My truck & my K&N, are going on 200k now. Both doing fine. I've serviced it maybe 5 times. I've never seen any dirt/oil down stream of the filter yet. I like an oiled filter during dry dusty, gravel road conditions. We've had a 3 year drought going in eastern Kansas, & it picks up it's fair share of dirt, even on the highway. I'd hate to guess how many cubic feet of air my K&N has processed over the years. Can I hear the turbo? U-bet!