consumed over the course of three years! This rubber is fantastic in my opinion! Soft, does not tan, ice and uphill - rows and rides, does not blunt in thick snow, spikes do not fly out, really quiet (compared to other competitors), and I do not see wear on the product. The fact that there is not a 20th radius was a major letdown for me. I had planned on purchasing this rubber for use in another vehicle; however, I am now faced with a decision. I AM VERY COMMITTED TO THIS! (before, there existed a pirelli ice zero r16, which was a sturdy solid rubber that had good handling in all weather, but it was very loud) I wish everyone success.