Oil is the life blood of an internal combustion engine. It keeps the parts moving efficiently and smoothly to ensure the safe operation of the engine.

The basics

While a vehicle’s engine is running, the oil circulates throughout the engine. It lubricates the parts to keep them all moving with very little friction. This helps to reduce heat buildup and to increase fuel efficiency by reducing friction during internal combustion.

Engine oil can be petroleum based, fully synthetic, or a blend of both. Fully synthetic oil tends to last longer because the chemicals do not break-down as fast as petroleum-based oil does. This can allow for less frequent oil changes. The vehicle manufacturer usually provides specification for when to change oil based on which type of oil is used.

Engine oil includes some cleaners that keep the engine running clean as the oil starts to pick up debris from normal engine operation. The lubrication system cycles the oil through an oil filter that keeps the oil clean throughout the life of the oil.

Normal wear

Petroleum-based oil breaks down over time and the rate of breakdown can increase each time it is heated and cooled. In other words, every time you drive your car and then park long enough to cool the engine. It is normal for modern engines to shed some material such as metal particles and moisture from foreign sources. The oil picks up this material and holds onto it. For the engine to run smoothly, the material must be removed periodically. The only way to remove the material is by changing oil, which is why the oil needs to be changed on a routine maintenance schedule.

Care and maintenance

Most manufactures recommend an oil change every 3,000 to 5,000 miles for non-synthetic engine oil. If a vehicle uses synthetic oil, the interval may be 5,000 to 10,000 miles. Check the vehicle manufacturer’s specifications for the optimal timing to keep the engine running smoothly.