[rdunk]

Hi Ponch! Since my tires are 17", I can't tell you what is the right pressure for your tires. But what I can talk about I will. As you know, it is all about axle weight. My truck sticker (for 2x4) says 60 lbs, front and rear, for the max load weight on my F350. What I have found is that when I am hitched to the 5er, with about 4200 lbs pin weight, the truck front axle weight only increases by a few hundred pounds, with the balance being carried by the rear axle. What this means for me is that my rear axle ends up weighing right at twice the front axle.

With that being the case, then that would mean that each of the four tires on the rear is carrying approximately the same load as each of the two tires on the front --- thus for my set-up, the tire pressures should be basically the same, front and rear, as is stated on my sticker door plate.

FWIW, when I had the identical truck in 4x4, the tire pressure for the front tires was 5 lbs higher than for the rear tires. I am sure that was for the fact that the front axle was carrying 500 lbs more, for the added weight of the 4x4.

Another FWIW --- The max tire pressure on my tires is 80 psi.

Good luck on your first tow with the new GMC.!