What oil should I use for my car? Your engine needs oil that is thin enough for cold starts and thick enough when the engine is hot. Since oil gets thinner when heated, and thicker when cooled, most of us use what are called multi-grade, or multi-viscosity oils.
What viscosity oil to use in modern cars?
Today, multi-viscosity oils are used almost exclusively over monograde oils since they function best in changing climates. SAE 30 motor oil, for example, is consistent with the viscosity of, say, 5W-30 oil when both are at 210 degrees, but the latter offers better performance in the cold as well. Multi-viscosity oils also contain additives that keep the oil from thinning out as it’s heated.
What kind of oil for my car if it’s a modern one?
Most modern car engines use 5W30 or 5W40 oil. Modern oils have a lower viscosity. This means they're thinner, helping the engine turn over more easily, and ensuring that the oil can circulate quickly around the engine soon after start up. Thinner oil helps fuel consumption too.
What kind of oil for my car if it’s an old one?
Older cars do not run well with these oils, as they are not designed for such tight tolerances. Cars that are 10 years old or older were designed to work with 10W30 or 10W40 motor oil.
What kind of oil to use if it’s a high mileage car?
High-mileage cars that have over 100,000 miles may even need 20W50 oil.