The current highest standard for gasoline engines (introduced in 2020). It’s designed to protect against "low-speed pre-ignition" (LSPI) in modern turbocharged engines. CK-4 / FA-4: Current standards for diesel engines.
This represents the oil's resistance to flow at operating temperature (212°F / 100°C). A higher number means a "thicker" oil film, which provides more protection for hard-working or older engines. 2. Performance Categories (The Letters) engine oil specs.7z
Many manufacturers have their own "house" specs that go beyond general API or ACEA standards. If you own a European car, look for codes like: BMW Longlife-01 Mercedes-Benz MB 229.5 GM dexos1™ or dexos2™ (common for Chevys and GMCs) Quick Tips for Choosing: This represents the oil's resistance to flow at
Refined crude oil. Good for basic, older engines with frequent change intervals. older engines with frequent change intervals.
You’ll see the symbol on bottles that meet GF-6 standards. These oils focus heavily on fuel economy and emission system protection. ACEA (European Automobile Manufacturers' Association):