There is no reason to not regularly change your air filter.
Dear Tom and Ray:
My father has a 1989 Chrysler LeBaron with 56,000 miles on it. I was amazed when he told me that he has never changed the air filter on it. I told him he was crazy and that it needs to be changed. He came back with the old "if it ain't broke, don't fix it." He says he does not drive on dirt roads, and the car has low mileage, so he does not have to change the air filter. Please settle this debate. Is he crazy? -- Paula
RAY: Well, he might be crazy, Paula. But we can say with certainty that he's an A-one cheapskate. And he's wrong about the air filter.
TOM: You don't have to drive on dirt roads to clog up your air filter. There's plenty of dirt in the air and around the engine.
RAY: The air filter is there to prevent that dirt from being sucked into the combustion chambers, where it can scratch and score the cylinder walls and ruin the engine.
TOM: Usually when a filter gets really dirty, the engine will start to run poorly due to lack of air. Some people (maybe your dad does this) then remove the filter and bang it against their hand to shake some of the dirt out of it. This can work for a while. But eventually, the paper that does the actual filtering disintegrates. And then you've got no filter at all.
RAY: And that's not good. Over time, the cylinder walls will get scored, and the car will start burning oil. So this is one of those things that IS worth "fixing," even though it isn't "broke."
TOM: Plus, it only costs 10 bucks. I mean, there's cheap, and then there's silly-cheap.
RAY: And he drives so few miles that who knows? He might only need two or three more air filters over the course of his lifetime. So get him one for Christmas and two for his birthday, Paula. That'll be a nice way to tell him you won the bet.