EPA/AA/CTAB/90-01
                                Technical Report


                     Downward  Trend in Passenger Car
                Fuel Economy— a View of Recent Data
                                      by
                               J. Dillard Murrell
                                      and
                              Robert M. Heavenrich
                                  January 1990
                                    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

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      UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

                   ANN ARBOR. MICHIGAN 48105
                                                       OFFICE OF
                                                    AIR AND RADIATION
MEMORANDUM
SUBJECT:   Exemption From Peer and Administrative  Review
FROM:
Karl H. Hellman, Chief
Control Technology and Applications Branch
TO:
Charles L. Gray, Jr., Director
Emission Control Technology Division
     The  attached  report entitled  "Downward Trend in  Passenger
Car Fuel  Economy—A View of  Recent Data,"  (EPA/AA/CTAB/90-01),
is a  brief  analysis of the two-year  trend in fuel economy  from
model  year  1988  to model  year  1990, and  where  the  data  may
indicate fuel economy is headed.

     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
                                    Date
               Cha
                                ECTD
Nonconcurrence:
                                    Date:
               Charles L. Gray, Jr., Dir.,  ECTD

cc:  E. Burger, ECTD

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   Last year's technology and MPG trend report[l] noted  an 0.4 MPG decline in average
passenger car fuel  economy  from  1988. Regarded as possibly just a  one-time blip  in
the curve, the decline was neither emphasized nor subjected to any close scrutiny.

   The  model year  1990 data is in, and it  shows another  decline in  fuel economy— it
is  now  a two-year  trend.  If  this backslide continues, problems with nationwide fuel
consumption  will increase and global warming trends will worsen  at a pace faster than
is  generally being assumed  by analysts. Thus  it is appropriate  to explore some of the
characteristics of, and causes for, of the downward MPG  trend.

   The  data  used for this  report  come from  the  auto manufacturers,  and  represent
their forecasts of production  for the  U.S. market. For the current model year and  its
predecessor  year  (prior  to  finalization  of  the official  data for.  fuel  economy
standards compliance),  the  data  are furnished for,  and  used primarily for,  the fuel
economy  labeling and  Gas  Mileage Guide programs.  The  data are checked against
subsequent, but  still pre-model-year, MPG and  production  volume figures furnished  by
the manufacturers  to the  Department  of Transportation and to  the  trade  press, and
adjusted accordingly. All  MPG figures herein  are EPA  combined  city-highway, "55/45"
MPG; no on-road or test procedure  correction factors have been applied to any of the
MPG data. Vehicle weights are "inertia weight," i.e. curb weight plus 300 Ibs.

   Table 1 summarizes the two-year MPG decline for  the passenger car fleet from 1988
to  1990, and the corresponding trends in vehicle weight  and engine and acceleration
characteristics (to prevent inter-year  changes  in the  sales mix among  manufacturers
from distorting the  comparison, the 1990 mix was  also  used with the 1988 data).

   From 1988 to 1990, there was  a 4% decline  in MPG  and a  6%  weight gain; yet,
average  zero-to-60  MPH  acceleration  time* continued  to decrease,  due to  the 10%
increase in average engine horsepower.  The horsepower  increase  is the  result  of a 7%
gain in average engine power density  (HP  per cubic  inch)  and a 4% rise  in average
cubic inch displacement.

   The  fleet-level trends  are mirrored directionally  in all three  of  the major market
sectors  (import figures  include cars built in the U.S.  by  foreign companies,  and cars
built  overseas for  sale  by U.S. companies). Domestic  cars, European cars,  and  Asian
cars all lost MPG, with Asian car  MPG dropping at a rate at least double that of the
other two  sectors.  All  three  sectors gained weight,  with Asian  cars  gaining it at  a
rate more  than double that  of  the other  two.  All three  sectors boosted horsepower
(more than enough  to offset their  weight  gain), with Asian  cars  increasing  in average
horsepower at a rate  three times that  of the .Europeans  and more than  four times that
of the Domestics.

   The  method  used  to increase power differs from  sector  to  sector:  the  Europeans'
power gain was due  entirely  to power  density  improvements, while the  Domestics' and
Asians'  power increases came by adding CID increases on top of HP/CID increases, in
about  equal  proportions.  Asian  cars'  average  CID is increasing by  5% a year, and
HP/CID even faster.

   Given no  more information than that the above parameters of concern are  changing
in the  same  direction  across all three market sectors,  it could be  inferred  that  all
manufacturers in  each  sector  share/contribute equally in  the sector's behavior.
However, only one  or two high-selling manufacturers in a  sector could  be driving the
sector  averages; hence  it is  pertinent  to  examine  the data  across the  manufacturers
in each sector.
* estimated; see [2].

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   Table 2 shows several aspects of the fuel economy trend,  by manufacturer. The  22
manufacturers  shown  are the  top-sellers; of  the total  projected 1990  sales,  each
represents 0.1% or greater,  and together they represent more than 98%. The upper part
of the table lists those  with MPG declines  between  1988  and  1990; the  lower part
lists those four whose MPG did not drop in that interval.

   The first numeric column in  Table 2 shows the 1988 to 1990 MPG change for each
manufacturer: the eight greatest losses were posted by Asian  companies,  the  Domestics
appear in the lower  half of the upper (backsliding) group, and three of  the  four non-
backsliding manufacturers are European.

   The second and third columns are reminders that MPG backsliding has  been going  on
for more than just the  last two years. Comparing each manufacturer's 1990 MPG to  its
highest average, whenever it occurred, all  these companies except Yugo have lost MPG
to some  degree; of the ten who have  lost it  in double  figures,  seven  are Japanese,
three  German.  Some companies  have a history of several consecutive  years of MPG
backsliding.

   The two rightmost  columns give linear projections of  the  two-year  MPG trend:  if
the current  rates of  decline continue,  15  of the  18 backsliding manufacturers
(including all three Domestics) will drop below 25  MPG before the end of the decade;
the fleet  will drop below 25 MPG by 1995.

   Table 3 shows the  1988 to 1990  change in average weight by  manufacturer. All
except BMW  gained  weight, and all  who  gained in  double figures  are  Japanese. The
figures for Mitsubishi and Daewoo do not fit the pattern of other Asian companies.

   Table 4 gives the two-year change in performance capability.  All manufacturers  in
double figures are Asian. Again, the  Mitsubishi and  Daewoo figures do  not  appear  to
be typically  "Asian".  Ford is not  on  the performance-increase  track  of  the  other
Domestics.

   The  magnitudes  of the horsepower  increases  in  Table  5 are  surprisingly  large
compared to past trends.  More than  half the  manufacturers  are increasing  their
average power in double figures; Asian  manufacturers lead the power growth trend;  in
fact,  every  Japanese manufacturer  except Mitsubishi  is  increasing power  in  double
figures.

   The two-year trends  in engine  specific power, Table  6. and engine displacement,
Table 7.  follow  the  pattern seen above: where there are double-figure increases there
are Asian companies.  Five of the  six companies who held average CID  constant,  or
decreased it  (Table  7), still gained in  average power  (Table  5) by improving  power
density (Table 6).

   Light-duty trucks have a downward trend in fuel economy too: see Table  8.


References


1. Heavenrich and Murrell, "Light Duty Automotive Technology and Fuel Economy Trends
Through  1989," Report  EPA/AA/CTAB/89-04, May 1989.

2. Heavenrich, Murrell, and Cheng, "Light Duty Automotive Fuel Economy and Technology
Trends Through 1987,"  SAE Paper 871088, May  1987.

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                               Table 1
       Two-year Trend: Percent Change, 1988 to 1990 Models
A.  55/45 MPG
B.  Weight
C.  0-60 Time
D.  Horsepower
E.  Engine HP/CID
F.  Engine CID
Fleet
-4
6
-4
10
7
4
Domestic
-3
4
-1
5
3
2
European
-2
4
-3
8
8
0
Asiz
-6
9
-9
22
11
10
    Note: the 1988 figures use the 1990 mix of sales volumes by manufacturer.

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                                     Table 2
             Manufacturers Decreasing Their Average Fuel Economy
Manufacturer
Isuzu
Toyota
Subaru
Nissan
Diahatsu
Hyundai
NUMMI
Mazda
Honda
Chrysler
Volvo
Saab
VW-Audi
GM
Ford
Jaguar
Daewoo/GM
Suzuki
% Change in
Co.Avg.F.E.
1988 to 90
-9
-9
-9
-8
-8
-7
-6
~5
-4
-4
-4
-3
-3
-3
-2
-2
-2
-1
% Change in
Co.Avg.F.E.
Max. to 90
-13
-10
-9
-15
-8
-7
-10
-17
-13
-4
-7
-3
-16
-3
-3
-2
-2
-12
No. Consecu-
tive Years of -
MPG Decline L

3


2
2


7
2
4
2
2
2




Linear Projection:
Year to Drop Below:
30 MPG 25 MPG
1993
now
now
now
1997
1993
1993
now
1991
now
now
now
now
now
now
now
>2000
>2000
1996
1994
1993
1993
2000
1997
1998
1996
1999
1994
now
1991
1998
1995
1994
now
>2000
>2000
Manufacturers Not Decreasing
 Their Average Fuel Economy
Manufacturer

Mitsubishi
Yugo
Mercedes
BMW
% Change in
Co.Avg.F.E.
 1988 to 90

      0
      0
      0
      3
% Change in
Co.Avg.F.E.
 Max, to 90

      -8
       0
     -21
     -19

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                               Table 3
Their Average Weight
Manufacturer

Subaru
Toyota
Suzuki
Isuzu
NUMMI
Nissan
Mazda
Chrysler
Diahatsu
Hyundai
Honda
VW-Audi
Mercedes
Volvo
Ford
Saab
GM
Mitsubishi
Daewoo/GM
Yugo
Jaguar
reasing
ight
% Change in
Avg. Weight
1988 to 90
16
13
12
11
10
9
8
8
8
7
5
5
5
4
4
3
3
2
2
1
1
Manufacturer Not Increasing
Its Average Weight
% Change in
Avg. Weight
Manufacturer 1988 to 90
BMW -1





















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Table 4
Manufacturers Increasing
Their Acceleration Performance
Manufacturer
Nissan
Isuzu
NUMMI
Hyundai
Diahatsu
Jaguar
Subaru
BMW
Mazda
Volvo
Suzuki
GM
Honda
Saab
Daewoo/GM
Toyota
Chrysler .
% Change in
0-60 Time,
1988 to 90
-23
-18
-17
-16
-12
-8
-7
-6
-6
-6
-5
-5
-4
-4
-3
-3
-3
Manufacturers Not
Their Acceleration
Manufacturer
Yugo
VW-Audi
Mercedes
Mitsubishi
Ford












Increasing
Performance
% Change in
0-60 Time,
1988 to 90
0
0
0
3
8













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                               Table 5
Manufacturers Increasing
Manufacturer

Nissan
Isuzu
NUMMI
Hyundai
Diahatsu
Subaru
Suzuki
Toyota
Mazda
Volvo
Jaguar
Chrysler
Honda
GM
Saab
VW-Audi
Daewoo/GM
Mercedes
BMW
Yugo
easing
sepower
% Change in
Engine HP
1988 to 90
51
43
37
35
31
29
21
20
16
12
12
11
11
10
8
8
7
6
6
2
Manufacturers Not Increasing
Their Average Horsepower
% Change in
Engine HP
Manufacturer 1988 to 90
Mitsubishi -2
Ford -6



















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                                Table 6
Manufacturers Increasing
Manufacturer

Isuzu
NUMMI
Nissan
Suzuki
Volvo
Mercedes
Hyundai
Diahatsu
Subaru
BMW
Toyota
Saab
GM
Mitsubishi
Chrysler
Honda
Mazda
Jaguar
VW-Audi
Daewoo/GM
asing
Density
% Change
inHP/CID
1988 to 90
39
37
23
18
13
13
13
11
10
10
8
8
8
7
6
5
5
4
3
1
Manufacturers Not Increasing
Their Engine Power Density
% Change
inHP/CID
Manufacturer 1988 to 90
Yugo 0
Ford -9



















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                                 Table?
Manufacturer

Nissan
Hyundai
Diahatsu
Subaru
Toyota
Mazda
Jaguar
Daewoo/GM
Honda
Chrysler
VW-Audi
Isuzu
Suzuki
Ford
Yugo
GM
reasing
lacement
% Change in
Engine CID
1988 to 90
23
20
18
17
11
11
7
6
5
5
4
3
3
2
2
1
Manufacturers Not Increasing
Their Engine Displacement
Manufacturer
Saab
NUMMI
Volvo
BMW
Mercedes
Mitsubishi










% Change in
Engine CID
1988 to 90
0
0
-1
-4
-6
-9











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                 Table 8
 Three-year MPG Trend, Light Trucks:
 Percent Change, 1987 to 1990 Models


                              % Change in
                               Avg. F.E.
                                1987 to 90

Fleet                                 -1

Domestic                              0
  Chrysler                             5
  GM                                 3
  Ford                                -6
  Grumman                           -6

European                              7
  Volkswagen                          11
  Rover                              -1

Asian                               -10
  Nissan                               4
  Suzuki                              -3
  Mazda                              -6
  Toyota                             -13
  Mitsubishi                          -16
  Isuzu                              -19

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Appendix

   It  is appropriate to show more detail  for some  specific  cases  to  illustrate how
trends in  some  of these  technical  parameters are influenced.   We  have chosen  two
cases  where  engine  size  and horsepower  changes are noteworthy; the  two cases are
Ford,  whose  overall  results indicate a  decrease in average power density (horsepower
per CID), and Nissan, who had the largest average horsepower increase.

   The tables below  show how  changes in  engine  offerings and sales  mix shifts among
them  combine  to produce  changes  in sales-weighted  average  values  for  CID  and
horsepower and,  correspondingly,  power density.   The Ford  trend  is  a result  of sales
shifts away from higher horsepower versions within each engine type.   Nissan's trend
results from  higher  CID offerings, higher  powered  versions within them,  and  sales
shifts (both within and among the  engines) toward higher  power.
       1988 Ford Engines:
                           1990 Ford Engines:

Cylinders
4
4

4
Avg.4
6
6
Avg.6
8
8
Avg.8
Co.Avg.

CID
113
140

152
129
182
231
206
302
351
303
201
Hp
Versions
81,84,90,108
96,98,100,
151,194
88
99
140
150
145
150,220
180
192
139

Cylinders
4
4
4
Avg.4
6
6
Avg.6
8
8
Avg.8
Co.Avg.

CID
113
140
152
132
182
231
209
302
351
304
206
Hp
Versions
84,90,108
96,98,100
88
95
140,220
120,140,210
140
150,225
180
162
130
       1988 Nissan Engines:
                           1990 Nissan Engines:
Cylinders
4
4
4
Avg.4
6
Avg.6
CID
98
110
120
103
181
181
Hp
Versions
70
125
94,97,99
78
157,165,205
160
                                               Cylinders   CID
        Co.Avg.
120
96
   4
   4
   4

 Avg.4

   6

 Avg.6

   8

Co.Avg.
 98
110
146

117

181

181

274

148
                                                 Hp
                                               Versions
                                                                      90
                                                                      125
                                                                    138,140
                                                                      110

                                                                  160,225,280
186

278

146

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