Why Does Engine Oil Need Changing?

Engine oil is a careful blend of substances with certain physical and chemical properties. With use, the oil becomes less effective due to the extreme operating conditions within the engine.

New engine oil is usually a thick smooth and slimy fluid with a golden-brown colour. With use, it turns dark and gritty. The thickness also changes and it can become thinner or thicker. The oil filter gets clogged with frequent use and beyond a a certain point it loses the ability to pump clean oil back into the sump.

Apart from the degradation of both the physical and chemical properties, the quantity of oil also starts falling as some of it gets burnt in the engine. Engine oil can be topped up, but if its quality has deteriorated beyond a point, it needs to be replaced or there is a risk of engine damage.

All vehicles whatever the make or mileage have regular servicing intervals at which the oil and oil filter must be replaced.

How does engine oil work?

Engine oil is stored in the oil reservoir (oil sump) and is pumped through the engine when it runs. The oil pump sucks the oil through a tube, pressurises it and sends it through the oil filter. Here, microscopic particles are removed and the oil travels along a circuit of pathways in the engine. The filtered oil flows over a number of critical components like the crank shaft, pistons and valve trains.

As it flows, it lubricates, cools pistons, keeps them clean and prevents wear in the drive trains. The oil is the only thing preventing metal to metal contact between moving parts.

After flowing through the engine, the oil returns to the sump. The whole trip takes only a few seconds. Regular oil maintenance preserves and protects the engine and should give you years of trouble-free performance.

What happens if the oil isn't changed in time?

Without proper engine oil, your engine could start to overheat and its efficiency will go down. Wear and tear will also increase. If oil is not replaced, the engine will eventually shut down. In most cases, you will need a new engine. That could cost could be extremely expensive depending on the make, model and engine type. Obviously, it is much cheaper to get regular oil and filter changes.

Although many modern cars are fitted with an oil change indicator, they are not very reliable. If you are getting your car serviced periodically at a good garage at the recommended time and mileage intervals, you are unlikely to face an oil problem.

If you are overdue for service or use your car a lot, you should do a monthly check on oil levels and quality. You will find the instructions in your car manual. If you decide to top up, use good-quality oil that confirms with the manufacturer’s specifications. If an oil change is required, bring your car to Prestige Cars Kent Service Centre, as used engine oil is toxic and DIY oil changes can be messy and not recommended.

We can carry out an oil service as a while you wait appointment for as little as £99+VAT - just ask for a quote or use our online pricing tool.