I bought my ‘18 SR5 used with those tires in July, ‘19. The truck had 24,000 miles on it when I bought it from a local dealer. Tread like new. I replaced them with BFG All Terrain T/A’s a few months later after I cut a sidewall while on a local 4x4 trail, which I had planned to do anyway even if I hadn’t cut the sidewall (cut tire didn’t loose air, but I had it rotated out right away). Still have the original spare. My 2¢, based on your driving mix, is at least 65,000 with normal care (rotation, inflation, alignment).