I looked at GBC's website. The Dirt Commander, Spartacus, and the new Grim Reaper are all 8 ply tires. The Spartacus is a mud tire, while the other 2 are all around tires. I like the fact that someone has come out with an 8 ply, and they aren't too heavy. I thought about going with an all around tire, but I think I'll stick with my Mud Lites. It'll be hard to give them up.