Audi is making some big claims for this, the e-tron Spyder. Its a two-seat open-top sports car with a 296bhp V6 twin-turbo TDI diesel engine that can sprint from 0-62mph in 4.4 seconds, but still average 128.4mpg and emit just 59g/km of CO2.
How does it do it?
The secret behind those impressive figures is that the car is a plug-in hybrid, with two electric motors that can boost the power of the diesel engine, as well as giving it a range of 31 miles under purely electric power with zero emissions.
This latest concept is a development of the first, all-electric e-tron concept that was shown at the Detroit Show in January. This new model is a little larger than the previous one at just over 4.0 metres long, 1.8 metres wide and 1.1 metres high but it retains what Audi calls the classic proportions of an open, high-performance sports car.
The styling of the car consciously borrows from the companys flagship R8 performance car, as well as from racing cars; and, Audi says, it gives hints as to the look of its future sports cars.
Inside, the car has a minimalist look, again with some elements inspired by motorsport. In addition, many of the controls including the touch-sensitive control panel on the steering wheel are inspired by the latest smartphones.
The 3.0-litre TDI engine in the concept is a development of the unit that recently debuted in the new A8. This drives the rear wheels though a seven-speed dual-clutch transmission, while the electric motors drive the front wheels. Normally, the drive is biased to the rear, but a central control unit works with the ESP system to vary the distribution of the power both from front to back and from side to side to give all the benefits of Audis renowned four-wheel-drive system.
Audi says the car which has perfect 50:50 weight distribution has go-kart-like handling: sharp in the bends, but neutral all the way to the limit.