These ratings tell you if the oil meets the latest technological standards for your engine type.
The most common spec is the SAE (Society of Automotive Engineers) grade, like . engine oil specs.7z
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. These ratings tell you if the oil meets
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) A higher number means a "thicker" oil film,
A mix of both. It offers better protection than conventional but at a lower price point than full synthetic. 4. OEM Approvals (Manufacturer Specs)
The "W" stands for Winter. This number indicates how well the oil flows at cold temperatures. A lower number (0W or 5W) means the oil stays thinner in the cold, helping your engine start more easily in winter.
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: