Abbreviations are used across lubricant standards, specifications, OEM documents, and product data sheets to shorten repeated technical terms. This page defines common abbreviations and symbols in a reference format.
Abbreviations can refer to viscosity grade systems, performance categories, formulation descriptors, and equipment or emissions system terminology.
Viscosity and grade systems
ISO VG
ISO viscosity grade, an industrial viscosity classification based on kinematic viscosity at 40°C.
SAE
Viscosity grade system used for engine oils and gear oils in automotive documentation.
NLGI
Grease consistency classification reference used for grease grades.
cSt
Centistokes, a unit commonly used for kinematic viscosity (equivalent to mm²/s).
Performance categories and specification shorthand
API
American Petroleum Institute engine oil performance classification framework.
ACEA
European Automobile Manufacturers Association engine oil sequences.
GL
Gear lubricant performance category shorthand used in gear oil references.
ATF
Automatic Transmission Fluid category term used in transmission fluid documentation.
UTTO
Universal Tractor Transmission Oil, a category term used for combined transmission and hydraulic service fluids in agricultural equipment documentation.
Additive and duty descriptors
AW
Anti wear, a descriptor indicating wear reducing chemistry for boundary lubrication conditions.
EP
Extreme pressure, a descriptor indicating chemistry intended for high load sliding contact conditions.
HV
High viscosity index, a descriptor commonly used for hydraulic oils formulated for wider operating temperature ranges.
R&O
Rust and oxidation inhibited, a descriptor used for selected circulating and turbine oil categories.
H1, H2
Food grade lubricant category shorthand used in selected food processing documentation (where referenced).
Hydraulic and industrial shorthand
HM
Hydraulic oil category term often used in standards based documentation for anti wear hydraulic oils.
HLP
Hydraulic oil category term commonly used in DIN aligned documentation for wear protection hydraulic oils.
HVI
High viscosity index hydraulic oil descriptor used in some documentation.
HPC
A product descriptor used in some hydraulic oil naming and literature, commonly associated with high pressure hydraulic system service.
LS
Load sensing, a hydraulic system term used in mobile and industrial hydraulics documentation.
Engine and emissions system acronyms
EGR
Exhaust gas recirculation.
SCR
Selective catalytic reduction.
DPF
Diesel particulate filter.
EURO IV, V, VI
European emissions standards references used in fleet and vehicle documentation.
TBN
Total base number, a measure of alkalinity reserve reported for engine oils.