Motor oil

Motor oil, engine oil, or engine lubricant is any one of various substances used for the lubrication of internal combustion engines. Motor oils typically consist of base oils enhanced with various additives, particularly antiwear additives, detergents, dispersants, and, for multi-grade oils, viscosity index improvers. The main function of motor oil is to reduce friction and wear on moving parts and to clean the engine from sludge and varnish (detergents).

It also neutralizes acids that originate from fuel and from oxidation of the lubricant (detergents), improves the sealing of piston rings, and cools the engine by carrying heat away from moving parts.

Back to Maintenance & Care →

Source: Wikipedia · Image: Wikimedia Commons · CC BY-SA 4.0

AUTOSHYPE

Cars, performance, and the road ahead — reviews, tech, and the calculators every driver needs.

Get new guides by emailOccasional emails. No spam. Unsubscribe anytime.

InformationAbout Contact Privacy Policy Terms of Service Disclaimer Affiliate Disclosure Cookie Policy

Every species, image, fact, and figure is drawn from Wikipedia and Wikimedia Commons, used under public-domain and Creative Commons licenses. No content is AI-generated.