The Car That Runs On Air

For more than a century, air cars have remained as a very large controversy for engineers and an idealistic exercise with little likelihood of entering mass production. As fuels goes, air has a many upsides to it: It’s found every where, clean, and, best of all, it's free. But air requires energy to store energy because it must be compressed, limiting the use of an all-air car. Two engineers from French automaker PSA Peugeot Citroen thought they could overcome that problem by pairing a gasoline engine and hydraulics. To test the concept, they formed the Hybrid Air Program in 2010 and connected the engine of a subcompact car to a commercial airplane’s hydraulic system. During normal driving, the system will switch between gas and air power, says Yarce. Much like with hybrid-electric vehicles, the gasoline engine provides a boost up steep hills and on the highway, and it re-pressurizes the nitrogen tank if the regenerative-braking system hasn't done so. The prototype was so successful that PSA has decided to manufacture and sell the production vehicles.The Hybrid Air power-train will appear in all subcompacts as an option in Europe and possibly other international markets in 2016.