[CapriRacer]

Isn't the real question: What's the alternative?

Oh and I want to correct one misconception. Tires are still made of pretty much the same materials they were 40 years ago. Carbon black (Soot?), natural rubber, synthetic rubber (No plastics, and silicone rubber if used at all, is used in very small quantities), steel, and fabric are still the major materials used. They just use less of them, because they've spent a lot of time and effort to make their designs more efficient (and less costly!)