I noticed the same thing with our 2304 Mini Lite after the optional 14" wheels were installed. There is about 2" clearance from the tires to the wheel well tubs. I asked the dealer about it and they weren't too overly concerned. So for our next outing I applied white paint to the tires tread to see if there was any transfer to the wheel wells. After a short drive down a moderately rough road there was no contact between the tires and the wheel wells as evidenced no colour transfer. So the rubber suspension must work as advertised.
I would like to go to 15" wheels to have a better selection of tires and to get a bit more clearance for the sewer connections, but with only 3" of separation between the tandum wheel tire combo and the limited space above the tires I can't see how to go to a larger wheel size. The tt currently has 205 x 14R's installed.
Anyway, our tires haven't hit the tubs yet and we have hit some substantial pot holes.
Steve & Millie
2011 RAM 1500 Quad Cab 2wd Hemi 3:55 gear
Rockwood Ultra-Lite 2604WS