How Often Should You Change Your Engine Oil?

The right oil change interval is the one in your car's service schedule. As a rough guide, most cars need an oil and filter change once a year or every 9,000 to 12,500 miles, whichever comes first. Cars on variable or long-life servicing can go longer, but only with the correct long-life oil.

Fixed and long-life servicing

• Fixed servicing sets a mileage and a time limit, often 12 months. The oil is changed at whichever comes first.
• Variable, long-life or condition-based servicing, used by VW Group, BMW, Mercedes-Benz and others, lets the car calculate when the oil needs changing. Intervals can reach up to two years or around 18,000 miles, but only with oil carrying the long-life approval, such as VW 504 00 / 507 00 or BMW Longlife-04.

If you are not sure which schedule your car is on, check the service book or ask your garage. If you switch a long-life car to an oil without the long-life approval, it must go onto fixed servicing.

When to change your oil sooner

Car makers describe some conditions as severe use, which calls for shorter intervals. They include:

• Lots of short journeys, where the engine rarely reaches full temperature.
• Towing, or carrying heavy loads.
• Taxi, delivery or stop-start town driving.
• Dusty roads or very cold weather.

If your driving matches these, fixed servicing with more frequent oil changes is the safer choice.

Do I need to change oil if I hardly drive?

Yes. Oil ages even when the car is parked, as moisture and fuel from short runs build up in it. That is why service schedules include a time limit as well as a mileage.

How to check your oil level

1. Park on level ground and wait a few minutes after switching off.
2. Pull out the dipstick, wipe it clean, push it fully back in, then pull it out again.
3. The oil should sit between the minimum and maximum marks. Top up a little at a time with the correct oil if it is low.

Some newer cars have no dipstick and show the level on the dashboard instead. Check your oil at least once a month and before long journeys.

Warning signs

• A red oil pressure warning light means stop the engine as soon as it is safe and check the level. Do not keep driving.
• An amber oil level warning means top up soon.
• Needing to top up often can point to a leak or wear, so have it checked.

Oil colour is not a reliable guide. Diesel oil turns black almost at once, and that is normal.

Getting the right oil

Use the grade and approval in your handbook. Our guide to choosing the right engine oil explains how to find them, and you can shop car and van engine oil by grade, specification or car make. Keep a 1 litre bottle of the same oil in the car for top-ups.

Frequently asked questions

Can I go longer between oil changes with fully synthetic oil?

Only if your service schedule allows it. The interval is set by the car maker, not the oil, although long-life schedules do require a synthetic long-life oil.

Should I change the oil filter every time?

Yes, in almost every case. Most service schedules change the filter with every oil change.

Is it worth changing oil more often than the schedule?

For cars used in severe conditions, yes. For normal driving, the manufacturer's interval is designed to protect the engine.