The MDI Air Car

Compressed Air: The Ultimate Fuel

Written by Green Chip Stocks
Posted January 24, 2008 at 7:07PM

All across the nation, jaws dropped in a collective gasp as markets plummeted as fast as GM’s popularity after “Who Killed the Electric Car?” showboated corporate scandal on a scale only rivaled by Big Auto and Big Oil’s dismantling of electric trolleys.

If it were not for the multitude of requests I’ve recently received to write about the Moteur Developpement International Air Car I would have loved to devote my weekly Green Chip Review slot to articulate my utter abhorrence of the economic reality that is rearing its sub-prime-pocked head and baring its needle sharp canines in the face of asinine fiscal policy.

But, in times of great distress I remember my colleague’s catchphrase, “periods of danger and crisis are also periods of great opportunity,” and as you can imagine, that is much more comforting than pulling a Jim Cramer and crumpling into a sobbing, gibbering, sweating mess on the office floor.

So come along my friends, hike up your skirts and take a line from the Foreign Legion, “March or die.” That’s right, onward to one of the most promising technologies of today . . . a car that runs on compressed air.

Compressed Air Technology is nothing new. Since 1896 when Rudolf Diesel made a patent claim for using a supercharger to provide a more dense charge of air to the first diesel engine, compressed air has been used to up power output in almost every internal combustion application.

1994 changed the entire name of the CAT game. Instead of using compressed air to force feed more oxygen and fuel to the engine, ex-Formula 1 designer Guy Negre of Nice, France, devised a way to make a car run purely on air. It can be refilled at modified air compressors found at gas stations for about $2 in only a matter of minutes.

If a compressor is not readily available, the Air Car can simply be plugged into an outlet and an on-board compressor can refill the tanks in about four hours, giving it a range of approximately 124 miles with a top speed of 68 mph.

Now, due to the sensitive nature of revealing how such a technology works, MDI has offered limited information on the drive system.

Here’s a brief rundown . . .

The Engine

To maintain adequate pressure so that the main large cylinder is given a burst of pressure instead of a continuous slow push, a smaller cylinder is used to build pressure.

As the smaller piston collects the air and travels downward on its stroke the “articulated con-rod” lets this smaller piston rotate its rod on the crankshaft while allowing the main piston to be held at top dead center 70% of the time, until the smaller piston reaches the bottom of its stroke. Then the blast of air is delivered, driving the main piston down.

A bit tricky to put into words, so here’s a video with the MDI engine on the right . . .

The Gear Box

The automatic, computer-controlled transmission is an in-house design of MDI that constantly monitors the speed of the vehicle and shifts with minimal loss of energy.


Located between the engine and the gear box, the moto-alternator produces brake power, starts the vehicle, provides extra power when needed and helps the CAT’s motor to allow the tanks to be refilled.

The Air Tanks

Constructed of carbon fiber, the three massive air storage tanks will not explode when damaged, which is a good thing considering they keep 4,000 psi under wraps. The fibers are designed to split apart and allow the pressure to drop without blowout.

The Body

The body is built with fiber and injected foam, offering several major advantages.

  • Reduced cost
  • Reduced weight

  • Easier repair

  • No rust

  • And arguably safer because the fiber body won’t crumple and cut like steel.

So, finally, after 14 years of research and development, the Air Car is ready for production in India under MDI’s new partnership with Tata (NYSE:TTM) Motors, the leading automobile manufacturer in The Land of the Tiger.

Called the MiniCAT, the Air Car for India is poised for success under this new partnership. With a cost of about $3,800, the car is affordable and will benefit from Tata’s stellar reputation—a reputation that has led to over four million of their vehicles being sold, totaling $5.5 billion from 2005-06.

So what does the future hold for the Air Car?

It was believed that the MDI Air Car would hit the showroom floors in Australia, Europe and India by the end of this year.

But recently, in the Mumbai Mirror, this was reported . . .

When contacted, Tata Motors’ Debasis Ray, who heads the company’s corporate communications, said: “The Air Car still requires nearly two years of work, to refine its technology.” He added that the company would only discuss the price point for the vehicle and its launch date after Tata Motors is ready to launch the car into the market.

A bit disheartening, but keep in mind this quote is in context of the Indian market only. And considering that MDI already has 50 factories across Europe waiting to go, I have a sneaking suspicion those two years will be spent working out minor kinks and tailoring the car to Indian market tastes.

Keep your hopes in the future but your sense in the present . . .

Field Palmer

P.S. For a chance at double-digit profits from another company making a novel, low-emissions enginge, read this report.