If more than half your journeys take fewer than 20km, you should change your oil every 7500km. Take note of the section in your handbook which specifies the wide range of conditions where 10,000km oil changes do not apply. This can include dusty conditions, heavy loads, sustained high speeds, frequent short trips, stopstart driving and towing.
If a modern engine rattles or taps when cold, it may need thinner oil. Heavy loads, sustained high speeds or towing may require a synthetic oil for best protection. Topping up an engine that uses oil with new oil is NOT the same as giving it an oil change. The contaminates left behind increase in concentration each time the oil level drops. They need to be drained out. A car used for frequent short trips may not appear to use oil but contaminates build up.
Oil must be checked on a long drive because there can be a sudden drop in oil level after they boil out. The latest unleaded engines produce nastier by-products and they also have less oil (for light weight and faster warm up); oil can clog up if not checked often enough. The 10,000km oil change should be treated as an absolute maximum. If your car does not cover that distance in 6 months, the oil should be changed regardless.
What Should You Do?
- Check the oil on level ground after the car has been switched off for a couple of minutes to let the oil drain into the bottom of the engine, otherwise the dipstick will show a false low reading. Over filling can damage the engine.
- Oil filters should be renewed with every oil change. Ask for one which meets the standards set by the manufacturer of your car.
- Choose an oil which bears a guarantee which meets the relevant standards.
- Don't ignore the oil warning light, even if there is plenty of oil in the engine.