Both BMW and Mercedes-Benz unveiled decidedly different concept cars in Frankfurt this week, as Michael Taylor reports.
Germany's green vision
The Germans are racing against the Chevrolet Volt to be the first to leapfrog Japan's dominant position in hybrid fuel-saving cars. While the American car has stolen the headlines, Mercedes-Benz and BMW will fight back at the Frankfurt International Motor Show with concept cars that not only usher in new fuel-saving technology, but signal sweeping changes in their design language as well.
BMW's Vision EfficientDynamics concept sports two electric motors, a production-ready small diesel and marks ground zero for the sweeping away of an entire generation of so-called "flame surfacing" from its controversial former design chief, Chris Bangle. The astonishing design used on the Vision ED clothes a new kind of environmentally friendly sports car still capable of outsprinting the M3. While people will hope it goes into production, BMW insists it is a showcase for its lightweight technology, hybrid-drive systems, interior ideas and even design concepts.
Mercedes-Benz, on the other hand, is using its BlueZero concept to showcase the final weapon in its three-pronged attack on fuel consumption. While it has already shown its fully electric and its fuel cell versions of the BlueZero, it has completed the concept line-up with a range-extending hybrid-electric powertrain, which will be launched before 2015, according to Daimler sources. Built around the patented sandwich-floor chassis of the existing B-Class, the BlueZero sees Mercedes mate a 1.0L, 67hp three-cylinder petrol engine directly to a generator, which then drives the car's electric motor. Known as a series hybrid, it is a step more advanced than the parallel hybrids offered by Lexus and Honda, which drive the wheels through either the electric or the petrol motors.
Oddly enough, both cars use three-cylinder engines, though while BMW debuts its all-new, 1.5L common-rail turbodiesel (which is headed for 1-Series and 3-Series duties), Mercedes new concept uses the existing smart engine. Dubbed the E-cell Plus, the Mercedes-Benz BlueVision hybrid might only have a nominal 94hp of power, but there's an astonishing, diesel-esque 320Nm of torque and, as it is coming from an electric motor, the maximum torque is available instantly, at any time.
Benz sits the petrol engine inside the sandwich floor at the back of the car, the 18kW/hour lithium-ion battery pack sits inside the middle of the floor and the electric motor sits in the engine bay, driving the front wheels. As yet, there are no official fuel consumption numbers, because the petrol engine only ever charges the battery pack and never directly drives the wheels, but Benz suggests it will emit around 32 grams of CO2 per kilometre.
Even so, it will still cover the 0-to-100kph sprint in less than 11 seconds and will hit 150kph as a top speed. On the flip side of the performance coin, Benz claims the five-door hatchback will stretch to 100km on a single battery charge, while the advanced battery pack can be fully recharged in under half an hour. Coupled with its petrol engine, the BlueZero E-cell Plus has a range of almost 600km.
The cementing of the car's future means Benz will also retain the expensive sandwich floor architecture, while the next generation A- and B-Class cars can move to cheaper, single-floor designs when they go on sale in 2011. While the Benz concept will, in one form or another, eventually go into production, the Vision EfficientDynamics is headed for the global show circuit, then straight into BMW's recently renovated museum in Munich.
Its design sets the theme for a series of upcoming BMW road cars and proves BMW is discarding the worst excesses of the Bangle design era in favour of a lighter and more aggressive look. Unlike the Benz, the BMW uses a diesel-electric hybrid system and the layout is more conventional, with the engine up front, driving the rear wheels through the M3's Getrag double-clutch, six-speed gearbox. The engine, with 163 horsepower and 290Nm of torque, is all aluminium and produces more power than the 116d's existing 2.0L turbodiesel.
The engine gets crushing acceleration by using two electric motors ahead of the gearbox. One of these drives the front wheels under acceleration and the other helps the diesel engine out by adding its torque to the rear axles. While the motor for the rear wheels produces just 34hp, it has 290Nm of torque (or, as much again as the diesel engine in its strongest part of the rev range), though it can be over boosted to 50hp.
The front motor is a different type, producing more power (80hp), but less torque (220Nm), even though it can flit to over 134hp in hard acceleration. BMW claims, then, that the car produces 356hp and 800Nm of torque and, given that it weighs only 1,395kg, it will be something of a rocket in a straight line. BMW is claiming 0-100kph times of just 4.8 seconds and it has been limited to 250kph - both numbers that bring to mind the M3. Almost the exact opposite of the M3, though, is the resources it consumes to get its performance.
BMW insists its concept will achieve 3.13L/100km with a CO2 number below 100 g/km. The company states people should be prepared for consumption and emissions numbers like these to become more common from its brand as hybrid-drive systems infiltrate its range of vehicles. The battery pack to power the electric motors sits inside the chassis tunnel and weighs 85kg and, like the Benz concept, it is a lithium-ion unit. Inside, the battery has 98 lithium polymer cells which generate 364 volts and can store 10.8kW/h of electricity. It can be charged from the engine and from regenerative braking or plugged in to a normal 220-volt/16-amp system in two-and-a-half hours.
The car is capable of running as either a pure diesel or a pure electric car, where it gets a range of 50km before the diesel offers another 643km of driving on its 25L tank. As the first car of the Adrian von Hooydonk's tenure as BMW's design chief, it also offers strong hints about where BMW wants to take its critical, new-generation 3- and 5- Series. Von Hooydonk has taken over as the BMW Group's design boss and has used the Vision Efficient- Dynamics to experiment with acres of glass, an all-new interior concept. firstname.lastname@example.org