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A car that runs on air and releases no pollutants into the atmosphere at low speeds could be on sale in India as soon as this year.

The three-seat fibreglass OneCAT weighs only 350kg (770lb) and is expected to be priced at about £2,500. The engine technology is backed by Tata, the Indian conglomerate that last month unveiled the world’s cheapest car, the £1,250 Nano.

Refuelling involves topping up on compressed air, which is used to power the OneCAT’s piston engine. In a couple of minutes - and at a cost of as little as £1 - the vehicle is ready to travel another 200 to 300 kilometres (125 to 185 miles), its inventors said.

The vehicle, which burns small amounts of conventional fuels at higher speeds, has been developed by Moteur Development International (MDI), a French-based, family owned group that has been working on an “air car” for the past decade. “The engine is efficient, cost-effective, scalable and capable of other applications, like power generation,” a spokesman said.

Vivek Chattopadhyaya, of the Delhi-based Centre for Science and Environment, said: “What counts is how much energy all the processes involved require - from manufacturing the car to compressing the air.”

Mass production moved a step closer last year when MDI agreed a partnership with Tata, under which the companies pledged to refine the technology. The Indian group said that the system may represent “the ultimate environ-ment-friendly engine” and is studying its commercial feasibility.

MDI, whose engine is competing with rival technologies that range from electric vehicles and biofuels to hybrid engines and hydrogen-based fuel cells, has said that its first mass-market model could go on sale this year.

Worldwide sales of “zero emission” cars are languishing in the thousands, but with oil prices running at record levels, energy efficiency has become a watchword across the car industry.

According to MDI, its fleet includes cars that could cover 100 kilometres for about 60p. A full tank of compressed air would last for up to ten hours. A top speed of about 70 miles an hour has been claimed. An oil change should be necessary only every 30,000 miles or more and the air expelled from the engine will be clean and cold and can be used in the air conditioning unit.

Vital statistics

Fuel: Compressed air (some conventional fuel at higher speeds)

Cost of refuelling: about £1

Range: 200km to 300km (a full tank should last up to ten hours)

Servicing: OIl change about every 30,000 miles

Seats: Three

Weight: 350kg

Price: about £2,500

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