Citroen's hybrid concept car gets 115 mpg from thin air (hands-on)

12 Oct 2014 • engadget.com

You know I just had an idea. What if we built a hybrid car that was powered by air? Neat, idea, eh?

With the Cactus Airflow 2L, Citroen thinks it’s found a way to bring the cost of hybrid technology down to earth using nothing but air. Based on a production Cactus model, the natty, low-roofed concept car has a unique hybrid compressed air/gas engine at its core. In a regular hybrid, batteries store energy from braking and coasting downhill. It’s the same idea here, but instead of storing electricity, the Airflow 2L compresses air and stocks it in a tank. It can then be released when needed, powering the car during wasteful acceleration or city driving.

Oh wait, that’s really a thing now?