I haven't pulled mine in while stock, but with the smarty jr. on the towing setting I was unpleasantly supprised to find mine bowed and crinkled up at less than 15K. I am a farmer that uses my truck for some off road towing and driving, but for the most part it pulls trailers on the highway or goes to town empty. I have a little Mazda for the real down and dirty work.
EDIT: the pulled in filter was a fram. I know, my bad, it's only fleetguards for me untill a bhaf.
EDIT: the pulled in filter was a fram. I know, my bad, it's only fleetguards for me untill a bhaf.