HI There, We did the TAT August 2012 two up on a 990. We had already done Route 66 from LA to Chicago so put new tyres on in Knoxville. We put a TKC80 on the rear and a Karoo on the front for the first half then put a fresh set on in Moab. Another TKC on the rear but for the sand a 606 on the front. I wouldn't like to try on the scorpions, asking for trouble. As one other guy said new shoes make a world of difference.