January 12, 2009 If one thing is immediately and staggeringly obvious at this year's Detroit NAIAS auto show, it's that electric, hybrid and extended-range electric cars have stepped out of the shadowy corners to which they were relegated in 2008, and they're now the main event for a lot of manufacturers. It seems the auto industry's well-documented woes in 2008, as well as consumer reaction to volatile petrol pricing, have galvanized even the most stalwart of old-school Detroit metal makers into action on gasoline alternatives. The extended-range electric seems to offer the most painless transition to primarily-electric motoring, and this is the way Cadillac have chosen to go with the Converj concept we saw unveiled earlier today. Capable of dealing with a typical 40-mile daily commute on full-electric, but with a petrol generator to make long trips possible, the 100mph Converj is a glamorous hint at what Cadillac intend to do with electric engines.

The Cadillac Converj concept is primarily a showcase for General Motors' Voltec electric powerplant, which uses a t-shaped 16-kWh lithium-ion battery pack, a powerful electric engine and a four cylinder petrol generator that can feed energy into the battery as charge decreases on longer trips.

The battery pack's 220 cells can be charged from a 240V wall socket within three hours, or closer to eight hours with a 120V setup. A single charge is good for around 40 miles, or a little more than the average American car travels in a day. When the battery gets low, the generator kicks in to deliver long distance motoring range without any concern that you'll end up stranded somewhere looking for a power outlet. Regenerative braking will also return a modest quantity of charge to the battery while stopping.

Power isn't mind-blowing at around 160 horsepower, and top speed only around 100mph - but the engine is capable of delivering a healthy 370 Nm of torque instantly from idle, so the Converj won't let you down when the lights turn green.

In the interests of extended economy, aerodynamics are a key consideration in the sleek body design. The underside of the vehicle is completely covered with a smooth bellypan, there's very few grilles or exterior openings to disturb airflow, and even the side mirrors have been left behind in favour of low-profile rearview cameras.

The 2x2-seater interior is trimmed in black leather and white suede, with polished aluminium and wood grain accents. The OLED instrument cluster can be reconfigured to the driver's choice of information display, and the audio and navigation systems are integrated into a single touch-screen console in the dash.

As nice as the Converj looks, it's the powertrain that matters, as this is the bit most likely to make it through to a production model sometime in the near future. 40 miles of full-electric commuting is a bit disappointing at this stage of the game, but it's good to see Cadillac getting on board and looking to inject some options into the market as the first wave of practical electrics hit the market sometime in the next couple of years.

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