BERLIN (Bloomberg) -- BMW AG will cocoon passengers of a battery-powered city car in the same lightweight material used to protect Formula One drivers.
Marking the auto industry's biggest bet on carbon fiber, BMW will use the fabric to construct a passenger-safety cell for the electric vehicle.
The amalgamation of carbon fiber and aluminum will offset as much as 350 kilograms (772 pounds) of additional weight from battery and electronic components, according to Klaus Draeger, BMW's development chief.
“The economics will be balanced on a razor blade,” said Christoph Stuermer, an analyst at IHS Automotive in Frankfurt, said in an interview. “The combination of using lots of carbon fiber and breaking it up into smaller pieces may be the magic trick to reduce costs and could make the frame only twice as expensive as aluminium.”
BMW is racing to build battery-powered vehicles as governments and consumers push for viable alternatives to fuel-burning cars.
PSA/Peugeot-Citroen SA and Nissan Motor Co. will introduce electric vehicles later this year. Investors snapped up shares in Tesla Motors Inc., the California-based electric-car maker, leading to a 41 percent surge on its first day of trading June 29.
BMW's carbon fiber for the vehicle will be spun at a $100 million factory near Seattle, Washington, that the Munich-based manufacturer is building together with partner SGL Carbon SE. The fibers, composed of 50,000 filaments that are each one-seventh as thick as a human hair, will be made into fabrics and then hardened into components at facilities in Germany.
BMW wouldn't discuss prices for the city car. Tesla's Roadster sells for as much as 84,000 euros ($105,000) in Europe. Nissan priced is mass-market Leaf electric car at just under 30,000 euros after incentives.
BMW is turning to carbon fiber, which is 50 percent lighter than steel, to reduce the size and cost of the battery needed to run the car.
The mega-city vehicle, which will be available in 2013, will be powered by a 96-cell lithium-ion power pack, compared with the bank of 5,088 laptop batteries that run the company's Mini E test vehicle.
“Weight in electric vehicles takes on a totally different dimension, and this weight improvement you can only get through carbon-fiber parts,” Herbert Diess, BMW's purchasing and logistics chief, said in a May interview.
Daimler to use carbon fiber
Carbon fiber has been rarely used in automobile manufacturing because its complex production process limits large-scale benefits, said Mohamed Mubarak, an analyst at Frost & Sullivan in Chennai, India. As weight becomes a bigger factor, “carbon fiber will play a major role in electric vehicles, especially for premium carmakers,” which can more easily pass on the extra costs, he said.
Daimler AG plans to introduce carbon-fiber materials in Mercedes-Benz vehicles by 2013, after signing a development agreement with Japan's Toray Industries Inc. in April. Toyota Motor Corp. used a carbon-fiber body to reduce the weight of its 1/X concept car by 67 percent compared with the Prius hybrid.
The BMW model's passenger cell provides enough space for four adults and is created by gluing several carbon-fiber components together. The cell is then glued and screwed onto an aluminum frame that will house the battery and electric motors, according to crash prototypes displayed at a presentation in Garching, near Munich, last week.
“It'll be the first large-scale vehicle with a passenger cell out of carbon,” Draeger said. “BMW will bring a revolutionary vehicle to the streets.”
The safety advantages of carbon-fiber materials were on display at the Formula One race in Valencia, Spain, on June 27. Red Bull's Mark Webber crashed out after he caught the wheel of Heikki Kovalainen's Lotus at 190 miles (306 kilometers) per hour. Webber's survival may have been linked to the carbon fiber, according to BMW.
BMW's city car won't go that fast. Speeds will be limited to about 170kph (about 106 mph) to avoid excessive drain on the battery.
The seating in the vehicle will be higher than a standard car, because of the battery's position on the floor. The rear-wheel-drive car will also likely have a hatchback, a stubby front-end, and large wheels, according to sketches displayed by BMW's design chief Adrian von Hooydonk.
The car will probably be a drag on profitability for a company that aims to boost its profit margins on cars to 10 percent by 2012 from 8 percent, said Arndt Ellinghorst, an analyst with Credit Suisse in London.
“If you can make money from a car like this, it would be revolutionary,” said Ellinghorst. “You're trying to make a car from expensive materials for an urban market, which is typically price-sensitive.”
The energy equivalent of a 40-liter fuel tank would require a battery weighing more than 3 metric tons, BMW's Diess said. The automaker's top-of-the-line 7 series weighs about 2 metric tons.
With such weights, “you'd never be able to move the car and would need an even larger battery,” said Diess. “You get caught in vicious weight spiral that's dominated by the battery."