VW's new 313mpg XL1 two-seater

Volkswagen has unveiled the latest in a line of ultra-efficient two-seaters at the Qatar motor show today.

The XL1 follows on from the L1 of 2009 and the one-litre car of 2002 which the former boss of VW Ferdinand Piech drove to his final board meeting.

It is constructed from lightweight materials, and an entirely new carbonfibre manufacturing process developed and patented by Volkswagen, the XL1 plug-in diesel hybrid returns an official average economy of 313mpg and has CO2 emissions of just 24g/km.

It has an electric-only range of up to 22 miles with its 26bhp electric motor, but can then go on to cover just over 340 miles in total with a 47bhp 800cc two-cylinder diesel engine matched to a seven-speed DSG gearbox.

Acceleration from 0-62mph takes 11.9sec, while top speed is limited to 99mph.

The XL1 uses every available material to keep its weight down including carbonfibre body structure, magnesium wheels, ceramic brake discs and aluminium suspension, steering system and brake calipers.

Although it's more than twice the weight of the L1, it still weighs less than a Smart or Toyota IQ.

VW says the XL1 is still very much a concept car at this stage but 'marks the next step towards the birth of a new class of Super Efficient Vehicles.'