The right motor oil is the one your engine was designed for. Everything you need is printed in your owner’s manual and on the bottle – here is how to match the two.
1. Start with the viscosity grade
Grades such as 0W-20, 5W-30 or 15W-40 describe how the oil flows. The number before the W is its cold-weather rating (lower flows more easily at start-up); the number after it is its thickness at operating temperature. Use the grade listed in your manual – many modern engines are built around thin oils, and a thicker oil does not mean more protection.
2. Check the specification
Look for the approvals your manual lists: an API service category (for example API SP for gasoline engines, CK-4 for many diesels), ILSAC, or a manufacturer approval such as dexos or a European OEM number. The approval matters as much as the grade.
3. Conventional, synthetic blend or full synthetic
- Conventional – suits many older, simpler engines when the manual allows it.
- Synthetic blend – a middle ground for mixed driving.
- Full synthetic – holds up better in heat, cold and turbocharged engines; required by many newer vehicles.
4. High-mileage oils
High-mileage formulas add seal conditioners that can help older engines with minor seepage. They still need to meet your manual’s grade and specification.
5. Don’t forget the filter
A fresh oil filter is part of every oil change. Buy it by your vehicle’s year, make, model and engine – thread size and bypass valve differ between filters that look alike.
Not sure? Bring your year, make, model and engine size, or call the parts counter at (909) 623-3151, and we will look it up with you.