Russel, I like you’re thinking. I am convinced that the more you read on here about tires the more confusing it becomes.
To make this tire thing even more complicated, one has to consider the RV wheels limitations. My RV has 16inch “SENDEL” wheels. I contacted the Manufacturer in an attempt to learn the max air pressure the wheel is rated. Below is the response I received.
“Max air PSI is 110lbs. You can run most load range E tires some a little stronger please look at the specs closely. Load range G can get you into some issues because it exceeds the wheels' max loads. What happens if you run load G tires is that the sidewall of the tire is so excessively stiff that it fatigues the bead seat area of the wheel which leads to potential cracks that leak air. The way the wheels are tested is that at 20% over the approved limit the wheel has to be able to handle a range of stresses. The Tire is responsible for absorbing a certain amount. When an excessively stiff or over-strong tire gets put in there is no longer any tire absorption which will prematurely fatigue the wheel.”