I put a set of four bass boat tires on in the spring of 2019 I just checked the sidewalls and I can see some small, cracking occurring In those five years, the boat was probably only trailered 125 days..... I also put tire protectant on the tires a few times each year..... five years seem about right or did these tires fail prematurely? And yes, my boat and trailer are stored outside year round !