You'll always want to follow the specs that are listed directly on the tires themselves. It sounds like you've got the Loadstar ST185/80D13 Bias Trailer Tire - Load Range D # AM1ST79, which are designed to be run at 65psi and have a capacity of 1710-lbs per tire; these tires are well rated for a camper that has a GVWR of almost 2000-lbs, so you've got nothing to worry about. view full answer...