I put in a couple of new BFG TKO's and the shop put in 35 lbs of air. I noticed the truck a little jumpier on bumps and the tire getting dirty only in the middle, which tells me I'm not using the whole tire and will not get the best grip on wet roads. True, I have the factory rim, but I will go down to 26 to use more of the tire grip and a better ride. I used to run the tires at 24 and it rode really nice and gripped well. The difference in gas milleage was maybe 1 or 2 mpg, not enough to warrant a back breaking air adjustment. I think I'll try and buy myself a Geo Metro for gas purposes and leave my Kia for long travels.