The following symbols, acronyms, and abbreviations apply to this part:

°C   degrees Celsius.

ASTM   American Society for Testing and Materials.

cc   cubic centimeters.

CFR   Code of Federal Regulations.

CH4   methane.

cm   centimeter.

CO   carbon monoxide.

CO2   carbon dioxide.

EPA   Environmental Protection Agency.

g/kW-hr   grams per kilowatt-hour.

HC   hydrocarbon.

ISO   International Organization for Standardization.

kPa   kilopascals.

kW   kilowatts.

LPG   liquefied petroleum gas.

m   meters.

MIL   malfunction-indicator light.

mm Hg   millimeters of mercury.

N2O   nitrous oxide.

NARA   National Archives and Records Administration.

NMHC   nonmethane hydrocarbons.

NOX   oxides of nitrogen (NO and NO2).

psi   pounds per square inch of absolute pressure.

psig   pounds per square inch of gauge pressure.

rpm   revolutions per minute.

SAE   Society of Automotive Engineers.

SI   spark-ignition.

THC   total hydrocarbon.

THCE   total hydrocarbon equivalent.

U.S.C.   United States Code.

[67 FR 68347, Nov. 8, 2002, as amended at 70 FR 40485, July 13, 2005; 74 FR 56510, Oct. 30, 2009]


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