Volkswagen is moving towards limited production of the radical Volkswagen XL1, with undisguised prototypes of the futuristically styled plug-in diesel-electric hybrid caught undergoing cold weather durability tests in Sweden.

Although no time frame has been officially announced for the introduction of the new car, Wolfsburg insiders hint it will be produced in numbers not exceeding 1000 units with pricing that is set to reflect its hi-tech construction and mechanical package. Right-hand drive is unlikely given the low volume.

Revealed in concept car form at the 2011 Qatar motor show, the teardrop shaped XL1 has been conceived to offer world beating fuel economy in a package suitable for both short hop city driving and longer highway jaunts.

Official figures put the 795kg two seat coupe’s combined consumption at 313mpg and CO2 emissions at 24g/km on the European test cycle – achieved primarily in pure electric mode alone, at which Volkswagen claims a 22 mile range.

These pictures, the first of the XL1 in prototype guise, reveal the upcoming production version will differ little from the earlier concept in the looks department. The only obvious changes are the adoption of conventional exterior mirrors and a lack of the concept’s car’s rear wheel spats used to smooth the flow of air around the rear of the flanks, although the latter can’t be ruled out for the production version.

The exterior, credited to Thomas Ingelath who now heads up design at Volvo, was conceived to offer the lowest possible drag co-efficient in combination with a staggered side-by-side two seat interior layout – as opposed to Volkswagen’s earlier L1 concept, which featured a wind cheating tandem two seat set-up.

At 0.186, the XL1’s Cd is significantly lower than any existing road car, thanks in part to its specially produced, ultra narrow profile tyres - 115/80 profile on 15 inch wheels up front and and 145/55 profile on the 16 inch wheels at the rear.

Power for the concept car comes from a compact rear-mid mounted 800cc two-cylinder common rail diesel engine producing 47bhp and electric motor delivering 26bhp – all of which is channeled through seven-speed DSG gearbox to the rear wheels. Official figures put the XL1’s 0-62mph time at 11.9sec and top speed at 99mph.

Whether this particular drivetrain will be retained for the production version of the XL1 remains unclear.