Believe it or not, the zilla came with two different sets of tires from the factory. Some had Dunlops, and some had Bridgestones. Either would be factory correct. From the research I've done, it doesn't appeat to be an option, but more what region the quad was purchased in. Most zilla's in the midwest came with the Dunlops. Most zillas purchased out West and down South came with the Bridgestones from what I've seen. Not sure about other regions.