28's by 10 in the front, by 12 in the rear...fit is fantastic. Maybe an inch and a half clearance between the rear tire and the cab, which is plenty. I mounted the center caps back on the wheels since the picture was taken.. I didn't think the center caps were going to fit, but they did perfectly.. just like they did on the grizzly.
Took them of my 2014 grizzly 550 I traded yesterday to get the wolverine.