When to change the fuel filter...

Dear Car Talk

Dear Car Talk | May 01, 1992

Dear Tom and Ray:

With a fuel injected car, how do you determine when to change the fuel filter? By mileage?

RAY: Yeah. Other than cutting it open and taking a look at it, there's really no way to know when a fuel filter needs to be changed. So you're right, Will, you really have to do it on the basis of mileage.

TOM: The fuel filter's job is to trap little pieces of junk that get sucked out of the gas tank. And when it gets old and saturated, one of two things can happen. Either the flow of fuel will be blocked, and the car will stop running. Or the filter will start to disintegrate and let some of the junk though. And that's bad news because fuel injectors are very sensitive to junk.

RAY: Unlike my brother, who, judging by the cars he drives, is completely de-sensitized to junk.

TOM: Seriously, Will, fuel filters these days can cost as much as $30 or $40 bucks a piece. That may sound like a lot, especially when it comes on top of the price of a standard $49.95 "tune-up." But if you don't change the filter, you run the risk of plugging up your injectors. And trust me, THAT runs into real money.

RAY: Most manufacturers tell you to change the filter every 30,000 miles. We recommend doing it at 15,000. When you compare the cost of a fuel filter to $600 worth of injectors, even my brother can figure out that it's a pretty wise investment.

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