K&N filters are shunned in the diesel world as well as most every other place for a several reasons. First ,they DO NOT filter as well as a paper filter, The turbo rigs draw in enough air they`ve been known to collaps and destroy high dollar turbos,the oil residue from the gauze can get on the compressor blades and act like glue for the passing dirt destroying compressor blades and turbos. Generally speaking 90% of the guys that had run them and done oil tests come up with elevated results from it not filtering worth a shit. its a well known fact, yes fact, their not a better filter, just a better flowing filter thats servicable. Read K&N`s statement, "the dirtier it is, the better it works" Look at a new unused factory oiled filter, see the open holes or voids in the gauze, yes the dirt and oil eventually plug off the open gauze voids, a true statement by K&N. Yes racers and hot rodders run them, they also rebuild every season. will you? Dont believe their marketing BS at your expense.