Actually, I think it is helpful to both look at the specs and discuss differences in brands. I just replaced 6 of my 8 G670s with Michelin XZA2s. I went up to 315/80R22.5 on the steers and stayed with 295s on the rest as the rims don't have the minimum offset for the 315s in a dually application.
We picked up about 1,400 lbs of capacity per side on the front - we were close to the limit on the 295s - and went from 16 to 20 plies.
Had the experience of driving over the same wretched road through Spokane and over the Snoqualmie pass. Not the worst roads, just bad ones. The Michelin's ride much nicer, period.
