As ST tires go Maxxis still is producing a quality tire as it pertains to this category. Heavy TH rigs would do better with a high-grade LT tire, but our TH comes in @ just over 10K# fully loaded and we have had good success using the 15" Maxxis 8008 ST225/75R15 LR E tire. We replace them every 4-5 years although they still have plenty of visible tread, mostly for piece of mind which has kept us off the side of the rode over the last 15 years of RVing. Carlisle's newly redesigned ST tire is receiving some good feedback, a couple of my buddies went that route and are happy thus far with the results.