API S - Gasoline Engines
The American Petroleum Institute (API) is the largest U.S. trade association for the oil and natural gas industry. It claims to represent nearly 600 corporations involved in production, refinement, distribution, and many other aspects of the petroleum industry.
Motor oils designed for cars, vans and light trucks with gasoline engines are included in the API "S" (Service) categories.
The current and previous API Service Categories are summarized in convenient charts. 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 SN oil, an API SP oil will provide full protection.
Note: The letters “SI”, “SK”, and “SO” have been omitted from the sequence of letter designations for API Service Categories because of their common association with other organizations or systems.
| Category | Status | Service |
|---|---|---|
| API SP | Current | Introduced in May 2020, designed to provide protection against low-speed pre-ignition (LSPI), timing chain wear protection, improved high temperature deposit protection for pistons and turbochargers, and more stringent sludge and varnish control. API SP with Resource Conserving matches ILSAC GF-6A by combining API SP performance with improved fuel economy, emission control system protection and protection of engines operating on ethanol-containing fuels up to E85. |
| API SN | Current | For 2020 and older automotive engines. |
| API SM | Current | For 2010 and older automotive engines. |
| API SL | Current | For 2004 and older automotive engines. |
| API SJ | Current | For 2001 and older automotive engines. |
| API SH | Obsolete | CAUTION: Not suitable for use in most gasoline-powered automotive engines built after 1996. May not provide adequate protection against build-up of engine sludge, oxidation, or wear. |
| API SG | Obsolete | CAUTION: Not suitable for use in most gasoline-powered automotive engines built after 1993. May not provide adequate protection against build-up of engine sludge, oxidation, or wear. |
| API SF | Obsolete | CAUTION: Not suitable for use in most gasoline-powered automotive engines built after 1988. May not provide adequate protection against build-up of engine sludge. |
| API SE | Obsolete | CAUTION: Not suitable for use in most gasoline-powered automotive engines built after 1979. |
| API SD | Obsolete | CAUTION: Not suitable for use in most gasoline-powered automotive engines built after 1971. Use in more modern engines may cause unsatisfactory performance or equipment harm. |
| API SC | Obsolete | CAUTION: Not suitable for use in most gasoline-powered automotive engines built after 1967. Use in more modern engines may cause unsatisfactory performance or equipment harm. |
| API SB | Obsolete | CAUTION: Not suitable for use in most gasoline-powered automotive engines built after 1951. Use in more modern engines may cause unsatisfactory performance or equipment harm. |
| API SA | Obsolete | CAUTION: Contains no additives. Not suitable for use in most gasoline-powered automotive engines built after 1930. Use in modern engines may cause unsatisfactory performance or equipment harm. |
