I can't say for certain, but it looks like the same width as the Bobsled, which is 66" wide. As for the wheels, well...they are something special that Mark came up with. I will let him explain it, but they are not traditional off road wheels.
I started another thread about wheels and tires for UTV's...particularly race UTV's. We all want bigger O.D. tires with enough side wall, that can run up to 30 psi, but not with the weight of a truck tire. I don't think anybody has come up with the perfect solution yet, but we keep trying.