can't you get very fine mesh covers to put on the filters so it doesn't let as much crap in
One mesh prefilter is not even nearly enough, it takes two stacked over each other to even begin to help. 25 years ago, before I learned how bad K&N air filters were, I installed one on my previous Wrangler TJ. Then a friend saw it on the trail and freaked out, said "let's take the air intake off and look inside your throttle body". We did and I freaked out how much dirt was inside the air intake tube and throttle body.
I installed a K&N PreCharger pre-filter and there was still WAY too much dirt getting past even K&N's prefilter so I had to add a second oiled-foam prefilter over the top of it to get the dirt level down to a lower level. Still not good but better than it was.
These photos are of my K&N with the two prefilters I ended up having to add.
Then there were some scientifically conducted lab tests done on air intake filters. The K&N came in dead last and past 18X more dirt, plugged up 3X faster, and captured 37% less dirt than the AC-Delco air filter did. That extra dirt ends up in your engine where it significantly increases engine wear.
This is one of the charts produced during the lab test. Note the very last sentence that I bolded for emphasis.
I now run the factory air intake system with a paper element air filter. And there was ZERO performance difference. The reason is because the factory air intake system was purposely designed to be 100% free-flowing. It in fact, according to Jeep engineering, is capable in STOCK form of passing 3X more air than the engine is capable of consuming at full redline RPMs and full throttle.
Would I run a K&N if I had a race car racing quarter-mile drags? Probably. But that'd be the only situation I'd run a K&N in.
Don't run a K&N. Not even to impress your buddies.
