I DD my K5 with the 37" Hummer tires. For this they are great, though they do chirp around corners (welded rear end). Any tire will do that though. I haven't done any "real" wheeling with them yet. The stuff I have been in though (mud, snow) they have been better than the old 36" Hummer tires. I know there is a thread on Pirate about these tires, seems alot of people like them.