I have noticed that on our Lazer Z the tires ( rear ) are wearing at what I think is an extremly fast rate, it has the dogbone type tread. It also looks as if the right side is wearing faster than the left side. The other Lazer ZHP has a more tractor type turf tread and there seems to be very little wear on those tires. Fronts on both units are the smooth type inflatable and seem to have normal wear / use. Anyone else notice or experience this on their ZTR mowers ?