Hello,
I run a 2005 PW Plateau, I found being E rated tires rear tires 80psi is fine at max pressure with front 65 .... If your running with the Firestone ride right rear airbags the manufacture recommends filling the airbag to rear tire pressure .... I found my airbags would not hold air very long, ( No compressor on board ) but two rear air zerks under rear bumper. after dismantling and inspecting all air couplers, which were tight and as manufactured, I removed the shredder valve and pumped in Green tire slime ( Pep Boys) reinstalled the shedder valve and filled the airbags with 80psi air, then drove around town, Now I lose 1 pound of air per month. perfect !!! I found the RV more stable at high speeds 70mph+ with a very comfy ride
I use that green slime in both my Harley Davidsons bike rims, which leaked air all the time ... Now when I ride to motorcycle rallies out of town I know my tires will be full the whole trip, I have used the stuff for 35 years in all my equipment tires, One down side is once put in tire you can never patch a tire ..... But I would never patch an RV tire any why, Only replace with new !
Hope this helps someone with Air bag suspension Firestones holding air longer
Happy trails