I had two set of Michelin's on my 2500 chevy that cracked.
one set on my van that cracked.
Michelin tires ride and drive good, I have never gotten the high mileage out of them like others.
but when you attach that trailer weight to the back of the truck and the old dodge diesel engine grinding tread off the tires each time you take off.
its going to be hard for any tire to get great mileage.
some said the strong chemicals used to wash the outside of the tires and tire shine takes the oils out of the outer skin of the tire, then they crack.
do not know about that, so I stopped putting any type coating on my tires.
the current set of Michelin tires on my truck have not cracked, but I will be lucky to get 35K out of them, worn almost down to the tread depth marker.
not good for $200+ ea tire.
I may go with firestone TransForce HT next time, some local guys use them and have had good luck, my truck is a 2x4, so I am not out mixing mud.
however, you must have good safe tires out on the road pulling that camper.