Not everyone races/drives on concrete or asphalt, the guys that run dirt know full well that gauze filters ruin ring seal, and cost longevity, and power as ring seal goes away.
I live in the country and drive on dirt roads occasionally, Everything I drive has paper air filters because I never know when I might be on a dirt road. I feel safer 100% of the time being able to go 0-60 in 5.0 seconds rather than 0-60 in 4.9 seconds in the LS2 GTO with a gauze filter.
Years ago sprint cars ran with no air filtration, open 8 stack fuel injection. Back at that time race teams pulled engines from junkyards and when one blew up they grabbed another one. Today a competitive late model or sprint car engine is $50,000, you'd never see a late model, or a sprint car without a filter system. Seems that poor to no filtration wore engines out rapidly, and cost money to repair. They tried gauze and it let too many fine particles through causing poor ring seal.
I've pulled engines down that still ran, but were run without adequate air filtration. They still ran, but the pistons and cylinder walls were scored, ring seal wasn't good, but they still ran good enough to get from point A to point B. If all you want is mediocre, then run gauze air filters. Run a bore scope into the cylinders of one of the engines that was running a gauze filter and see what it looks like, then tell me that there is no downside to mediocre air filters.
I'm curious that if mediocre filtration is all that is required, why is it that all manufacturers spend a ton of money on air induction systems, then equip their cars with paper filters. I've never seen a production car with a gauze filter from the manufacturer. Maybe it's because the manufacturer has to stand behind a warranty for drivetrain, and emissions that would be compromised with a gauze filter.
K&N isn't going to rebuild anyone's engine if it fails early from ingested particulate are they? Aftermarket performance parts really have little to no warranty, Even if they said that they'd warranty an engine, you'd be on the hook to prove in a court of law that their product contributed to an engines early demise.
K&N in their videos says that their product falls into the Moss Magnuson Act
, which states that the manufacturer must prove that an aftermarket part caused damage to the manufacturers product to void the manufacturers warranty. That puts the cost on the manufacturer to undertake testing to prove the aftermarket part caused harm. It's going to involve a lot of time and money to prove that. Cheaper to just settle out of court.
Of course someone will argue that point because they know someone's uncle that never ran any air filter and their engine ran 40 years without incident, or they called some self appointed expert, and asked their opinion, they said, gauze filters perfectly.......................
Arguing the point is fruitless, I know what I've seen and done in real time during my life, and was trying to convey what I've experienced in the hope it would help someone. Anyone that wants to run gauze filters is perfectly free to do so. Knowing what I know from real life experience I won't be doing that. I just try to help members here from the school of hard knocks, I'm getting too old to argue every little point on this board with the naysayers that find joy in contradicting me, cheap thrills I guess.
Anyone can disregard what I say, but some people have to go 180 degrees and voice their opinion for everyone to see. I dismiss a lot of internet opinions, and just go on with my life, some people just can't leave it alone.