A/C—Air conditioning.

AECD—Auxiliary emission control device.

A/F—Air/Fuel

ALVW—Adjusted Loaded Vehicle Weight.

API—American Petroleum Institute.

ASTM—American Society for Testing and Materials.

BAT—Bench-Aging Time

C—Celsius.

cfm—Cubic feet per minute.

CFV—Critical flow venturi.

CFV-CVS—Critical flow venturi—constant volume sampler.

CH3OH—Methanol.

CID—Cubic inch displacement.

Cl—Chemiluminescence.

CO—Carbon monoxide.

CO2—Carbon dioxide.

conc.—Concentration.

CST—Certification Short Test.

cu. in.—Cubic inch(es).

CVS—Constant volume sampler.

DDV—Durability Data Vehicle.

deg.—Degree(s).

DNPH—2,4-dinitrophenylhydrazine.

EDV—Emission Data Vehicle.

EP—End point.

ETW—Equivalent test weight.

F—Fahrenheit.

FEL—Family Emission Limit.

FID—Flame ionization detector.

ft.—Feet.

FTP—Federal Test Procedure.

g—gram(s).

gal.—U.S. gallon(s).

GC—Gas chromatograph.

GVW—Gross vehicle weight.

GVWR—Gross vehicle weight rating.

H2O—Water.

HC—Hydrocarbon(s).

HCHO—Formaldehyde.

HDV—Heavy-duty vehicle.

HEV—Hybrid electric vehicle.

HFID—Heated flame ionization detector.

Hg—Mercury.

HLDT—Heavy light-duty truck. Includes only those trucks over 6000 pounds GVWR (LDT3s and LDT4s).

HLDT/MDPV—Heavy light-duty trucks and medium-duty passenger vehicles.

hp—Horsepower.

HPLC—High-pressure liquid chromatography.

IBP—Initial boiling point.

in.—Inch(es).

IUVP—In-Use Verification Program.

K—Kelvin.

kg—Kilogram(s).

km—Kilometer(s).

kPa—Kilopascal(s).

lb.—Pound(s).

LDT1—Light-duty truck 1.

LDT2—Light-duty truck 2.

LDT3—Light-duty truck 3.

LDT4—Light-duty truck 4.

LDV/LLDT—Light-duty vehicles and light light-duty trucks. Includes only those trucks rated at 6000 pounds GVWR or less (LDT1s and LDT2s).

LDV/T—Light-duty vehicles and light-duty trucks. This term is used collectively to include, or to show that a provision applies to, all light-duty vehicles and all categories of light-duty trucks, i.e.

LDT1, LDT2, LDT3 and LDT4.

LEV—Low Emission Vehicle.

LPG—Liquefied Petroleum Gas.

m—Meter(s).

max.—Maximum.

MDPV—Medium-duty passenger vehicle.

mg—Milligram(s).

mi.—Mile(s).

min.—Minimum.

ml—Milliliter(s).

mm—Millimeter(s).

mph—Miles per hour.

mV—Millivolt

N2—Nitrogen.

NDIR—Nondispersive infrared.

NLEV—Refers to the National Low Emission Vehicle Program. Regulations governing this program are found at subpart R of this part.

NMHC—Nonmethane Hydrocarbons.

NMHCE—Non-Methane Hydrocarbon Equivalent.

NMOG—Non-methane organic gases.

NO—nitric oxide.

No.—Number.

O2—Oxygen.

OEM—Original equipment manufacturer.

NO2—Nitrogen dioxide.

NOX—Oxides of nitrogen.

Pb—Lead.

pct.—Percent.

PDP-CVS—Positive displacement pump—constant volume sampler.

ppm—Parts per million by volume.

PM—Particulate Matter.

ppm C—Parts per million, carbon.

psi—Pounds per square inch.

R—Rankin.

RAF—Reactivity adjustment factor.

rpm—Revolutions per minute.

RVP—Reid vapor pressure.

s—Second(s).

SAE—Society of Automotive Engineers.

SBC—Standard Bench Cycle

SFTP—Supplemental Federal Test Procedure.

SI—International system of units.

SRC—Standard Road Cycle

SULEV—Super Ultra Low Emission Vehicle.

TD—dispensed fuel temperature.

THC—Total Hydrocarbons.

THCE—Total Hydrocarbon Equivalent.

TLEV—Transitional Low Emission Vehicle.

UDDS—Urban dynamometer driving schedule.

ULEV—Ultra Low Emission Vehicle.

UV—Ultraviolet.

vs—Versus.

W—Watt(s).

WOT—Wide open throttle.

Wt.—Weight.