At the Tokyo Motor Show, Toyota unveiled its concept for airless tires—technology that could potentially reach public roads as early as 2020.
Airless tire development has been underway for several years. Michelin introduced a prototype of its airless radial tire, the X-Tweel, at the Paris Motor Show in 2014. That design featured a central hub connected to a rubber tread via flexible polyurethane spokes. Today, similar airless tire designs are already used on low-speed vehicles such as lawn mowers and golf carts. Bridgestone has also developed its own airless tire concepts.
The lightweight construction of airless wheels is particularly attractive for the rapidly evolving sector of vehicles powered by alternative energy sources, where weight reduction is critical to maximizing driving range. However, for mainstream automotive use, fully commercial products remain some years away—despite ongoing investment and development by major manufacturers, including Toyota.
Toyota showcased its airless tire concept mounted on the hydrogen-powered Fine-Comfort Ride concept vehicle at the Tokyo Motor Show. The vehicle features electric in-wheel motors paired with wheels composed of a rubber tread wrapped around a plastic and aluminum structural rim.
Including the integrated electric motors, the wheels currently weigh about the same as standard pneumatic tire assemblies. However, Toyota’s chief engineer, Takao Sato, believes further optimization could reduce weight by five pounds per wheel by 2025—roughly a 30 percent reduction.
“For car manufacturers, airless tires are primarily an attractive alternative for electric cars. Fine-Comfort Ride works well as a crossover/SUV, but these wheels could be used on any electric vehicle,”
— Takao Sato, speaking to Autonews
Sumitomo Rubber Industries, the company manufacturing the tire component, has already tested the design on golf carts and small urban vehicles. Interest from additional automakers is now growing.
One technical challenge remains: current airless tires generate 10–20 percent more rolling resistance than conventional pneumatic tires. On the positive side, manufacturing costs are estimated to be comparable to those of traditional tires.
“Airless tires contribute to greater safety and peace of mind in transportation by freeing drivers from worries about punctures and the need to manage tire pressure,”
— Sumitomo Rubber Industries, official statement
Sumitomo believes a commercially viable airless tire product could become available by 2020.