Originally Posted by pcbueg
Refer to the tire psi rating range instead of the motorhome manual. Usual 10-15 pound or less than the max rating is a good starting place. Ride, fuel economy, and tire life are other factors. More importantly check tire pressure on a regular interval.
I do not agree that picking some arbitrary amount less than tires max pressure is a good way to do it.
Tire manufacturers publish charts for their tires. It gives the appropriate pressure for various weight loads.
The first thing to do is weigh the vehicle configured as it is going to be used. Then find the appropiate pressure for that weight load in the tire manufacturer's specs . Then use that pressure in your tires.