Mercedes-Benz is presenting its Concept BlueZERO at the North American International Auto Show in Detroit. It’s just one car, but it comes with three drive options – electric, fuel cell, and electric with a petrol range extender engine.
• The BlueZERO E-CELL has a battery-electric drive and a range of up to 120 miles using electric drive alone
• The BlueZERO F-CELL (fuel cell) has a range of well over 248 miles using electric drive
• The BlueZERO E-CELL PLUS has electric drive and additional internal combustion engine as power generator (range extender). This version has an overall range of up to 370 miles and can cover a distance of up to 60 miles using electric drive alone.
The three BlueZERO variants are based on the unique sandwich-floor architecture which Mercedes-Benz introduced some 10 years ago, initially for the A-Class and then for the B-Class, one of the aims being to integrate alternative drive systems. Advantages of the modified construction include the positive effect of the major drive components on the centre of gravity, their space-saving design and the fact that they are extremely well protected within the vehicle underbody. The five-seater BlueZERO concept cars also set standards in terms of lightweight design, interior layout and body form.
“The flexible BlueZERO concept allows electromobility for every requirement and highlights the fact that Mercedes-Benz is the world’s only car manufacturer to already have in place all the key technologies for electric cars offering full everyday practicality,” says Dr Dieter Zetsche, Chairman of the Board of Management of Daimler AG and Head of Mercedes-Benz Cars.
Compared to electric cars based on conventional vehicle platforms and originally only designed for use in combination with internal combustion engines, Mercedes claims that Concept BlueZERO offers the following conclusive advantages:
• Interior space is retained in full. As the energy accumulators/generators are integrated into the spacious sandwich floor, no compromises are necessary when it comes to passenger space, luggage capacity or variability.
* The powertrain technology built into the sandwich floor ensures a low centre of gravity and, consequently, extremely reliable and agile handling.
* Crash safety is of the extremely high standard associated with Mercedes thanks to the sandwich concept and the housing of major powertrain components between the axles.
As a result, the BlueZERO models are very different to conventionally constructed electric cars, which have the heavy and voluminous storage battery housed in the boot or in the rear-seat area, for example.
“Our modular system allows different drive configurations for every customer requirement,” says Dr Thomas Weber, the member of the Daimler AG Board of Management responsible for corporate research and development at Mercedes-Benz Cars. “The modified sandwich-floor platform provides the perfect basis for a wide model range with electric drive systems. We are also developing a new, additional platform for future compact models with power units based on optimised internal combustion engines. The intelligent networking of both architectures enables us to develop our product portfolio extremely flexibly and efficiently. From 2009, we will be producing the first Mercedes fuel-cell cars on a small scale. Small-scale production of Mercedes-Benz cars with battery-electric drive alone will then commence in 2010. This means we are extremely well equipped for the future.”
All three BlueZERO models feature front-wheel drive, which is typical for this class of car. The Mercedes engineers have put together a modular system comprising several flexibly combinable drive components. These include state-of-the-art liquid-cooled lithium-ion batteries with a storage capacity of up to 35 kWh and the compact electric motor with a maximum output of 100 kW (continuous output 70 kW), which develops a peak torque of 320 Nm. All three variants accelerate from 0 to 62 mph in less than 11 seconds. Their top speed is electronically limited to 93 mph in the interests of optimal range and energy efficiency.
With a charging capacity of 15 kW, the powerful lithium-ion batteries in the BlueZERO E-CELL and the BlueZERO E-CELL PLUS can store enough energy for a range of 30 miles within 30 minutes. In terms of purely electrical drive, one or two hours of charging time is needed for a range of 120 and 240 miles respectively. The charging times are doubled if the charging capacity is 7 kW, as would be the case in a normal household. Both of these BlueZERO vehicles incorporate an electronic control unit that supports intelligent charging stations and billing systems.
At the rear, the BlueZERO E-CELL PLUS has the same 1.0-litre turbocharged petrol engine as the smart fortwo as an additional range extender. This compact three-cylinder powerplant has an output of 50 kW at a constant 3500 rpm. If required, it can recharge the 17.5-kWh lithium-ion battery by means of a similarly rated alternator. A range of up to 370 miles is possible on a single tank. The purely electrical, locally emission-free range is up to 120 miles. The BlueZERO F-CELL with fuel-cell drive achieves a range of well over 248 miles with zero emissions (as per NEDC).