Stephen, The best way to determine what your tire pressure should be is to load your coach as if you are going on a trip to include and fuel then have each corner (tires weighted) and both Goodyear and Michelim have guides available to tell you what the pressure should be. By doing this you will find out if you have one side loaded more than the other.

Go by the sticker information unless you know better. And you can know better by actually measuring your coach's true weight distribution. Who would want to blindly believe a sticker when you can find out what's real? I have a 2001 Storm, which came OEM with Goodyear Load Range F tires (which had a maximum tire pressure rating of 80 psi (and the Goodyear rating tables said that pressure was good for 3200 pounds loading). I have a measured weight of 6000 pounds on my front axle and 12000 pounds on my rear axle. How about that, at maximum air pressure, Fleetwood had loaded those tires to their maximum capacity. I was running at 100%, with no safety reserve. When it was time to get new tires, I bought Michelin XZW's, slightly larger diameter, in Load Range H. These have a maximum pressure rating of IIRC, 120 psi. In the Michelin data tables, I can support 3000 pounds per tire at 75 psi, so I run my tires at 80 psi, which gives me about a ton of safety margin while not making the tires rock hard. (At 120 psi, I think those tires could support about 4500 pounds per tire.) The short answer is that a newer tire, of better quality and with a higher load range, can give you a whole lot more safety margin in operation.