Michelin requires proof of rotation at least every 5,000 miles and alignment checks on your vehicle at least once or twice a year to approve a manufacturer adjustment claim. You're not obligated, really, but if something ever happens to any of your tires, and you need a new one, Michelin has their hands tied if you haven't been having your tires rotated and getting the car aligned properly. For your information, here in the states, misalignment is the most common cause of irregular/premature tire wear (usually toe wear). It's strange to me that you don't have that in EU...because you should. At least for Michelin America, that's what is required of you to make a claim. If you let your winter tires sit on rims for 4 years in a garage, then well they should still be good to go unless they're dry rotted in which case you need a new set of tiresStill, seems like there is a good customer care when dealing with warranty Good to hear that. Michellin seems like a good guy hehe I don't understand what you mean with rotations and alignment checks. Are you obligated to do that regularly or something? What if you just let your winter tires sit on some rims in a garage for 4 years? Here in EU we don't have that, everyone does so, if not, it is your fault if the whole car will shake when your tires aren't weighted correctly.