Fifth Wheel tires

Are you sure you have P type tires? For that trailer wt, and size tire, I would recommend one of the newer style ST tires. They are cooler running, allowing a higher speed rating, and nylon wrapped for durability. The choices are Provider ST225/75R15, Carlisle HD (same size), or made in US GY Endurance. A load range D is sufficient for your wt, or a load E, for added capacity. I would run them at full sidewall pressure 65#s for D, or 80#s for E-rated.

Jerry