I've got the 88 4X4 1/2 ton and it has the standard P225/75/15 tires on it... Presently they are a M&S tire. Somebody please enlighten me on whether I could go to just a regular passenger car tire in the same size... My truck never sees off-road use... strictly a 4X4 for winter driving, and most winter it's in 2WD anyway... was thinking that a passenger car tire would be quieter and a little better fuel-economy wise... Any pearls of wisdom? (...she's old, high-mileage, doesn't get driven a lot these days, and I'm cheap...)