Introduced in March 2025 for the latest gasoline-engine requirements. SQ adds protection against both fresh- and aged-oil low-speed pre-ignition (LSPI), improved timing-chain wear protection, high-temperature deposit control, and sludge and varnish control.

Introduced in May 2020 with stronger requirements for LSPI protection, timing-chain wear, high-temperature deposits, oxidation, sludge and varnish control. API SP oils include the requirements previously identified by API SN Plus.

Gasoline-engine service category for 2020 and older automotive engines. SN remained the main API gasoline category until the introduction of API SP.

SN Plus was a supplemental designation identifying API SN oils that met a higher level of performance, particularly for protection against low-speed pre-ignition in modern gasoline engines. It was an interim step before API SP, which incorporates all SN Plus requirements.

An earlier gasoline-engine service category retained by API for vehicles whose manufacturers specify it.

An earlier gasoline-engine service category retained for older applications.

An older gasoline-engine service category still listed by API for legacy applications.

For high-speed four-stroke diesel engines designed around 2017 on-highway and Tier 4 non-road emissions requirements, as well as many earlier engines. CK-4 provides enhanced protection against oxidation, shear-related viscosity loss, aeration, wear, deposits and soot-related viscosity increase.

For high-speed four-stroke diesel engines designed around 2010 on-highway and Tier 4 non-road emissions requirements, as well as previous-model-year engines.

Introduced in 2002 for high-speed four-stroke diesel engines designed around 2004 emissions requirements, including engines using exhaust-gas recirculation (EGR).

CI-4 Plus identified CI-4 oils meeting a higher level of protection against soot-related viscosity increase and viscosity loss due to shear. API CK-4 and CJ-4 include all CI-4 Plus performance requirements.

Introduced in 1998 for high-speed four-stroke diesel engines designed to meet 1998 exhaust-emission standards. CH-4 oils were formulated for diesel fuels containing up to 0.5% sulfur by weight.

FA-4 covers certain XW-30 oils formulated for selected high-speed four-stroke diesel engines designed around 2017 on-highway greenhouse-gas requirements. API specifies an HTHS viscosity range of 2.9–3.2 cP and diesel fuel sulfur content up to 15 ppm.

Introduced in March 2025 for modern passenger-car gasoline engines. GF-7A adds protection against both fresh- and aged-oil low-speed pre-ignition (LSPI), improved timing-chain wear protection, high-temperature deposit control, sludge and varnish control, improved fuel economy, enhanced emissions-system protection and improved low-temperature pumpability.

Introduced in March 2025 as the successor to GF-6B. GF-7B provides the latest ILSAC performance requirements for the separate SAE 0W-16 branch, including fresh- and aged-oil LSPI protection, fuel economy, timing-chain wear protection and emissions-system compatibility.

Introduced in May 2020 with added protection against LSPI and timing-chain wear, improved piston and turbocharger deposit control, stronger sludge and varnish control, improved fuel economy and enhanced emissions-system protection.

Introduced alongside GF-6A in May 2020 as a separate standard for SAE 0W-16 oils. It provides the GF-6 generation's LSPI, timing-chain, deposit, fuel-economy and emissions-system performance for this lower-viscosity application.

A stable, stay-in-grade high-SAPS engine oil category for passenger-car and light-duty gasoline and diesel engines. It may also be specified for extended oil-drain intervals where approved by the engine manufacturer and requires an HTHS viscosity of at least 3.5 mPa·s.

A stable, stay-in-grade high-SAPS category for gasoline and direct-injection diesel engines designed for lower-viscosity oils and extended drain intervals. It uses a lower HTHS range than A3/B4 and is unsuitable for some engines.

A lower-HTHS high-SAPS category related to A5/B5, with additional protection against low-speed pre-ignition and wear in turbocharged gasoline direct-injection engines, plus turbocharger compressor-deposit protection for modern direct-injection diesel engines.

A mid-SAPS category for gasoline and direct-injection diesel engines designed for lower-viscosity oils. C2 supports aftertreatment-system compatibility and extended drain intervals where specified.

A mid-SAPS catalyst-compatible category for gasoline and direct-injection diesel engines requiring a higher HTHS viscosity than C2. It is widely encountered in European vehicle specifications.

A low-SAPS catalyst-compatible category for gasoline and direct-injection diesel engines requiring an HTHS viscosity of at least 3.5 mPa·s. It has different chemical limits from C3 and should not be treated as interchangeable.

A mid-SAPS category intended to support improved fuel economy in engines specifically designed and approved for lower-HTHS oils. C5 is not a universal replacement for C2, C3 or C4.

A fuel-economy-oriented mid-SAPS category based on C5, with additional LSPI and wear protection for turbocharged gasoline direct-injection engines and turbocharger compressor-deposit protection for modern direct-injection diesel engines.

The lowest-HTHS current ACEA C category, introduced for applications designed and approved for very low-viscosity oils. C7 is based on C6 performance levels with enhanced fuel-economy requirements.

A high-SAPS heavy-duty diesel category with a high minimum TBN, intended for specific on- and off-highway applications. Suitability for exhaust-aftertreatment systems, fuel sulfur levels and drain intervals depends on the engine manufacturer's requirements.

A high-SAPS heavy-duty diesel category used across a range of on- and off-highway applications. ACEA's application guidance shows that suitability varies with emissions hardware and fuel type, so the OEM recommendation remains essential.

A low-SAPS heavy-duty diesel category designed for modern engines and exhaust-aftertreatment systems. E8 replaced the former E6 category in the 2022 Heavy-Duty Oil Sequences.

A low-SAPS heavy-duty diesel category for modern engines, including applications using exhaust-aftertreatment. E11 replaced the former E9 category when the revised heavy-duty sequences were introduced.

Introduced with the 2024 Heavy-Duty Oil Sequences, F01 is a fuel-economy-oriented heavy-duty diesel category with specific XW-30 viscosity requirements and an HTHS range of 2.9–3.2 mPa·s.