Kamranmotors Shop — Engine Oil Viscosity Grades | kamranmotors.shop
Three bodies publish the codes printed on a bottle: API for the service category, ILSAC for the fuel-economy GF series, ACEA for European handbook categories — each with dates and numeric limits behind it.
The API service category is a two-letter code. The first letter, S, marks passenger-car service; the second letter runs forward through the alphabet as the category is superseded. API SL carries a Noack volatility limit of 14%, the same ceiling that applies under ILSAC GF-3, and some manufacturer specifications require less than 10%. The code tells you which bench tests the oil passed, not how it will behave in your engine.
The ILSAC GF series runs in step with API but adds fuel-economy and volatility requirements. GF-3 shares the 14% Noack ceiling with API SL. GF-6 was published in 2019 and licensed from May 2020; GF-6A is backward compatible with GF-5, so a GF-6A oil can be used where GF-5 was specified, while GF-6B covers SAE 0W-16 only and is not a general-purpose grade.
On narrow screens, swipe or scroll the plate sideways.
European handbooks often name ACEA categories instead of, or alongside, the American codes. ACEA A3 covers a wider viscosity tolerance typical of older designs; ACEA A5 covers a lower-viscosity, fuel-economy oriented band. Both sit next to API and ILSAC codes on a bottle rather than replacing them, and a handbook that names an ACEA category expects that category specifically.
The tests behind these codes are specific and measurable. The Sequence IIIG test runs a 3.8-litre GM V-6 at 125 horsepower and 3,600 rpm with the oil held at 150 °C for 100 hours, and the oil must hold its viscosity and limit deposits through the whole run. Noack volatility is a separate heated test whose result is capped at 14% under API SL and ILSAC GF-3.
Reading a bottle therefore means reading three lines: the API service category, the ILSAC GF number with its licensing date, and the ACEA category where the handbook names one. All three must match what the handbook specifies, because each code certifies a different set of tests and a different set of limits.
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