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Lighter vehicles roll from research to road

By: Rhoda Miel

August 9, 2013

TRAVERSE CITY, MICH. — There was something new about the discussion on lighter-weight cars and trucks at the Center for Automotive Research's Management Briefing Seminars this year.

As the 2013 session kicked off Aug. 5 in Traverse City, new lighter vehicles are hitting the road, using new technology and new materials and moving what had just been laboratory research out onto the assembly line as automakers begin the push to meet higher fuel economy standards.

"Quite frankly, it's staggering to see where we have to get to," said Mike Regiec, manufacturing chief and technical fellow for body in white engineering at General Motors Co. "Getting to 54½ [miles per gallon by 2025] is going to require us to make every subsystem, every component as efficient as possible."

Every 10 percent of weight savings in a car adds up to 3-4 percent in fuel savings, Regiec said, which is putting new emphasis on lighter technologies.

Regiec was a key part of the team creating one of the highest-profile lightweight vehicles going into production this year.

The 2014 Corvette Stingray has an aluminum frame and a composite-intensive body structure. To drive its lightweight, high-style point home, GM had both a complete Corvette parked in the shade outside the conference's home base of the Grand Traverse Resort in Traverse City, and the stripped-down aluminum and composite frame on display inside.

"As the saying goes, this is not your father's Oldsmobile," Regiec said.

The Corvette's standard carbon-fiber hood and roof panels — made by Plasan Carbon Composites at its new plant in Walker, Mich. — have already gotten attention from the industry, but the car's developments in composites go beyond those parts.

The car's aluminum frame has a composite underbody panel made with nanocarbon and fiberglass reinforcement. The sheet molded compound used on exterior panels is a lower-density composite that is 17 kilograms lighter than the SMC used on previous models of the Corvette.

For the aluminum frame, GM developed new joining technologies to reduce the number of welds. Each weld, baffle and rivet adds weight to a car, Regiec said, and needs to be considered as part of the process of reducing weight.

"The full range of lightweighting technology will expand," he said.

The Corvette is far from being the only example of new, lightweight technology that is finally going into production. Jaguar Land Rover has a new aluminum frame on its latest sport utility vehicle. BMW AG's carbon-fiber i Series of all-electric cars are being rolled out this fall after more than a decade of R&D.

"There is no one answer for lighter-weight solutions, but [companies] are reaching out to their R&D operations and starting to bring a lot of things out into production," said Dave Mason, vice president of global automotive for Altair Engineering Inc. of Troy, Mich.

Altair sponsored the new Enlighten Award — presented to BASF AG for 2013 for a composite seat pan structure — to recognize lightweighting efforts throughout the global auto industry. Its 10 finalists took in the seat used in a model of GM's Opel Astra in Europe, as well as a composite leaf spring, aluminum chassis and carbon-fiber body panels.

"Every system, every component throughout the vehicle is a candidate for weight savings," said Mike Day, DuPont Automotive Performance Polymers development director in North America.

Don't expect other material suppliers to welcome composites with open arms. Phil Martens, president and CEO of aluminum maker Novelis Inc., downplayed the potential of carbon fiber to move into mainstream production. Martens maintained the carbon fiber is too expensive and takes too long to mold, saying it is only good for "esoteric" vehicles.

In DuPont's annual auto survey, more than 60 percent of the 1,300 participants said the value of lightweighting is increasing. Mason noted that the closer the industry gets to its 2025 fuel economy mandate, the more important lighter-weight parts will be.

Many of the fuel performance improvements that have taken place so far represent the low-hanging fruit of improved efficiency of a traditional internal combustion engine or greater use of hybrid power systems.

Since 2005, Toyota Motor Co. has improved its fuel economy by 18 percent, said Justin Ward, general manager of the powertrain system control department for the Toyota technical center in North America. In the next 10 years, it will have to push for another 25 percent in improvements.