I just switched out some 8 year old Michelins with TOYO 245/75 R22.5 and so far could not be happier. Of course my next 1300 mile trip will tell me plenty more. My issue is I don't understand how Airstream determined the inflation pressure on my RIG. Both Michelin and Toyo pretty much have identical weight charts. My rig weighs Right Rear 7875 and Left Rear 7900. Also I don't carry much equipment with me. the placard on the 1999 airstream cutter says 90PSI on the rear duals. Referencing the chart that equates to:
3765*2=7530. I would be 370lbs over weight for that pressure. To me I don't understand how the placard being federally mandated could be so wrong.
I decided to inflate to 100PSI which is 4055*2 = 8110 according to Toyo Chart. That gives me 210 pounds of wiggle room with 20PSI buffer till I hit the 120PSI Max Inflation for the tire since I travel in hot climate.
If anyone can comment on whether or not their Placard is way off like mine I would be interested to hear.