Tata Motors Air Car—Is it Really Coming?

There been quite a bit of buzz for several years now about the Tata Motors MiniCAT Air Car, a car that could purportedly run entirely on compressed air. Tata made an agreement back in 2008 with Zero Pollution Motors to market the car in the US by the end of 2009. The US version of the car would run exclusively on compressed air at low speeds. Above 35 mph, a small gasoline engine would kick in to provide the car with enough additional power to stand a chance of holding its own on US highways.

Then, early in 2009, Tata Motors’ vice-president S. Ravishankar told DNA Money the project was facing difficulties in terms of vehicle range and cooling. Ravishankar said, “Air is not a fuel, it is just an energy carrier. So a tank full of air does not have the same energy as a tank full of CNG. Any vehicle using only compressed air to run would face problems of range.” The car was also reported to have problems at low temperatures. (For more information on how air cars work, click here.)

In a Triple Pundit article last fall, Steve Puma reported that from a carbon emissions perspective, Zero Pollution’s AirPod, “an extremely strange-looking precursor to the Mini Cat” outperformed the Tesla Roadster (by 27%), the 2010 Toyota Prius (by 39%), the 2009 Honda Civic non-hybrid (by 63%) and the VW Jetta TDI Diesel (by 62%).

Now a report from the Australian web-based The Motor Report claims that the MiniCat will be on sale in India by August of 2012.

The lightweight car will be mostly made of fiberglass with a bonded tubular chassis. This compressed air-only version will cost roughly $2 to fill up with enough compressed air to take you 300 km (186 miles). That’s ten times better cost per mile than what you would get with gas today at 37 mpg. The fill-up will take only take a few minutes in a properly equipped service station, though a home compressor can fill up the car in three to four hours. And since this car has no combustion engine, it will only need its oil changed every 50,000 km (30,000 miles).

The estimated cost of the car is $8000, roughly four times the cost of Tata’s Nano, “the world’s most affordable car.” The MiniCAT was jointly developed with Motor Development International who has been working on compressed air engines since 1996.

According to an earlier release, the Air Car runs a specially developed piston engine that uses a new thermodynamic cycle offering exceptional energy efficiency. The compressed air is stored in carbon fiber tanks, at 4,351 psi.

The operation of the engine is as follows: Fresh air is drawn into the compression chamber and compressed to 290 psi. At the highest point of pressure (‘top dead center’), the air reaches 688°F, at which point, compressed air from the storage tank is injected into the combustion chamber. This compressed air heats and expands rapidly in the chamber, pushing the piston down.

This earlier release describes an 80 gallon a tank that will last for 120 miles. This differs from the recent announcement which claims 180 miles, so some additional changes must have been made.

The MiniCAT uses an electronically controlled continuously variable transmission (CVT)

There is no news yet on when a US version of this car might be available, though it will clearly be substantially different from the Indian version. There is no mention of either model on the company’s website as of this writing. Perhaps because of previous delays, the company is keeping a low profile this time until it is sure that the car will be ready. Though I don’t ever see this becoming a touring car or a family sedan, it certainly could be a worthy competitor to something like the Smart car.

[Image credit: Triple Pundit]

RP Siegel, PE, is the President of Rain Mountain LLC. He is also the co-author of the eco-thriller Vapor Trails, the first in a series covering the human side of various sustainability issues including energy, food, and water. Now available on Kindle.

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RP Siegel

RP Siegel, author and inventor, shines a powerful light on numerous environmental and technological topics. His work has appeared in Triple Pundit, GreenBiz, Justmeans, CSRWire, Sustainable Brands, PolicyInnovations, Social Earth, 3BL Media, ThomasNet, Huffington Post, Strategy+Business, Mechanical Engineering, and engineering.com among others . He is the co-author, with Roger Saillant, of Vapor Trails, an adventure novel that shows climate change from a human perspective. RP is a professional engineer - a prolific inventor with 52 patents and President of Rain Mountain LLC a an independent product development group. RP recently returned from Abu Dhabi where he traveled as the winner of the 2015 Sustainability Week blogging competition.Contact: bobolink52@gmail.com

9 responses

  1. It ain’t going to happen. The Australian article appears to be a recycled version of the 2007 articles that said Tata would introduce the MiniCat in August 2008. (“next summer”). That article reappeared in 2008, with introduction still “next August”.

    Now the article has yet again been born again, with the introduction date still “next August”.

    If you were to contact Tata, they would tell you that the launch date is indeterminate.

    Aircars.tk is a website with reasonably accurate info on aircars, particularly the MDI and Tata work.

    The introduction date has been “next year” ever since Zero Pollution Motors and MDI announced in 1999 that production would start in 2000.

    1. u shut up.. bc.. im the employ o ftata motors n i know wich vehicle going to be launched.. u australians are geleous of use.. proud to be th epart of tata motors..

  2. Last announced range was 7.22 km (10 or 12 years ago) – & a huge laundry list of anticipated improvements – none of which has been announced, nor presumably achieved. 

    Vapourwair – 

    Send an engineer or two to the factory to request a fully ‘fuelled’ car, to be tested for a few days. 

    (& they should take a long tow rope – maybe 150 km – 7.22 km = 142.78 km long?)

    Also test ‘efficiency’ of system – considering that air is only an energy transfer system, not an energy source.

  3. It is going to happen!
    Still there’s a lot of mistaken informations in the article above, which I will put right here:
    – Tata Motors signed an exclusive licence agreement with MDI in 2007, limited strictly to the Indian market.- today 2 Tata Motors models are re-engineered with MDI’s present compressed air engine to the entire satisfaction of TML’s R&D division
    – the new generation of MDI’s compressed air engine will have an extremely high efficiency.- the MDI city car is a pure MDI development, nothing to do with TML.- Zero Pollution Cars has nothing to do with MDI.
    – simply go to TML’s website, have a look at the press release and you’ll understand. 

  4. I’m with Charlie. The thermodynamics and physics does not stack up anywhere close to what’s claimed, and the press releases are smoke and mirrors, aimed squarely at credulous stockholders rather than technologically and scientifically literate scrutiny. 

  5. My aluminum 50 pound scuba tank holds 80 cubic feet of air at 4000 psi…..my Toyota has a 2 liter, or 120 cubic inch engine….a cubic foot has 1728 cubic inches….as the article mentions, “it is only a storage system”…and a poor one at that.

  6. If the compression temperature is over three times the boiling point of water, why not just spray in water which will turn to steam thereby driving the pistons down. No polution whatsoever, not even water vapor as the steam can be condensed and re-used over and over again

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