To know that you are running the correct air pressure in your tires you need to know the weight of your front and rear axle. Better yet each individual wheel position. Check out this link. I'm certainly not a Michelin fan, but this is very good information, including handling your coach in the event of catastrophic air loss.
Also if you have switched from a load range G (14 ply) to a load range H (16ply) it will not allow you to run a lower pressure than the G rated tire. Air supports the weight, not the tire. A load range H tire just allows more air pressure hence a larger load capacity.
Your coach should have a min pressure posted also.
Tom, Patty, Hannah "The Big Dog" and Abby Kat, Indianapolis, Indiana 2000 36' FDS 72232 Our Photos
We live out in our old van. Travel all across this land. Drive until the city lights dissolve into a country sky, me and you - hand in hand.