Michelin says 80 lbs.
I took our F53 to Pilot and put it on the CAT scale. Front with 2 people and small dog 7,200 lbs. Rear with coach loaded, goods, water & gases 13,740 lbs. Michelin chart 235/80 22.5 XRV tires should have 80 lbs of air all around. Previous owner had 80 lbs and ride was fine.
Mike, Janet & Duchess (cavalier King Charles)
2008 35B windsport, Brazel's rear TracBar, Koni shocks & Safe T plus steering