What is the function of engine oil in a car?

[BrooklynFitz]

Functions of automotive engine oil: 1. As a lubricant: It reduces friction and wear between moving parts, such as between cylinder liners and piston rings, or camshafts. 2. As a coolant: It absorbs heat generated in the combustion chamber and piston crowns, cooling the engine and preventing overheating. 3. As a sealant: It fills the gaps between piston rings and cylinder liners to prevent pressure leakage. 4. As a cleaner: It prevents contaminants and oxide impurities from combustion from adhering to the engine internals, maintaining cleanliness. 5. As a rust inhibitor: It neutralizes acidic substances produced by combustion gases, preventing rust and corrosion in the engine.