You are here
Federal Exhaust Emissions Standards for Newly Manufactured Motorcycles (g/km)
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 motocycles 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.
KEY: cc = cubic centimeters; g = gram; HC = hydrocarbon; CO = Carbon Monoxide; kg = kilogram; km = kilometer; lb = pound; mi = miles; mph = miles per hour; NOx = Nitrogen Oxides.
a A motorcycle is any motor vehicle with a headlight, taillight, and stoplight, and having two or three wheels and a curb mass less than or equal to 793 kg (1,749 lb). (The limit was 680 kg, or 1,499 lb prior to the 1998 model year.) A motorcycle is excluded from the standards if it has a displacement of less than 50 cc (3.1 cubic inches) or if with a 80 kg (176 lb) driver it cannot start from a dead stop using only the engine or exceed a speed of 40 km/h (25 mph) on a level, paved surface.
b Readers who wish to compare motorcycle regulations with passenger car and truck regulations should note that 5.0 g/km = 8.0 g/mi and 12 g/km = 19 g/mi.
c Estimates of emissions rates prior to controls are ranges of emissions for all engine displacements. Not available for motorcycles powered by fuels other than gasoline.
d Useful life is expressed in years and kilometers, whichever comes first.
e Starting with the 2006 model year EPA (Environmental Protection Agency) 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.
f This is an optional standard that allows manufacturers to average their emissions or transfer emission credits across classes.
g With model year 2006-2009, Class III motorcycles must comply with the EPA Tier 1 Exhaust Emission Standards and shall not exceed the HC + NOx of 1.4 g/km.
h 2010 and later model year, new Class III motorcycles must comply with the EPA Tier 2 Exhaust Emission Standards and shall not exceed the HC + NOx of 0.8 g/km.
Emissions prior to controls:
40 CFR 86 Subpart E (July 1, 2000). U.S. Environmental Protection Agency, Office of Air and Radiation, personal communication, Aug. 28, 2001.
1978 and later model year:
United States Environmental Protection Agency, Office of Transportation and Air Quality, EPA-420-B-16-016, Highway Motorcycles: Exhaust Emission Standards, available at https://www.epa.gov/emission-standards-reference-guide/epa-emission-stan... as of Nov. 6, 2019.