We bought a 40foot Heartland Torque 321 in Agust of 2013. Pulling it with 2012 Chevy 3500 Dually. Took our first long trip 600 miles one way in October of 2014, blew out a Towmax going to Big Bend, TX. Few more short trips within w 200 miles no problems May of 2015 blew a tire and it damaged the RV fender. July of 2015 blew a tire on the opposite side, blew the whole fender well out. Our RV max weight is 15,500 lbs. tires are rated 3080 @ 80 psi. 4 tires are only rated for 12,320 lbs. so the tires are not rated to carry the total weight of our RV. The Towmax manufacturer Dynamic is located in Canada not sure if tires are made in China. Not wanting to get new rims for bigger tires. We are looking at out of pocket for RV damage due to out deductible, calling Heartland tomorrow!