Understanding API and ACEA Oil Specifications

Oil specifications can be confusing. This guide breaks down API and ACEA ratings to help you choose the right oil with confidence.

i-GlooOil Team2 min read
Understanding API and ACEA Oil Specifications

When shopping for engine oil, you will encounter a maze of specifications: API SN Plus, ACEA C3, MB 229.51, VW 504.00. Understanding these codes is essential for choosing the right oil and maintaining your warranty.

API (American Petroleum Institute) Ratings: The API uses a two-letter code. The first letter indicates the engine type: S for petrol (spark ignition) and C for diesel (compression ignition). The second letter indicates the performance level — later letters are more recent and advanced.

Current API petrol ratings: SP (latest), SN Plus, SN Current API diesel ratings: CK-4, CJ-4, CI-4

ACEA (European Automobile Manufacturers Association): ACEA uses a letter-number system: - A/B categories: For petrol and light-duty diesel (A3/B4 being the most common) - C categories: For catalyst-compatible oils (C1, C2, C3, C4, C5, C6) - E categories: For heavy-duty diesel (E4, E6, E7, E9)

The C-categories are particularly important for modern vehicles with diesel particulate filters (DPF) and three-way catalytic converters. Using the wrong ACEA category can damage these expensive emission control devices.

OEM (Original Equipment Manufacturer) Approvals: Many vehicle manufacturers have their own specifications that go beyond API and ACEA requirements. Examples include BMW LL-04, Mercedes MB 229.52, and VW 504.00/507.00. These often require specific testing and approval from the manufacturer.

At i-GlooOil, our product labels clearly display all relevant specifications, and our technical team can help you match the right oil to your vehicle requirements.