Reviews of K&N air filter

K&N filters are reusable. Totally worth the upfront cost.

if you want a performance oriented filter James Baron Racing sells a dry flow panel filter that's a drop in replacement for most 2012+ Mazda's. They're made by K&N but have no oil whatsoever. They flow better than OEM and they're cleanable. Probably your safest option.

The K&N high flow filters actually make a large difference... IF and ONLY IF you upgrade the intake and delete the OEM airbox with it. If you plan to keep the OEM intake and airbox, it will make not much of a difference.

IMO they're not worth it. Modern intake systems flow fairly well, adding a K&N filter will provide almost no benefit. Hell even adding an aftermarket intake these days add nothing but sound. they can also get oil residue on the MAF sensor which can be expensive to replace.

I went with the K&N high flow filter, keeping the cover on. I’ve noticed a bit of a difference, but I’m too scared to take the cover off, as I don’t want particulates in my engine

A filter shouldn't void a warranty, and K&N even offers to fight warranty disputes with dealers who claim the filter did it. The top actually secures the filter in place. You can take it off, but I would check it once a week to be sure it didn't pop off the intake tube. a high flow filter is for increased air flow (easier/faster air intake) and not temp decreases. I have a snorkel and I have NEVER had water on the filter, but I also leave the airbox lid on (my 2013 has a ~1" gap between the hood and bumper that water likes to go through to the engine compartment). Oil coated air filters require you to wash and re-oil them every so often. The oil is what catches most of the dust.

I've run them on basically everything I've owned for the past 15 years. People hate them because they claim the oil fouls the MAF and that they let in more junk. I've never had a MAF fail and I've had two F-150s go over 200,000 miles on them with their original motors. My current F-150 has 239,000 and counting, no problems with it. Why buy them? I do it because they're re-usable. I think the K&N for my current F-150 was $45 when I got it, and the Motorcraft filters are $10-12. So over time it will save money, kind of, if you don't mind the work. Would I do it again? Nah. I'm done with them because it *is* kind of a pain in the butt to clean and oil them all the time. On two vehicles they added a bit of pleasing intake noise but again, eh. No big deal. I wouldn't waste the money. Just get the manufacturer filter and swap it out every year.

Had K&N's for years. Never had a problem with them.

I went with K&N, perfect fit in the stock box and reusable so you don't need to replace each time, just wash. It's a little pricy up front. But worth it in my opinion.

Noticeable difference off the line and cruising at low speeds with the K&N filter and pipe. Pre-tune I still noticed a small difference. Maybe combined with the turbo muffler it does something. Once tuned it will make a larger difference.