I have posted on the K&N type filters before, but I'll say it again......throw them in the bush. I've seen them on engines and the intake is full of crap stuck to the runners, like I mean oily dirt , they let in more air but don't filter out the fine stuff cause less restriction to air flow. And seen the turbo's wear out too , guy wonders why he can't start his diesel anymore well how can it when you have been sucking dirt through that filter and wear the turbo and rings out. My opinion on them but advertising has done a good job of promoting them. Remember the old Fram oil filter commercial, " You can pay me now or pay me later ".