Today: Are reusable air filters right for your car?

Dear Car Talk

Dear Car Talk | Aug 01, 2011

Dear Tom and Ray:

I just found out that cars can use reusable air filters! But that's all I know about them, except that they're more expensive and claim to be more efficient.

Do they improve mileage? I love a sensible opportunity to be green, but I wonder if reusable filters work on cars. I use washable filters at home, but my home doesn't go driving along dusty forest roads! I'd appreciate your thoughts or speculative dialogue.

-- Tom

RAY: Speculative dialogue? Is that just a nice way of referring to our usual, unsubstantiated BS?

TOM: Actually, reusable air filters are environmentally friendly, Tom. Instead of throwing out your air filter after 30,000 miles, tossing it in a landfill and buying a new one with its own, new set of packaging, you can install a reusable air filter, clean it yourself and use it again.

RAY: They do cost more than throw-away filters. But you can do the math. You figure out how often you normally change your air filter and how long you plan to keep your car, and see if that many throw-away filters cost more than one reusable filter and its cleaning supplies.

TOM: There's a company called K&N that's been making these for several decades. The quality of their filtration is supposed to be quite good.

RAY: With K&N, you remove the filter, spray it with the special air-filter cleaning solvent (by the way, we have no idea if THAT stuff is environmentally friendly, and I'm not sure I'd bet on it), then you rinse the filter with a garden hose. You let it dry, spray some special oil on it, which helps capture dirt, let it dry again and then pop it back in the car.

TOM: FRAM also has come out with a metallic filter, called SynWash, that's even easier to clean. You fill up a bottle with dishwashing liquid, clean it off and pop it back in. And that's it. Unfortunately, we don't know how the FRAM compares with the K&N in terms of filtering ability.

RAY: There are some claims that these filters will increase your horsepower or gas mileage, but I'd take those with a large grain of filtered salt. Certainly, those aren't the main reasons to go this route. The main reason to get a reusable filter is so you can stop throwing away filters.

TOM: And so you have one more excuse on Saturdays to avoid a trip to your mother-in-law's. Now you can say, "Sorry, hon, I have to wash the air filter this weekend."

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