So we finally know what the production version of Chevrolet’s Volt will look like – not much like the concept, in short. Gone are the aggressive proportions, huge-but-narrow wheels, and the transparent Lexan tops to the door skins – Chevy’s designers having used the somewhat cheaper trick of black paint to suggest the double-beltline effect of the concept.

Last year, when the concept was unveiled at the Detroit Motor Show, GM designers enthused that the Volt’s extreme wheel-at-each-corner stance was possible because the engine didn’t need to be connected to the wheels. It’s a shame, then, that their final effort has such conventional proportions.

Thankfully the range-extended electric vehicle concept of the underlying E-Flex platform remains unscathed, which is of more consequence in the end. Unlike, say, a Toyota Prius hybrid, the Volt uses electricity alone to move the wheels at all times and speeds. That electricity comes either straight out of a battery, or from the petrol-powered on-board generator.

For trips up to 40 miles (at unspecified speeds – energy consumption tends to go up with the square of speed) – the Volt is powered by its 16kWh, lithium-ion battery pack. When the charge runs out, the engine coughs into life to get the electrons going again. GM says this eliminates "range anxiety," which will be familiar to any EV driver – and of course anyone who has ever wondered if they’ll make it to the next filling station.

A full recharge will take eight hours from a standard US household 120V outlet, according to GM, while a 240V socket will cut the time to under three hours, apparently.

The Volt’s 220 lithium-ion cells are arranged in a T-formation, down the car’s centre spine and behind the rear seats. The drive motor offers 150bhp and 273 lb-ft maximum torque. Electric motors run out of puff at high revs, explaining the low-ish top speed of 100mph.

All of which is still academic as the first customers won’t get behind the wheel until late 2010, with the first European Volt sales due a year later.

An E-Flex-based Vauxhall/Opel Astra is due around the same time, which will probably be a diesel-electric and will probably be quite a bit nicer to sit in than the US-aimed Volt.

At least European buyers won’t be underwhelmed when that car arrives, as many have been by the Volt’s transition from motor show to showroom. The European E-Flex concept car, the Opel Flextreme, had realistic proportions and silly details. Just about the opposite of the Volt concept, in other words.