Freight Facts and Figures 2008
Table 5-11. Estimated National Average Vehicle Emissions Rates of Heavy-Duty and Light-Duty Vehicles: 1990-2007
Air quality is affected by emissions from freight vehicles. Compared with gasoline- fueled cars and trucks, diesel-fueled heavy trucks emit small amounts of carbon monoxide (CO) but large amounts of nitrogen oxides (NOx).
Table in Excel format | Historical data
Grams per mile
 |
1990 | 2000 | 2006 | 2007 |
|---|---|---|---|---|
| Gasoline (assuming zero RFG) | ||||
| Cars | ||||
| Exhaust HC | 2.79 | 0.97 | 0.46 | 0.42 |
| Nonexhaust HC | 1.21 | 0.92 | 0.68 | 0.62 |
| Total HC | 3.99 | 1.89 | 1.13 | 1.04 |
| Exhaust CO | 42.89 | 18.53 | 10.87 | 10.28 |
| Exhaust NOx | 2.70 | 1.29 | 0.79 | 0.73 |
| Light trucks | ||||
| Exhaust HC | 3.68 | 1.45 | 0.69 | 0.64 |
| Nonexhaust HC | 1.36 | 0.97 | 0.71 | 0.66 |
| Total HC | 5.04 | 2.42 | 1.40 | 1.31 |
| Exhaust CO | 56.23 | 26.81 | 14.33 | 13.52 |
| Exhaust NOx | 2.62 | 1.54 | 1.09 | 1.02 |
| Heavy trucks | ||||
| Exhaust HC | 3.66 | 1.22 | 0.53 | 0.48 |
| Nonexhaust HC | 2.74 | 1.62 | 1.14 | 1.07 |
| Total HC | 6.40 | 2.84 | 1.67 | 1.54 |
| Exhaust CO | 85.61 | 31.08 | 14.51 | 13.55 |
| Exhaust NOx | 7.19 | 5.26 | 3.73 | 3.33 |
| Diesel | ||||
| Cars | ||||
| Exhaust HC | 0.68 | 0.80 | 0.48 | 0.36 |
| Exhaust CO | 1.49 | 1.78 | 1.41 | 1.21 |
| Exhaust NOx | 1.83 | 1.81 | 1.11 | 0.85 |
| Light trucks | ||||
| Exhaust HC | 1.59 | 1.02 | 0.79 | 0.63 |
| Exhaust CO | 2.67 | 1.77 | 1.34 | 1.06 |
| Exhaust NOx | 2.71 | 1.76 | 1.30 | 1.09 |
| Heavy trucks | ||||
| Exhaust HC | 2.21 | 0.79 | 0.51 | 0.48 |
| Exhaust CO | 10.06 | 4.10 | 2.90 | 2.66 |
| Exhaust NOx | 23.34 | 18.05 | 10.55 | 9.60 |
Key: CO = carbon monoxide; HC = hydrocarbon; NOx = nitrogen oxides; RFG = reformulated gasoline.
Source:
U.S. Environmental Protection Agency, National Vehicle and Fuel Emissions Laboratory, personal communication, August 13, 2008.
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