The MiniC.A.T Air Car is a remarkable car designed for urban use that costs about one-tenth as much to operate as a car that runs on gas. The MiniC.A.T Air Car, you see, runs on compressed air. The vehicle has a top speed of 68 miles per hour, and a range of 125 to 185 miles (depending on your driving habits and route).
This incredible vehicle has a tubular chassis that is glued together (not welded) and a fiberglass body. The car has only one electrical cable (compare this to the wire harnesses found in a standard automobile) because the vehicle uses wireless communication between its components. The engine weighs less than half that of a standard car - no combustion process to withstand. The air "tanks" (there are three) are made of carbon fiber.
The car is built to integrate with any external electronic system you could imagine (consider voice recognition, internet connectivity, telephone connectivity, a GPS guidance system, fleet management systems, emergency systems, and digital entertainment devices).
A hybrid model is also under development; the gasoline would be used to run a generator to supply compressed air. It is estimated that one tank of fuel would be enough for a cross-country trip. Prices are expected to start at $15,000.
What powers it? Ninety cubic meters of air is stored in fiber tanks at high pressure. The expansion of the air stored in the tanks pushes against pistons to create movement. The car's AC system makes use of the expelled cold air. Oil change (it uses one liter of vegetable oil every 31,000 miles). A "professional" fill-up at a modified gas station (few and far between, obviously, at present) takes about three minutes, and costs about $2. A fill-up with the (included!) small compressor can fill the tank in 3-4 hours when connected to 220V AC.
(Air Car youtube video)
This is a remarkable development; the MiniC.A.T Air Car is just now on the verge of commercial production by the Tata group, India's largest automotive manufacturer.