The API Engine Oil Licensing and Certification System provides a simple designation of letters and numbers that allows engine manufacturers and oil marketers to clearly provide users with the information they need to ensure that the proper oil is selected for an engine. Each letter/number designation identifies a service category (e.g., CI-4) which is linked to a series of tests that the oil must pass before it is allowed to carry that designation. The API “S” series describes oil standards primarily for gasoline engines while the API “C” series describes oil standards for diesel engine service.
Diesel API specification:
|
Category |
Status |
Service |
|
CK-4 |
Current |
For use in high-speed four-stroke cycle diesel engines designed to meet 2017 model year on-highway and Tier 4 non-road exhaust emission standards as well as for previous model year diesel engines. These oils are formulated for use in all applications with diesel fuels ranging in sulfur content up to 500 ppm. However, the use of these oils with greater than 15 ppm sulfur fuel may impact exhaust aftertreatment system durability and/or oil drain interval. API CK-4 oils are especially effective at sustaining emission control system durability where particulate filters and other advanced aftertreatment systems are used. API CK-4 oils are designed to provide enhanced protection against oil oxidation, viscosity loss due to shear, and oil aeration as well as protection against catalyst poisoning, particulate filter blocking, engine wear, piston deposits, degradation of low- and high-temperature properties, and soot-related viscosity increase.API CK-4 oils exceed the performance criteria of API CJ-4, CI-4 with CI-4 PLUS, CI-4, and CH-4 and can effectively lubricate engines calling for those API Service Categories. When using CK-4 oil with higher than 15 ppm sulfur fuel, consult the engine manufacturer for service interval recommendations. |
|
FA-4 |
Current |
API FA-4 describes certain XW-30 oils specifically formulated for use in select high-speed four-stroke cycle diesel engines designed to meet 2017 model year on-highway greenhouse gas (GHG) emission standards. These oils are formulated for use in on-highway applications with diesel fuel sulfur content up to 15 ppm. Refer to individual engine manufacturer recommendations regarding compatibility with API FA-4 oils.API FA-4 oils are blended to a high temperature high shear (HTHS) viscosity range of 2.9cP-3.2cP to assist in reducing GHG emissions. These oils are especially effective at sustaining emission control system durability where particulate filters and other advanced aftertreatment systems are used. API FA-4 oils are designed to provide enhanced protection against oil oxidation, viscosity loss due to shear, and oil aeration as well as protection against catalyst poisoning, particulate filter blocking, engine wear, piston deposits, degradation of low- and high-temperature properties, and soot' related viscosity increase.API FA-4 oils are neither interchangeable nor backward compatible with API CK-4, CJ-4, CI-4 with CI-4 PLUS, CI-4, and CH-4 oils. Refer to engine manufacturer recommendations to determine if API FA-4 oils are suitable for use. API FA-4 oils are not recommended for use with fuels having greater than 15 ppm sulfur. For fuels with sulfur contents greater than 15 ppm, refer to engine manufacturer recommendations. |
|
CJ-4 |
Current |
For high-speed four-stroke cycle diesel engines designed to meet 2010 model year on-highway and Tier 4 nonroad exhaust emission standards as well as for previous model year diesel engines. These oils are formulated for use in all applications with diesel fuels ranging in sulfur content up to 500 ppm (0.05% by weight). However, the use of these oils with greater than 15 ppm (0.0015% by weight) sulfur fuel may impact exhaust aftertreatment system durability and/or drain interval. CJ-4 oils are especially effective at sustaining emission control system durability where particulate filters and other advanced aftertreatment systems are used. Optimum protection is provided for control of catalyst poisoning, particulate filter blocking, engine wear, piston deposits, low- and high-temperature stability, soot handling properties, oxidative thickening, foaming, and viscosity loss due to shear. API CJ-4 oils exceed the performance criteria of API CI-4 with CI-4 PLUS, CI-4, CH-4, CG-4 and CF-4 and can effectively lubricate engines calling for those API Service Categories. When using CJ-4 oil with higher than 15 ppm sulfur fuel, consult the engine manufacturer for service interval. |
|
CI-4 |
Current |
Introduced in 2002. For high-speed, four-stroke engines designed to meet 2004 exhaust emission standards implemented in 2002. CI-4 oils are formulated to sustain engine durability where exhaust gas recirculation (EGR) is used and are intended for use with diesel fuels ranging in sulfur content up to 0.5% weight. Can be used in place of CD, CE, CF-4, CG-4, and CH-4 oils. Some CI-4 oils may also qualify for the CI-4 PLUS designation. |
|
CH-4 |
Current |
Introduced in 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 |
Obsolete |
OBSOLETE: 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 |
Obsolete |
OBSOLETE: 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 |
Obsolete |
OBSOLETE: Introduced in 1994. For severe duty, two-stroke-cycle engines. Canbeusedinplaceof CD-II oils. |
|
CF |
Obsolete |
OBSOLETE: Introduced in 1994. For off-road, indirect-injected and other diesel engines including those using fuel with over 0.5% weight sulfur. Canbeusedinplaceof CD oils. |
|
CE |
Obsolete |
CAUTION: Not suitable for use in most diesel-powered automotive engines built after 1994. |
|
CD-II |
Obsolete |
CAUTION: Not suitable for use in most diesel-powered automotive engines built after 1994. |
|
CD |
Obsolete |
CAUTION: Not suitable for use in most diesel-powered automotive engines built after 1994. |
|
CC |
Obsolete |
CAUTION: Not suitable for use in most diesel-powered engines built after 1990. |
|
CB |
Obsolete |
CAUTION: Not suitable for use in most diesel-powered engines built after 1961. |
|
CA |
Obsolete |
CAUTION: Not suitable for use in most diesel-powered engines built after 1959 |
Gasoline API specification
Category |
Status |
Service |
|
SN |
Current |
Introduced in October 2010, designed to provide improved high temperature deposit protection for pistons, more stringent sludge control, and seal compatibility. API SN with Resource Conserving matches ILSAC GF-5 by combining API SN performance with improved fuel economy, turbocharger protection, emission control system compatibility, and protection of engines operating on ethanol-containing fuels up to E85. |
|
SM |
Current |
For 2010 and older automotive engines. |
|
SL |
Current |
For 2004 and older automotive engines. |
|
SJ |
Current |
For 2001 and older automotive engines. |
|
SH |
Obsolete |
OBSOLETE: For 1996 and older automotive engines. |
|
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. |
|
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. |
|
SE |
Obsolete |
CAUTION: Not suitable for use in most gasoline-powered automotive engines built after 1979. |
|
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. |
|
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. |
|
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. |
|
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. |
