It’s here! Road test validates better fuel efficiency in CarbonX tires

Road tests confirm CarbonX® improves rolling resistance by 6.5% without compromising grip or durability. Here’s what it means in terms of reducing emissions and why OEMs are putting more focus on tires… 


Studies have shown that more than 80% of tire-related CO2 emissions occur in the use phase. But tire makers have had limited options when it comes to improving fuel efficiency without compromising grip or durability. So most sustainability initiatives in the tire industry today focus on the production phase or sourcing of raw materials.

Commercial success inspires confidence in CarbonX®

CarbonX® is a new material whose unique structure made us think it could go well beyond these limitations – and partnerships with two tire makers helped prove this to be the case.

Ere Research, a European manufacturer for high-end cycling components, found that CarbonX® was able to improve speed, grip and puncture resistance at the same time. The company launched its first product line of high-performance cycling tires containing CarbonX® at Tire Technology Expo 2022 last month.

Meanwhile, a premium tire manufacturer in Europe found that CarbonX® was able to improve durability and safety without compromising the exceptional fuel efficiency of their PCR winter tire. The company is currently producing about 600,000 tires containing CarbonX®, which were introduced onto the market in early 2022.

Encouraged by our success, we decided to accelerate innovation and explore the full potential of CarbonX® in terms of performance and our impact on sustainability. And the only way to do that was to roll up our sleeves, make our own tires, and test them on the road.


Designing a summer tread – with a twist!

So we set out to formulate our own summer tread compound designed to maximize the fuel efficiency, wear, and grip. The best performance was achieved when CarbonX® was used to substitute silica as well as carbon black – making our new tread compound truly unique.

The reference contained 5 phr N375 and 90 phr Silica, whereas our formulation contained 20 phr CarbonX X5 and only 75 phr Silica. The filler content was kept constant for both compounds.

A life cycle analysis (LCA) conducted according to ISO:14040 verified that CarbonX® could reduce CO2 emissions where solutions are needed the most: downstream.

When it comes to sustainability, we do not have the luxury of time. Inspired by the impact our material could have on CO2 reduction, we decided to take our formulation one step further. We wanted to show that the benefits of CarbonX® could translate into the real world and that our technology could be scaled up for any formulation and ready-to-use in less than two years.


Taking CarbonX® from lab to tire… in less than 2 years!

Intrigued by our material and our mission, the experienced team at Kraiburg Austria helped optimize our formulation to meet factory-scale requirements, where it was compounded along with the reference under the same conditions.

Tests showed that CarbonX® did not experience the property losses that typically occur with carbon black compounds from the lab to factory scale. Our compounds were ready for re-treading at Reifen Hinghaus – and we were one step closer to benchmarking our first tires in the real world!


Watch our video to get a better look at the making of our re-treaded tires:

Want to know more? Click here to visit our business cases in tires and to watch the full video.

Road test confirms that CarbonX® improves fuel efficiency by 6.5%

Our re-treaded tires were tested by Prüflabor Nord according to standards specified in the EU regulations for tyre energy labelling. Once again, our tread compound did not experience significant property losses in the curing process – underscoring the uniqueness of CarbonX®.

Moreover, the tests confirmed that CarbonX® was able to improve rolling resistance by 6.5% without affecting wet grip or noise. While the reference tire containing carbon black saw no improvement in fuel efficiency, CarbonX was able to move up into Class B.

6.5% seems like a small number, but it actually corresponds to an increase of 1 unit in fuel efficiency class. In fact, the ability to improve rolling resistance by just 2% without compromising grip or wear is already considered an achievement!

Source: Regulation (EU) 2020/740, Annex 1 

CarbonX® reduces CO2 emissions for both electric and conventional ICE cars

Using a conversion factor of 1:5 to translate rolling resistance into fuel efficiency and the emission intensity for gasoline fuel, our LCA determined that compared to a conventional ICE vehicle tire, CarbonX® would save 20.7 kgCO2 per tire over its lifetime and 82.8 tCO2 for every tonne of CarbonX® used.

In the case of EV tires, we determined CarbonX® could extend battery range by more than 2%. In an EV with an electricity consumption of 17.6 kWh/100km, this would translate into savings of  8.1 kgCO2 per tire over its lifetime and 32.2 tCO2 for every tonne of CarbonX® used.

Net Zero by 2050? Targets cannot be met without improving tire performance

In order achieve a 55% reduction in GHG by 2030 and net zero emissions by 2050, the EU will strengthen tailpipe emission targets and require all new cars sold in the EU be electric by 2035. In fact, the EU is already aiming for 30 million zero-emission vehicles on the road by 2030.

With zero emissions at the tailpipe, OEMs already rely on electric vehicles to meet their emission targets. But we shouldn’t forget that electricity still has a CO2 cost and that greater fuel efficiency will be needed to extend EV battery range.

Car manufacturers are realizing that tires may be one of the biggest factors when it comes to reducing CO2 emissions and extending battery range.

To compensate with added weight and torque in EVs, tires need lower rolling resistance and more durability just to match the fuel efficiency and lifetime of their ICE counterparts. Durability is also an issue when it comes to reducing pollution from tire and road wear particles.

Despite the growing share of EVs on the road, ICE cars will still be on the road well beyond 2050 – not just in the EU, but globally. If we want to keep reducing global transport emissions, we should not ignore the impact of making ICE tires more sustainable as well. Investing in technologies that improve fuel efficiency in tires could be one of the most effective means for reducing CO2 emissions no matter what the vehicle type. 

What’s next?

CarbonX tires are currently undergoing road testing for wear. When the testing is complete, the tires will have driven over 35,000 km in real-world conditions. Results will be announced later this fall.


To learn more about our material and we can help you develop next-generation tires for EVs and ICE vehicles, visit our product  & services page and fill out the form or contact our Head of Sales, Sophie Dik, directly at

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