Fuel Efficiency StridesGeneral Motors engineer John Bednarchik points a smoke wand to the nose of a 2013 Chevy Malibu to test air flow. Reducing aerodynamic drag is just one way automakers around the world are ramping up fuel economy.Gasoline consumption in the developed world is seen as leveling off due to mileage standards in the United States that will force automakers to double the average efficiency of their fleets to 54.5 miles per gallon (23 kilometers per liter) by 2025, and in the European Union, to achieve 57.4 mpg (24.4 km/l) by 2020. (See "Pictures: A Rare Look Inside Carmakers' Drive for 55 MPG.")Today's drive for efficiency is just the latest chapter in a two-century-old story that began with Richard Trevithick's 1803 London Steam Carriage. (See "Cars that Fired our Love-Hate Relationhsip with Fuel.")The next phase, designing tomorrow's cars, has inspired seasoned experts and a new generation alike. Auto engineering guru Gordon Murray, who designed championship race cars for a living, is now hoping to use weight-shaving techniques from the track in more fuel-efficient consumer autos. (See "Formula One Legend Murray Sets Course for Energy-Efficient Car Design.")Meanwhile young students around the world are designing their own super-efficient vehicles and putting them to the test in competitions like the Shell Eco-marathon. (See "Pictures: Students Design Super-Efficient Cars in Eco-Marathon.")—Brian Handwerk

Photograph by Jeffrey Sauger, National Geographic