My recommendation is to run a much lower pressure during empty driving, and then increase pressure when towing or hauling heavy loads. I generally run a higher pressure in the front than the rear while empty (trucks are heavier in the front when empty, plus have more lateral force when turning on the front). I will then only raise the rear pressure up when needed as towing and loads in the bed mainly put weight on the back. Now exactly what the pressures are depends on the truck and driving style. The chalk test is a good starting point. On an 80 psi max tire on a 1500 a starting point would be 55-60 psi front and 45-50 psi rear.....you can likely go lower but better to start at higher pressure. It's not unusual for new factory 3/4 tons to come with 80 psi max tires but only recommend 65 psi front at max weight. Also when I say raise the psi in the rear tires when towing, I do mean when towing heavy. You don't need to increase psi when towing your 2,500 lb. lawnmower trailer around.
