How often should I change my car's oil?

Change your oil as often as your owner's manual says. It gives an interval by distance and by time, and whichever comes first is the one that counts. That's usually at every regular service, so if your car is serviced on schedule, the oil is too.

The catch is the "whichever comes first" part. Plenty of cars around Albany and the North Shore do short trips and low kilometres, so it's the time limit, not the distance, that comes round first.

Why does the time limit matter if I hardly drive?

Oil doesn't only wear out from distance. It ages. Short trips are hard on it, because the engine often doesn't get fully warm, so moisture and fuel that would normally burn off stay in the oil instead. Over months that thins it and makes it less able to protect the engine.

So a car that does 4,000 km a year still needs its oil changed when the time interval comes up, even though the odometer says it's nowhere near due.

What changes the interval?

Your manual's normal interval assumes normal driving. Many manuals also have a shorter "severe" schedule for cars that:

• mostly do short trips, where the engine rarely warms up properly
• spend a lot of time in stop-start traffic (the motorway at Constellation Drive counts)
• tow a trailer, boat or caravan
• drive on dusty or gravel roads
• are older, or use a bit of oil between changes

If that sounds like your car, check whether your manual has a severe schedule, and use that one. Some newer cars also have an oil life reminder on the dash that works out the interval from how the car is driven. Go by it, but don't let it run past the time limit in the manual.

Does the type of oil matter?

Yes. Use the grade and specification your manual asks for, such as 5W-30 or 0W-20. The right oil for the engine matters more than the brand on the bottle. Modern engines are built to tight tolerances, and the wrong grade can affect protection and fuel economy.

When we change your oil, we use the grade your car needs and change the oil filter at the same time. Fresh oil through an old filter is half a job.

How do I know my oil is overdue?

Some signs it's time, or past time:

• The service reminder or spanner light is on. That's the car telling you it's due.
• The level is low on the dipstick. Check it on flat ground with the engine off for a few minutes (your manual says whether to check it warm or cold). Low oil is worth topping up and worth asking about.
• It's dark and gritty. Oil darkens with use, so colour alone isn't a perfect test, but thick, gritty or sludgy oil is overdue.
• The engine sounds louder or ticks more than it used to, especially when cold.
• You can't remember the last change. Check the sticker on the windscreen or the service book.

If the red oil pressure light comes on while you're driving, that's different. It's not a reminder, it's a warning that the engine may not be getting enough oil. Pull over safely, turn the engine off, and call us before driving further. Our guide to dashboard warning lights explains the others.

Should I change my oil myself?

You can, if you have the tools, the right oil and filter, and somewhere to take the old oil. Many people find it's not worth the mess. When we do it, the car is up on the hoist, so we also get a look underneath for leaks and anything else worth knowing about.

Quick questions

Oil changes in Albany and the North Shore

Midas Albany, 3C Saturn Place, Albany. Family owned since 2004, MTA Assured. We do oil and filter changes on their own or as part of a full service. Call with your make and model and we'll give you the price before you book. If we spot anything else, you get the price first, and nothing extra is done without your OK in writing.

See our car servicing.

Call Robin on 09 415 6595, book online, or request a callback. Monday to Friday 7:30am to 4:30pm, Saturday 8am to 12pm.

Written by the Midas Albany team.