Are you saying that using the total weight of the towable divided by four plus a 10% cushion, should be the weight on each axle, and that you should adjust the tire pressure to what is called for by this number, based on the weight chart for that tire?
I wanted to make sure I understood you correctly.
That would put me at 7000/4 = 1850*110% = 1925 lbs for the weight per tire. The 7000lb is the GVWR. My actual weight, weighed on a scale, is around 5500 fully loaded for camping, but I'll use the max for this comparison.
With LRE ST225/75R15E Goodyear Endurance tires, that would put me at 45-50 psi instead of the max of 80?
https://www.goodyearrvtires.com/pdfs/rv_inflation.pdf
I changed to LR E tires from LR D when I replaced them a few years ago. Maybe I didn't need to? Interesting... Although the only tire Goodyear makes in my size is a LR E.
You can see in my sig that I have a TT older than 2017, so the sticker is the old style, but it still says to carry 65psi in the load range D tires that came with it. That is still overinflated, even by the tire manufacturers specs.
http://www.trailerkingtires.com/tire...2-product-line
I have been running my current tires(the Goodyears), at 70 psi, but it seems, according to this, that is overinflated, even for the max load the trailer can handle(GVWR).
Hmmm...
Edit:
Based on the 20-25% reserve capacity you talk about in your blogs, the China Bombs LR D at 65 psi(max psi) would be well over that reserve capacity. However, if they had been LR C, they would have been a little under at 50psi(max inflation), so that's probably why they were LR D.
Also based on the 20-25% reserve capacity, at 7000 lb, my current tires should be about 55 psi. At my "normal" camping weight of around 5500 lb, that could drop to around 40psi...
I have had a constant problem of the dealer over inflating the tires on my truck also. After an oil change at the Ford dealer, they are always at 45 psi, the max inflation psi on the tire. The door sticker says 35psi. When I tried to explain to them that these same tires are used on trucks heavier than mine, I'm told that "all trucks need to be at the max tire pressure on the sidewall". HUH??? I don't go to that dealer anymore...