My main reason for replacing the factory tires right away is for added ground clearance. I ride in really rocky areas and I just didn't trust the cheap PXT tires. Once you have good trail tires like the Bighorns or Roctanes you will understand. The Rangers are heavy, the added 8 ply rating makes for a better more capable machine on the trails. As for the factory wheels, I sold the tires and wheels together on a local classifieds site.