How often should you change your oil?

The old rule is every 3,000 miles, and it's hung on, but it's not valid anymore. Even the car dealers are suggesting longer intervals -- Toyota says our Highlander should get new oil every 5,000 miles.

Alina Tugend reports:

“There was a time when the 3,000 miles was a good guideline,” said Philip Reed, senior consumer advice editor for the car site Edmunds.com. “But it’s no longer true for any car bought in the last seven or eight years.”

Oil chemistry and engine technology have improved to the point that most cars can go several thousand more miles before changing the oil, Mr. Reed said. A better average, he said, would be 7,500 between oil changes, and sometimes up to 10,000 miles or more. 

The California Integrated Waste Management Board has a list of cars on its Web site and how often they need oil changes.

You'll need to look at how you drive -- stop and go for short distances in town is harder on the car. The reason is that if you take a trip of less than 10 miles or so, the engine and the oil are not completely warmed up. And if the oil is still cool it cannot absorb the contaminants that come from internal combustion as efficiently.