At the beginning of the twenty-first century, the head of Volkswagen, Ferdinand Piëch, gave his engineers the mandate to design a fuel-economy car that would use no more than 1 litre of gas per 100 kilometres. Several unsuccessful prototypes were subsequently produced by Volkswagen, including the models “1-Litre” and “L1”, unveiled in 2002 and 2009, respectively. While these concept cars met Volkswagen’s objective of low gas mileage, they included very few accessories and their safety was rather questionable. Far from abandoning the idea, however, Volkswagen worked hard to overcome several technical challenges in designing the XL1, the new pride and joy of Mr. Piëch. The secret of the XL1 does not lie solely in its power train to be able to claim gas mileage as low as 0.9 L/100 km. This vehicle had to be designed to be both streamlined and very light. The drag coefficient of the carbon fibre body is therefore relatively low (0.189), and the vehicle’s curb weight is only 795 kg. To reach their goal, designers flattened the vehicle to a height of barely 1.15 metres, with scissoring doors to facilitate entry. The XL1 is powered by an 800cc two-cylinder diesel TDI engine that turns out 48 horsepower, along with a 27-horsepower electric motor that can run on its own, lithium-ion batteries, and a seven-speed dualclutch gearbox. Top speed is around 160 km/h, with acceleration from 0 to 100 km/h in 12.7 seconds. For the time being, the XL1 production will be limited to around 100 cars, and the asking price at its European release will likely hover around $50,000. We’ll all have to hope that hi-tech fuel economy becomes more affordable in the future!