AECD—Auxiliary emission control device.

API—American Petroleum Institute.

ASTM—American Society for Testing and Materials.

°C—Degrees Celsius.

CH4—Methane.

CI—Compression ignition.

CO—Carbon monoxide.

CO2—Carbon dioxide.

disp.—volumetric displacement of an engine cylinder.

EGR—Exhaust gas recirculation.

EP—End point.

EPA—Environmental Protection Agency.

FEL—Family emission limit.

ft—foot or feet.

FTP—Federal Test Procedure.

g—gram(s).

g/kW-hr—Grams per kilowatt hour.

gal—U.S. gallon.

h—hour(s).

HC—hydrocarbon.

Hg—Mercury.

hp—horsepower.

ICI—Independent Commercial Importer.

in—inch(es).

K—Kelvin.

kg—kilogram(s).

km—kilometer(s).

kPa—kilopascal(s).

kW—kilowatt.

L/cyl—liters per cylinder.

m—meter(s).

max—maximum.

mg—milligram(s).

min—minute.

ml—milliliter(s).

mm—millimeter.

NIST—National Institute for Standards and Testing.

NMHC—Non-methane hydrocarbons.

NTIS—National Technical Information Service.

NO—nitric oxide.

NO2—nitrogen dioxide.

NOX—oxides of nitrogen.

No.—number.

O2—oxygen.

pct—percent.

PM—particulate matter.

PMM—post-manufacture marinizer.

ppm—parts per million by volume.

ppmC—parts per million, carbon.

rpm—revolutions per minute.

s—second(s).

SAE—Society of Automotive Engineers.

SEA—Selective Enforcement Auditing.

SI—International system of units (i.e., metric).

THC—Total hydrocarbon.

THCE—Total hydrocarbon equivalent.

U.S.—United States.

U.S.C.—United States Code.

vs—versus.

W—watt(s).

wt—weight.