I ran the 19.5's on my 06 Ford swb dually and was totally happy with them, I tried the 22.5's and it made a miserable pos out of my truck. As far as mileage, I ran mine 15000 miles and the still looked like new, I would have to guess on a private use vehicle with any maintinance at all they would run 75 to 100000 miles, just don't skimp on tire quality, and dont run adapters. I used Michelin 265/70r19.5 xde+2's on Brentz custom predrilled wheels.