Ever since I got this HTT a month ago. I for some reason didn't trust the tires. I looked at them and I didn't see any cracks, the treads were at 8-9/32 so I thought well they are 6 years old perhaps that is it. I will replace them in the spring. We went on three trips (about 600 miles in total) before the end of our season. Now I'm putting the camper in it's winter spot and getting ready for hibernation. I went around and filled the tires to 50psi. I pulled the cover off the spare to check tire pressure and inspect its condition. What did I find? A bubble in the sidewall. That got me thinking I should inspect all of the MUCH closer. So I took a MUCH closer look at all 4 of tires on the HTT and wouldn't you know it I found another bubble forming. It was small and I must not have seen it when I first bought it. That was a nasty blowout just waiting to happen. I guess I will be putting on 4 new ones in the spring.