Treading lightly

New tires are being designed to roll with less friction, maintain inflation better, and use fewer petroleum-based ingredients.

The first pneumatic car tires were environmentally sustainable-green-products. Manufacturers in the late 19th and early 20th centuries fabricated tires primarily from natural rubber that had been derived from a renewable and sustainable source-the latex sap of certain trees and plants.

As time passed, though, and greater performance and lower costs were demanded from tire designs, makers began to throw into the compounding mix more man-made ingredients-in particular, synthetic rubber and chemical additives often derived from petroleum. Today, from 5 to 10 gal (19 to 38 L) of crude oil goes into making a standard car tire.