Reviews of K&N air filter

Over cleaning a K&N does more harm than good. K&N's need dirt to be effective. Clean K&N's let through too much dirt, until they become effective.

There was a "performance" K&N filter and lots of detritus in the bottom of the air box I scrubbed down the box, and it is looking fresh. Except for the super greasy valve covers and rest of the engine bay. Oh, and I'm getting rid of the K&N filter--never been a fan.

new air cleaner (K&N cone filter)

I have used K&N filters on many applications with 0 problems.

I'm not a believer in K&N. I've always thought of it as being rather gimmicky.

K&N Filter Replacement

Installed the K&N. No butt dyno difference, but overall acceleration feels smoother and there's a tad bit intake noise i can hear at WOT.

K&N is one of the worst. I run my engine in dusty conditions and was finding oily, dirty crud in my intake with K&N. I ditched it and went back to paper filters.

K&N if it's available. Million mile warranty, and never need to purchase another filter... ever. All you have to do is every few months take it out and clean it, then spray with the recharging oil and reinstall. I've had one on every single vehicle I've ever owned. The HP and MPG gains are smaller than advertised, but still noticeable.

Removed the K&Ns for some new paper filters. It'll suck to lose the 10% horsepower gain but I'll try not to die trying to pass Ford Flex's on the highway without it. The air box had a bunch of dirt/scum so I cleaned that out too.