I had a k&n on my old Chevy truck for 165,000 miles before I sold it. I have one now on my new grand prix. My old truck blew better on the sniffer test than my mom`s newer grand marquis. It`s all in proper care and maintenance as far as how they do with regards to the oiling. It`s just like any other part of the car...neglect it too long and you`ll have problems.