Ahead of this year's Sustainability in Tires 2024, we spoke with Nick Molden, Founder & CEO at Emissions Analytics, to get a sneak peek of what we can expect from his presentation on 'Tire wear particles from electric vehicles: wear rates and toxicity' Here's what he had to say…




Q1. Your topic will be “Tire wear particles from electric vehicles: wear rates and toxicity”, can you give us a snapshot of what delegates will hear? And why it is important for others in the industry to hear this message?

Firstly, thank you for inviting me to speak.   The issue of tyre wear rates and toxicity of compounds released is an under-appreciated one that is rapidly growing in importance as more battery electric vehicles hit the road.  It is important for the industry to hear these messages as new regulations, restrictions and possibly taxes are coming.  Manufacturers will need to understand the effect of tyres on the environment as the science advances and evidence more becomes more complete, as it will point to the scale of interventions coming from governments.  By understanding these topics now, it will allow optimal strategies to be developed, and investment to be made in good time.  If a manufacturer does not act, that may lead to a long-term reduction in competitive advantage, and a growing set of restrictions on the ability to sell tyres into developed markets – such as can be seen with California’s focus on replacing the 6PPD preservative.

My presentation will cover a summary of the physical properties of the current tyres on the market for different types of vehicle, which will then be linked to real-world wear rates, as measured by Emissions Analytics, and the chemical composition of tyres and their wear.  The presentation will further show results from our programme that reverse-engineers the composition of tyres, such that the differences with electric vehicle tyres can become evident.  These environmental factors will be put in the context of other performance characteristics of the tyres, which will reveal the trade-offs being made with electric vehicle tyres, not least in their being more expensive.

Q2. In the sustainable context, what do you think are the key challenges facing the tire industry?

The industry is suddenly facing elevated scrutiny from governments, regulators and consumers around the sustainability of tyres.  Further, there are many dimensions to this sustainability.  Decarbonising the materials and energy that go into making tyres is leading to more ‘bio’ materials and there is a pressure to move factories to regions with lower carbon electricity.  How to handle end-of-life tyres is a growing problem as developed countries are increasingly nervous about exporting used tyres to developing countries for use or disposal.  There are not enough domestic uses without burning the tyres for fuel.  There are opportunities in reprocessing tyres for chemicals, which are making progress, although remain challenging economically.

Emissions Analytics specialises in the in-use emissions from tyres.  This includes the solid particles shed through abrasion – both measured as mass and the number of ultrafine particles.  How to limit these particle emissions is a major challenge without compromising grip, noise and other performance criteria.  One risk is that wear is reduced by putting more toxic chemicals into the formulations.  This comes with the risk of worse chemical leachate from the tyres particles when they settle in the environment, and the off-gassing of volatile organic compounds from the surface of the tyres, especially in hot conditions.




Q3. What do you think of the impact of electric vehicles on the tire industry? How is EV influencing the future of the tire value chain?

Battery electric vehicles are typically around 400 kg heavier than an equivalent conventional internal combustion engine car, which will typically lead to greater tyre wear.  That rate may well be 25% greater from our testing, leading to more particles and chemicals shed into the environment per kilometre driven, and more end-of-life tyres.  Therefore, the growing penetration of these electric vehicles will have a profound impact on the tyre industry.  Regulators will exert pressure to reduce wear rates and reformulate tyres chemically.  Manufacturers will happily create bigger and more sophisticated tyres to carry to weight and handle the torque of battery electric vehicles.  But how will consumers react to the increased cost?  Reactions might include trading down to smaller cars, driving fewer miles, or adopting gentler driving styles to minimise acceleration rates and maximising use of regenerative braking.

Current evidence is that battery electric vehicles tyres are significantly larger than the tyres on an equivalent traditional vehicle – to the extent that the surface area is almost double.  This is relevant to the contact area with the road and for the rate of chemical off-gassing from the tyre surface.  Evidence as to the rate of wear suggests it is sensitive to driving style, with eco-drivers managing to extend the life of their tyres, while more normal drivers are seeing tyres worn out thousands of miles more quickly than before.


Q4. What are you most looking forward to at Sustainability in Tires 2024?

Conferences such as Sustainability in Tires are vital as a forum for playing out the tension between new sustainability requirements and embedded technology practices.  How is the research and science being advanced to plug current gaps in knowledge?  How is sustainability being balanced against the economics of the industry?  Which tyre manufacturers and suppliers want to deepen their understanding of the environmental impact of tyres and then develop solutions, and which ones are ignoring the challenges and hope they will go away?