I get about 6 months out of a set of trailer tires. 10 ply were on the trailer when purchased, ran them for about 5 months till I decided I wanted the extra safety cushion of a better, higher rated tire. The 10 ply didn't look that beat up, but with the trailer I was running at just about the max rating for the tire. 14 Ply went on, but still a knock off named company. next tire change will be a higher ply, better rated tire ( commercial ). about 50$ more each tire. But should be able to get a year out of a set, so worth the $$$>I run a gooseneck with 16 inch tires, you want a good tire that will last you go 14 pl rated tires. I have easily put on 100k miles on the trailer, going 14 pl rated was my second best decision after converting to disc brakes. 10 ply tires I would get 4k miles till I needed replacement, 14ply I would get 20k miles till they wore out. the tire guys wanted 20% more per tire, but I got 4x the life, seemed like a good deal to me.