The American Petroleum Institute (API) engine oil classification system was set up as a joint effort by API, ASTM (American Society for Testing and Materials) and SAE (Society of Automotive Engineers). The letter classification system is a method of classifying engine oils according to their performance characteristics, and relating this to their intended type of service.

American Petroleum Institute service classifications are a two-letter rating beginning with “S” (Spark Ignition) for petrol engine oils and “C” ( Compression Ignition),for diesel engine oils. The second letter designates the oil’s quality standard, beginning with the letter “A”. The lower down the alphabet of the second letter, the higher the oil’s quality. Many oils meet standards for both petrol and diesel engines and will be marked with a dual service classification, for example SL/CF.

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 SL or SM oil, an API SN oil will provide full protection. For diesel engines, the latest category usually, but not always – includes the performance properties of an earlier category.

SN Plus Introduced 2018. Offering enhancements for direct injection and turbocharged petrol injected engines.

SN Introduced 2010 Developed with a focus on emission controls, with improved high temperature deposit protection, sludge control and seal compatibility. Energy Conserving characteristics. Improved Fuel Economy and offering protection for engines using part ethanol included fuels.

SM  Introduced for 2004 to 2010 and older engine requirements. For 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.

SL Introduced for 2001 to 2004 and older engines. 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 Introduced for 1998 to 2000 and older engines.

SH  Now obsolete. Introduced for 1994 to 1997 and older engines.

SG Obsolete. Introduced for 1989 to 1993 and older engines.

SF  Obsolete. Introduced for 1980 to 1988 and older engines.

SE Obsolete. Introduced for 1972 to 1979 and older engine and their requirements.

SD Obsolete. Introduced 1968 to 1971 and older engine requirements.

SC Obsolete. Introduced for 1964 to 1967 and older engine requirements

SB Obsolete. For older engines. Contains basic performance enhancement properties. Use only when specifically recommended by the manufacturer.

SA Obsolete. For older engines; no performance requirement. Use only when specifically recommended by the manufacturer.

CK-4 Introduced 2016. Developed for use in high-speed four-stroke diesel engines, on-highway and Tier 4 exhaust emission standards as well as being backwards compatible with previous classifications. CK-4 oils are designed to provide enhanced protection against oil oxidation, viscosity loss due shear and oil aeration as well as protection against catalyst poisoning, particulate filter blocking, engine wear, and soot related viscosity increase. These oils are effective at sustaining emission control system durability where advanced  after treatment systems are used including particulate filters. CK-4 Service Classified oils exceed the performance criteria  of CJ-4; CI-4/CI-4 PLUS and CH-4  and can effectively  lubricate engines calling for the earlier API Service Classifications.

CJ-4 for Heavy Duty Diesel Engine Service; Exhaust After treatment – 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 sulphur content up to 500 ppm (0.05% by weight). However, use of these oils with greater than 15 ppm (0.0015% by weight) sulphur 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.

CI-4 PLUS Introduced 2004 in the USA and in Australia in 2008. An enhancement on the CI-4 classification in respect to shear viscosity and further performance additions.

CI-4 Introduced in 2002 for Severe-Duty Diesel Engine Service – The API CI-4 Service category describes oils for use in those high-speed, four-stroke cycle diesel engines designed to meet 2004 exhaust emission standards, to be implemented October 2002. These oils are compounded for use in all applications with diesel fuels ranging in sulphur content up to 0.05% by weight. These oils are especially effective at sustaining engine durability where Exhaust Gas Recirculation (EGR) and other exhaust emission devices may be used.

CH-4 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 sulphur content up to 0.5% weight. Can be used in place of CD, CE, CF-4, and CG-4 oils.

CG-4 Introduced in 1995. For severe duty, high speed four-stroke engines using fuel with less than 0.5% weight sulphur. 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 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 Introduced in 1994. For severe duty, two stroke-cycle engines. Can be used in place of CD-II oils.

CF Introduced in 1994. For off-road, indirect injected and other diesel engines including those using fuel with over 0.5% weight sulphur. Can be used in place of CD oils.

CE 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 Introduced in 1987. For two-stroke-cycle engines.

CD Introduced in 1955. For certain naturally aspirated and turbocharged engines.

CC For engines introduced in 1961.

CB For moderate duty engines from 1949 to 1960.

CA For light duty engines (1940’s and 1950’s).

The ACEA classification system is the European equivalent of the American API classification system, if differs in the categorization approach and is more application specific when compared to its counterpart. ACEA is an abbreviation for “ Association des Constructuers European de ‘lAutomobile”.

Lubricants that meet both API & ACEA specifications are recognised as being a higher quality as they use better quality additives to meet requirements. The ACEA has three groups in which specific oils fall. “A/B” for petrol and light duty diesel (B) engines. The “C” group is for light duty three way catalyst (TWC) involved engines and (DPF) Diesel Particulate Filter compatible oils, which are normally both Low and Mid SAPS chemistry. (Sulphated Ash Phosphorus Sulphur). Finally, “E” grouped oils designated for  heavy duty diesel engines.

A1/B1 Stable, stay-in-grade oil intended for use at extended drain intervals in gasoline engines and car & light van diesel engines specifically designed to be capable of using low friction low viscosity oils with a high temperature / high shear rate viscosity of 2.6 mPa.s for xW/20 and 2.9 to 3.5 mPa.s for all other viscosity grades. These oils are unsuitable for use in some engines. Consult owner manual or handbook if in doubt. ( Now obsolete ).

A3/B3 Stable, stay-in-grade oil intended for use in high performance gasoline engines and car & light van diesel engines and/or for extended drain intervals where specified by the engine manufacturer, and/or for year-round use of low viscosity oils, and/or for severe operating conditions as defined by the engine manufacturer.

A3/B4 Stable, stay-in-grade oil intended for use in high performance gasoline and direct injection diesel engines, but also suitable for applications described under A3/B3.

A5/B5 Stable, stay-in-grade oil intended for use at extended drain intervals in high performance gasoline engines and car & light van diesel engines designed to be capable of using low friction low viscosity oils with a High temperature / High shear rate (HTHS) viscosity of 2.9 to 3.5 mPa.s. These oils are unsuitable for use in some engines. Consult owner manual or handbook if in doubt.

C1 Stable, stay-in-grade oil intended for use as catalyst compatible oil in vehicles with DPF and TWC in high performance car and light van diesel and gasoline engines requiring low friction, low viscosity, low SAPS oils with a minimum HTHS viscosity of 2.9 mPa.s. These oils will increase the DPF and TWC life and maintain the vehicles fuel economy. ( Now regarded as obsolete ).

Warning: these oils have the lowest SAPS limits and are unsuitable for use in some engines. Consult owner manual or handbook if in doubt.

C2 Stable, stay-in-grade oil intended for use as catalyst compatible oil in vehicles with DPF and TWC in high performance car and light van diesel and gasoline engines designed to be capable of using low friction, low viscosity oils with a minimum HTHS viscosity of 2.9mPa.s. These oils will increase the DPF and TWC life and maintain the vehicles fuel economy.

Warning: these oils are unsuitable for use in some engines. Consult owner manual or handbook if in doubt.

C3 Stable, stay-in-grade oil intended for use as catalyst compatible oil in vehicles with DPF and TWC in high performance car and light van diesel and gasoline engines, with a minimum HTHS viscosity of 3.5mPa.s. These oils will increase the DPF and TWC life.

Warning: these oils are unsuitable for use in some engines. Consult owner manual or handbook if in doubt.

C4 Stable, stay-in-grade oil intended for use as catalyst compatible oil in vehicles with DPF and TWC in high performance car and light van diesel and gasoline engines requiring low SAPS oil with a minimum HTHS viscosity of 3.5mPa.s. These oils will increase the DPF and TWC life.

Warning: these oils are unsuitable for use in some engines. Consult owner manual or handbook if in doubt.

SAPS : Sulphated Ash, Phosphorus, Sulphur

DPF : Diesel Particulate Filter

TWC : Three way catalyst

HTHS : High temperature / High shear rate viscosity

E4 Stable, stay-in-grade oil providing excellent control of piston cleanliness, wear, soot handling and lubricant stability. It is recommended for highly rated diesel engines meeting Euro I, Euro II, Euro III, Euro IV and Euro V emission requirements and running under very severe conditions, e.g. significantly extended oil drain intervals according to the manufacturer’s recommendations. It is suitable for engines without particulate filters, and for some EGR engines and some engines fitted with SCR NOx reduction systems. However, recommendations may differ between engine manufacturers so Driver Manuals and/or Dealers shall be consulted if in doubt.

E6 Stable, stay-in-grade oil providing excellent control of piston cleanliness, wear, soot handling and lubricant stability. It is recommended for highly rated diesel engines meeting Euro I, Euro II, Euro III, Euro IV and Euro V emission requirements and running under very severe conditions, e.g. significantly extended oil drain intervals according to the manufacturer’s recommendations. It is suitable for EGR engines, with or without particulate filters, and for engines fitted with SCR NOx reduction systems. E6 quality is strongly recommended for engines fitted with particulate filters and is designed for use in combination with low sulphur diesel fuel. However, recommendations may differ between engine manufacturers so Driver Manuals and/or Dealers shall be consulted if in doubt.

E7 Stable, stay-in-grade oil providing effective control with respect to piston cleanliness and bore polishing. It further provides excellent wear control, soot handling and lubricant stability. It is recommended for highly rated diesel engines meeting Euro I, Euro II, Euro III, Euro IV and Euro V emission requirements and running under severe conditions, e.g. extended oil drain intervals according to the manufacturer’s recommendations. It is suitable for engines without particulate filters, and for most EGR engines and most engines fitted with SCR NOx reduction systems. However, recommendations may differ between engine manufacturers so Driver Manuals and/or Dealers shall be consulted if in doubt.

E9 Stable, stay-in-grade oil providing effective control with respect to piston cleanliness and bore polishing. It further provides excellent wear control, soot handling and lubricant stability. It is recommended for highly rated diesel engines meeting Euro I, Euro II, Euro III, Euro IV and Euro V emission requirements and running under severe conditions, e.g. extended oil drain intervals according to the manufacturer’s recommendations. It is suitable for engines with or without particulate filters, and for most EGR engines and for most engines fitted with SCR NOx reduction systems. E9 is strongly recommended for engines fitted with particulate filters and is designed for use in combination with low sulphur diesel fuel. However, recommendations may differ between engine manufacturers so Drivers Manuals and/or Dealers should be consulted if in doubt.

ILSAC is an abbreviation for International Lubricants Standardisation and Approval Committee. It is made up of automobile manufacturers from the USA and Japan. ILSAC specifications are related to the API Classification System.

ILSAC specifications are backwards compatible and suitable for use in place of earlier ILSAC classifications.

ILSAC grades are relevant to viscosities XW-20 and XW-30. GF-4 has had a phosphorus limit of 0.08% and a sulphur limit of 0.2% added while GF-5 has seen new requirements added relating to phosphorus volatility and compatibility requirements with ethanol based fuels.

2020 saw the introduction of GF-6A classification, which applies to viscosities such as 0W-20; 5W-20; 0W-30 and 10W-30 grades. While GF-6B classifications has applications for viscosities lower than XW-20, such as 0W-16, 0W-12 and 0W-8.

GF-1 Now Obsolete.

GF-2  is equivalent to API SJ

GF-3  is equivalent to API SL

GF-4  is equivalent to API SM

GF-5  is equivalent to API SN

GF-6A is equivalent to API SP ( XW-20 AND XW-30 )

GF-6B is equivalent to API SP ( XW16 grades and below )

JASO  is an abbreviation for Japanese Automotive Standards Organization.

There are three classifications.

JASO DL-1 is applied to Light duty engines oil specification for engines that are equipped with exhaust after treatment devices such as a Diesel Particulate Filters or Catalyst devices.

JASO DH-1 is applied to heavy duty diesel with performance standards superior to API CF-4. This classification also carries with it improved  piston cleanliness and valve train  wear requirements.

JASO DH-2 has applications for heavy duty diesel specifications similar to API CJ-4 and ACEA E9. It was developed for use in engines equipped with emission control devices.

Motorcycle

Motorcycle oils that meet the JASO T 903:2006 standard can be classified into four grades: JASO MA, JASO MA1, JASO MA2 and JASO MB. The classification is based on the results of the JASO T 904:2006 clutch friction test.

JASO MA Japanese four-stroke motorcycles, non-friction modified engine oil suitable use with wet clutches. This classification has been divided into MA1 and MA2 based on the clutch friction test referred to earlier.

JASO MB  For small motorcycle based design units with automatic transmissions such as scooters. Oils that meet this classification contains friction modifiers to aid in improved transmission changes and better fuel economy.

These listings are the result of the ACEA – “ Association des Constructuers European de ‘lAutomobile, the EMA – Engine Manufacturers Association and JAMA – Japanese Automobile Manufacturers Association, as they relate to diesel lubricants with different requirements and limits. The designations are arrived at from test requirements that meet each of the authorities standards.

Heavy Duty: DHD-1

 Light Duty: DLD-1, DLD-2 and DLD-3