The following symbols, acronyms, and abbreviations apply to this part:
° - degrees.
ASTM - American Society for Testing and Materials.
ATV - all-terrain vehicle.
cc - cubic centimeters.
CFR - Code of Federal Regulations.
CH4 methane.
cm - centimeter.
C - Celsius.
CO - carbon monoxide.
CO2 - carbon dioxide.
EPA - Environmental Protection Agency.
F - Fahrenheit.
g - grams.
g/gal/day - grams per gallon per test day.
g/m2/day - grams per meter-square per test day.
HC - hydrocarbon.
Hg - mercury.
hr - hours.
km - kilometer.
kW - kilowatt.
LPG - liquefied petroleum gas.
m - meters.
mm - millimeters.
mW - milliwatts.
N2O nitrous oxide.
NARA - National Archives and Records Administration.
NMHC - nonmethane hydrocarbons.
NOX - oxides of nitrogen (NO and NOX).
psig - pounds per square inches 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 40510, July 13, 2005; 74 FR 56511, Oct. 30, 2009]