Michelin develops EV-specific prototype tire

“All electric vehicles place unique demands on tire performance,” says Dr. Patrick Oliva, Michelin’s global vice president for sustainable development. “Michelin designers must account for more torque on the low end and apply our Green X technology to maximize vehicle range,” he explains.

“We must employ new materials to reduce tire mass in order to help offset battery weight. Unmasked by engine noise, tires for electric vehicles have to be quiet and require increased uniformity to maintain vehicle comfort, Oliva observes.

“Aerodynamics also plays a key role in extending the range of an electric vehicle without compromising handling or safety. Those aerodynamic demands extend to the tire-wheel assembly, with rim size, tire width and overall shape playing pivotal roles,” he says.

The new EV prototype achieves energy efficiency; maximum grip, especially in challenging driving conditions; and a long wear life, according to the company.

“In addition to these qualities, the prototype offers a fourth quality – quiet ride – that is ideally suited for a power source that is relatively noise-free.”

The tire incorporates:

• The latest technology in tread rubber with new silica compounds;

• A new tire profile designed specifically for urban use;

• A specific tread design optimizing the surface of rubber in contact with the road.

“The EV prototype tire has all the benefits of a traditional Michelin tire in terms of grip and mileage, but its rolling resistance is reduced significantly to maximize the range of an electric vehicle,” the firm reports.

“In fact, the work the company has done on the EV concept tire shows that it is possible to reduce even more the level of rolling resistance compared to traditional passenger car tires by 15 percent. The current Michelin Energy Saver A/S passenger tire is already 30 percent better in rolling resistance than the market average.”

In order to minimize rolling resistance, the EV prototype has a long diameter and is relatively narrow, thereby reducing energy consumption since there is less front rubber in the contact patch.

A long diameter combined with a low profile helps reduce energy consumption because the tire turns fewer times when covering a given distance. Consequently there is less deformation and heat build up, resulting in additional energy savings, according to the company.

“At the same time, the longer diameter means more rubber in the tread, thereby increasing total mileage and reducing overall operating costs.”

The company’s research and development engineers “have developed a unique tread design comprised of long, narrow, directional longitudinal grooves that provide a quiet ride as well as good grip on wet roads.”