In our desperate quest to develop an alternative to dwindling fossil fuels, it has been suggested that cars could run on everything from solar-generated electricity to food waste. Most of these technologies are still far too costly for the average consumer, and usually don’t deliver the power we’ve come to expect from combustion engines.

So when Tata Motors, India’s largest automobile manufacturer, announced in 2008 that it had plans to produce a car that would run on nothing but compressed air, it was met with tempered enthusiasm. This skepticism seemed justified when Tata Motors’ Vice President of Engineering S. Ravishankar admitted that the project was facing difficulties just a year later.

At that time, Ravishankar declined to say whether the company was officially calling off the project, but commented that excessively low engine temperature caused by the compressed air was causing major problems. It seemed that dreams of pulling up to the pump and filling your car’s tank up with a few cents of compressed air had vanished in the wind.

MDI-minicat

But Tata Motors remained committed to its original plan, and just last week the company announced that it’s beginning phase two of development to bring this technology to market. Working with Motor Development International (MDI), which is pioneering the technology, Tata has successfully implemented compressed air engines into two of its vehicle models. MDI has previously unveiled several compressed air concepts of its own, including the four-seater AirPod (top) and the center-driven MiniCat (above).

As DiscoveryNews explains, a compressed air car engine works in a way similar to the internal combustion version: Fuel forces pistons to turn a crankshaft and power the car. The difference is that in a compressed air engine, the pistons are moved by air and not gasoline.

There’s no denying that these cars would be inexpensive, both to buy and fuel. Also, the fact that nothing but clean air would go in or come out means drastically reduced carbon emissions, an especially attractive idea for nations with rapidly growing populations like India. But the air-powered car is still far from commercial reality. Tata Motors says now that it’s tested the engines successfully, the next step is to set up the manufacturing plants where they can actually be built.

Photo Credits: MDI