View Full Version : Compressed air car

01 March 2011, 0908
A report from 2008 says that a French company licensed the technology for a car powered by compressed air to Tata, who planned to introduce a small, slow-speed, urban car to the US in 2010. So what happened to this car? Did the air leak out of its tank? Read about it here:


01 March 2011, 0919
I think they discovered that if they mixed a little gasoline with the compressed air at a 14.7:1 ratio, they got a tremendous amount of power from the engine, however this caused undesirable pollutants to be discharged in the process and are now looking at other alternatives.......

01 March 2011, 0921
If you hunt around the web, you can find all sorts of info on it.
Tata is an Indian manufacturer, and the news a couple of years before that was that Guy Negre had licensed the technology to Tata.
Among other things, he also had a compact, efficient compressor, and while I never read anything quoting him directly saying it, many articles had statements saying that once that was perfected, the car would compress it's own air as it drives (why, oh why do so many reporters lack high-school level physical chemistry knowledge?)


IMHO, the reason it never went anywhere is that it was hype, and not very practical.

Sure, you can power a car by air, but the long and the short of it is that compressed air, at pressures that can be contained for a reasonable cost and safety level (I've known 2 people killed by just 3,000 psi dive tank ruptures) doesn't have very good energy density, so you're not going to go too far on a fill - and you can't refuel all that fast, because fast-filling overheats tanks and fittings (composite tank manufacturers like Luxfer tell you not to flash-fill their tanks). The other drawback to the heat generated by fast-filling is that your pressure drops back down once the air in the tank cools, so a tank that you fill full, won't be full after it cools off, you could easily lose 15% or more of your range just sitting there.

It looks like the US distributor/hype center for Negre, may not be around any more - their web site is down - http://zeropollutionmotors.us/ but as recently as a year ago, they were still raising money.

Edit: And Negre's company is still around - and still has opportunities for us to invest in the future of air powered cars: http://www.mdi.lu/english/investisseurs.php They also have plans for engines that burn fuel to heat the air and expand it - like a steam engine, but less effective, because the expansion from snesible heating is much less than during a phase change from liquid to steam.

01 March 2011, 1033
Their stuff was quite noisy with low power and rather inefficient. He managed to attract a lot of money though. As far as I'm concerned, they have no credibility .

02 March 2011, 0938
Just go put your hand near the copper pipe on a 120psi home air compressor to gets good idea of how inefficient this is. The other thing is the were moving supper light 800# cars with virtualy no safety designed into them.