How Often Should You Change the Oil on Modern Cars?

If you learned to drive before about 2005, somebody told you to change your oil every three thousand miles. That advice was correct once. It is now, for most cars on the road, roughly twice as often as necessary.

What changed

Two things. Oil got much better — modern full synthetics resist breaking down at high temperature far longer than the conventional oils of the 1980s. And engines got much cleaner, with tighter tolerances and better filtration keeping contaminants out of the oil in the first place.

The result is that most manufacturers now specify somewhere between 7,500 and 10,000 miles for normal driving on full synthetic. Some go further.

The only source that matters

Your owner's manual. Not the sticker the quick-lube shop put on your windscreen, which is often set at a conservative interval that happens to be good for their business.

If you do not have the manual, most manufacturers publish maintenance schedules online by year and model. It takes two minutes to look up and it is the single most useful maintenance fact about your car.

When to go shorter anyway

The manual usually lists a "severe service" interval as well, and more people qualify for it than realise. Severe service typically means:

• Lots of short trips where the engine never fully warms up
• Extended idling, or stop-and-go traffic most days
• Towing or hauling heavy loads
• Sustained very hot or very cold conditions
• Frequent driving on dusty or gravel roads

That last one covers a fair number of people around here. If two or three of those describe your week, use the shorter interval.

Older engines and higher mileage

If you are driving something with well over a hundred thousand miles, particularly an engine with a known appetite for oil, checking the level monthly matters more than the exact change interval. An engine that is a litre low is being damaged regardless of how fresh the remaining oil is.

Pull the dipstick once a month. It costs nothing and it is the cheapest engine insurance there is.

Ask about the specific vehicle

Service history varies from one vehicle to the next, and the honest answer is that we will tell you what we know about the one in front of you rather than make a blanket promise about the whole lot. Where a vehicle came to us with records, we will show you the records.