The 1-liter is back!

Along with the fast comes the frugal.

As well as showcasing the production-ready Golf R on the stands at Frankfurt, Volkswagen is stunning fans with its ambitious L1 concept.

The newcomer is a development of VW’s original ‘1-liter’ car – the brainchild of VW boss Ferdinand Piech – which made its debut in 2002.

The L1 uses only 1.49 litres of fuel for every 100km it travels, which is equivalent to 189mpg economy.

This closer-to-production version keeps the tandem-style two-seat interior, but gets even more refined aerodynamics to improve stability and efficiency.

Updates have been made to the design elsewhere to give the car a contemporary look. Highlights include a more aggressively shaped nose and chiselled flanks.

However, the unconventional ‘doors’ remain, so the cabin is still accessed by popping open the roof, fighter jet-style.

Power is from an 800cc, two-cylinder diesel-electric engine, linked to a DSG gearbox.

This delivers only 28bhp, but as the carbon-bodied L1 weighs 380kg, it should give a top speed of 99mph.

Speculation suggests the car could be on sale by 2012.