I have owned 3 fifth wheels.
The 1st had C rated tires, psi on label showed 50 psi
The 2nd had D rated tires, psi on label showed 60 psi
The 3rd has E rated tires, psi on label shows 80 psi
I upgraded the tires from C to D on the first and on the 2nd from D to E.
The tire pressure was always the max cold pressure printed on the tire.
2011 351RLTS Eagle, Mor/Ryde suspension & pin box
06 F350 PSD, SRW, LB, CC, 16K DrawTite hitch, Timbrens, TST TPMS
"Wag more, Bark less"