I got lucky and kept the stock Mission tires for over a year. When I started to read about them failing while driving far away from home, I had them replaced at the local Americas Tire with the "E" rated Carlisles. Good thing too, two of the Missions had huge hernia bulges on the not visible side. It was just a matter of time and luck. Decided to upgrade the wheels at the same time. Got about 1200lbs more capacity (safety factor) by going to the "E" rated tires. Larger sizes would not fit. Americas Tire is a great place for product and service.
Total tire capacity is now 11,320 lbs @80 psi. Actual tandem weight fully loaded is approx 7800 lbs.
Total 5th wheel weight is 10,800 lbs with 3000 lbs on kingpin (rear axle of truck)