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Emission Standards Reference Guide

Glossary: Acronyms and Abbreviations

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | Z


A/C: air conditioning
ABT: averaging, banking & trading
AGA: American Gas Association
ALVW: adjusted loaded vehicle weight
ANSI: American National Standards Institute
ATV: all-terrain vehicle

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bhp: brake horsepower

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CAA: Clean Air Act
cc: cubic centimeter
CCD: EPA’s Certification and Compliance Division
CFR: Code of Federal Regulations
CFV: Clean Fuel Vehicle
CI: compression-ignition
CNG: compressed natural gas
CO: carbon monoxide

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E10: a mixture of 10 percent ethanol and 90 percent gasoline
EPA: Environmental Protection Agency

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FEL: Family Emission Limit
FTP: Federal Test Procedure 

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g: grams
g/bhp-hr: grams per brake horsepower-hour
g/kN: grams per kilonewton
g/kW-hr: grams per kilowatt-hour
g/mi: grams per mile
GPA: Geographic Phase-in Area
gpm: grams per minute
GVW: gross vehicle weight
GVWR: gross vehicle weight rating

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HC: hydrocarbons
HC+NOx: hydrocarbons + nitrogen oxides
HDDE: heavy-duty diesel engine
HDE: heavy-duty engine
HDV: heavy-duty vehicle
HHDDE: heavy heavy-duty diesel engine
HLDT: heavy light-duty truck
hp: horsepower
HS: high sulfur (greater than 500 ppm sulfur)

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ICAO: International Civil Aviation Organization
ILEV: Inherently Low Emission Vehicle
ISO: International Organization for Standardization

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K: Kilo- (thousand)
kN: kilonewton
kW: kilowatt

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L: liter
lbs: pounds
LDT: light-duty truck
LDT2: light-duty truck 2
LDT3: light-duty truck 3
LDT4: light-duty truck 4
LDV: light-duty vehicle
LEV: Low Emission Vehicle
LHDDE: light heavy-duty diesel engine
LLDT: light light-duty truck
LM: locomotive and marine
LPG: liquefied petroleum gas (Propane)
LVW: loaded vehicle weight

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M10: a mixture of 10 percent methanol and 90 percent gasoline
max: maximum
MDPV: medium-duty passenger vehicle
MHDDE: medium heavy-duty diesel engine
mi: mile
min: minimum
mph: miles per hour
mw: megawatt
MY: model year

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NGV: natural gas vehicle
NLEV: National Low Emission Vehicle
NMHC: non-methane hydrocarbon
NMHCE: non-methane hydrocarbon equivalent
NMOG: non-methane organic gases
NOx: nitrogen oxides
NOx+HC: nitrogen oxides + hydrocarbons
NR: nonroad
NRLM: nonroad, locomotive, and marine
NTE: not to exceed

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OBD: on-board diagnostics
ORVR: on-board refueling vapor recovery

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PM: particulate matter
ppm: parts per million
PWC: personal watercraft

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rO: rated output
rpm: revolutions per minute
rPR: rated pressure ratio

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s: seconds
SAE: Society of Automotive Engineers
SFTP: Supplemental Federal Test Procedure
SI: spark-ignition
SN: smoke number
SULEV: Super-Ultra-Low Emission Vehicle

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THC: total hydrocarbons
THCE: total hydrocarbon equivalent
TLEV: Transitional Low Emission Vehicle

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UDDS: Urban Dynamometer Driving Schedule
ULEV: Ultra-Low Emission Vehicle

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ZEV: Zero Emission Vehicle


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This page is maintained by EPA's Office of Transportation and Air Quality (OTAQ).
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