TRANSPORTATION ENERGY DATA BOOK: EDITION 22 - Center for ...

7–26
The two earlier studies by the Federal Highway Administration (FHWA) indicate maximum fuel efficiency was
achieved at speeds of 35 to 40 mph. The recent FHWA study indicates greater fuel efficiency at higher speeds.
Note that the 1973 study did not include light trucks.
Table 7.24
Fuel Economy by Speed, 1973, 1984, and 1997 Studies
(miles per gallon)
Speed
(miles per hour)
1973 a
(13 vehicles)
aModel years 1970 and earlier automobiles.
bModel years 1981–84 automobiles and light trucks.
c Model years 1988–97 automobiles and light trucks.
dData are not available.
1984 b
(15 vehicles)
1997 c
(9 vehicles)
15 d 21.1 24.4
20 d 25.5 27.9
25 d 30.0 30.5
30 21.1 31.8 31.7
35 21.1 33.6 31.2
40 21.1 33.6 31.0
45 20.3 33.5 31.6
50 19.5 31.9 32.4
55 18.5 30.3 32.4
60 17.5 27.6 31.4
65 16.2 24.9 29.2
70 14.9 22.5 26.8
75 d 20.0
Fuel economy loss
24.8
55–65 mph 12.4% 17.8% 9.7%
65–70 mph 8.0% 9.6% 8.2%
55–70 mph 19.5% 25.7% 17.1%
Source:
1973- U.S. Department of Transportation, Federal Highway Administration,
Office of Highway Planning, The Effect of Speed on Automobile Gasoline
Consumption Rates, Washington, DC, October 1973.
1984 - U.S. Department of Transportation, Federal Highway Administration, Fuel
Consumption and Emission Values for Traffic Models, Washington, DC,
May 1985.
1997 - West, B.H., R.N. McGill, J.W. Hodgson, S.S. Sluder, and D.E. Smith,
Development and Verification of Light-Duty Modal Emissions and Fuel
Consumption Values for Traffic Models, FHWA Report (in press),
Washington, DC, April 1997, and additional project data, April 1998.
(Additional resources: www.fhwa-tsis.com)
TRANSPORTATION ENERGY DATA BOOK: EDITION 22—2002