There are other issues as well. “You have a juxtaposed target: On the one hand you have to manage and withstand the weight of a battery-powered car with stronger brakes, stronger axles, strong suspension,” Mr. Dahncke added. “At the same time, you need to optimize everything for aerodynamics.”
These “ground up” procedures involve collaboration between suppliers and manufacturers, Mr. Coke said. They must consider the brakes, the wheels, the side mirrors, wind noise, chassis noise, tire noise. The issues are not unique to one manufacturer; in his case, Pirelli, whose home base is Milan, has been working closely with Rivian, which is based in Michigan, to fit tires to its products.
Tires, of course, are Mr. Coke’s singular concern. And among his priorities in developing for E.V.s is reducing a tire’s rolling resistance, a key factor in extending battery life. Longer battery life means less range anxiety, and a bigger potential market for electric cars.
“Our compounds are designed with a high content of silica to deliver very low resistance,” Mr. Coke said. Silica decreases the tire’s energy consumption. “And our challenge is to balance that with handling, braking wet and dry, and tire life. And in an E.V., we try to tailor the tires to the application: if the vehicle is front-, rear- or all-wheel drive; if the use is for summer, winter or all-season.”
Then there’s torque. “There’s immense torque in E.V.s,” Mr. Coke said. “The tendency to put your foot down and deliver that power is obviously a tendency that wears out tires very quickly. So you need to have grip, but you don’t want too much resistance.” And around and around.
While weight reduction is important to all cars and trucks, it’s especially crucial with E.V.s, mainly because of the battery load. And because the batteries often are set low in the vehicle, the center of gravity in electrics is different from that in a conventionally powered car. Is this change of sensation disconcerting for some drivers?
The Link LonkFebruary 04, 2021 at 06:00PM
https://www.nytimes.com/2021/02/04/business/electric-vehicles-gm-tesla.html
E.V.s Force Carmakers to Reinvent the Wheel, and Brakes, and Mirrors … - The New York Times
https://news.google.com/search?q=Wheel&hl=en-US&gl=US&ceid=US:en
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