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Emission Standards Reference Guide

Highway Motorcycles -- Exhaust Emission Standards

  Year Class Engine Size
(cc)
HC
(g/km)
HC + NOx
(g/km)
CO
(g/km)
Useful Lifea Warrantya
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
2006-2009 III
(Tier 1)
280+ - 1.4 12.0 5 / 30,000 5 / 30,000
2010+ III
(Tier 2)
280+ - 0.8 12.0 5 / 30,000 5 / 30,000

 

Notes:
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+

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