[Lee Stewart]

Here's Why Tires Are Black:

“Original tires had a lighter shade because of the natural color of rubber,” a Michelin company representative told me. “Carbon black [a fine manufactured soot] was added to the rubber compound in [circa 1917] and produced a tenfold increase in wear resistance.”

This increased longevity is confirmed by award-winning chemical engineer Jack Koenig, who says in his book Spectroscopy of Polymers that a tire without carbon black would last “less than 5,000 miles.” Consider that most tires are driven between 12,000 and 15,000 miles a year, and are meant to last three or four years or more, and you get how low that was.