How Often Should You Change Your Oil?

You know you should change your oil at regular, reasonable intervals to make sure your car runs smoothly, but a common question remains: How often should you change your oil? What is a reasonable amount of time — or mileage — between oil changes?

The traditional recommendation is that you should change your oil every 3,000 miles or six months, whichever comes first. However, the new standard is that you can typically change your oil every 5,000 miles worry-free (especially if you are driving a relatively new car or it's in “optimal operating conditions).

The truth is that the frequency in which you change your oil depends on your manufacturer’s recommendations, your operating conditions (environment), and how much wear and tear your car has already experienced.

Oil change frequency

Before we dive into the different conditions that can impact oil change frequency, we must understand why we even need to get an oil change! Dirty oil just doesn't do the job as well as fresh oil does. The additives in dirty oil boil out, contaminants form in the crankcase and eat metal parts, and water collects over time and forms sludge.

The oil holds more and more abrasive particles of metal suspended in it, and these particles wear away the parts of the engine the oil is supposed to protect.

All oil looks pretty black within a couple of days after an oil change, so the only way to avoid running on oil that's so dirty it becomes a liability is to keep a record of when it was last changed and to change it frequently — as often as every 1,000 miles in extreme operating conditions. By changing your oil frequently, you may get twice the mileage out of an otherwise good engine.

Oil changes in extreme operating conditions

You'll be surprised by what some "extreme operating conditions" are: If you do a lot of stop-and-go driving in city or rush-hour traffic, make a lot of short trips each day, leave the car parked long enough to have your engine cool down between them, and don't often get up to high speeds on a highway, your engine rarely gets hot enough to evaporate the water that forms in the crankcase and builds up sludge in the engine.

Other extreme conditions include driving in very hot weather or in areas with a lot of blowing dust or dirt, or if you tow or haul heavy loads all the time. In any of these circumstances, change the oil as often as every 1,000 to 3,000 miles on older vehicles. On new vehicles, follow the manufacturers' recommendations for extreme use.

Oil changes in optimal operating conditions

How often to change oil can be dependent on the car manufacturer — some manufacturers suggest that oil be changed every 7,500 miles or more, but that's based on optimum operating conditions, and the manufacturers are the ones who get to sell you a new vehicle if your old one wears out prematurely.

Although new vehicles can run longer on the same oil than older ones can, and improvements in motor oil have extended its efficiency over longer periods of time, to be on the safe side, you might want to change your oil every 5,000 miles or every six months, whichever comes first.

If you're a freeway driver who goes on a lot of long journeys at high speeds, you can probably extend the oil change interval. But on anything but the newest vehicles, don't go longer than 5,000 miles between oil changes. And never, under any circumstances, go farther than the manufacturer's recommended maximum interval between oil changes.