Engine Oil & Filters
Why oil changes matter more than any other job, what oil grades mean, and how air, oil, fuel and cabin filters keep a new car healthy.
Engine oil does far more than lubricate. It carries heat away from the hottest parts of the engine, holds combustion by-products in suspension until the next change, protects against corrosion and keeps seals supple. As oil ages it thins, oxidises and fills with contaminants, and an engine run on tired oil wears at a rate that no later repair can reverse. That is why the oil and filter change sits at the centre of every scheduled service.
Filters do the quiet work in between. The oil filter traps the particles the oil collects, the air filter stops dust reaching the cylinders, the fuel filter protects injectors and the cabin filter keeps the air you breathe clean. South African dust and long-distance driving load these filters faster than the intervals used in Europe assume, which is why local dealers sometimes recommend earlier replacement on gravel-road cars. If your car is under a service plan, all of this is handled at each scheduled visit.
Engine Oil & Filters — questions
The questions people ask about engine oil & filters, answered plainly.
How often should engine oil be changed on a new car?
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Change it at every scheduled service, at the interval the manufacturer sets in kilometres and months. Modern synthetic oils and long-life filters allow longer intervals than older cars needed, but the time limit still applies because oil degrades even when the car is parked. Drivers who do a lot of short trips or dusty driving may benefit from changing sooner.
What do the numbers on an oil bottle such as 5W-30 mean?
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They describe viscosity, or how thick the oil is. The number before the W indicates how easily the oil flows when cold, and the second number describes its thickness at operating temperature. Your service book specifies the correct grade and the approval standard the oil must meet. Using the wrong grade can affect fuel consumption, emissions and, in a worst case, warranty cover.
Can I top up engine oil myself between services?
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Yes, and you should check the level regularly, especially before a long trip. Use the grade specified in the service book, add a little at a time and never fill above the maximum mark on the dipstick or display, because overfilling can damage seals and the catalytic converter. If the car needs frequent topping up, have the dealer investigate.
How do I know when the air filter needs replacing?
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A blocked air filter shows up as sluggish acceleration, higher fuel consumption and sometimes a warning light. It is inspected at every service and replaced according to the schedule, but cars that spend time on gravel roads or in dusty areas may need it changed between services. A quick visual check by the technician is usually enough to decide.
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