Emission Standards Reference Guide
Highway Motorcycles -- Exhaust Emission Standards
|Year||Class|| Engine Size
| HC + NOx
|Federal||1978-2005||I||50-169||5.0||-||12.0||5 / 12,000||5 / 12,000|
|II||170-279||-||5 / 18,000||5 / 18,000|
|III||280+||-||5 / 30,000||5 / 30,000|
|2006+||I-Ab||< 50||1.0||1.4c||12.0||5 / 6,000||5 / 6,000|
|I-Bb||50-169||1.0||1.4c||12.0||5 / 12,000||5 / 12,000|
|II||170-279||1.0||1.4c||12.0||5 / 18,000||5 / 18,000|
|280+||-||1.4||12.0||5 / 30,000||5 / 30,000|
|280+||-||0.8||12.0||5 / 30,000||5 / 30,000|
General applicability: These standards apply to 1978 and later model year, new gasoline-fueled motorcycles built after December 31, 1977, and to 1990 and later model year, new, methanol-fueled motorcycles built after December 31, 1989, and to 1997 and later model year, new, natural gas-fueled and liquefied petroleum gas-fueled motorcycles built after December 31, 1996, and to 2006 and later model year new motorcycles regardless of fuel.
a Useful life and warranty period are expressed in years and kilometers, whichever comes first.
b Starting with the 2006 model year EPA re-defined Class I to include motorcycles with engines smaller than 50 cubic centimeters. These new previously unregulated vehicles are Class I-A, and the pre-existing Class I became Class I-B.
c This is an optional standard that allows manufacturers to average their emissions or transfer emission credits across classes.
Code of Federal Regulations (CFR) Citations:
- 40 CFR 86 Subpart F = Motorcycle emission test procedures
- 40 CFR 86.410-90 = Emission standards for MY 1990-2005
- 40 CFR 86.410-2006 = Emission standards for MY 2006+