If you're concerned, consider another coach. Right at max weight your tire pressures will need to be high and that makes for a lumpy ride.
Also consider that a number of members here have posted about their newer Thor coaches and are not happy with the build quality. You really need a good dealer to work out the warranty issues. Really, for $140K you could find nicer 3 yo coach in the 26000 pound range.
Jerry & Jeanne
1996 Safari Sahara 3530 - 'White Tiger'
CAT 3126/Allison 6 speed/Magnum Chassis
2014 Equinox AWD / Blue Ox