Tires: Tire Pressure, 5th wheel trailer, 2007 gmc 3500

Question
Hi,
I have 2007 GMC 3500 dual wheel truck. Tire size is 215-85-R16 Load Range E. Sidewall says it is max cold pressure is 80psi...truck specs on drivers doors  says run front tires at 70psi and rear tires at 65psi.  The question I have is what is proper pressure for correct tire wear as everything I read says do not run under-inflated...the weight I carry fluctuates from no pay load to a 5th wheel trailer with a "pin weight" of 2500 pounds.
Thanks

Answer
Mark,

If you are running the same size as listed on the vehicle tire placard, go by what that says.  the tire doesn't know what vehicle it is going on so it only lists a maximum.

But you need to be sure the vehicle tire placard is appropriate - and it will be if you are towing within the limitations published by the vehicle manufacturer.  So look in your owners manual.