Engine oil is a carefully engineered blend of substances designed to protect your engine under extreme heat and pressure. As your car is driven, this oil gradually loses its effectiveness due to constant exposure to high temperatures, friction and contaminants. Over time, degraded oil can no longer protect your engine properly.
This guide explains how engine oil works, why it needs replacing, and what happens if oil changes are ignored.
What Happens to Engine Oil Over Time
New engine oil is thick, smooth and golden-brown in colour. As it circulates through the engine, it collects microscopic metal particles, carbon deposits and dirt. With continued use, the oil becomes darker, gritty and less effective at lubricating moving parts.
The oil’s thickness also changes as it degrades. It can become either too thin to protect components or too thick to flow properly. At the same time, the oil filter gradually becomes clogged and loses its ability to remove contaminants, meaning dirty oil is pumped back into the engine.
Why Oil Levels Fall Between Services
In addition to quality degradation, the quantity of engine oil naturally decreases over time. Small amounts of oil are burnt during normal engine operation, especially in high-mileage or high-performance vehicles.
Although oil can be topped up, topping up alone does not restore degraded oil. Once the oil’s protective properties have deteriorated beyond a certain point, it must be fully replaced to avoid the risk of engine damage.
Why All Cars Need Regular Oil Changes
Every vehicle, regardless of make, model or mileage, has manufacturer-recommended service intervals at which the engine oil and oil filter must be replaced. These intervals exist to ensure the engine remains properly lubricated and protected.
Skipping oil changes or extending service intervals increases wear and tear, reduces efficiency and shortens engine life. Regular oil servicing is one of the simplest and most cost-effective ways to protect your car long term.
How Engine Oil Works Inside Your Engine
Engine oil is stored in the oil sump and pumped through the engine whenever it is running. The oil pump draws oil from the sump, pressurises it and forces it through the oil filter, where microscopic contaminants are removed.
The filtered oil then flows through internal engine pathways and over critical components such as the crankshaft, pistons and valve train. As it moves, the oil lubricates moving parts, reduces friction, cools hot components, keeps surfaces clean and prevents direct metal-to-metal contact.
After completing this cycle, the oil returns to the sump. This entire process takes only a few seconds and repeats continuously while the engine is running.
What Happens If Engine Oil Is Not Changed in Time
If engine oil is not replaced when required, it gradually loses its ability to lubricate and cool vital components. This causes increased friction, rising temperatures and accelerated wear throughout the engine.
Over time, the engine can begin to overheat and lose efficiency. In severe cases, lack of proper lubrication can cause catastrophic engine failure. When this happens, the engine may seize completely and require replacement, which can cost thousands of pounds depending on the vehicle.
Regular oil changes are far cheaper than repairing or replacing a damaged engine.
Why Oil Change Warning Lights Are Not Always Reliable
Many modern vehicles are fitted with oil change indicators or service reminders. While helpful, these systems are not always perfectly accurate and may not account for real-world driving conditions such as short journeys, heavy loads or high-performance driving.
If your car is serviced regularly at the recommended mileage or time intervals, you are unlikely to experience oil-related problems. However, if you drive frequently, make short trips or are overdue for a service, checking your oil level and condition monthly is a sensible precaution.
When to Top Up and When to Replace Oil
Topping up engine oil can help maintain safe oil levels, but it does not restore degraded oil quality. If the oil has become dark, gritty or excessively thin or thick, a full oil and filter change is required.
When topping up, it is important to use high-quality oil that meets your manufacturer’s specifications. Using the wrong oil can cause damage and reduce engine efficiency.
If an oil change is due, it is best carried out by a professional service centre. Used engine oil is toxic, and DIY oil changes are messy, inconvenient and not recommended for most drivers.
Book an Oil Service at Prestige Cars Kent
At Prestige Cars Kent, we offer professional oil and filter changes as a while-you-wait service. Our experienced technicians use the correct oil grades for your vehicle and ensure your engine is properly protected.
Our customers regularly mention clear advice and honest servicing in our Google reviews, which is exactly what you want when trusting someone with your engine.
If your car is due an oil change, contact Prestige Cars Kent Service Centre today to book your appointment.
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