What role does engine oil play in a car?

Engine oil has important functions in the car:

Reduces friction between components
The engine is made of moving parts and there is certainly friction between them. Wherever there is friction, there is heat. Engine oil eliminates friction between metal parts so that the resulting heat does not overheat the engine. It also prevents wear of parts. You know that repairing and replacing worn engine parts can be costly. So with the right engine oil, you save money.

It removes heat from the combustion cycle
The engine works by producing controlled explosions or combustion inside the cylinders. Now if the heat from friction is added to these controlled explosions, the car engine will have a problem. Engine oil, like insulation, prevents heat from reaching this cycle.

Absorbs unwanted by-products
The combustion process produces unwanted products such as acids and silicon oxide, which can be damaged if they enter other parts of the engine. Engine oil absorbs these substances like a magnet and suspends them.

Minimizes rust
In the combustion process, the fuel must be mixed with air, which contains oxygen. Oxygen causes metals to corrode and rust. It is true that we can not prevent air from reaching the engine, but by using engine oil we can minimize its oxidizing effects.