Each tire is rated at 4079 lbs at 110PSI. For my rig, that is 16,316 lbs of carrying capacity.
Hooked up, on the scale, I weigh 12,440 lbs on the trailer axles. That's half loaded (some of my clothes, all of my tools and dinnerware/cookware, full propane, full water, no people/pets/food).
16316-12440 = 3876 lbs of unused capacity for those tires.
Over inflation is just as bad as under inflation. And we're not even talking about the amount of bounce a fifth wheel is subjected to with tires that are hard as a rock.
If I can find a load/inflation table, I might get more miles out of those tires, less of a chance of a 'tire bomb' event, and less wear and tear of the coach.
In the absence of that information, I run max psi.
2017 CC38EL Silverado 3500HD