Michelin intensifies tyre r&d efforts

By Larry Edsall, Automotive News

"Energy costs are not going to fall, and raw materials are not going to revert to five years ago. This is a new reality we must face." - Edouard Michelin, Group Michelin

Clermont-Ferrand, France-Facing higher raw materials and energy costs as well as the growing number of vehicles worldwide, Group Michelin is intensifying its efforts to cut materials use and rolling resistance while improving tyre performance.

Among the company's targets are car and light-truck tyres that double the durability of current tyres, yet are built from half the raw materials. The company also wants medium-truck tyres that cut stopping distances by 20 to 30 percent and tyres designed to reduce rolling resistance by half.

Each target was discussed in briefings at Michelin's world headquarters here and its primary r&d center in nearby Ladoux.

While Michelin executives were eager to entice, they were reluctant to provide many details. Demonstrations on the Ladoux test track showed the benefits of reduced rolling resistance, maintaining proper tyre pressures, the Pax run-flat tyre/wheel system and the company's state-of-the-art wet test track. The wet track draws automakers and their heavily camouflaged prototype vehicles for pre-production testing.

More r&d needed

Michelin said its motivation for such r&d targets includes the escalating prices of raw materials and the expanding size of the world's vehicle fleet.

Didier Miraton, who heads a staff of 4500 scientists, engineers and technicians working in Michelin r&d facilities globally, noted that the number of vehicles on the road is expected to double to 1600 million in the next 30 years.

Much of the growth will be in developing nations such as China, India, Russia and in eastern Europe and South America-areas all experiencing not only rapid expansion of their fleets but of roads to carry them.

Miraton used the word "breakage" in describing the severity of the environmental impact if drastic developments are not made.

The executives said that 20 to 25 percent of the pollution generated by a typical vehicle's internal combustion engine is expended to overcome the rolling resistance of that vehicle's wheels. As rolling resistance decreases, fuel efficiency rises.

"The collective benefit for society is decreased pollution and exhaust emissions," Miraton said.

Michelin's introduction of radial tyres in the late 1940s reduced rolling resistance to around 15 kg/tonne from 25. Michelin said its Energy line of car tyres in the early 1990s reduced that number to 11, and the third-generation Energy tyres launched last year cut the number to less than nine.

In the last 10 years, Michelin also has reduced rolling resistance by cutting more than 4 pounds from the weight of a typical car tyre. Reducing a tyre's flex and changing the mix of rubber and using more silica in the tread also cut rolling resistance.

"But it is of no interest to us to reduce the rolling resistance if the life of the tyre is compromised," said Michelin technical communications director Pierre Menendes. The tyre's lifespan, in mileage, may not deteriorate, and hopefully will be increased.

"The idea is not to limit mobility, that would be crazy," Menendes added. "Human beings have a big thirst for individual mobility. Michelin is responding to this need, but in a responsible way."

Menendes spoke standing on the Ladoux test track, where Michelin showed two identical cars, one equipped with third-generation Energy tyres and the other with a future-generation prototype. The cars accelerated to 20 mph, then were put into neutral and allowed to coast.

The car with the experimental tyres with a rolling resistance of around 6.5 coasted an extra 200 feet. Michelin's goal is to produce car tyres with rolling resistance figures in the 4.5 range.

It also wants to build tyres that last twice as long but consume only half the raw materials currently needed to construct a tyre.

Increasing costs

"We're already experiencing a number of shortages in raw materials, and this will become worse and worse," Miraton said.

Shortages also mean higher costs. Michelin said its bill for natural rubber increased 35 percent in 2002, 35 percent in 2003 and last year jumped another 16 percent. Another double-digit increase is forecast for 2005.

While natural rubber is the largest single ingredient in tyres, other components such as steel, synthetic rubber and chemicals such as butadiene and styrene, both obtained from the cracking of oil, all are experiencing higher pricing inflation than natural rubber.

"The next decade is a world of more expensive resources," said Edouard Michelin, chief executive of Group Michelin. "Energy costs are not going to fall, and raw materials are not going to revert to five years ago. This is a new reality we must face."

Herve Coyco, head of Michelin's car and light-truck tyre division, said that while his company's tyres may carry a 15 percent price premium, in Europe they provide 30 percent longer wear and a 15 percent reduction in fuel consumption compared with industry averages.

Coyco said that balancing rolling resistance and grip is a challenge that Michelin tackles on two major fronts: tyre architecture and tread, and materials.

Weighty issues

Complicating the work for tyre company research scientists and engineers is the fact that vehicles are getting heavier and more powerful and thus put more weight and more tyre-eating torque to their tyres.

The proliferation of SUVs isn't the only culprit. Coyco said the recently launched fourth-generation Volks-wagen Golf weighs several hundred pounds more than the third-generation Golf.

He also said that the growing diesel and hybrid fleets with electric motors that provide instant high torque are responsible for increasing tyre wear.

One solution being pursued by Michelin is the elimination of unneeded tyres. Pax tyre/wheel systems were designed to operate safely even when they lose air and thus eliminate the need for a spare tyre. Eliminating spare tyres not only frees raw materials for other uses but helps decrease a vehicle's weight.

Michelin's X-One truck tyre was designed to replace dual tyres on semi trailers, turning 18-wheelers into 10-wheelers. Reducing the number of wheels and tyres can allow tractors to be reconfigured to an even heavier cargo.