We have had a 2006 Thor Mandalay since Sep 08.It came with XZA3 on it from Freightliner. It had 9009 miles on it when I got it home from purchase. I still have 3 of the 6 originals on it. They show no weather check at all. Of course I wash only the rims. I have had 2 XZA3 blow outs. I cut down a rear on a culvert. One blow out had less than13k miles there on. The other had about 41k there on. The machine has about 65k on it. In between blow outs I tried Toyo stear and put it down on the right front new. It was mostly used up within 21k, wearing on one side. The tire that blew had flat ware. I put another XZA3 in its place and it is wearing flat. I had the alignment checked twice because of what I call wheel 'hop' in the front some how. The shops found nothing wrong and made no changes. I keep the fronts at 107 PSI cold and the rears at 100. Rarely notice any 'hop' at this setting now. I am not sure that I can get even 150k miles out of any one of them without regroving. By that time they will be old enough to retire*.*! I have a monitoring system and like it. [At one point in my working period of existence I owned 5 tractor trailers and three extra trailers.] What I can say with some authority is that tires have become absurdly expensive even with the modest discount FMCA provides. I will stay with the Michelin XZA3 design until I can be shown better. What I can say about the Freightliner chassis is that it is ridiculous that there are three different wheel rims/hubs. Bad news bears! That just ain't right!