315/80R-22.5 tires

[Rick Adams]

Does anyone have experience with putting 315/80R-22.5 tires on 2004 Beaver Marquis 42' or similar coach. The factory size is 295/80-22.5. I know they will work on the front nicely but am not sure about the rear.

[Keith Oliver]

I don't know how much room you will have for the increase in diameter of 6.7%.  You will need to lower your coach as far as possible and measure, to see if things are getting close, and if adequate room still exists.  Then you will need to find some way to recalibrate your speedometer, as what used to be 60 mph will now be 64 mph.
At the front you should turn you wheel as far as you can to each side, while the coach is as low as possible and  see what clearance, if any, is left, then add your extra height and see if there really is any room left.  It might surprise you.
I know that on my Contessa, with the factory specified tires, they touched if turned as far as possible and lowered.  This attitude will closely simulate turning into a driveway with a sidewalk crossing, as eg. going for fuel.  On my present coach, there is much more room.

[David T. Richelderfer]

There are a couple threads here on the Forum that would be informative.  If you have not read them, then I suggest you perform a search to find them.  Note:  Does your coach have 9" wide rims?  If not, then you cannot get full value from increasing your tire size to 315s.