Here are the pictures that show Audi is on a real charge when it comes to electric sports cars.

This is the preview of the new R4 – a production version of the stunning electric e-tron concept car, revealed at last month’s Frankfurt Motor Show.

The R4 is also likely to spawn petrol-engined versions, giving the R8 a much anticipated smaller brother coupé that sits above the TT in the range.

Wowing crowds with its zero emissions electric powertrain, the e-tron was a big hit at Frankfurt. But only now has Audi of America’s president Johan de Nysschen confirmed the Tesla Roadster rival will reach showrooms.

The project is likely to be helped by Audi’s joint venture with fellow VW Group firm, Porsche, which will see the R4 share a new chassis with the next-generation Boxster and Cayman.

This new sports car range will feature an electric version at the very top of the line-up, with petrol versions underneath.

As you can see from our illustrations, it will look striking. It mixes the compact, squat proportions of the e-tron concept car with amazing design cues such as those LED C-shaped headlights, along with a trademark Audi grille and scalloped sides. Seen here in targa-topped roadster trim, it will also be available as a coupé and a drop-top.

The new flagship will be powered by a development of the e-tron’s electric powertrain. There’s a lithium-ion battery pack with four electric motors, two on each axle, giving it a fresh take on Audi’s quattro four-wheel-drive theme.

These give an output of around 300bhp, as well as an incredible 4,500Nm of torque, delivering instant acceleration with 0-60mph in 4.8 seconds. Top speed is likely to jump from the concept’s 124mph to a more supercar-like 140mph – all with no tailpipe emissions.

As in the concept, the 470kg lithium-ion battery is placed in the middle of the car, where the engine would be. Once fully charged, it promises to deliver a range of about 155 miles.

Drive is biased towards the rear – just like the R8 – and the chassis is a new aluminium spaceframe set-up with plastic body panels to keep weight down to around 1,500kg.

De Nysschen said he expects to see prototypes on the road within two years, so showroom-ready versions could arrive in 2012. That gives Audi time to refine the electric powertrain and decide whether it wants to lease batteries to customers – as Renault is planning – or include them in the price of the car.

Further down the range, the R4 will feature several engines from the current TT line-up, including a 335bhp 2.5-litre five-cylinder turbo. It’s likely to arrive within the next two years.