API Service Designations
| Gasoline Engines |
| Category |
Status |
Service |
| SM |
Current |
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 |
Current |
For all automotive engines presently in use. Introduced July 1, 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 |
Current |
For 2001 and older automotive engines. |
| SH |
Obsolete |
For 1996 and older engines. Valid when proceeded by current C categories. |
| SG |
Obsolete |
For 1993 and older engines. |
| SF |
Obsolete |
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. |
| Diesel Engines |
| Category |
Status |
Service |
| CH-4 |
Current |
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 |
Current |
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 |
Current |
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 |
Current |
Introduced in 1994. For severe-duty, two-stroke engines. Can be used in place of CD-II oils. |
| CF |
Current |
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 |
Obsolete |
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 |
Obsolete |
Introduced in 1987. For two-stroke engines. |
| CD |
Obsolete |
Introduced in 1955. For certain naturally aspirated and turbocharged engines. |
| CC |
Obsolete |
For engines introduced in 1961. |
| CB |
Obsolete |
For moderate-duty engines from 1949 to 1960. |
| CA |
Obsolete |
For light-duty engines (1940s and 1950s). |
Notice: API intentionally omitted "SI" and "SK" from the sequence of categories because the letters are commonly associated with other organizations or systems. This guide is provided as a service to the motoring public courtesy of the American Petroleum Institute. For more information about the API Engine Oil Program, call the American Petroleum Institute at 202-682-8516 or visit its Web site at www.api.org/eolcs.
