I'm surprised that your door tag states that low. Is it the correct door tag for your truck? What is your truck year and model? You should put it in your signature so we can give you better information. My tag states 58 front 80 rear.
I'm glad to see you looked at the tag many people do not and just look at the tire and run what it say's on the sidewall which is the incorrect thing to do on any vehicle. The sidewall psi is the max psi the tire can take. The door tag is what the factory engineers calculated it should be based on the size tire on the tag that originally came with the vehicle. Now it's still not writin in stone. On cars yes, but our trucks the factory looked at max payload, towing, and tires they installed and gave you that psi for the rear tires. So if you have an empty bed and are not towing it is way to high. If you run that 80 psi in them they will wear the center of the tire out. I find 60 psi is good unloaded. That tire psi info is also in any owners manual too.
