Air filters - are expensive "reusable" ones worth the money?

I just purchased a used car and I was going to preemptively replace the air filter because I have no idea when it was done last and they’re only $10-$15. However, in shopping around, I’ve come across more expensive filters (such as those made by K&N) that run $50-$60. They claim to boost HP/gas mileage and are reusable/washable. Are these things worth it? Do they actually increase performance? Are they truly reusable so that I’d make back up the excess cost over a few years? Unless you can go longer between cleanings than between replacements of normal filters, I’m kind of doubting the latter as I notice you have to use a $15 “cleaning kit” every time. Thanks!

I’ve used K&N filters on a few of my car/trucks over the years. I’ve never noticed any improvement in performance or mpg. However, the cleaning kit is good for 2 or 3 cleanings. At this point , I’m going to stay with paper filters.

Ed B.

I reject the mpg claims, and any hp is only at wide open throttle. The also let more dirt through. Paper for me.

They claim to boost HP/gas mileage and are reusable/washable. Are these things worth it?

The operative word there is CLAIM. They do add some increase in performance at the higher rpm range. Not at lower end. There has never been any proven increases in mpg.

The cost to these filters is they don’t filter as well. Which isn’t good.

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…and if you use just a bit too much oil when you “re-oil” them after cleaning, then you run the risk of damaging your MAF.

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Stick with the paper ones. You’ll probably not spend fifty bucks for air filters for the life of this car.

Thanks everyone! I was skeptical of the performance claims from the get-go. Good, old fashioned paper it is.

You made the right decision.

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Air filters have no effect on gas mileage. An air filter will only have an effect on horsepower when running at wide open throttle, as is done at the racetrack or on street racing.

More trouble than they’re worth; stick with the paper filters!

agree, for WOT users, even they would tell you to stick with paper

You’ve made the right decision, but I did want to add to the thread for others following along that many of these filters require oiling, and oil has been known to coat mass airflow sensors causing operating problems and requiring a new MAF sensor. I strongly recommend against them.

I have a K&N filter on my Mustang, I have on my F-150, and I had one on my Bronco (which I sold with around 268k miles on it). Performance gains aren’t much, but I do like only having to service them every 40k miles or so. You hear about MAF sensors being ruined by them, but most of the time the fault is with the user over-oiling the filter media after cleaning. I’ve never had a MAF sensor go bad

TSMB–Isn’t that essentially what I stated, earlier in this thread?

"…and if you use just a bit too much oil when you “re-oil” them after cleaning, then you run the risk of damaging your MAF."


Sorry my friend, I missed that. :blush:

I am amused by the reference to “Good old fashioned paper filters”. I can remember when every car on the market had an oil bath air filter.

In England up through the 70’s(?) quite a bit of racing was done with no filter.
The dampness keeps the dust down.

With an OBD-II scanner it’s possible to track the MAF sensor on an open throttle run and see any differences in engine breathing with different filters or no filter.

Haha I’m quite young, oldtimer. I guess I just assumed the filter that costs 5x as much and makes apparently false promises of better performance and gas mileage was some new creation to part people from their money.

I’ve seen the oil bath air filters on '50s cars, but turns out I didn’t know how they worked. I thought the element sat in the oil, with oil wicked up to coat the element and catch the dirt. Wrong was I:

“An oil bath air cleaner consists of a sump containing a pool of oil, and an insert which is filled with fibre, mesh, foam, or another coarse filter media. When the cleaner is assembled, the media-containing body of the insert sits a short distance above the surface of the oil pool. The rim of the insert overlaps the rim of the sump. This arrangement forms a labyrinthine path through which the air must travel in a series of U-turns: up through the gap between the rims of the insert and the sump, down through the gap between the outer wall of the insert and the inner wall of the sump, and up through the filter media in the body of the insert. This U-turn takes the air at high velocity across the surface of the oil pool. Larger and heavier dust and dirt particles in the air cannot make the turn due to their inertia, so they fall into the oil and settle to the bottom of the base bowl. Lighter and smaller particles are trapped by the filtration media in the insert, which is wetted by oil droplets aspirated there into by normal airflow.”

Good Texases,I didnt know either,make mine paper-after spending over a $100 dollars on a foam CAI(The cheap bunch didnt even include a bottle of oil to service the filter with,after pricing the recommended oil for the foam filter-I threw it away and reinstalled paper and never looked back)