Ran the Maxxis that came on the machine until there wasn't anything left to dig with. Got a set of ITP 27X14 XTR Mudlite. Super nice ride; dig well when climbing in loose shell/dirt; travels well over deep powder snow without digging deep; nice smooth ride on hard pack dirt/blk-top. What muddin I've taken them through, not a problem, handled it with ease. Can handle very low air pressure. But the tread wear is not the highest.