This article was adapted for Mobility Weekly, our free weekly newsletter. Register for a subscription here.
Even though many COVID-skittish companies opted out of traveling to Las Vegas last week to the annual Consumer Electronics Show, there was no shortage of mobility innovation on display both on The Strip and virtually — from BMW’s color-morphing concept car to a gazillion electric bikes to John Deere’s fully autonomous tractor. One writer called CES the best show for new automotive technology in years.
I still haven’t figured out why tractors are considered consumer products, but I digress. And as I learned long ago, innovation doesn’t have to be flashy to be impactful.
Take tires, one of the most underappreciated topics when it comes to sustainable mobility. They are central to improving the fuel economy and efficiency of trucks and cars using internal combustion engines — simply adjusting the air pressure does wonders for fuel economy. But how are they being evolved to accommodate electric vehicles? And, more important, what is the automotive industry doing about all those big, black circular hunks of natural rubber, petroleum, steel, nylon, polyester, silica and other materials that are no longer roadworthy?
As I reported last year, the U.S. alone discards something like 6 billion pounds of tires annually. Some of that material is finding its way back into other tires through circular manufacturing processes, but a lot of it is burned or turned into things such as surfaces for playgrounds.
Goodyear Tire & Rubber Co. was front and center last week with something to say about all of these topics. The centerpiece of its news was a demonstration tire (meaning that it's being road-tested by the company) that is made of 70 percent sustainable materials — its goal is to reach 100 percent by 2030. For perspective, most tires on the market today are made with 25-30 percent sustainable materials.
What the heck does that mean in plain English? I’m not a tire engineer, but one big focus for Goodyear is simply decreasing the amount of unsustainable material — especially virgin petroleum and polyester — and finding viable replacements. In case of the tire it’s testing, there are several materials of particular note:
- Three new types of carbon black that are made out of carbon dioxide, methane or plant-based oils
- Leftover soybean oil from food/agricultural applications
- Silica created from rice husk ash, a byproduct of rice production that usually finds its way into landfills
- Polyester made from recycled plastic bottles and other waste
What do all of the above have in common? They are highly dependent on circular economy processes and, by association, on supply chains that you wouldn’t typically associate with a tire manufacturer.
Ellis Jones, vice president and chief sustainability officer at Goodyear, told me that one of the biggest challenges when choosing new materials for tires is balancing the performance and safety factors with sustainable business considerations. The company is already using soybean oil in its commercial portfolio, including its WeatherReady all-season tire. That line is considered to be one of the best-performing tires on the market, Jones said, and Goodyear is starting to market some of the sustainability aspects. The rice husk silica also factors in some products.
As other sustainability professionals can appreciate, however, every material choice or change comes with sourcing considerations. Does using soybean oil for automotive applications, for example, create issues for the food system? Will land be converted to grow the beans or is there a large enough supply of waste oil? When it comes to rice husks, will this create an unsustainable reliance on sources in Asia-Pacific countries? "The challenge is creating a supply chain that is viable and resilient," Jones told me.
To that end, it’s worth noting that Goodyear is already working on an alternative source for carbon black — a substance made from the combustion of residual oil or coal tar oil that typically accounts for 15-20 percent of the "typical" consumer tire by weight. In December, it announced a relationship with Monolith, a producer of carbon black processed from methane. A life cycle assessment touted by the company suggests that switching to this source would result in a reduction of carbon emissions for that particular material.
By the way, Goodyear considers the natural rubber in its tires to be a sustainable material, given changes made to its procurement policy back in 2018. The company is part of the 16-year-old Tire Industry Project, a forum of the World Council for Sustainable Business Development that represents about 65 percent of the world’s tire manufacturing capacity.
Aside from its sustainable materials push, Goodyear is letting the air out of some of its new tires, literally — something that Michelin began talking up a couple of years ago with its Uptis technology. News about this project emerged late last year, but Goodyear officially announced a non-pneumatic product designed for a company in its venture portfolio, Starship Technologies.
Starship operates autonomous robots that deliver packages and food door to door; the concept is being tested at Bowling Green State University in Akron, Ohio. Why airless? This approach is seen as having benefits for treadwear, braking scenarios and also for reducing vibrations (who needs scrambled eggs before they even make it to your doorstep?).
The other big place where airless tires could play a huge role is on EVs. It’s worth noting that the test car for the Goodyear video that surfaced in November was from Tesla and Michelin’s initial test fleet for Uptis were electric vehicles from General Motors. When I chatted with Goodyear’s Jones last week, he said the weight of EVs adds another dimension of complexity — the rolling resistance and torque dynamics are very different. There’s also the matter of how much noise a tire generates, especially consider that EVs are generally quieter than gasoline-powered vehicles. "Those are the performance envelopes we are designing for," he said.
Goodyear introduced its first EV replacement tire for North America in December, the ElectricDrive GT. It expects to have more EV tires on the road later this year.