It depends on the tire installed, and the tires on truck, are usually not the same type as trailer. Most RV trailer tires are ST, and just adequate when oem installed. These I run at max pressure, no matter the load. With the truck tires, it is more important to go with the psi, according to the load. My door sticker shows 75 front 80 rear, which I use when towing heavy. When unloaded, I keep the front near the 75 psi, but lower the rear to 65-70 psi.
Some people way over tire their RV trailer tires, then reduce the air to suit the load. Usually going from oem D-rated 65 psi, to an E-rated tire is not a problem. I would still run the Es at full 80 psi to take advantage of the extra capacity, and keep them running cooler. replacing a D with a G makes no sense, and no, you wouldn't want to run them at 110 psi
Jerry