Your can put bigger / wider tires on the same rims. I went up a couple of sizes on my with no problem. If you get too big you will have a problem with wearing the center of the tire out and you also have to watch and make sure that you are not going to rub a fender or the fire wall when you install them. There are limits on everything so who ever put the tires on for you have them check to make sure everything is clear.