I have 60,000 miles in 6 years on my Michelin LT 265/75R16 E tires for my duramax .
No cracking .
I swap snow tires and wheels for the winter season so the Michelins are stacked in my garage for 4 months each year on their own wheels .
At 60K they are not to the wear bars yet .
The cracking in the pictures may be exaggerated because Michelin has SMOOTH SIDEWALLS unlike most of the other brands .
The other brands have much " gingerbread " on the sidewalls so as to not show scuffing when being curbed .
One thing I like about the Michelins with the smooth sidewall is that I can apply tire dressing with a very quick swipe .
Applying the dressing to other brand tires takes more care due to the corrugated surface .