API Motor Oil Classifications

API (American Petroleum Institute) Motor Oil classifications

The current and previous API Service Categories are listed below.

Vehicle owners should refer to their owner's manuals before consulting these charts. Oils may have more than one performance level.

For automotive gasoline engines, the latest engine oil service category includes the performance properties of each earlier category. If an automotive owner's manual calls for an API SH or SJ oil, an API SL oil will provide full protection. For diesel engines, the latest category usually, but not always - includes the performance properties of an earlier category.

Petrol Engines

SM For Gasoline Engine Service. For all automotive engines currently in use. Introduced in 2004, SM oils are designed to provide improved oxidation resistance, improved deposit protection, better wear protection, and better low-temperature performance over the life of the oil. Some SM oils may also meet the latest ILSAC specification and/or qualify as Energy Conserving.

SL For all automotive engines presently in use. Introduced July 2001. SL oils are designed to provide better high temperature deposit control and lower oil consumption. Some of these oils may also meet the latest ILSAC Specification and/or qualify as Energy Conserving.

SJ For 2001 and older automotive engines.

SH For 1996 and older engines. Valid when preceded by current C categories.

SG For 1993 and older engines.

SF For 1988 and older engines.

SE Obsolete For 1979 and older engines.

SD Obsolete For 1971 and older engines.

SC Obsolete For 1967 and older engines.

SB Obsolete For older engines. Use only when specifically recommended by the manufacturer.

SA Obsolete For older engines; no performance requirement. Use only when specifically recommended by the manufacturer.

Note: API intentionally omitted 'SI' and 'SK' from the sequence of categories because the letters are commonly associated with other organizations or systems.

Diesel Engines

CJ-4 for Heavy Duty Diesel Engine Service; Exhaust After treatment - Introduced in 2006. For high-speed, four-stroke engines designed to meet 2007 model year on-highway exhaust emission standards. CJ-4 oils are compounded for use in all applications with diesel fuels ranging in sulfur content up to 500 ppm (0.05% by weight). However, use of these oils with greater than 15 ppm (0.0015% by weight) sulfur fuel may impact exhaust aftertreatment system durability and/or oil drain interval. CJ-4 oils are effective at sustaining emission control system durability where particulate filters and other advanced aftertreatment systems are used.

CI-4 Intorduced in 2002 for Severe-Duty Diesel Engine Service - The API CI-4 Service category describes oils for use in those high-speed, four-stroke cycle diesel engines designed to meet 2004 exhaust emission standards, to be implemented October 2002. These oils are compounded for use in all applications with diesel fuels ranging in sulfur content up to 0.05% by weight. These oils are especially effective at sustaining engine durability where Exhaust Gas Recirculation (EGR) and other exhaust emission componentry may be used.

CH-4 Introduced December 1, 1998. For high speed, four-stroke engines designed to meet 1998 exhaust emission standards. CH-4 oils are specifically compounded for use with diesel fuels ranging in sulfur content up to 0.5% weight. Can be used in place of CD, CE, CF-4, and CG-4 oils.

CG-4 Introduced in 1995. For severe duty, high speed four-stroke engines using fuel with less than 0.5% weight sulfur. CG-4 oils are required for engines meeting 1994 emission standards. Can be used in place of CD, CE, and CF-4 oils.

CF-4 Introduced in 1990. For high-speed, four stroke naturally aspirated and turbocharged engines. Can be used in place of CD and CE oils.

CF-2 Introduced in 1994. For severe duty, two stroke-cycle engines. Can be used in place of CD-II oils.

CF Introduced in 1994. For off-road, indirect injected and other diesel engines including those using fuel with over 0.5% weight sulfur. Can be used in place of CD oils.

CE Introduced in 1987. For high-speed, four stroke, naturally aspirated and turbocharged engines. Can be used in place of CC and CD oils.

CD-II Introduced in 1987. For two-stroke-cycle engines.

CD Introduced in 1955. For certain naturally aspirated and turbocharged engines.

CC For engines introduced in 1961.

CB For moderate duty engines from 1949 to 1960.

CA For light duty engines (1940's and 1950's).