My BMW has been using 205/50ZR17 Continental ExtremeContact DWS tires for the last 5 years. Over those 5 years I have had to replace 10 of them due to blisters (usually on the inner sidewall), cuts or blowouts all but one caused by potholes. And twice two at a time. Potholes are epic in Pennsylvania due to dramatic freeze/thaw cycles and poor maintenance budgets. All of the inner blisters were discovered at annual PA State Inspections and came as a complete surprise. I have never had any of these problems in 55 years of driving before owning a car with 50 profile tires. You are driving on 40 profile tires, yikes.The guy at the tire shop is going to call Continental in the AM and he checked and said they should be covered fully for replacement...so I am hoping I will not be out $$...but the question remains..how could this happen?
I’m going with POTHOLES!
BTW: Continental has paid for the tires (4 of them) when they were less than 1 year old.