Ive know this fact for a while now that the k&n doesnt offer the best filtration, but only after buying it... so i stuck with. if im honest, if i did it again, i would probably look about for a few other makes that offer better filtration, because after taking my throttle body off you could see the dust buildup (which aint good for any engine!). and i wasnt too impressed by that and stuffed the standard filter in. i would probably look into the blitz one on fensports site, look into green cotton filters, or look for a better flowing paper filter. then if all else fails, go for the k&n.