Answer: Without oil a vehicle’s engine would never function. Oil circulates throughout the engine and is responsible for lubricating all of the moving parts. In a vehicle’s engine there are many moving parts that operate together. Without oil, these moving parts would rub against each other, create extreme levels of friction, and tear each other apart. Without oil, these parts would wear excessively, and the engine would ultimately fail. With the extreme levels of friction created by the engine’s moving parts, some microscopic wear particles eventually fall from the engine’s parts. These tiny particles can do much damage to the engine. Engine oil absorbs these wear particles and transfers them out of the engine and into the oil filter. Oil serves another function; it minimizes the engine’s exposure to oxygen, therefore limiting oxidation (rust) and corrosion. Oil also serves as an engine coolant. The engine’s moving parts create much heat energy, and oil is responsible for absorbing some of that heat. An oil change replaces the engine’s old, dirty oil with new oil that will help the engine operate at a more satisfactory, safer level.