Tier 4 Final/Stage IV

Tier 4 Final/Stage IV emissions standards for reducing levels of particulate matter (PM) and oxides of nitrogen  (NOx) takes effect in 2014 and will reduce NOx by an additional 80 percent taking PM and NOx emissions to near zero levels.

The Emission Standards Reference Guide contains the complete listings of federal emission standards for on-road and nonroad vehicles and engines, and related fuel sulfur standards

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