Tire Inflation Question

Your best tire pressure is the lowest pressure that the tire will not overheat. to determine that, you use a tire monitoring system and adjust the tire pressure for the operating environment.

I have the same tire and wheel size as you on my chassis when it was new in 03. My manual said to inflate the tires to 85 psi rear and 90 psi front. These tire pressures did not work for me due to rear tire squirm. I was also worried about heat build up inside the tire at 85 psi. I experimented with different pressures every time that I went out on a RV trip. I ended up using 100 psi all around. I get a slightly rougher ride at 100 psi (compared to 85 psi) but, 100 psi eliminated the rear tire squirm, eliminated the heat build up inside the tire casing at and, at 100 psi my tires get exceptional road wear (I ended up getting 10 years out of those tires @ 100 psi), I'm now into the 2nd year, on my second set of XRV's at 100 psi. Good Luck in whatever works for you!

Your post indicates that you are aware that proper tire pressures are related to axle loading (actually the weight on the heaviest side of each axle).

There should be a sticker somewhere that indicates the recommended tire pressure for each axle. These pressures are based on the max weight capacity of each axle. For our Class C, the sticker says 65psi front and 80psi rear. Our tires are rated for 80psi max.

We got our RV weighed at a scrap metal recycling place and were able to get individual weights for each side of each axle. Based on these weights, we run 60psi front and 75psi rear.

There must be recycling places in Florida that could weigh your RV.

The only way to set pressure is to weigh the vehicle. Moving companies , and a lot of the places that sell diesel for big rigs have scales.

Tires are all wearing evenly at 100psi.

Lower pressure and the tires will run hotter.
Typically there are two PSI ratings on tires. One for singles and another for duals. Improper PSI will also cause several other problems. Running hot, premature tire wear, poor handling. Look at the steer tires closely. Worn more in the middle? Overinflated. Worn on both outside edges? Underinflated. Worn evenly across the entire tread? Properly inflated