Electric cars (EVs) can be demanding on their tyres, but does this limit your options when it comes to replacing them? We take a closer look
Claire Evansclaire.evans@haymarket.com
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THERE ARE A whole host of new questions to ponder when you switch from an internal combustion-engined (ICE) car to an electric one. How will you cope with the logistics of charging? What do you do in the event of a flat battery? Even the simple prospect of choosing replacement tyres throws up a new quandary: should you buy tyres that have been specially designed for electric vehicles (EVs), or will any tyres do the job just as well?
What makes EV tyres different?
Continental Tyres produces the tyres fitted to many new EVs, including those made by BYD, Kia, Mercedes-Benz, Porsche and Tesla. The company’s head of technical services in the UK, Steve Howat, explains how the growth of electric car popularity has forced tyre design to rapidly evolve.
“If you think about a popular car from the 1990s, such as the Mk3 Volkswagen Golf, it weighed around 1000kg and had 14in tyres. The latest comparable model is the ID 3, which weighs around 1800kg and has 18in or larger tyres. As you can imagine, the demands both of these vehicles put on their tyres are very different,” he says.
Load capacity is an important consideration when designing a tyre. Because EVs are often heavier than their petrol or diesel equivalents, the largest, fastest models need heavy load (HL) rated tyres to cope with the extra strain put on them. In fact, the heaviest electric SUVs might need extra load (XL) tyres that have been reinforced to cope with greater loads and higher speeds than other tyres.
Another big consideration, explains Howat, is efficiency. “Range potential has been a big issue for EV buyers, and improving a tyre by just one rolling resistance class, as shown on its EU tyre label [see panel], can increase an EV’s range by around three to four percent.
“Our engineers even look at seemingly insignificant details, such as the rotational aerodynamics of a tyre and how the letters on its sidewall can create drag, because tweaking these small things can give marginal improvements in performance.”
Noise from the road and tyres is more of a concern for EV drivers than for owners of other types of car, because this can be more noticeable without the sound of an engine to drown it out. To help mitigate this, some tyres have a layer of polyurethane foam b
