Your car weighs roughly a ton, and the engine that powers it needs some serious weight too. So how come your engine purrs like a lap cat? It’s all about the oil.

The Basics

Oil is the life blood of your vehicle’s engine. While your car is running, the oil circulates through the engine. It lubricates the parts to keep them all moving with very little friction, which makes the engine run smoothly—and even purr.

Two things work to keep the engine running smoothly: cleaners added to the oil and oil filters. The cleaners do just what you might imagine. As the oil moves through the oil circulation system, the cleaners do their part to keep the engine clean and free from contaminants. The oil filter removes the worst of the foreign materials from the circulating oil.

Types of oil

There are three main types of oil, the normal petroleum-based oil, semi-synthetic oil and full synthetic oil. Your car’s manufacturer specifies which type of oil to use for the best performance.

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.

What Can Go Wrong

Without oil or with insufficient lubrication, the parts of the engine wear more rapidly. If the added friction generates too much heat, the engine could seize. A seized engine will no longer work without either a complete replacement or a major rebuild. Major engine work costs a lot of money. In comparison, simple oil changes are inexpensive.

Care and Maintenance

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