What is the primary function of motor oil in an engine?

The primary function of motor oil in an engine is to lubricate moving parts. Lubrication is essential because it reduces friction between the engine's components, which generates heat. By minimizing this friction, motor oil helps prevent wear and tear on the engine parts, ensuring smoother operation and extending the engine's lifespan. Effective lubrication contributes to the overall efficiency and performance of the engine.

While motor oil does play a role in cooling by helping to dissipate heat and maintaining the optimal operating temperature, its core purpose is to provide lubrication. Additionally, motor oil does not directly influence the combustion process or significantly increase fuel efficiency as its primary role. Instead, its main job is to protect moving components from damage and to facilitate the efficient functioning of the engine.