Your car’s engine is composed of steel parts rubbing together at very high speeds and in very close tolerances. In simple physics, friction keeps two objects from sliding past each other in close proximity. When power is applied, and friction is overcome, heat is the result. An example of this is rubbing your hands together rapidly. If your car’s engine were to be operated without reducing the friction and resulting heat, it would completely seize up and become inoperable.

This is where petroleum based engine oil comes in. Petroleum molecules do not bind together but slide past each other easily. The technical term for this is lubricity. In your car’s engine, the petroleum molecules form a slippery, protective barrier between two moving components. The effect is less friction resulting in heat reduction. Another benefit of reducing friction and heat is less wear, increasing the life of your engine. However, to be effective, the oil needs to be clean and fresh.

Petroleum oil looses its lubricity over time. This is due to molecular breakdown caused by heat. The oil also becomes contaminated by dirt and acids formed by the internal combustion process. Most dirt and debris is filtered out by the oil filter, a soup can shaped object on the side of the engine block. The oil is pumped through this filter as it circulates throughout the engine during operation.

The condition of your car’s engine oil can easily be gauged by a simple inspection. Pull the engine’s dip stick. This is a device that measures the level of oil within the engine and on most cars has a yellow handle. New oil is a translucent, golden brown and about the viscosity of maple syrup. If the oil is black, has a burnt smell, and a thin, watery consistency, it is no longer effective at protecting your car’s engine. It is high time for an oil change. To prevent damage from worn-out oil, most manufacturers recommend replacing it at 3,000 mile increments.

Changing the engine oil in your car is a fairly straight forward procedure. The oil is in a chamber at the bottom of the engine in what is known as the oil sump or oil pan. The car is raised to a comfortable working height. A container is placed under the oil sump. The drain plug is removed and the waste oil is drained into the container. The old oil filter and filter gasket are removed from the engine block. A new oil filter and gasket are installed. The drain plug is reinserted after the old oil is completely drained. The proper type, viscosity, and capacity of oil required by your car’s engine is then poured into the filler spout. The engine is restarted and checked for leaks at the drain plug and filter gasket.

Regular engine oil changes are a necessity to maintaining the dependability and longevity of your car. Check your owner’s manual or with a trusted auto technician for other recommendations on maintaining your car.