Fisker Karma

Here’s a supercar that will ease your conscience. Called the Karma, the eco-friendly machine was unveiled at the Detroit Motor Show by US maker Fisker Automotive.

The Aston Martin Rapide rival is on sale late next year, and uses a rear-wheel-drive, plug-in hybrid system. It’s capable of travelling 50 miles on its battery packs alone.

On longer trips, a small-capacity petrol engine fires up, producing power for the electric motors. This extends the range to 620 miles. Fisker claims the Karma can return around 100mpg, yet sprint from 0-60mph in less than six seconds and hit a 125mph top speed.

The highly sophisticated powertrain, called Q-Drive, has been developed by Quantum Technologies – the firm responsible for GM’s groundbreaking Chevrolet Volt.

To give the best possible balance and handling, the battery is located low and in the middle of the car. The swooping bodywork has been designed by Henrik Fisker, who penned the stunning Aston Martin DB9. However, it’s also a little reminiscent of the Maserati GranTurismo, with a massive slatted grille, angular headlamps and a long, sleek bonnet.

Even though the four-door coupé is no taller than a Porsche 911, it can carry four adults in comfort. Under the skin is an all-new lightweight platform honed by ex-BMW engineering guru Thomas Fritz.

The Karma will cost from around ,000 (£40,000).