I just recently had to replace four Michelin tires on our 2005 Mercury Mariner. I had tread left but the side walls were rotting and unsafe, I will admit that the were 7 years old and had only about 15% tread life left. Today I had our Honda Accord in for service and again the side walls are weather rotting. This time, the tires are 3.6 years old and have 90% (near new tread)and they need replaced. I am done with Michelin.