What are the ACEA oil sequences?
Specification · ACEA
The ACEA sequences are European engine-oil performance classes grouped into A/B for gasoline and diesel, C for low-SAPS catalyst- and DPF-friendly oils, and E for heavy-duty diesel. They are performance standards, separate from the viscosity grade, and an oil should meet the class your manual lists AND the correct grade.
- Specification
- ACEA sequences
Manual-first check
A match needs all three
- Viscosity grade The cold-start and operating-temperature grade listed in the manual.
- Oil specification The required API, ILSAC, ACEA or manufacturer performance claim.
- Exact vehicle context Engine, model year and market, including manual footnotes and exceptions.
Standards map
How to read an ACEA requirement
- A/B · C · EApplication family
A/B covers light-duty gasoline and diesel categories, C covers catalyst-compatible light-duty categories, and E covers heavy-duty diesel sequences.
- HTHSHigh-temperature shear behavior
HTHS requirements help distinguish operating-temperature film behavior; the category sets the limit, not the viscosity grade alone.
- SAPSAftertreatment and SAPS
C categories combine performance with different chemical limits intended around emissions systems; C is not one interchangeable level.
- OEMExact category and OEM rule
Match the full ACEA category and any manufacturer approval in the manual. A viscosity grade cannot replace either.
This conceptual map does not rank categories or claim compatibility; use the current ACEA sequence and the exact vehicle manual.
Check a bottle label
If your manual lists ACEA sequences, use the oil spec checker to compare the manual requirement with what an oil bottle says. Verify issuer-controlled evidence with the approval and license guide. Need the source first? Start with the owner's manual finder. Viscosity and approvals are separate requirements.
What the ACEA sequences are
The ACEA oil sequences are a set of European performance classes for engine oils, published by the European Automobile Manufacturers’ Association. Rather than a single standard, they form a family of categories grouped by engine type and aftertreatment needs. Each class defines a level of performance that an oil must be tested against, which is why European vehicle makers frequently reference ACEA classes in their requirements.
The categories are organised into broad letter groups. The A/B group covers oils for gasoline and diesel passenger-car engines. The C group covers low-SAPS oils — meaning reduced sulphated ash, phosphorus, and sulphur — which are designed to be friendlier to catalytic converters and diesel particulate filters. The E group covers heavy-duty diesel applications such as commercial vehicles.
How the classes differ
Because each group targets different demands, the classes are not freely interchangeable. A C-class low-SAPS oil is formulated with aftertreatment protection in mind and is not the same as an A/B oil, even if the viscosity grade matches. Choosing the wrong class can be unsuitable for engines with sensitive emissions hardware.
It is best to think of the ACEA class and the viscosity grade as two separate pieces of information. The grade — for example 5W-30 — describes flow behavior, while the ACEA class describes the performance and chemistry level. An oil should meet the class your manual calls for AND the correct grade.
What to follow
ACEA sequences are revised over time, and individual classes within each group carry numeric identifiers that change between revisions. For that reason this overview keeps to the general structure rather than specific sub-numbers.
For the exact class your vehicle needs, rely on the owner’s manual. It is the authoritative source and accounts for the specific engine and emissions setup your car uses.
Frequently asked questions
What does low-SAPS mean in the C class?
Low-SAPS oils limit sulphated ash, phosphorus, and sulphur, which helps protect catalytic converters and diesel particulate filters. The ACEA C class covers these formulations.
Can I substitute one ACEA class for another?
Not freely — the classes target different engine and aftertreatment needs, so a C-class oil is not interchangeable with an A/B oil. Use the class your owner's manual specifies.
Do ACEA sequences replace the viscosity grade?
No. The ACEA class and the viscosity grade are separate, and an oil must meet both. Your manual lists each one.