I didn't even have a shred of question about the type of rubber that was used; when I was given the opportunity to take such tires out for a spin, I determined right away that I had no choice but to purchase them. With its positives being: Rubber is wonderful. Taxiing, braking, maneuvering, aquaplaning - everything is on top. Cons: On a low profile, you need to be careful when driving on asphalt faults; nevertheless, this is not an issue of rubber, but rather of our never-ending source of misery — roads. Fairly rapid wear, but these tires are not for those who measure millimeters of wear with a ruler; rather, they are designed for individuals who enjoy a lively and dynamic ride.