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.
|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|