We bought a 2011 Heartland in 2010 and it came with Tow Maxx Power King tires. We have driven a total of 2000 miles on it with a lot, and I mean a lot of sitting in between, in our side yard on a gravel driveway. We keep them inflated to the recommended psi and look good still. We inspect them before every trip. There are no side cracks or crazing. The tread looks good. According to the code on the side, we should replace them by May 2015. I'm not sure if yours is premature wear or faulty manufacturing. We do keep ours covered with white vinyl tire covers when it's sitting in our yard. We did have Goodyears on our last TT and we had to replace them after owning it for 2 years due to crazing on the sidewalls.