Volkswagen reveals the XL1, a 261-mpg Beetle for the 22nd century

Eleven years ago, the head of Volkswagen popped out of a capsule-shaped vehicle barely able to hold two people and announced his ambition to construct the most efficient car the world has ever seen. Today, VW revealed the production version of that car known as the XL1, which it vows will travel 261 mpg on a gallon of diesel fuel. It's an amazing engineering feat, a Beetle reborn for the 22nd century — but the world may not be ready for it.

Saving energy in an automobile usually requires running a smaller engine, cutting weight and reducing aerodynamic drag to a minimum, and in the XL1, VW pushes all three steps to their modern limits. Power comes from a two-cylinder, 0.8-liter diesel — essentially half of VW's standard 1.6-liter four-cylinder diesel plant — mounted in the rear of the XL1, linked to a 7-speed transmission, a 5.5 kWh lithium-ion battery and electric motor. The two-seat body of the XL1 has a 0.189 coefficient of drag (a Toyota Prius has a 0.25 Cd) and it weighs just 1,752 lbs., about half of a typical American midsize sedan.