We've brought you news of the French-designed MDI compressed air-powered car in the past, and we've followed Tata's movements in the small car segment, and its desire to get into the European and American markets. Now there's news of Tata's move to back the MDI's release of its new OneCat and CityCat models.

The three-seat OneCat and six-seat CityCat (pictured) will be sold thorugh MDI's U.S. affiliate Zero Pollution Motors (ZPM). The larger CityCat is expected retail for $17,800 when it arrives in late 2009 or 2010. No word yet on pricing of the OneCat, but given its smaller size, it seems reasonable to guess it might be priced even more reasonably than the CityCat.

When you take the performance of the air-powered six-cylinder into account, these are really very interesting vehicles. The CityCat's motor is rated at 75hp, and is capable of propelling the six-seater to 96mph, reports BusinessGreen. At lower speeds (below 35mph) the car is completely air-powered, resulting in zero tailpipe emissions. Over 35mph, the CityCat uses a small burner to heat the air to improve power and range. The burner can use petrol, ethanol or bio-fuels as its heat source, and emits just 0.158lb CO2 per mile (45g/km CO2). That's less than half the emissions of the Toyota Prius.

Equally impressive is the vehicle's range: a single tank of air will yield 800 to 1,000 mi (1,280 to 1600 km), and takes only an hour to fill. Compared to electric cars, the CityCat has roughly triple the range of the very best prototypes, a much shorter delay for refueling and very similar emissions. ZPM rates the CityCat at the equivalent of 106mpg. Not bad for a six-seater with a range of more than 800mi.

The first plant to build the air-cars is already under rights, but the firm is seeking investors to purchase licenses to build plants throughout the U.S. MDI and ZPM hope for more than one plant per state, on average, once the car is established. That would be an unprecedented level of production, and at €300,000 per license on top of the actual plant construction costs, it would reflect a substantial investment, totalling over €15 million (US$22 million). Although by industry standards, that is but a drop in the bucket.

If you'd like to learn more about the concept and technology, watch the video below detailing the cars made by MDI since the late 1990s. It's a bit heavy on the utopianism, but it gives a good look at the cars and engines and even shows some driving.