What is the primary function of motor oil?

The primary function of motor oil is to lubricate the moving parts within an engine. Lubrication is crucial for minimizing friction between metal surfaces, which in turn reduces wear and tear on engine components. Proper lubrication helps to maintain engine temperature by reducing heat generated from friction and also facilitates smoother operation of various engine parts, such as pistons and bearings.

While motor oil does have secondary benefits, such as cleaning engine components and contributing to the overall efficiency of the engine, its main role is to provide a protective film that prevents metal-to-metal contact, ensuring the engine runs smoothly and efficiently over time.