How Often Do You Need To Change Your Oil?

Oil change time intervals rely on a number of mitigating factors that determine when one should get their vehicle's oil changed. Manufacturers, mechanics, and lube shops tend to differ on their estimated mileage for when you should change your oil because of this very reason. Knowing which factors affect the cleanliness of your oil can help you make an informed choice as to when you'll need to get around to changing it.

Where To Start
A good jumping off point would be to look at your owner's manual, which will probably supply a number around 7,500 miles. The manufacturer actually built the car, meaning they generally know more about it than a service shop whose interest might be more financial than it would care to let on. Though, manufacturer recommendations are based on ideal driving conditions - driving short distances, never over the speed limit, that kind of thing - something the average driver would be hard-pressed to accomplish.

What Affects Oil Change Intervals
So, once you've uncovered the carmaker's estimated oil change mileage, there are a few issues that need to be reviewed to adjust that estimate. Hard driving is a major wear and tear factor in determining the mileage amount for an oil change. If you're driving a lot in extreme conditions (both hot and cold), stop-and-go traffic or hanging out on dusty roads, you must change your oil more frequently.
Robert Kim, owner of Action Auto Care in San Francisco, CA believes, "If you're driving in the city most of the time, you should change your oil every 3,000 miles."

Conversely, and perhaps obviously, if you're not driving very much, you'll be able to get away with longer periods in between oil changes. This is a situation when you wouldn't need to change your oil as regularly and could stick closer to the manufacturer's suggestion. But remember, it is good to change the 'black gold' in your car even if you don't drive it that much.

If your car has been around the block a couple of times, oil changes should be at increasingly more frequent intervals compared to how often you changed it when your car was new. This is due to "blowby": compressed fuel and air that has leaked into the engine's crankcase through the rings. Over time, soot and grime builds up on the rings, making them slightly permeable and resulting in contaminated oil that needs to be changed more regularly.

Kim says, "Having regular oil changes prevents oil leaks, you usually get better gas mileage, and you're maintaining your vehicle for the long-term."

Though having to only change your oil every 7,500 miles is something we would all prefer, 3,000 to 5,000 miles are numbers more representative of actual driving conditions. By erring on the side of caution, you'll help to extend the life of your car.