Volkswagen has unveiled a hybrid version of its Up! city car.

Dubbed the Twin Up! it uses a 0.8-litre two-cylinder turbo-diesel engine coupled with a 27kW electric motor, driving the front wheels through a seven-speed DSG gearbox.

VW say this drive-train offers fuel consumption up to an incredible 256.8mpg.

Power for the electric motor comes from an 8.6kWh lithium-ion battery pack located between the rear seats and the boot, together with a 33-litre fuel tank.

A clutch between the diesel and electric motors allows each to operate independently.  This allows the Twin Up to drive on electricity alone for around 31 miles, during which it can reach speeds of up to 77mph and accelerate from 0-37mph in 8.8 seconds.

With both diesel and electric motors working together, 0-62mph arrives in a sedate if planet-friendly 15.7 seconds, with a top speed of 87mph.

During braking, the electric motor acts as a generator, recharging the lithium-ion battery.  The diesel engine can also be used to recharge the battery when needed.

The VW Twin Up is styled similarly to the electric e-Up, with Sparkling White paintwork and double blue stripes.

The instruments are all-digital, with the theme changing from white to blue when switching from hybrid to electric-only mode.

There’s no word on whether the VW Twin Up will make it to production.