BMW i3: first photos and details

* i3 concept car at Frankfurt show * 100-mile range, six-hour battery recharge * On sale in 2013...

BMW i3: first photos and details

BMW will unveil its electric i3 concept car at the Frankfurt motor show in September, although it won't go on sale until 2013.

The supermini-sized i3 is powered by a 125kW electric motor mated to a single-speed gearbox. It has a range of between 80 and 100 miles, does 0-62mph in 7.9 seconds and can reach a full charge in six hours (it takes 1 hour to reach 80% charge). Top speed is 93mph.

BMW says an i3 range-extender version will also be available, where a 1.0-litre two-cylinder petrol engine can be used to recharge the car's batteries, thereby doubling the car's range.

The four-seat i3 is designed for city driving. It's a little wider and taller than a Volkswagen Polo, for instance, but the Polo is longer and lighter. A tight turning circle enhances the i3's city credentials.

It has rear-hinged doors and no central pillar, so access to the front and rear seats is easy, says BMW. There's no central transmission tunnel, so BMW is promising a spacious cabin. Boot space is just a little bigger than a Fiat 500's at 200 litres.

The i3 is crammed with interesting technology, including a sophisticated brake-energy recuperation system and Traffic Jam Assistant. This maintains the car at a specified distance from the vehicle in front and, in heavy traffic, can bring the car to a standstill.

Unlike other similar systems, BMW's Traffic Jam assistant can actively provide steering input. Camera and radar technology allow the i3 to follow the road, based on the road markings, helping the driver to stay on course up to speeds of 25mph. The driver must have at least one hand on the steering wheel, however.

Owners can also activate the car's doors, headlights and horn from their smartphone, as well as check the status of the car's batteries and the available range.

Prices for the i3 have yet to be revealed however BMW board member Ian Robertson said i models will be sold, leased and pushed through 'new channels'.