Why are car tyres always black? The surprising reason has nothing to do with colour

Carbon black is a fine carbon material produced from hydrocarbon-based feedstocks.

When incorporated into rubber, it acts as a reinforcing filler. It changes the physical properties of the compound, making it better suited to the demands placed on a tyre.

It also helps with resistance to abrasion and heat, two factors that are unavoidable during driving.

There is another benefit: carbon black helps protect rubber from ultraviolet radiation, which can contribute to the deterioration of rubber over time.

The familiar black colour is therefore a visible side effect of an ingredient that has several important jobs inside the tyre.