FOR LIGHT-DUTY VEHICLES
To account for the global warming effects of pollutants
other than CO2, emission of these other pollutants can be
converted into C02 equivalents by considering their relative
global warming reactivity. Relative warming estimates for
methane (CH4) and nitrous oxide (N20) appear in Future
Atmospheric Carbon Dioxide Scenarios and Limitation Strategies
by J. A. Edmonds, et al., Noyes Publications, Park Ridge N.J.,
1986.On a mass basis these were determined to be approximately
50 for CH4 and 230 for N20.
Another evaluation of the global warming impact of CH4
and N2O is contained in "Comparing the Impacts of Different
Transportation Fuels On the Greenhouse Effect," a Consultant
Report to the California Energy Commission, by Acurex
Corporation, Report P500-89-001, April 1989. Converting the
molecule values from Table 2 of that report, values from 16 to
116 can be associated with CH4 and 286 to 449 can be
associated with N2O for relative global warming impact.
The overall global warming index, GWI, will be a
combination of the emissions from the vehicle and the relative
global warming impact factors assigned to CH4 and N2O. In
general:
GWI. = C02 + a CH4 + b N20
And, GWI = GWI(a,b) if specificied in this way will leave
no ambiguity in the values chosen for the index. For this
discussion, we have chosen to use GWI (a,b) = GWI (65,300).
Constructing the index then requires finding the emission
data for C02, CH4, and N20 from the vehicle of interest.
The values associated with gasoline-fueled vehicles are
typically 0.100 grams per mile for CH4 from Compilation of
Air Pollutant Emission Factors Volume II: Mobile Sources,
AP-42, Fourth Edition, September 1985, and 0.015 grams per mile
N20 from Regulated and Unregulated Exhaust Emissions From
Malfunctioning Three-Way Catalyst Gasoline Automobiles,
EPA-460/3-80-004, January 1980.
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The report entitled "Emissions, Fuel Economy, and
Performance of Light-Duty CNG and Dual-Fuel Vehicles," by
Bruetsch, R. I., EPA/AA/CTAB/88-05, June 1988, contains data
taken on dual-fuel vehicles, ones that can use either gasoline
or natural gas as the fuel. Using the data from that report,
we can construct a GWI (65,300) from the same vehicles using
different fuels.
Table A-l illustrates the importance of the emission
values in constructing GWI (65,300). Table A-l also can be
used to conclude that reliance on C02 only when considering
global warming may produce incorrect conclusions.
Table A-l
Calculated Global Warming Index,
Gasoline and CNG-Fueled Vehicles
Vehicle
C02 CH4 NZ0*
Fuel (gm/mi) (gm/mi) (gm/mi) GWI(65,300)
Delta 88
Delta 88
Gasoline
CNG
Crown Victoria Gasoline
Crown Victoria CNG
Celebrity
Celebrity
0
2
0
3
0
1
.145
.456
. 103
.164
.024
.478
0
0
0
0
0
0
.015
.015
.015
.015
.015
.015
632 0.145 0.015 646
464 2.456 0.015 628
582 0.103 0.015 593
429 3.164 0.015 639
Gasoline 435 0.024 0.015 441
CNG 354 1.478 0.015 455
N20 was not measured in this test program; the same
nominal value is used for all entries.
In SAE Paper 890492, "Nitrous Oxide N20 In Engines
Exhaust Gases - A First Appraisal of Catalyst Impact," by M.
Prigent and G. DeSoete, a summary of N20 values is provided.
The values in Table 1 of that paper range from 4.8 to 101 mg/mi
N20, with an average value of 52 mg/mi. Using 52 mg/mi in
the calculations in Table A-l (instead of the 15 mg/mi used)
would increase the GWI (65,300) values by approximately 11
units, but it would not change the ranking. Given the spread
in the values summarized in Paper 890492, it would appear,
however, that measured N20 data is a desirable part of any
estimates of global warming impact, and measurements of C02,
CH4, and N20 from a variety of engines and fuels would be
the minimum needed before a definitive ranking could be
attempted.
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APPENDIX B
RELATIONSHIP BETWEEN
CO2 AND FUEL ECONOMY
The carbon balance method for calculating fuel economy
used by EPA computes miles per gallon as the ratio of grams of
carbon per gallon of fuel to grams of carbon per mile. One
version of this equation for gasoline-fueled vehicles from the
Federal Register, Volume 51, No. 206, Friday, October 24, 1986,
page 37,846 is:
MPG = 2421
0.866 HC + 0.429 CO + 0.273 C02
Where, HC, CO, and CO2 are the grams per mile of the
carbon containing exhaust constilatients. Another form of the
same equation is:
MPG = 8868 1
C02 (1 + 3.17 HC/C02 +1.57 CO/CO2)
For today's cars, the term in parentheses represents
roughly a 1 percent adjustment to the 8868/C02 term. The use
of HC/CO2 and C0/C02 ratios different from those of today's
cars results in a larger adjustment if the emission ratios are
larger. Using higher emission values lowers the value of the
conversion constant. The use of a constant value (8777) in
this analysis, therefore, tends to overestimate the CO2
emissions from the earlier years when the HC and CO emissions
were higher. This error is at most about 5 percent. The
benefits gained from using the simple inverse relationship
between MPG and C02 are that an existing MPG database can be
converted directly into a C02 database. The conclusions in
this paper are also not sensitive to the error introduced by
the use of the simplified relationship.
The MPG - C02 relationship is based on the tests used to
determine the primary variable. For this report, we have used
the EPA composite "55/45" MPG value to infer the CO2
results. Therefore, the C02 values also correspond to a
composite city-highway C02 value. Considered as an emission,
this treatment of C02 is different from the treatment of
other regulated emissions like HC, CO, and NOx, whose values
and standards are determined using the "city" cycle only.
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APPENDIX C : TREND IN C02 PER VEHICLE
C02/
Model
Year
Domestic
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
European
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
55/45 Sales Vehicle
MPG Millions (
Passencrer
18.74
19.26
21.95
23.47
24.50
24.14
25.09
25.76
26.58
26.63
27.16
26.81
Passencrer
23.91
24.40
27.98
29.36
28.58
27.17
26.75
26.31
26.03
25.90
25.65
24.59
Cars
9.084
8.761
6.820
6.261
5.506
5.682
8.102
7.797
7.515
6.702
6.616
6.233
Cars
.582
.520
.699
.525
.494
.441
.640
.666
.735
.745
.643
.593
'gm/mi)
468.4
455.8
399.9
373.9
358.2
363.5
349.8
340.7
330.2
329.6
323.2
327.3
367.1
359.7
313.7
299.0
307.1
323.0
328.1
333.5
337.2
338.8
342.2
356.9
Asian Passencrer Cars
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
28.67
26.72
28.97
30.93
31.22
32.70
32.73
32.23
32.91
32.09
32.57
31.88
1.510
1.513
1.924
1.948
1.819
1.879
1.933
2.328
2.765
3.364
3.401
3.461
306.1
328.5
303.0
283.8
281.1
268.4
268.2
272.3
266.7
273.5
269.5
275.3
55/45 C02/
MPG Sales Vehicle
0.656
0.674
0.768
0.821
0.858
0.845
0.878
0.902
0.930
0.932
0.951
0.938
0.837
0.854
0.979
1.028
1.000
0.951
0.936
0.921
0.911
0.907
0.898
0.861
1.004
0.935
1.014
1.083
1.093
1.145
1.146
1.128
1.152
1.123
1.140
1.116
0.852
0.822
0.640
0.587
0.517
0.533
0.760
0.731
0.705
0.629
•0.621
0.585
0.055
0.049
0.066
0.049
0.046
0.041
0.060
0.062
0.069
0.070
0.060
0.056
0.142
0.142
0.180
0.183
0.171
0.176
0.181
0.218
0.259
0.316
0.319
0.325
1.525
1.484
1.302
1.217
"1.166
1.183
1.139
1.109
1.075
1.073
1.052
1.065
1-.195
1.171
1.021
0.973
1.000
1.051
1.068
1.086
1.098
1.103
1.114
1.162
0.996
1.069
0.986
0.924
0.915
0.874
0.873
0.886
0.868
0.890
0.877
0.896
Note : 1.000 = All 1988 Cars
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C02/
Model
Year
Domestic
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
Imported
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
55/45 Sales
MPG Millions
Light Trucks
14.55 2.915
13.83 2.616
16.80 1.293
18.22 1.310
19.03 1.459
19.64 1.806
19.23 2.608
19.52 2.938
19.93 3.055
20.45 3.160
20.43 3.705
20.29 3.604
Licrht Trucks
25.07 .358
23.14 .473
24.34 .571
27.34 .510
27.14 .454
27.11 .495
26.56 .737
26.34 .730
26.15 1.296
25.55 1.146
24.50 .899
24.16 .942
Vehicle
(gm/mi)
603.4
634.8
522.5
481.8
461.3
447.0
456.5
449.6
440.5
429.2
429.6
432.6
350.1
379.3
360.6
321.0
323.4
323.7
330.5
333.2
335.7
343.5
358.2
363.3
55/45 C02/
MPG Sales Vehicle
0.689
0.655
0.795
0.863
0.901
0.930
0.911
0.924
0.944
0.968
0.967
0.961
1.187
1.096
1.152
1.295
1.285
1.284,
1.258
1.247
1.238
1.210
1.160
1.144
0.633
0.568
0.281
0.285
0.317
0.392
0.567
0.638
0.664
0.687
0.805
0.783
0.078
0.103
0.124
0.111
0.099
0.108
0.160
0.159
0.282
0.249
0.195
0.205
1.452
1.527
1.257
1.159
1.110
1.076
1.098
1.082
1.060
1.033
1.034
1.041
0.842
0.913
0.868
0.772
0.778
0.779
0.795
0.802
0.808
0.827
0.862
0.874
Note 1.000 = All 1988 Light Trucks
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C02/
Model
Year
Domestic
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
European
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
55/45
Sales
MPG Millions
Trucks
17.51
17.66
20.93
22.36
23.11
22.88
23.36
23.69
24.24
24.28
24.29
23.99
Trucks &
23.89
24.29
27.81
29.37
28.54
26.86
26.47
26.14
25.89
25.71
25.52
24.44
Asian Trucks & Ca
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
27.92
25.81
27.81
30.12
30.34
31.47
30.90
30.68
30.45
30.19
30.51
29.89
& Cars
11.999
11.376
8.112
7.571
6.965
7.488
10.709
10.736
10.570
9.862
10.321
9.837
Cars
.584
.529
.741
.569
.523
.456
.667
.685
.746
.760
.651
.603
rs
1.865
1.977
2.453
2.414
2.244
2.358
2.643
3.039
4.049
4.495
4.292
4.392,
Vehicle
(am/mi)
501.2
497.0
419.4
392.6
379.8
383.7
375.8
370.5
362.1
361.5
361.4
365.9
367.4
361.4
315.6
298.8
307.6
326.7
331.6
335.8
339.0
341.4
343.9
359.1
314.4
340.1
315.6
291.4
289.3
278.9
284.1
286.0
288.2
290.7
287.7
293.7
55/45 C02/
MPG Sales Vehicle
M—
0.678
0.684
0.811
0.866
0.895
0.886
0.905
0.918
0.939
0.940
0.941
0.929
0.925
0.941
1.077
1.137
1.105
1.040
1.025
1.012
1.003
0.996
0.988
0.947
1.081
1.000
1.077
1.167
1.175
1.219
1.197
1.188
1.179
1.169
1.182
1.158
0.786
0.745
0.531
0.496
0.456
0.491
0.702
0.703
0.692
0.646
0.676
0.644
0.038
0.035
0.049
0.037
0.034
0.030
0.044
0.045
0.049
0.050
0.043
0.040
0.122
0.130
0.161
0.158
0.147
0.154
0.173
0.199
0.265
0.294
0.281
0.288
1.475
1.462
1.234
1.155
1.117
1.129
1.106
1.090
1.065
1.064
1.063
1.076
1.081
1.063
0.929
0.879
0.905
0.961
0.976
0.988
0.997
1.004
1.012
1.056
0.925
1.001
0.929
0.857
0.851
0.821
0.836
0.841
0.848
0.855
0.846
0.864
Note : 1.000 = All Light Trucks and Cars
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-18-
C02/
Model 55/45 Sales Vehicle
Year MPG Millions (gm/mi)
All Passencrer Cars
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
All Licrht
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
All Trucks
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
19.89
20.25
23.48
25.13
26.04
25.89
26.30
26.96
27.89
28.06
28.57
28.17
Trucks
15.24
14.73
18.56
20.10
20.48
20.87
20.47
20.58
21.45
21.60
21.12
20.99
& Cars
18.61
18.70
22.50
24.09
24.72
24.57
24.63
25.00
25.70
25.86
25.82
25.50
11.175
10.794
9.443
8.733
7.819
8.002
10.675
10.791
11.015
10.811
10.660
10.286
3.273
3.088
1.863
1.821
1.914
2.300
3.345
3.669
4.350
4.305
4.603
4.546
14.448
13.882
11.306
10.554
9.732
10.302
14.020
14.460
15.365
15.116
15.264
14.832
441.2
433.3
373.8
349.3
337.1
339.0
333.7
325.5
314.7
312.8
307.2
311.5
575.7
595.7
472.9
436.8
428.6
420.5
428.7
426.4
409.3
406.4
415.6
418.2
471.7
469.5
390.1
364.4
355.1
357.2
356.4
351.1
341.5
339.5
339.9
344.2
55/45 C02/
MPG Sales Vehicle
0.696
0.709
0.822
0.880
0.911
0.906
0.921
0.944
0.976
0.982
1.000
0.986
0.722
0.697
0.879
0.952
0.970
0.988
0.969
0.974
1.016
1.023
1.000
0.994
0.721
0.724
0.871
0.933
0.957
0.952
0.954
0.968
0.995
1.002
1.000
1.048
1.013
0.886
0.819
0.733
0.751
1.001
1.012
1.033
1.014
1.000
0.965
0.711
0.671
0.405
0.396
0.416
0.500
0.727
0.797
0.945
0.935
1.000
0.988
0.947
0.909
0.741
0.691
0.638
0.675
0.919
0.947
1.007
0.990
1.000
1.436
1.410
1.217
1.137
1.097
1.104
1.086
1.060
1.024
1.018
1.000
1.014
1.385
1.433
1.138
1.051
1.031
1.012
1.032
1.026
0.985
0.978
1.000
1.006
1.388
1.381
1.148
1.072
1.045
1.051
1.049
1.033
1.005
0.999
1.000
0.988
0.972 1.013
Note : 1.000 = All Cars, All Light Trucks or
All Light Trucks and Cars as indicated above
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