How Often Should You Really Change Your Oil?

Many of us still go by the old rule of changing oil every 5,000 kilometers. That number made sense for older engines and conventional oils, but it isn't a one-size-fits-all answer anymore. The right interval depends mainly on what kind of oil your car uses and how you drive.

Match the Interval to Your Oil

Conventional oil is the most basic option, and it's usually changed every 5,000 to 7,500 km. It gives standard protection and suits older engines that were designed for it. Synthetic blends sit in the middle, typically lasting 7,500 to 10,000 km with a good balance of performance and everyday reliability. Full synthetic oil resists breakdown much better, so many modern and turbocharged engines can go 10,000 to 20,000 km between changes. That range is wide, though, so check your owner's manual before stretching the interval that far.

Whatever oil you use, the manual is the final word. It lists the viscosity and standards your engine needs, and those matter as much as the change interval.

When Your Driving Shortens the Interval

Your habits can wear oil out faster than the mileage suggests. If your driving includes short trips under about 10 minutes, which never let the engine fully warm up and allow moisture and fuel to build up in the oil, reduce the intervals above by roughly a third. The same goes for city traffic with constant stop-and-go driving and long stretches of idling, heavy loads like towing a trailer or driving in the mountains, and extreme climates, whether that means deep cold, intense heat, or dusty and sandy roads. Many people who commute in town or make quick errands fall into this category without realizing it.

Two Rules That Apply to Everyone

First, change your oil at least once a year, even if you haven't reached the mileage limit. Oil breaks down with age, and moisture can collect in it over time, so a car that barely moves still needs regular service. Second, replace the oil filter every time you change the oil. The filter traps metal particles and sludge that would otherwise circulate through the engine, and reusing an old filter with fresh oil defeats the purpose of the change.