Rat - I put the Michelin XM37's on the EF-500. They're exactly like the XM27's, except that they're an industrial version vs. an ag version. Tougher and thicker carcass for puncture and abrasion resistance. They're a lot smaller than the rear tires I had on the L4310, though. Of course, with 11,000 pounds on them (unloaded), it takes a fair bit of power to spin 'em in most anything. It will spin them on asphalt, but only barely. To me, that says it's a pretty well balanced system. I can't think of any reason I'd ever want to spin them on asphalt, except that, if it wouldn't, I'd always be wondering if I was getting enough power to the wheels. Not that I'm fanatical about it or anything... /forums/images/graemlins/grin.gif