I can't answer the question, but I can add to it. I've asked this question here, the dealerships, the tire "experts" at chain stores and Tire Rack and while I don't think I've seen the answer here, all to the others say a flat out no....but when you ask why not, almost as though they are cloned they say "there has to be a reason with the computer". Yet the manual says to run the same size tires in the rear as the stock front for winter driving and says nothing about period of time.

Since I managed to find the Exclaim UHP's from Tire Rack at a price that when mounted was around 800, I didn't even worry about trying. But if these don't hold up much better than the stock Conti's, I'm going to be looking back to going with same size all around so I can rotate them....yes, that will mean the 255/35/19's will be gone.