Googled the Carlisle tire in ST 235/80R16 and found 3520lbs AT 85 psi.
HereWhile the Maxislist gives for that same tire 3420 lbs AT 80 psi.
When I calculate that from 80 to 85psi then even with the formula America uses still for LT wich would give the lowest max load it would give 3580 lbs max load for carlisle.
So they even are being conservative, so not more maxload then other ST tires of same sise.
The tire below with 235/
85R16 has more maximum load at 80 psi , but this is because of the slightly bigger sise.
Have not seen that sise in ST at other brands, can use this for my maxload in compare to speedcode topic because there is exactly the same sise in LT tire.
so the carlisle is not having substantially more maxload then other ST tire as is stated here.
The 225/75 R 15 tire of carlisle and Maxis ( and others like Goodyear) have exactly the same maxload at the same loadrange.