BTS | Table 4-38: Estimated National Average Vehicle Emissions Rates by Vehicle Type and Fuel

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Table 4-38: Estimated National Average Vehicle Emissions Rates by Vehicle Type and Fuel

(Grams per mile)

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	1990	1991	1992	1993	1994	1995	1996	1997	1998	1999	2000	^E2001
GASOLINE (assuming zero RFG)
Light-duty vehicles
Exhaust HC	2.05	1.92	1.81	1.72	1.66	1.60	1.55	1.51	1.47	1.44	1.42	1.41
Nonexhaust HC	1.04	0.99	0.96	0.93	0.91	0.89	0.87	0.85	0.82	0.79	0.74	0.69
Total HC	3.09	2.91	2.77	2.65	2.57	2.49	2.42	2.36	2.29	2.23	2.16	2.10
Exhaust CO	24.68	23.42	22.40	21.65	21.10	20.52	20.14	19.86	19.52	19.36	19.28	19.23
Exhaust NO_x	1.81	1.76	1.72	1.69	1.67	1.61	1.56	1.51	1.45	1.41	1.38	1.35
Light-duty trucks
Exhaust HC	3.24	3.03	2.80	2.61	2.46	2.31	2.21	2.13	2.05	1.99	1.95	1.92
Nonexhaust HC	1.44	1.31	1.21	1.16	1.11	1.07	1.03	1.01	0.96	0.94	0.90	0.87
Total HC	4.68	4.34	4.01	3.77	3.57	3.38	3.24	3.14	3.01	2.93	2.85	2.79
Exhaust CO	36.32	34.01	31.78	30.03	28.62	27.41	26.83	26.38	25.69	25.29	24.99	24.79
Exhaust NO_x	2.36	2.25	2.16	2.10	2.04	1.97	1.95	1.92	1.87	1.84	1.80	1.77
Heavy-duty vehicles
Exhaust HC	7.45	6.79	6.22	5.53	4.92	4.51	4.13	3.73	3.33	3.07	2.82	2.63
Nonexhaust HC	4.44	4.11	3.84	3.71	3.57	3.38	3.17	2.97	2.78	2.63	2.50	2.37
Total HC	11.89	10.90	10.06	9.24	8.49	7.89	7.30	6.70	6.11	5.70	5.32	5.00
Exhaust CO	131.19	120.49	111.05	101.92	93.61	85.10	76.97	69.13	61.07	54.65	48.67	43.65
Exhaust NO_x	6.49	6.28	6.05	5.85	5.69	5.48	5.36	5.25	5.05	4.89	4.72	4.56
Motorcycles
Exhaust HC	2.31	2.19	2.11	2.05	2.02	1.96	1.93	1.92	1.90	1.89	1.89	1.89
Nonexhaust HC	2.37	2.37	2.37	2.36	2.36	2.37	2.36	2.37	2.37	2.37	2.37	2.37
Total HC	4.68	4.56	4.48	4.41	4.38	4.33	4.29	4.29	4.27	4.26	4.26	4.26
Exhaust CO	20.89	20.61	20.60	20.59	20.59	20.47	20.47	20.47	20.35	20.35	20.35	20.35
Exhaust NO_x	0.85	0.85	0.85	0.85	0.85	0.84	0.84	0.84	0.83	0.83	0.83	0.83
DIESEL
Light-duty vehicles
Exhaust HC	0.73	0.74	0.75	0.75	0.76	0.77	0.76	0.74	0.71	0.67	0.63	0.59
Exhaust CO	1.68	1.71	1.72	1.73	1.74	1.74	1.74	1.71	1.67	1.62	1.57	1.53
Exhaust NO_x	1.65	1.67	1.68	1.68	1.66	1.64	1.60	1.55	1.48	1.40	1.33	1.26
Light-duty trucks
Exhaust HC	1.08	1.14	1.15	1.14	1.13	1.11	1.09	1.05	0.98	0.91	0.84	0.78
Exhaust CO	2.03	2.10	2.09	2.07	2.04	2.02	1.99	1.95	1.88	1.80	1.73	1.68
Exhaust NO_x	1.97	2.00	1.99	1.97	1.94	1.90	1.85	1.78	1.67	1.56	1.46	1.38
Heavy-duty vehicles
Exhaust HC	3.30	3.08	2.89	2.75	2.65	2.54	2.44	2.36	2.30	2.25	2.22	2.19
Exhaust CO	13.71	13.38	13.07	12.76	12.50	12.28	12.08	11.93	11.77	11.63	11.53	11.45
Exhaust NO_x	21.05	19.59	18.14	16.89	15.81	14.79	13.96	13.33	12.66	11.93	11.24	10.59
AVERAGE OF ALL VEHICLES, GASOLINE AND DIESEL
Exhaust HC	2.56	2.40	2.25	2.13	2.03	1.93	1.86	1.80	1.74	1.70	1.67	1.64
Nonexhaust HC	1.18	1.12	1.06	1.02	1.00	0.97	0.94	0.91	0.88	0.84	0.80	0.76
Total HC	3.75	3.52	3.31	3.15	3.02	2.90	2.80	2.71	2.62	2.54	2.47	2.40
Exhaust CO	29.97	28.29	26.81	25.62	24.68	23.75	23.11	22.58	21.94	21.53	21.20	20.95
Exhaust NO_x	3.09	2.99	2.89	2.80	2.73	2.63	2.56	2.50	2.41	2.34	2.27	2.21

KEY: CO = carbon monoxide; E = estimate; HC = hydrocarbon; NO_x = nitrogen oxide; R = revised; RFG = reformulated gasoline.

NOTES: As of July 1 of each year. Vehicles types are defined as follows: light-duty vehicles (passenger cars up to 6,000 lb GVWR); light-duty trucks (pickups and minivans up to 8,500 lb GVWR); heavy-duty vehicles (8,501 lbs or more GVWR); motorcycle (highway only). This table is based on MOBILE5b, the U.S. Environmental Protection Agency's (EPA) latest highway vehicle emissions factor model. Interested readers can learn more about the Mobile5b model at the following USEPA Internet site http://www.epa.gov/otaq.

MOBILE5b is undergoing a major revision and is expected to be replaced by MOBILE6 in early 2002. Emissions factors are national averages based on the following assumptions: ambient temperature 75 ºF, daily temperature range 60-84 ºF, average traffic speed 19.6 mph (representative of overall traffic in urban areas), standard operating mode (cold-start, hot-start, stabilized), vehicle-miles traveled fractions, no inspection/maintenance or antitampering programs, and gasoline volatility 9.0 per square inch RVP (Reid vapor pressure).

See Table 4-39 for emissions from vehicles operating on reformulated gasoline.

Data for nonexhaust HC is negligible for diesel light-duty vehicles, light-duty trucks, and heavy-duty vehicles.

SOURCE: U.S. Environmental Protection Agency, National Vehicle and Fuel Emissions Laboratory, personal communication, Sept. 13, 2001.