API Service Classification (Engine Crankcase Oils)

The following descriptions in the categories in the API Engine Service Classification System are intended as guides to aid in the selection of proper engine oils for significantly different engine service conditions. The performance requirements for these categories are technically described on the API Web site

“S”  - SERVICE OILS
(For Gasoline / Spark Ignition engines)


SA - Formerly for Utility Gasoline and Diesel Engine Service ( Obsolete)
Service typical of older engines operated under such mild conditions that the protection afforded by compounded oils is not required. This category should not be used in any engine unless specifically recommended by the equipment manufacturer.

SB - For Minimum Duty Gasoline Engine Service( Obsolete)

Service typical of older gasoline engines operated under such mild conditions that only minimum protection afforded by compounding is desired. Oils designed for this service have been used since the 1930’s and provide only antiscuff capability and resistance to oil oxidation and bearing corrosion. They should not be used in any engine unless specifically recommended by the equipment manufacturer.

SC - For 1964 Gasoline Engine Warranty Maintenance Service ( Obsolete)

 

Service typical of gasoline engines in 1964 through 1967 models of passenger cars and some trucks operating under engine manufacturers’ warranties in effect during those model years. Oils designed for this service provide control of high and low temperature deposits, wear, rust and corrosion in gasoline engines.

SD - For Gasoline Engine Warranty Maintenance Service ( Obsolete)

Service typical of gasoline engines in 1968 through 1970 models of passenger cars and some trucks operating under engine manufacturers’ warranties in effect during those model years. Also may apply to certain 1971 and/or later models as specified (or recommended) in the owners’ manuals. Oils designed for this service provide more protection against high and low temperature engine deposits, wear, rust and corrosion in gasoline engines than oils which are satisfactory for API Engine Service Category SC and may be used when
API Engine Service Category SC is recommended.

SE - For 1972 Gasoline Engine Warranty Service ( Obsolete)

Service typical of gasoline engines in passenger cars and some trucks beginning with 1972 and certain 1971 models operating under engine manufacturers’ warranties. Oils designed for this service provide more protection against oil oxidation, high temperature engine deposits, rust and corrosion in gasoline engines than oils which are satisfactory for
API Engine Service Categories SD or SC and may be used when either of these classifications is recommended.

SF - For 1980 Gasoline Engine Warranty Maintenance Service ( Obsolete)

Service typical of gasoline engines in passenger cars and some trucks beginning with the 1980 model year operating under manufacturers’ recommended maintenance procedures. Oils developed for this service provide increased oxidation stability and improved anti-wear performance relative to oils which meet the minimum requirements for API Service
Category SE. The oils also provide protection against engine deposits, rust and corrosion. Oils meeting API Service Classification SF may be used where API Service Categories SE, SD or SC are recommended. Oils meeting the performance requirements measured in the following gasoline engine tests: The IID gasoline engine test has been correlated with vehicles used in short-trip service prior to 1978, particularly with regard to rusting. The IIID gasoline engine test has been correlated with vehicles used in high temperature service prior to 1978, particularly with regard to oil thickening and valve train wear. The V-D gasoline engine test has been correlated with vehicles used in stop-and-go service prior to 1978, particularly with regard to varnish, sludge and valve train wear. The L-38 gasoline engine test requirement provides a measurement of copper-lead bearing weight loss
under high-temperature operating conditions.

SG - For 1989 Gasoline Engine Warranty Maintenance Service (Obsolete)

Service typical of gasoline engine in passenger cars, vans and light trucks beginning with the 1989 model year operating under manufacturers’ recommended maintenance procedures. Category SG quality oils include the performance properties of API service category CC. (Certain manufacturers of gasoline engines require oils also meeting API Category CD). Oils developed for this service provide improved control of engine deposits, oil oxidation and engine wear relative to oils developed for previous categories. These oils also provide protection against rust and corrosion. Oils meeting API Service Category SG may be used where API Service Categories SF, SF/CC, SE or SE/CC are recommended.

SH - For 1992 Gasoline Engine Warranty Maintenance Service (Obsolete)

Category SH covers the performance requirements of SG oils tested to the latest CMA protocol on engine testing. In addition, SH oils must meet various bench test requirements including volatility, filterability and foaming tests.

SJ - For 1997 Gasoline Engine Warranty Maintenance Service

API Service Category SJ was adopted for use in describing engine oils available in 1996. These oils are for use in service typical of gasoline engines in current and earlier passenger-car, sport utility vehicle, van, and light truck operations under vehicle manufacturers’ recommended maintenance procedures.
Engine oils that meet API Service Category SJ designation may be used where API Service Category SH and earlier Categories have been recommended. Engine oils that meet the API Service Category SJ designation have been tested in accordance with the CMA Code, may use the API Base Oil Interchangeability Guidelines and the API Guidelines for SAE Viscosity-Grade Engine Testing.
Engine oils that meet these requirements may display API Service Category SJ in the upper portion of the API Service Symbol.

SL - For 2001 Gasoline Engine Warranty Maintenance Service

API Service Category SL was adopted for use in describing engine oils available in 2001. These oils are for use in service typical of gasoline engines in current and earlier passenger cars, sport utility vehicles, vans, and light-duty trucks operating under vehicle manufacturers’ recommended maintenance procedures.
Engine oils that meet API Service Category SL designation may be used where API Service Category SJ and earlier Categories have been recommended. Engine oils that meet the API Service Category SL designation have been tested in accordance with the ACC Code and may use the API Base Oil Interchangeability Guidelines and the API Guidelines for SAE Viscosity-Grade Engine Testing.

SM – 2004 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.


“C”- SERVICE OILS
(For Diesel / Compression Ignition Engines)


CA — Diesel Engine Service
(Obsolete)

 Service typical of diesel engines operated in mild to moderate duty with high-quality fuels; occasionally has included gasoline engines in mild service. Oils designed for this service provide protection from bearing corrosion and ring-belt deposits in some naturally aspirated diesel engines when using fuels of such quality that they impose no unusual requirements for wear and deposit protection. They were widely used in the 1940s and 1950s but
should not be used in any engine unless specifically recommended by the equipment manufacturer.

CB — Diesel Engine Service (Obsolete)

 Service typical of diesel engines operated in mild to moderate duty, but with lower quality fuels, which necessitate more protection from wear and deposits; occasionally has included gasoline engines in mild service. Oils designed for this service were introduced in 1949. They provide necessary protection from bearing corrosion and from high-temperature deposits in naturally aspirated diesel engines with higher sulfur fuels.

CC — Diesel Engine Service (Obsolete)

 Service typical of certain naturally aspirated, turbocharged or supercharged diesel engines operated in moderate to severe-duty service, and certain heavy-duty gasoline engines. Oils designed for this service provide protection from high-temperature deposits and bearing corrosion in these diesel engines, and also from rust, corrosion, and low-temperature deposits in gasoline engines. These oils were introduced in 1961.

CD — Diesel Engine Service (Obsolete)

 Service typical of certain naturally aspirated, turbocharged or supercharged diesel engines where highly effective control of wear and deposits is vital, or when using fuels with a wide quality range (including high-sulfur fuels). Oils designed for this service were introduced in 1955 and provide protection from high-temperature deposits and bearing corrosion in these diesel engines.

CD-II — Severe-Duty Two-Stroke Cycle Diesel Engine Service (Obsolete)

 Service typical of two-stroke cycle diesel engines requiring highly effective control of wear and deposits. Oils designed for this service also meet all performance requirements of API Service Category CD.

CE — 1983 Diesel Engine Service (Obsolete)

 Service typical of certain turbocharged or supercharged heavy-duty diesel engines, manufactured since 1983 and operated under both low-speed, high-load and high-speed, high-load conditions. Oils designated for this service may also be used when API Service Category CD is recommended for diesel engines.

CF-4 — 1990 Diesel Engine Service (Obsolete)

Service typical of high-speed, four-stroke cycle diesel engines. API CF-4 oils exceed the requirements for the API CE category, providing improved control of oil consumption and piston deposits. These oils should be used in place of API CE oils. They are particularly suited for on-highway, heavy-duty truck applications. When combined with the appropriate "S" category, they can also be used in gasoline and diesel powered personal vehicles — i.e., passenger cars, light trucks, and vans — when recommended by the vehicle or engine manufacturer.
CF — Indirect-Injected Diesel Engine Service

 Service typical of indirect-injected diesel engines and other diesel engines that use a broad range of fuel types, including those using fuel with high sulfur content; for example, over 0.5% wt. Effective control of piston deposits, wear and copper-containing bearing corrosion is essential for these engines, which may be naturally aspirated, turbocharged or supercharged. Oils designated for this service have been in existence since 1994 and may be used when API Service Category CD is recommended.

CF-2 — Severe-Duty Two-Stroke Cycle Diesel Engine Service (Obsolete)

 Service typical of two-stroke cycle diesel engines requiring highly effective control over cylinder and ring-face scuffing and deposits. Oils designed for this service have been in existence since 1994 and may also be used when API Engine Service Category CD-II is recommended. These oils do not necessarily meet the requirements of API CF or CF-4 unless they pass the test requirements for these categories.

CG-4 — 1994 Severe-Duty Diesel Engine Service

 API Service Category CG-4 describes oils for use in high-speed four-stroke-cycle dieselengines used in both heavy-duty on-highway (0.05% wt sulfur fuel) and off-highway (less than 0.5% wt sulfur fuel) applications. CG-4 oils provide effective control over high-temperature piston deposits, wear, corrosion, foaming, oxidation stability, and soot accumulation. These oils are especially effective in engines designed to meet 1994 exhaust emission standards and may also be used in engines requiring API Service Categories CD, CE, and CF-4. Oils designed for this service have been in existence since 1994.

CH-4— 1998 Severe-Duty Diesel Engine Servic

API Service Category CH-4 oils are suitable for high-speed, four-stroke diesel engines designed to meet 1998 exhaust emission standards and are specifically compounded for use with diesel fuels ranging in sulfur content up to 0.5% weight. CH-4 oils are superior in performance to those meeting API CF-4 and API CG-4 and can effectively lubricate engines calling for those API Service Categories

CI-4— 2002 Severe-Duty Diesel Engine Service

API Service Category CI-4 oils are suitable for high-speed, four-stroke diesel engines designed to meet 2004 exhaust emission standards. CI-4 oils are formulated to sustain engine durability where exhaust gas recirculation (EGR) is used and are intended for use with diesel fuels of up to 0.5% mass sulphur. CI-4 oils are superior in performance to those meeting API CF-4 , API CG-4 and CH-4 and can effectively lubricate engines calling for those API Service Categories

CJ-4 – 2006 Heavy Duty Diesel Engine Service; Exhaust Aftertreatment

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. 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.