Toyota Thinks Airless Tires Will Lead To Lighter Electric Cars

FEB 8 2018 BY MARK KANE 34

The Toyota Fine-Comfort is more a technology demonstrator than an actual concept car.

Toyota Fine-Comfort

Besides the hydrogen fuel cell and four-motor all-wheel drive, Toyota presented airless tires – which (in theory) could lead to a lower weight of electric vehicles.

So far, airless tires have only been used in light vehicles, as they need to prove their performances in mainstream passenger cars. Their ultimate potential is to lower the weight of the wheels (hopefully by 2025) by up to 30% (some 11 lbs / 5 kg), so in light EVs these would partially, or entirely, offset the weight of the motors.

One of the problems of such type of tires is there typically 10-20% higher rolling resistance…not a good starting point when you one is scrambling for all the extra range possible.

Toyota chief engineer Takao Sato said:

“Since such tires comprise a band of rubber encircling a plastic-aluminum hub, the premise is that they could one day compensate for the weight of the motors”

“For automakers, the attraction of airless tires is for electrified vehicles,”


source: Automotive News

Categories: Toyota

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34 Comments on "Toyota Thinks Airless Tires Will Lead To Lighter Electric Cars"

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They use airless tires on Light Construction equipment such as Bobcats . I don’t think they would be a good idea for higher speed vehicles such as cars.

They should fill the tires with Hydrogen if they really wanted to make a weight difference. Plus, I hear Toyota really likes hydrogen and this way they could put some of it to good use.

It’d be amusing to see how quickly hydrogen would leak out of a conventional tire, at conventional pressures.

(⌐■_■) Trollnonymous

The “Tweel” comes to mind. MICHELIN bought that company I think..

I can seem them filling up with snow and ice and causing nasty vibrations.

(⌐■_■) Trollnonymous

lol, that would be a good joke to pull on someone.
Glue some lead weights on the tire/rim……lol


No more flats to fix. Yahoooo!

Volt#671 + BoltEV

interesting about the higher rolling resistance….never would have guessed

You also save on the weight of the spare tire.

Who am I kidding, they already got rid of those.

Pneumatic tires replaced airless tires 120 years ago, and airless tires have been making a comeback ever since. Same for EVs. I guess Toyota thought they could speed the return of EVs by saddling them with airless tires. 🙂

About time! – In Wheel EV Motors, as to airless or not the unsprung weight is critical.

As to Fuel Cell …. just bury it in a grave and move on with solid state batteries. 🙂

I think the latest gen airless tires have better or at least the same rolling resistance.

For effiency gains, try designing vehicle bodies that don’t look like they come from a transformers film. What is the aero drag coefficient of the above pictured vehicle?

Please don’t insult the Transormers like that. The Cybertronian vehicles had a lot of style. However, I saw this and said “It looks like a Decepticon coffee table, made out of the remains of an Autobot fallen in battle,” so I don’t disagree entirely!

J P DeCaen
“For effiency gains, try designing vehicle bodies that don’t look like they come from a transformers film. What is the aero drag coefficient of the above pictured vehicle?”

Efficiency of it should be fine actually, despite ultra-futuristic concept looks. It is just concept after all. Essentially a minivan like Sienna, and does 1000 km JC08 on 6 kg of hydrogen. Vs 650 km JC08 of Mirai on 5 kg.

100% bull, unless you’re talking 60kg scooters.
5kg makes no difference whatsoever on a 1500kg+ EV — and even compact-class EVs will weighh that much the next few years.

If they mean lower _unsprung_ weight specifically, that’s a totally different matter… And even then, I doubt it’ll matter that much on anything except extreme sport cars.

They are talking about saving weight against the in-wheel electric motor, not the overall weight of the car. This is NOT to lighten the car, it’s to reduce the unsprung mass of the wheels. Adding an electric motor to each wheel is the ideal for total performance control. However it adds significant weight to the unsprung mass. Toyota’s claim here is that the airless tire can be light enough to offset the mass of the motor, thus retaining the handling and dynamics we consumers expect.

My inner Grammar Nazi says:

One of the problems of such type of tires is there typically 10-20% higher rolling resistance…

That would be “their”, rather than “there”.

Is there an editor in the house? 😉

I think it is actually “they’re”.

Carefull…the Grammar Nazi is watching! He is not fun if shown to be wrong!

So we’re lucky PP is correct then! ?

Actually, it’s a rather poorly constructed sentence. Perhaps it could better have been expressed something like this:

“One of the drawbacks of solid tires is that they typically have 10-20% higher rolling resistance than regular tires.”

Now I’m waiting in fear of someone embarrassing me by pointing out an error in my correction. Should it be “drawbacks OF” or “drawbacks WITH” . . .?

The subject is “one”, which would make “there’s” correct. I think.

Yes. But I think it was just the wrong word used. Should have been “their”, which would have read well. The grammatical subject is the problem, but the context at that point is the tires, so “their … rolling resistance” is reasonable.

I have airless tires on my bicycle. Both Citizen and Specialized bikes have them and maybe many others. Polaris has them on an ATV but no one seems to have them on a car yet.
I feel it’s the next great break through. The GM EV1 have very good RUN FLAT tires and with no spare on many cars they are really needed. I’d buy them and help test and improve them anytime.

One intriguing aspect is that “tweels” currently offer some damping…At a minimum that allows you to use cheaper and/or lighter suspension parts…However, imagine if “tweels” could some day replace a vehicles suspension? Nothing but benefits such as cheaper vehicles, quicker to R&D, less moving parts, less maintenance, less complex to build, more cargo room without strut towers and some weight savings…

curious how an airless tire is less weight then a tire filled with air? Last I checked, Air was lighter than solid material.

There would be less tire. If you don’t have air, you don’t need the sidewall.

But what about the extra spokes mass?

Presumably they think they can have alloy wheels with plenty of air and so low effective density for the outer volume, especially if they’re looking at in-wheel motors.

Hey Toyota,

Quite focusing on the individual trees and see the friggin’ forest!

Why are they higher rolling resistance, I wonder? Did they change the design of the suspension, to accommodate the different dynamics of the tires?

Toyota just trying to muddy the waters. They are in no position to comment on anything regarding EVs. The company that should have been trailblazers are pathetic laggards.

The pneumatic tire is light for what it does. Let’s say you could save 15-20 pounds, so what?