Ref 275/80R22.5 XZA3, New 3/29/10......replaced 1/8/14.......55,000 miles
FYI, coach driven every two weeks, partially covered storage, DOT only one month earlier than purchase.
Four tires exhibited cracking, with broken belt upon closer exam on DS tire, otherwise tires looked good. Problem was dry rot.
Contacted Michelin, explained the issue. They discussed with the Loves tire center, then replaced all six tires with XZA3+ at a really good price.