I won't say that since it hasnt happend to me it must not be possible, but how dangerous would it to to cruise for 4 hours at 120 in a teg down to LA or something? I've done it twice now and the average speed is probably 110 or so. I'm running Z rated tires and am very carefull about the tire pressures I run. I'm suprised there is any aprehension about it. I figured it was a very safe bet if you had a properly designed tire and air pressure.