Ever wonder why car tires are black instead of blue, green or even red? Rubber and plastics can be virtually any color we want, all we need to do is add the right chemical or dye during the manufacturing process. However, most tires that are filled with compressed air (bicycle, automotive & construction vehicles) are a boring shade of black, and have remained that color for nearly as long as automobiles have existed.
But why? Is there a specific reason for this color selection, or is it simply a coincidence?
While different colored novelty tires exist and are available for customers to purchase, they aren’t meant to be used for daily driving. Your black, boring, yet reliable tires actually have a good reason for their specific color, and it has to do with the longevity and safety of your tires.
Being black is the result of the manufacturer’s attempts to extend the life of their automotive products. And extend it, it does – by a considerable amount. The color originates from the combination of stabilizing chemicals which are added and blended with the tire polymer during the production of a tire.
Super Carbon Black
The chemical responsible is called ‘carbon black‘ and it’s added to protect your tires against ozone and UV damage. Manufactures found that by adding the chemical, it drastically prolongs the life of the tire. So much so, that all tire manufacturers use this same additive in tire production.
Carbon black also has the capability to resist the corrosive effects of ozone and absorb the UV rays to convert them into heat. Heat is preferable because as the tires cool down or heat up, it can expand or contract to accommodate the added stress. Where ozone will attack the molecules and chemical bonds which weaken the overall integrity of a tire, expansion and contraction are less damaging and less dangerous. The result is a safer, longer life tire.
Since UV light and ozone are one of the biggest factors that contribute to tire rot, protecting against them is of the utmost importance to manufacturers – right along with safety and performance. Without the additive, the tires would weather and dry rot much more quickly.
Unfortunately, these chemical absorbers do get used up and lose their effectiveness over time. They expend themselves in the process of changing UV to heat and absorbing ozone. As the carbon black additive loses its ability to perform, it will turn a light gray. This is one of the main reasons why black tires will fade and turn a near white as they age.
Bonus Fact: In 1961, Goodyear Tires introduced an experimental tire that was illuminated from the inside. Small incandescent bulbs were mounted inside the tire through holes inside the rim and the actual tire was made from a single piece of synthetic rubber. The synthetic rubber was created much thinner than a regular tire to allow for the light to penetrate the thick rubber. Unfortunately, due to the strict laws regarding the manufacturing of street-legal tires and the obvious hazard of having fragile glass inside them, Goodyear’s illuminated tires never actually saw mass production. Their flashy tires were regulated to being a novelty at several car shows throughout the early 60s.
Bonus Fact: The first car tires were white!