Mercedes-Benz BlueZERO Concept
Mercedes-Benz must be developing a split personality. Next to the million-dollar SLR Stirling Moss roadster, the German automaker is also showing off a trio of small electric vehicles this week at the 2009 North American International Auto Show in Detroit.
They're called BlueZERO and could be the cornerstone in a monumental culture shift for the luxury carmaker, which until recently has largely resisted the trend toward greater fuel efficiency in favor of continued emphasis on power and performance. But now it looks ready to embrace zero-emission electric cars, too.
Mercedes’ three BlueZERO variants showcase three different propulsion systems. The BlueZERO E-Cell is a plug-in electric vehicle that can drive around 125 miles on a single charge.
The BlueZERO E-Cell Plus adds a small 3-cylinder gasoline engine like the one in the smart fortwo, which acts like an onboard generator to recharge the batteries that power the electric motor. The E-Cell Plus has a range of more than 370 miles, about 60 miles of which can be driven emissions-free on battery power alone. After that, the gas engine kicks in to recharge the batteries, though it doesn’t drive the wheels directly.
The E-Cell and E-Cell Plus can charge up from a regular household power socket and store enough energy after a couple of hours to drive about 60 miles. Both models also incorporate an electronic control unit that supports intelligent charging stations and billing systems.
The third BlueZERO variant, called the BlueZERO F-Cell, has a fuel cell that converts compressed hydrogen into electricity. It can drive 350 emissions-free miles on one tank of gaseous hydrogen.
All three BlueZERO variants are front-wheel drive and share modular components, including liquid-cooled lithium-ion batteries with a storage capacity of up to 35 kilowatt-hours in the E-Cell and 17.5 kilowatt-hours in the E-Cell Plus. Their electric motor puts out 236 lb-ft of torque, which is more power than a Honda Civic generates.
Mercedes says all three BlueZERO variants will accelerate from zero to 62 mph in less than 11 seconds, which isn’t fast but should at least allow the cars to keep up with traffic. To conserve energy and extend driving range, top speed is limited to 93 mph.
Mercedes attributes many benefits to the BlueZERO’s “sandwich-floor” architecture, introduced about a decade ago on its smallest model, the A-Class, and later adopted on the next-smallest B-Class. (Neither is currently sold in the U.S.) The so-called sandwich construction saves space by housing bulky components such as the battery pack under the passenger-compartment floor so that they don’t impinge on passenger or trunk space.
Another benefit is that the powertrain components housed within the sandwich floor are well-protected, which makes the car safer. Passengers also sit higher off the pavement, further improving crash protection and visibility.
Lastly, the sandwich construction allows for better driving dynamics because it creates a low center of gravity and concentrates the car’s mass between the axles, Mercedes said.
The company will begin limited production of fuel-cell vehicles in 2009 and battery-powered electric vehicles in 2010. Both will undergo testing to help further develop the technology… No sale date has been set for full-scale production versions.