_id	Speed	1973a	1984b	1997c	2012d
1	(miles per hour)	(13 vehicles)	(15 vehicles)	(9 vehicles)	(74 vehicles)
2	15.0	e	21.1	24.4	e
3	20.0	e	25.5	27.9	e
4	25.0	e	30.0	30.5	e
5	30.0	21.1	31.8	31.7	e
6	35.0	21.1	33.6	31.2	e
7	40.0	21.1	33.6	31.0	33.2
8	45.0	20.3	33.5	31.6	e
9	50.0	19.5	31.9	32.4	31.9
10	55.0	18.5	30.3	32.4	e
11	60.0	17.5	27.6	31.4	27.9
12	65.0	16.2	24.9	29.2	e
13	70.0	14.9	22.5	26.8	24.1
14	75.0	e	20.0	24.8	e
15	80.0	e	e	e	20.5
16	Fuel economy loss	""	""	""	""
17	50–60 mph	0.103	0.135	0.031	0.125
18	60–70 mph	0.149	0.185	0.146	0.136
19	50–70 mph	0.236	0.295	0.173	0.245
20	""	""	""	""	""
21	Sources:	""	""	""	""
22	"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. "	""	""	""	""
23	""	""	""	""	""
24	""	""	""	""	""
25	"1984 - U.S. Department of Transportation, Federal Highway Administration, Fuel  
     Consumption and Emission Values for Traffic Models, Washington, DC, May 1985."	""	""	""	""
26	""	""	""	""	""
27	"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-RD-99-068, U.S. Department of Transportation, Federal Highway 
     Administration, Washington, DC, March 1999. "	""	""	""	""
28	""	""	""	""	""
29	""	""	""	""	""
30	""	""	""	""	""
31	"2012 - U.S. Department of Energy and U.S. Environmental Protection Agency, Fuel Economy 
     Guide website:  www.fueleconomy.gov.  The Green Car Congress, ""ORNL researchers 
     quantify the effect of increasing highway speed on fuel economy."" February 8, 2013."	""	""	""	""
32	""	""	""	""	""
33	""	""	""	""	""
34	""	""	""	""	""
35	""	""	""	""	""
36	       a Model years 1970 and earlier cars.	""	""	""	""
37	       b Model years 1981–84 cars and light trucks.	""	""	""	""
38	       c Model years 1988–97 cars and light trucks as shown in Table 4.30.	""	""	""	""
39	       d Model years 2003-2012 cars and light trucks.	""	""	""	""
40	       e Data are not available.	""	""	""	""