With the dust settling on press days at the Frankfurt Auto Show, we can take a breath, think about what we saw, and start to sort out our impressions.

One very clear message: German carmakers are taking electric cars seriously. Finally.

Both Audi and BMW unveiled electric-car concepts that are thinly disguised versions of models that will go into production in 2013 and 2014. Mercedes-Benz showed a range-extended electric version of its new B-Class compact hatchback, and Volkswagen again showed its Golf Blue eMotion prototype electric car.

Together, these are four plug-in electric cars from the four makers that are the bulk of German car sales in the U.S.

All are subcompact or compact five-door hatchbacks. Two are dedicated minicar or subcompact designs that share no body panels with any other model in the carmaker's range; the other two are adapted versions of gasoline compact cars.

2011 Audi A2 Concept

2011 Audi A2 Concept

How do they compare?

STYLING

  • Audi A2 Concept: With the exception of the beltline light band that encircles it, the A2 Concept isn't that adventurous, although it does pay tribute to the original, highly fuel-efficient A2. If you ignore the blanked-out grille, you might never know it was electrically powered--or even particularly special.
  • BMW i3 Concept: The division between the aluminum lower portion (which holds the powertrain and seats) and the carbon fiber-reinforced plastic upper body sets the little i3 apart from the rest. The glass roof and doors (which won't make it into production) add flash, but the absence of a B-pillar and the rear-opening "carriage doors" at the rear to ease access make the i3 the most distinctive of the group.
  • Mercedes-Benz B-Class E-Cell Plus: The new B-Class is less upright and stodgy than its predecessor (not sold in the States), and it will be the smallest Benz ever sold in the U.S. Styling changes for the E-Cell electric model are unknown.
  • Volkswagen Golf Blue eMotion: The production version of the all-electric Golf will be built on the next (seventh-generation) Golf, which will be launched in 2013 or so. Today's prototypes use the previous, current generation. We don't know what the next Golf will look like--but expect the electric version not to vary much from the rest of the lineup.

The Mercedes-Benz B-Class E-Cell Plus concept. Image: Mercedes-Benz

The Mercedes-Benz B-Class E-Cell Plus concept. Image: Mercedes-Benz

POWERTRAIN

  • Audi A2 Concept: 31-kWh lithium-ion battery pack; 85-kilowatt (114-hp) electric motor driving the front wheels; optional range-extending gasoline engine of unspecified design and output.
  • BMW i3 Concept: 21- or 22-kWh lithium-ion battery pack; 125-kilowatt (170-hp) electric motor driving the rear wheels; optional rear-mounted 600cc twin-cylinder range-extending gasoline engine.
  • Mercedes-Benz B-Class E-Cell Plus: Lithium-ion battery pack of unspecified capacity; 100-kilowatt (134 hp) electric motor driving the front wheels; front-mounted 1.0-liter turbocharged three-cylinder range-extending gasoline engine.
  • Volkswagen Golf Blue eMotion: 26.5-kWh lithium-ion battery pack; 85-kilowatt (114-hp) electric motor driving the front wheels; no range extender.

2011 Audi A2 Concept

2011 Audi A2 Concept

INTERIOR

  • Audi A2 Concept: Sparse, clean, white, and very modern, bristling with electronics, somewhere between stark and spaceship-like.
  • BMW i3 Concept: Spacious, with the customary thin seats and a pod-like instrument panel--and, of course, a large display screen.
  • Mercedes-Benz B-Class E-Cell Plus: Presumably adapted from the production B-Class interior
  • Volkswagen Golf Blue eMotion: Presumably adapted from the interior of the upcoming seventh-generation Golf.

The Mercedes-Benz B-Class E-Cell Plus concept. Image: Mercedes-Benz

The Mercedes-Benz B-Class E-Cell Plus concept. Image: Mercedes-Benz

INNOVATION

  • Audi A2 Concept: Like the i3, Audi plans to offer an autonomous driving mode, though the company calls it "piloted driving" mode, to underscore that the human driver is ultimately responsible for whatever happens to and with the car.
  • BMW i3 Concept: Will offer not only the usual range of mobile-phone control apps and eco-routing navigation options, but also a Traffic Jam Assistant function that will drive the car autonomously in low-speed, stop-and-go traffic--as long as the driver's hands stay on the steering wheel.
  • Mercedes-Benz B-Class E-Cell Plus: The full range of Mercedes-Benz electronics, including adaptive cruise control, blind-spot detection, lane-keeping assist, active parking assist and the Pre-Safe collision intervention system. No word on any unique electric-car features as yet.
  • Volkswagen Golf Blue eMotion: Unspecified

Volkswagen Golf Blue e-Motion

Volkswagen Golf Blue e-Motion

VERDICT

For sheer audaciousness, we have to give the laurels to BMW. For a company that had zero experience with electric cars six years ago, the i3 is a remarkable concept with many technological advances.

The Audi A2 comes a close second, losing points only because its exterior design seems far from distinctive. It might move up if its range extender proves to be the tiny Wankel rotary shown in the A1 e-tron concept, however.

The Mercedes-Benz B-Class E-Cell Plus and VW Golf Blue eMotion, as adaptations of existing cars, represent a more conservative approach to electric-car design, not to mention a less costly one for the company to develop.

Plans for U.S. sales of any of these cars are nebulous at best, though we expect one or two (most likely: BMW i3) to arrive on our shores. Mercedes-Benz has already said it does not plan to offer the B-Class E-Cell Plus in the States.

But which of these four cars do you find most (or least) appealing? Which would you choose if you could have only one?

Leave us your thoughts in the Comments below.

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