Why Airless Tires for Cars Aren't Available to Buy yet

Why Airless Tires for Cars Aren’t Available to Buy yet

  • In recent years, we’ve seen prototypes of airless tires for everyday cars.
  • Major tire companies like Goodyear say they may not be certified to buy until 2030.
  • We explore the engineering challenges standing in the way of this technology becoming available.

Narrator: From the wheels of NASA’s moon rover to Michelin’s Tweel, we’ve seen tires that don’t need air for decades. We’ve even seen prototypes for everyday cars that roll over sharp nails with ease. So why do companies like Michelin and Goodyear say anywhere from 2024 to 2030 is the soonest these products will be ready to buy? What is taking so long for airless tires to hit the shelves? It’s one thing to run around the lunar surface for a couple of miles and a few hours.

Paul Eisenstein: Here on Earth, it is much more difficult than you’d expect to replace pneumatic tires.

Narrator: “Pneumatic” means anything that uses air pressure. That’s why you’ll hear airless tires like the Tweel referred to as non-pneumatic.

Paul: They’re going to have to come up with, first of all, with a way to design them. Then they have to manufacture them, dealing both with cost and durability. And certainly, people are not going to be happy if these airless tires wind up not lasting very long.

Narrator: What could cause them to wear so easily? As tires roll, they constantly compress and then decompress due to the weight of the car. Going 70 miles per hour down the highway, this happens about 1,000 times per minute and generates a lot of heat. Luckily, air allows heat to disperse easily. Typical pneumatic tires can last for around 60,000 miles if you don’t hit a nail. But if you replace air with more material, the potential for heat to build up and tires to wear much faster grows exponentially.

Paul: The reality is when a tire rolls down the road, it does generate a lot of heat. And heat is one of the big enemies of a rubber pneumatic tire. If they can make the spokes or the supporting elements in an airless tire able to handle the compression pressures, all the deformation and all the impacts, they should be able to keep it relatively cool.

Narrator: Another concern is efficiency. This constant deformation of your tires increases rolling resistance, or the energy your car needs to send them to keep rolling. While pneumatic tires waste some of that energy as heat, they can easily be inflated more to reduce friction against the road. Airless tires that replace lightweight air with heavier materials need to be perfectly designed, or else drivers will need much more fuel to keep rolling. But as improvements in design continue, like eliminating the need for a wheel, airless tires could actually become the more efficient option.

Chris Helsel: It’s basically four components. the tread, which is that part that’s made of the rubber and other polymers. Then from there, you have what’s called the shear band, and the shear band is very close to the belt package on a radial tire. But now from there is this connecting web structure that you see. That’s really new to us. That’s made of thermoplastics. So then the fourth component is simply the hub, and the hub is where, of course, that web structure connects in, and that’s what’s going to connect into the axle of the vehicle.

You do have to also recognize you don’t have materials in the tire to keep the air in. You are replacing it with new materials, those thermoplastics, which we can do some further engineering on and potentially manage that trade-off differently.

Narrator: No matter how durable or fuel-efficient airless tires become, the number-one factor in making any new car technology available to the masses is safety.

Chris: One is the amount of load that the tire has to carry for its size. The second thing is how fast you can go and that tire is going to remain durable for a long period of time of running at that speed. And that’s why you see the evolution and the applications that we’ve been working on. Starts with a low speed, low load, a zero-turn mower. We move to an autonomous shuttle. Why? An autonomous shuttle has the load of a vehicle like a car, but it only goes maybe 35 miles per hour, so it’s slow speed.

Narrator: Still, as a company that makes over 150 million tires a year, Goodyear claiming its airless tires won’t be road-ready until 2030 seems a bit long to wait unless they were designed to last virtually forever.

Chris: Well, the 2030 date actually coincides with our bold goal around having a tire that’s made of completely sustainable materials as well as is maintenance-free. When you think of maintenance-free, especially think of electric vehicles and the fact that they’re not going to need much maintenance up to, say, 30,000 miles. Today, what triggers a lot of maintenance on your tires is the need for oil changes. And so when people go in for an oil change, what happens? They get the air pressure checked, topped off if needed, as well as rotation of tires. And that makes tires, of course, last longer because they’re properly maintained.

And the sustainability piece, one thing to keep in mind is the materials of these thermoplastics can be recycled. You can claim those and use those directly after you reprocess them into the next non-pneumatic. Today for tires, you can’t do that. They are reused at end of life, but not in for-like application. You can’t take a tire at end of life, reprocess it, and directly use it in the next tire.

Narrator: Goodyear’s testing of its current airless prototype on autonomous shuttles and delivery carts isn’t just for show, either. Airless tires could be the key to getting self-driving vehicles on the road faster.

Chris: So 60% of roadside incidents, let’s say, for commercial trucks as one example, are due to tires. So what happens is a human who’s driving that vehicle takes action to get it taken care of. Well, who’s going to do that in an autonomous-driven vehicle? That’s a difficult thing to train an autonomous driving system to deal with. So once again, if you could get rid of that being one of the use cases that autonomous vehicle developers even have to contemplate by putting in a tire that won’t instantaneously lose air, you could unlock autonomy potentially sooner.