When I picked up my new 2500HD Duramax 4x4 today it had 80lbs in reat and 55lbs up front. I had dealer adjust all to 65 psi, as i don't plan on towing or carrying heavy loads till next summer. Is this an ok pressure for the back, or is it better for economy to have rear higher, giving up traction in snow?

If your not loading down then I would run with 65 so the tires wear better.

I have tried my rears both at 80 and 65 and could not tell the difference in the snow.

I have never checked the gas mileage. Until the truck is broken in I could not see tire pressure making that much difference but if it does let me know.

I am running the stock pizza cutters so I think for better traction I better get a better tire.

I found that with my Duramax being so heavy I need to run the fronts at 80psi or it wears the sides funny. The rears I run at 65 psi and I also have a dually...