Everyone Is Working on Non-pneumatic Rubber for Your Future Car

Airless tires are one of those things that crop up every few years, but they never seem to stick around long enough to become commonplace. Already, certain construction vehicles use flat-proof rubber, and tire manufacturers have been playing with airless systems for some time. For example, Hankook has the iFlex, its fifth attempt at non-pneumatic tires, and Goodyear has actually begun selling airless donuts on commercial lawnmowers. Michelin even has a 3D-printed round that it claims will last the lifetime of a vehicle.

Unfortunately, nobody seems able to come up with a solution that works at higher speeds. While they’re great at taking impacts, the existing designs aren’t so good at coping with high levels of heat. But it’s not for a lack of trying — there may even be a breakthrough just around the bend, especially since everyone seems so interested. Rolling resistance and weight are two of the electric car’s worst enemies. If an automaker could mitigate those issues effectively, that would be another leg up on the competition.

It’s an issue weighing heavy on the top minds at Toyota at the moment. The company’s recent concept EV, the Fine-Comfort Ride, came equipped with a set of experimental airless tires from Sumitomo Rubber Industries, boringly named the Smart Tyre Concept-A. Toyota’s theory is that non-pneumatic tires, consisting of a solid band of rubber encircling lightweight alloys, could eventually compensate for the weight of wheel-mounted electric motors.

The end result is better efficiency stemming from lessened rolling resistance and overall heft. However, the way Sumitomo tells it, the technology wouldn’t have to be limited to EVs. The company is approaching the airless-tire endeavor as a way to improve safety and free drivers from the plight of having to manage tire pressure. Sure, it’s focusing on the “mobility” angle and promoting the use of sustainable materials, because that’s what you do in 2017. But you could theoretically slap these babies on a 1993 GMC Sierra and burn all the gas you can afford.

But first, you’ll have to wait until they’re ready for market. According to Bloomberg, Sumitomo is only running them as test platforms on ultra-small Japanese kei cars and golf carts right now. So, exactly how long you’ll have to bide your time with ancient radials is up in the air. While Sumitomo intends to include some of the lessons learned in pursuit of non-pneumatic rubber on production tires within a few years, genuine airless tires aren’t anticipated until the latter half of the next decade. Wako Iwamura, head of the five-year airless-tire project at Sumitomo Rubber, said his personal goal is to have a commercial product ready by 2020 — though it wouldn’t be an all-weather application.

Currently, the concept tires weigh about the same as their aired counterparts, but Toyota’s chief engineer, Takao Sato, believes developments will eventually shave 11 pounds from each tire’s total weight by 2025. Interestingly, that’s just about the same time that most automakers plan to have fleet-wide electrification.

[Image: Toyota]