MiniCat driven on air

But while there’s no sign of them on the Champs-Elysee just yet, it looks like they might soon be on the streets of Delhi.

While it might sound like a lot of … erm, hot air … Indian manufacturer Tata Motors is getting set to release an air-powered car.

The auto giant plans to have about 6000 of the MiniCAT – short for Mini Compressed Air Technology, as they’ve sexily christened it – on the streets over there by the middle of next year, with a retail price of around $8000.

This should make it an attractive option for small commercial enterprises, and go some way to avoiding the kind of pollution problems that are growing in India and other emerging economies.

The MiniCAT is said to have a range of 300km, and can be refuelled for just a couple of dollars because the fuel is needed only to run the compressor that fills the air tank in about four hours.

The car has a superlight fibreglass body built on a tubular chassis – which somewhat scarily is held together by glue rather than anything as reassuring as metal welding. On the other hand, we spent several teenage years in the company of a station wagon that used increasing amounts of fencing wire as the primary structural element (and a large flat-bladed screwdriver jammed into the open transmission linkage to change gears), so perhaps glue can do the job just as efficiently.

The drivetrain, if you can use that term for something that is more like a drivebellows, uses 300 litres of compressed air stored in carbon fibre tanks under the body.

Essentially, outside air is pulled into the engine chamber and compressed to 290psi, by which time has a temperature of 400C. Compressed air from the tank is then injected, and being much colder expands quickly in the heated chamber, pushing the piston. The process is called a thermo dynamic cycle and admittedly there’s a bit more too it than our simple explanation, but this is not Mechanics Monthly and we don’t really care.

The MiniCAT uses a continuously variable transmission that relies on belts rather than cogs – so no chance a screwdriver will get you out of trouble – and produces a, well, continuously variable set of gears.

The Tata baby is the invention of an insane Frenchman (if that’s not a tautology) called Guy Negre, who was an engineer in Formula 1, where he became fascinated by the compressed air system used to start the race cars. And also designed a W12 engine – think two V6s jammed together – which only serves to reinforce the insanity tag.

However, Negre is adamant that his car will be a solution for the increasingly crowded streets of India and any other countries where presumably people are looking for cars glued together from leftover lego and styrofoam, sitting on top of a highly pressurised balloon.