Sorry to revive an old thread, but I just bought an RZR1000 XP and I am in the beginning stages of making it street legal. Searched with the same question and found this thread.

Called these guys today and they assured me these 6-plys (I like a little heavier ply) are street legal and approved by the US D.O.T. This site is for Golf Cart Tires, but they carry the right size for my new wheels on my DOT setup. I am mounting these tires on a set of 14" ITP SS wheels:

http://www.golfcarttiresupply.com/efx-b … -set-of-4/

Tires are 23" tall, so I don't anticipate losing TOO much ride height. As soon as the rest of my stuff gets here I'll post pics and info on my build to help future searchers.

Merry Christmas!