Cars have changed over the years. Once, with a little knowledge, many owners could manage basic service requirements on their own driveways. These days however, our vehicles are fairly complex and built to tight tolerances. The result is that, unless technically skilled, most drivers never open their bonnets between services except maybe to top up the screen wash container.
One of the most important things those automotive do-it-yourself home mechanics from bygone days would attend to was the engine oil and filter and it is just as an important factor, if not more so, today. It’s crucial for the health of the car that owners ensure the oil in the engine is changed regularly at the appropriate service intervals.
Electric car owners can look away now (although they have their own service requirements) but any vehicle with an internal combustion engine under the bonnet, including hybrids, need oil to survive.
What Does The Oil Do?
The interior of an engine is a living thing. Various components, often moving at high speed, work alongside each other; they rub together. That’s what friction is. For example, in very cold weather, we might rub our hands together to warm them up: That’s friction and it generates heat. Well, it’s the same in an engine. The energy that is used in overcoming friction is converted into heat and that heat needs to be dissipated. That is one of the functions of oil: to lubricate moving parts and absorb that excess heat. Keeping the moving parts separated also helps to reduce wear, helping the engine to live longer.
Oil, as mentioned, absorbs heat on its travels around the engine. It carries that heat back to the oil sump at the bottom of the engine, where it dissipates the heat before continuing its journey around the engine, en route, passing through a filter which collects any contaminants, keeping the oil clean.
In higher performance engines this circulation might not be sufficient so an oil cooler is added. This is usually a small radiator fitted near to the coolant radiator, through which air passes and cools the oil.
Changing The Oil
Regardless of how efficient the lubrication system is or how expensive the oil, an oil change is recommended periodically. Oil will become exhausted over time and owners can check this themselves: The car’s manual will point out the location of the engine’s oil dipstick. Follow the instructions and remove the dipstick. New oil will be amber in colour but old oil will be dark or even black. That’s the signal to get it changed. Note that different cars and different engines require different types or grades of oil. This should be listed in the handbook or, if in doubt, your car servicing garage can advise.
Whenever an oil changed is needed, remember to have the filter changed as well. Ignoring this step to save money is a false economy as allowing fresh oil to pass through a dirty filter is defeating the object of the exercise. In any event, oil filters are not expensive in most cases.
The oil change is an integral and vital part of any car servicing regime. Car makers recommend servicing at specific intervals either by time or by mileage. Drivers who routinely do very high miles may wish to consider an interim engine service by their local car servicing provider to keep the motor running in tip-top condition. Once again, your garage professionals can advise.
The opposite is also true. If a vehicle is stored or is rarely used and is left standing for periods of time it’s important to know how long the oil is good for. Oil that remains stagnant in an engine faces the same issues as an opened bottle of wine that has been left for a couple of days. Oil will oxidize and potentially a sediment could build up. If an engine is operated with old oil in the sump, it can cause permanent damage.
The message is clear: Always ensure that your car is professionally serviced. Not just the engine either: All the moving parts need attention over time for safety’s sake if nothing else. That’s why we have the MOT test. We talk about oiling the wheels of industry to keep commerce working efficiently. Why should it be any different for your car?