Enlarge / This woody desert shrub called guayule could be coming to a tire near you before too long. (credit: Cassidy Araiza/Bloomberg via Getty Images)

In 2022, the tire company Bridgestone used the IndyCar racing series to debut a new sustainable natural rubber that it has been testing as a replacement for less environmentally friendly rubber. The new tires used rubber from a desert shrub called guayule ( Parthenium argentatum ). Now, Bridgestone is ready to try the rubber in a more practical application and has produced a demonstration run of road-going tires using guayule rubber and a high percentage of recycled materials. The company will conduct tests with automakers to prove the concept.

The world produces about 2 billion tires each year, and while synthetic rubbers are used in modest amounts, most road tires use a lot of natural rubber from the para rubber tree ( Hevea brasiliensis ). But 90 percent of para rubber is grown in Southeast Asia and has to be shipped around the world to reach tire factories.

Bridgestone has been looking at guayule as an alternative for a little over a decade now. The guayule plant is a short, woody shrub that grows easily in the deserts of the American southwest and requires much less water than crops such as alfalfa or cotton, which are grown in places like Arizona, where Bridgestone has been breeding guayule and conducting research and development on its use in tire-making.

Enlarge / A Firestone race tire made from guayule plants, pictured next to the little woody shrubs that made it possible. (credit: Bridgestone)

There's still a lot of petroleum hanging onto electric cars, specifically around the rims. It takes about seven gallons of oil to make each standard car tire , and the world produces more than 2 billion tires every year . Now, some tire companies are turning to a desert shrub and a novel means of pulling natural rubber compounds out of it.

Bridgestone Americas has been working with guayule ( Parthenium argentatum ) since 2012. The tire company broke ground on a research facility in Mesa, Arizona, in 2012, started evaluating sample tires in 2015, and received multiple grants from the US Departments of Agriculture (USDA) and Energy for its research and molecular breeding work. Just last month, the company committed another $42 million to expanding its harvesting partnerships, with 350 acres in the short term and 250,000 more planned. That's part of more than $100 million invested into guayule-based rubber, the company says.

"With guayule, we can reduce the environmental impacts that come with overseas sourcing while also realizing a more sustainable agricultural system for parts of this country that are facing persistent and worsening climate conditions, so it’s really something with many benefits for our environment and our economy," said Nizar Trigui, chief technology officer for Bridgestone Americas, in a press release .