API S (Service) oils for four-stroke gasoline engines in passenger cars, vans and trucks
Here is current and previous API (American Petroleum Institute) service categories for four-stroke gasoline engine oils. Vehicle owners should consult their owner’s manuals before reviewing these tables. Oils may have more than one performance level.
For automotive gasoline engines, the latest API service category includes the performance characteristics of each previous category and can be used to service older engines for which previous category oils are recommended.
Gasoline engine oil classification (S)
| Category | Status | Service |
| SP | Valid | Introduced in May 2020, and is designed to provide Low Speed Premature Ignition (LSPI) protection, protection against wear on the timing chain, improved protection against high temperature deposits on pistons and turbochargers, and more stringent control of sludge and varnish. The API SP category with Resource Conserving complies with ILSAC GF-6A, combining API SP performance with improved fuel economy, emission control system protection, and protection for engines using fuels with ethanol up to E85. |
| SN | Valid | Introduced in October 2010, designed to provide increased protection against high-temperature piston deposits, tighter deposit control and seal compatibility. API SN with Energy Conservation complies with ILSAC GF-5, combining API SN performance with improved fuel economy, turbocharger protection, emission control compatibility, and protection for engines using fuels with ethanol up to E85. |
| SM | Valid | For engines manufactured before 2010 and earlier |
| SL | Valid | For engines built before 2004 and earlier |
| SJ | Valid | For engines built before 2001 and earlier |
| SH | Old | WARNING: Not suitable for use in most gasoline-powered engines developed after 1996. May not provide protection against sludge buildup, oxidation or engine wear. |
| SG | Old | WARNING: Not suitable for use in most gasoline engines developed after 1993. May not provide protection against sludge accumulation, oxidation, or engine wear properly. |
| SF | Old | WARNING: Not suitable for use in most gasoline engines developed after 1988. Cannot provide protection against accumulation of sludge in the engine. |
| SE | Old | WARNING: Not suitable for use in most gasoline engines developed after 1979. |
| SD | Old | WARNING: Not suitable for use in most gasoline engines developed after 1971. Use in more modern engines may result in poor performance or equipment damage |
| SC | Old | WARNING: Not suitable for use in most gasoline engines developed after 1967. Use on more modern engines may result in poor performance or equipment damage |
| SB | Old | WARNING: Not suitable for use in most gasoline engines developed after 1951. Use on more modern engines may result in poor performance or equipment damage |
| SA | Old | WARNING: Does not contain additives. Not suitable for use in most gasoline engines developed after 1930. |
Notes
Letters “SI”, “SK” and “SO” have been removed from the sequence of letter designations for API service categories due to their common connection with other organizations or systems.
For complete and up-to-date information on API motor oil classification, please refer to the website: www.api.org.