Instead of the "standard" LT235/85R-16E all steel construction Michelin XPS Rib that is most commonly used (load rating of 3042 lbs @ 80 PSIG, 32.0" diameter), take a look at the Michelin XPS Rib in size LT245/75R-16E. This will give you the same 3042 @ 80 PSIG load rating but with a smaller 30.6" diameter. See
HERE.
Yes, the upgrade is well worth it. Many users who have had tire problems with heavy 5th wheels using the LT235/85R-16E tires have switched to the XPS Ribs and eliminated their tire problems - myself included on our previous 5th wheel. I'm so impressed with these tires that I have 6 on my truck right now. They're not cheap, but the peace of mind is worth it to me.
Rusty