Which one is NOT the function of engine oil in car engines?

The function of engine oil in car engines is to provide lubrication and reduce friction between the moving parts, thus preventing excessive wear and damage. Additionally, engine oil also helps to cool the engine by dissipating heat generated during operation. It also acts as a sealant, preventing leaks and maintaining the integrity of the engine. However, engine oil does not play a role in the combustion process itself. Combustion is the process of burning fuel in the presence of oxygen to generate energy, and it is facilitated by the spark plugs, air-fuel mixture, and ignition timing, but not influenced by engine oil. Thus, combustion is not a function of engine oil in car engines.