What is one of the basic functions of oil in an engine?

One of the fundamental functions of oil in an engine is to clean. Engine oil circulates throughout the engine and helps to remove contaminants, debris, and carbon deposits that can accumulate during the combustion process. The oil picks up these impurities and carries them to the oil filter, where they are trapped and removed from the circulation system. This cleaning function is essential for maintaining engine performance and longevity, as it helps prevent wear and damage caused by buildup.

While other functions such as insulating, expanding, or injecting may relate to different aspects of engine operation or oil systems, cleaning is critical to ensuring the engine remains efficient and operates smoothly over time.