Table 4-33:  Federal Exhaust Emissions Standards for Newly Manufactured Motorcyclesa (g/km)b,,,,,,
Pollutant,Engine displacement,Emissions prior to controlsc,1978-79,1980-89,1990-96,1997+
Gasoline-powered,,,,,,
HC,50-169 cc,1.0-13.8,5,5,5,5
,170-749 cc,1.0-13.8,5 + 0.0155(D-170)d,5.0,5.0,5.0
,750 cc and greater,1.0-13.8,14,5.0,5.0,5.0
CO,50 cc and greater,11.0-31.0,17,12,12,12
Methanol-powered,,,,,,
Total HC equivalent,50 cc and greater,,,,5.0,5.0
CO,50 cc and greater,,,,12,12
Natural gas and LPG-powered,,,,,,
HC,50 cc and greater,,,,,5.0
CO,50 cc and greater,,,,,12
Useful life (Class I),50-169 cc,,"5 years or 12,000 km (7,456 mi), whichever comes first","5 years or 12,000 km (7,456 mi), whichever comes first","5 years or 12,000 km (7,456 mi), whichever comes first","5 years or 12,000 km (7,456 mi), whichever comes first"
Useful life (Class II),170-279 cc,,"5 years or 18,000 km (11,185 mi), whichever comes first","5 years or 18,000 km (11,185 mi), whichever comes first","5 years or 18,000 km (11,185 mi), whichever comes first","5 years or 18,000 km (11,185 mi), whichever comes first"
Useful life (Class III),280 cc and greater,,"5 years or 30,000 km (18,641 mi), whichever comes first","5 years or 30,000 km (18,641 mi), whichever comes first","5 years or 30,000 km (18,641 mi), whichever comes first","5 years or 30,000 km (18,641 mi), whichever comes first"
KEY: cc = cubic centimeters; D = engine displacement; g = gram; HC = hydrocarbon; h = hour; kg = kilogram; km = kilometer; lb = pound; LPG = liquefied petroleum gas; mi = miles; mph = miles per hour. ,,,,,,
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"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. The formula for 1978-79 HC emissions by motorcycles 170-749 cc becomes, in g/mi., approximately 8.0 + 0.025(D-170). ",,,,,,
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 D = engine displacement in cubic centimeters (cc).  For example, the standard for a 300 cc engine would be 5.0 + 0.0155(300-170) = 7.0 g/km. ",,,,,,
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SOURCE:,,,,,,
"40 CFR 86 Subpart E (July 1, 2000).  U.S. Environmental Protection Agency, Office of Air and Radiation, personal communication, Aug. 28, 2001. ",,,,,,
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