U.S. Department of Energy - Energy Efficiency and Renewable Energy
Vehicle Technologies Program
Fact #502: January 21, 2008
Off-Road Diesel Equipment Facing Tougher Emissions Regulation
The Environmental Protection Agency began regulating off-road diesel emissions in 2000 with the phase in of Tiers 1-3, which only applied to diesel engines above 50 horsepower. Beginning in January 2008, Tier 4 regulations will include all diesel engines and will in some cases reduce nitrogen oxide and particulate matter limits to levels similar to current on-road diesel engines. Tier 4 regulations will be phased in over a seven year period beginning with the smallest engines and gradually including larger off-road diesel equipment.
Tier 4 Off-Highway Diesel Emission Standards
(grams per horsepower-hour)
| Engine Horsepower |
Effective Year |
PM |
NOx |
| Less than 25 |
2008 |
0.3 |
- |
| 25 to 74 |
2013 |
0.02 |
3.5 |
| 75 to 174 |
2012-2013 |
0.01 |
0.3 |
| 175 to 749 |
2011-2013 |
0.01 |
0.3 |
| Over 750 |
2011-2014 |
0.075 |
2.6/0.50* |
| Over 750 |
2015 |
0.02/0.03** |
0.5*** |
|
Notes:
PM: Particulate Matter
NOx: Nitrogen Oxides
hp: horsepower
* The 0.50/g/hp-hr applies to generator sets more than 1200 hp.
** The 0.02/g/hp-hr applies to generator sets; the 0.03 g/hp-hr applies to other engines.
*** Applies to all generator sets only.
- Not regulated
Source: U.S. Environmental Protection Agency. |
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