From what some Goodyear Endurance load D owners have said the tires sidewall says to "inflate to 65 psi"...which indicates Goodyear like Carlisle and other ST tire makers wants their tires to be used at max psi for max reliability and max performance.
Its been my experience wheels can crack or split the wheel bead seat when over pressured when carrying weight. BTDT in my younger and dumber days when I first got into the hauling business.....even after my trailer dealer warned me not to over inflate a wheel or tire above their recommendation.
As mentioned wheels have a max psi and load capacity. If your don't then find out from their mfg or importer what it is.
Goodyear also says:
Goodyear Tire and Rubber .... weighing RVs
Special Considerations
Unless trying to resolve poor ride quality problems with an RV trailer, it is recommended that trailer tires be inflated to the pressure indicated on the sidewall of the tire. Trailer tires experience significant lateral (side-to-side) loads due to vehicle sway from uneven roads or passing vehicles. Using the inflation pressure engraved on the sidewall will provide optimum load carrying capacity and minimize heat build-up.
Many older 14" trailer wheels centers and rims were made from thinner material and had a 50 psi max rating. Most newer wheels have thicker or are a higher tensile strength and can carry a 65 psi. Let the wheels load/pressure ratings determine the tires load range (psi). It make no cents/sense to use 50 psi in a 65 psi rated tire in a trailer position...JMO.
