Tires: tire pressure, tire placard, rotating tires

Question
My truck,GMC Sierra 1500HD, calls for 50 psi on front tires and 80 psi on rear tires. Is higher pressure on rear tires only necessary when under heavier load or towing. I've been running with 50 on front and 60 on rear, topping up rear tires when towing. Rear tires are wearing much faster than front.

Answer
Darren,

It is my understnding that unless the vehicle manufacturer specifies otherwise, the pressure listed on the vehicle tire placard is to be used for all conditions - empty and loaded.

Tire wear?  You need to be rotating tires every 5,000 to 8,000 miles in order to even out the waer - both rate and evenness.