You have probably been told by a mechanic to change your oil at regular intervals, perhaps every 4,000 or five 5,000 miles or even as frequently as 3,000 miles. However, when that time comes around, you may think you can go longer without changing it as long as your car is running fine. If you don't think your car is being harmed by skipping a couple oil changes, then you may be surprised at what not changing your oil can do to your engine.

Detergents and additives break down:

All brands of oil contain special additives that improve lubrication and keep your engine from accumulating dirt and varnish. Additives also work to manage the moisture that can cause additional problems. Over time, these additives can break down and become less effective. That could mean that more dirt and sludge will clog your filter and build up in the engine. This can cause more friction and can lead to direct wear on your engine parts.

The oil breaks down and thickens:

Though oil is usually very durable and can tolerate high temperatures, it will begin to lose its effectiveness as a lubricant over time. Natural oils tend to break down sooner than synthetic blends, so you will need more frequent oil changes if you use the natural kind. Eventually, the oil will turn into sludge and become completely useless. This sludge often accumulates and thickens to the point where it can cause interference with the engine's operation. Your engine could seize if you let this go on for a long time. Even if your engine still keeps running, you are seriously shortening its life by letting dirt and sludge build up.

Changing the filter is equally important:

Problems aren't just limited to not changing the oil. Not changing the filter can be just as bad. The oil filter takes out all those dirt particles and contaminants which eventually contribute to thickening and buildup. Eventually, all the contaminants build up in the filter to the point where it can't take any more and it becomes totally ineffective. This means that, even though you change your oil often, all the dirt and contaminants will be circulating through the engine.

The good news is that changing the oil and the filter is a fast and inexpensive maintenance item, so there's no excuse to skip that oil change. Check with your mechanic as to how often you need to have the service. The intervals are usually based on whether you have natural, synthetic blend, or full synthetic oil.

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