Now available in Europe in the sporty Golf GT, Volkswagen's Twincharger system consists of a highly economical 1.4-liter direct-injection four-cylinder engine equipped with both a supercharger and a turbocharger. The supercharger, belt-driven off the crankshaft, compensates for the engine's small displacement by forcing air into the cylinders at low revs to bolster torque. As the tachometer climbs, an exhaust-gas-driven turbocharger further boosts the horsepower. The GT hits 62 mph in 7.9 seconds and goes on to 136 mph, while returning an impressive average of 39 mpg.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.