Low carbon supercars let you drive faster... with a clean conscience

Charging down the motorway at full speed while retaining a clear conscience might seem like mutually exclusive activities.

Or are they?

Thanks to a number of new low carbon German sports cars, this contradiction does not necessarily apply. For the time being at least the privilege will be reserved for an affluent few since these high-tech vehicles do not come cheaply.

To show how the technology works in practice we need to fast-forward to the pitlane on the Nordschleife at Nuremberg's famous race track.

Only a few minutes ago the furious howl of a 12-cylinder Paganini Zonda was ringing out across this course but the next sportster to be put through its paces is virtually silent.

This green car is a representative of a new automotive era, a car which produces no potentially harmful emissions and yet can sprint in 4.6 seconds from a standstill to 100 kilometres an hour.

The coupe now storming around the circuit at up to 200 km/h is the Audi R8 e-Tron. If it goes into production well-heeled customers will be able to drive this car at full speed without pangs of conscience since the Audi does not tank fossil fuel. It runs entirely on electric power.

In 2013 Mercedes-Benz's in-house tuner AMG will unveil the SLS Electric Drive.

This high-performance machine is propelled by four electric hub motors, providing a massive 751 horsepower and stump-pulling torque to match. Although the batteries weigh more than half a tonne the SLS touches 100 km/h after just 3.9 seconds. Top speed is governed to 250 km/h.

Fast and furious motoring quickly drains the batteries of these green supercars. When driven more gingerly, the Audi can manage 215 kilometres before the power pack needs replenishing.

Mercedes quotes 250 km between charges for the SLS. Porsche tackles the range problem by using plug-in technology for its 918 Spyder. The petrol-electric is still in the development stage and should enter showrooms in 12 months.

With its twin electric motors generating a total of 245 hp, the Porsche can only manage 30 kilometres in purely electric mode and top speed is limited to 150 km/h. Mated to the e-motor however is a 4.6 litre V8 petrol engine which puts out 580 hp.

According to project head Michael Hoelscher, the car, which uses a good deal of lightweight carbon fibre, can reach a top speed of 325 km/h yet uses no more fuel than a compact for the first 100 kilometres of a journey - this equates to a CO2 output of 70 g/km.

Jaguar has surprisingly bucked the trend by announcing this month that work on its hybrid supersports car, the C-X75, is being halted. The company told Britain's Autocar magazine that the move was prompted by the economic crisis. Five working prototypes will be developed up until mid-2013.

The coupe was first shown at the 2010 Paris car show. Jaguar said investment was not wasted since the technology would find its way into other cars. The C-X75 features two electric hub motors and batteries mated to a turbocharged four-cylinder engine. An all-electric range of 60 km was cited.

Plug-in technology has been chosen by BMW for its i8 which is set to roll into showrooms in late 2013. The car features an electric motor driving the front wheels with a three-cylinder petrol engine acting on the back wheels.

Together the two power plants turn out 224 hp and hurl the 2+2-coupe to 100 km/h in less than five seconds. With 35 km of pure electric drive available, fuel consumption for the first 100 km is down to 2.7 litres with CO2 output at 64 g/km.

Green supercars do not however come cheaply. The Mercedes SLS Electric Drive will carry a price tag of at least 416 500 euros (550 674 dollars) and Jaguar estimated that the C-X75 might even cost 800 000 euros.

Porsche plans to launch the Porsche 918 Spyder with a base price of 760 026 euros which would make it the most expensive German production car of all time.

Despite the price hurdle, interest in these green supercars is apparently considerable. Porsche says it has had 300 expressions of interest for the 918 Spyder.

Regardless of the ecological and economical aspects, Christian Guhl from Dornier Consulting in Berlin believes green supercars could pave the way for general electromobility acceptance. The cars act as testbeds for more affordable, user-friendly e-cars and help establish the electric car as a desirable consumer item.

Gerd Lottsiepen of the ecologically-minded German Transport Club VCD is of a different opinion. He regards the green supercars as "big boys toys" and believes they have about as much to do with sustainable mobility as "teflon frying pans and space travel." Electric cars should be energy-efficient too, said Lottsiepen.