Why Are Tires Black, Even Though Rubber Is White?

Tires are black due to a substance known as “carbon black,” which is used to enhance the strength and durability of tires. This is also why tires consistently appear black rather than any other color.

In a world filled with vibrant colors, why do all tires have to be monotonously black? We see them every day, yet we often overlook this detail. Before we can explore the reason behind the black color of tires, we need to understand a bit about rubber—the material used to make tires.

Harvesting rubber latex

Rubber is naturally extracted from a sticky white substance known as latex, which originates from rubber tree sap. Latex is sticky and opaque white. To extract the latex from the rubber tree, harvesters must make incisions in the bark. Once the cuts are made, the white liquid rises and begins to flow down the incisions. This white liquid is collected and then treated with acid to produce natural rubber.

For the latex to flow out of the tree smoothly, the temperature needs to be appropriate; generally, it should be quite cool. If the temperature is too high, the latex will solidify and cannot flow out of the tree. This is why harvesters work from 2 to 5 AM when the temperatures are at their lowest.

Carbon black is a powder that gives tires their black color

Now, let’s visit a tire manufacturing plant to continue this story. The first thing we see is a massive block of natural white rubber. Clearly, natural rubber is white, and you will then see workers adding some synthetic rubber, which is also not black. The next step in this process is where the color change occurs, as carbon black is added to the rubber.

Carbon black enhances tire durability.

Carbon black is simply carbon in the form of extremely small particles. It is a byproduct of fossil fuels that undergo incomplete combustion. Carbon black is one of the blackest substances in the world and is the component that creates the black color for our tires.

You might wonder why carbon black is used in tire production. Carbon black is known for its ability to act as a reinforcing material. The carbon black color helps increase tire durability. Additionally, carbon black helps dissipate heat from critical tire components, such as the tread and sidewalls. When tires run on the road or any surface, heat is generated due to friction. This heat can damage the rubber and reduce the lifespan of the tire.

The first car tires were white.

Now that you know natural white rubber turns black during production because of carbon black, have tires always been black from the beginning?

Let’s take a brief look back at tire history. In the late 19th century, automobiles reached a limit in traction due to wooden wheels. By 1895, the first rubber tires were created with a design that was anything but original. At that time, rubber was simply shaped without any manufacturing methods, so they retained the original white color of the material.

Primitive car tires had the milky white color of rubber.

However, tire manufacturers quickly realized that primitive tires would harden in cold weather and soften in hot weather, leading to rapid deterioration and unsafe usage. A series of tire manufacturing technologies were tested until Sidney Charles Mote and a team of scientists in England discovered a solution named carbon black in 1904.

After years of research and production, carbon black became an indispensable component that ensured the black color of tires became iconic.