IVe had k&n filters on nearly everything. My 04 GTO had a drop in from the get go and then a CAI. Ran it 86,000 miles. Sold it, and the guy who has it now just crossed 145k, same intake and filter. Car still doesnt use oil. I did UOAs on it and air filtration was never an issue. It may let more stuff through but doesnt seem to be enough to harm the motor, particularly with as much as we change the oil around here. YMMV