To show you why this is so important, take your hand and rub it back and forth along your arm. What do you notice? Very quickly the two surfaces start to heat up because of the friction. Now imagine if there was some sand or grit on the surface of your skin. How long before you might to really feel some discomfort or damage to your skin? Now apply a lubricant to your skin. Do your fingers glide along much smoother? Is there less heat and friction? This same principle applies to the moving parts of your engine.

Your engine is full of moving parts: cam shafts, pistons, valves, crankshafts, lifters, rods, etc. All working together properly gets your vehicle moving. Your engine’s oil not only has to keep every part lubricated – it also prevents excessive heat from building up.

The reason your oil needs regular changing is because with all the work it does, oil wears out. The additives that are in the oil to increase its effectiveness have broken down. That’s to be expected. Oil becomes contaminated with dirt, sludge and possible metal filings. Left unchanged, your oil can go from being a lubricant to an abrasive.

Part of the process of having your engine oil changed is to also replace the oil filter. As good as oil filters are, they don’t get all the dirt, grit and sludge. Some of it will be trapped throughout the engine. Your engine channels the oil to every moving part. When it gets plugged with sludge, the oil can’t get to where it’s needed. Two things can happen if the sludge is left in – it will contaminate your new oil, and secondly, it may lead to a potentially costly repair to any number of those moving parts.