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Perpetual Motion Compressed Air Engine?

A friend and I got into a heated discussion a few nights ago over this. He insists some guy in France has invented a compressed-air car that recharges its own air tanks as you drive it down the road and can thus run indefinitely without fuel. I tried to explain that it was not possible because of the laws of thermodynamics and conservation of energy, but he was adamant and says the oil companies are keeping it from being marketed (the old conspiracy theory). Any truth to it and why don’t we hear more about it?

There is truth to the fact that it’s impossible. There’s no truth to the perpetual motion machine.

There is, however, an all-electric car in final prototype called the Tesla roadster that will do 0-60 in 4 seconds, go well over 100 mph easily, go over 200 miles between charges, and takes only 3-1/2 hours to fully charge from a total drain. And it’s absolutely gorgeous. You might want to visit their website.

Your friend needs to INVEST in this GREAT idea!

Better yet, tell him you’ll act as an intermediary in a fiduciary capacity. Then you can invest for him! Shouldn’t be a problem as your friend seems pretty gullible.

Everyone WANTS to believe there is something like this. It just can’t be true however.

Still not enough miles per charge in the Tesla to run over to Albuquerque and back, the inherent drawback of all electric vehicles out here in the wide open spaces.

What they said, plus it sounds like your friend got a garbled description of an actual compressed air-powered vehicle. It’s nothing magic, fill up some tanks with compressed air and basically run a compressor backward. Here are some comments that point out the weakness of the approach:

"This car is for the naive. The energy density of compressed air at 300 Bar (about 4500 psi), the pressure at which it is advertised for the MDI car, is 4 MJ/Kg. The energy density of gasoline is 47 MJ/Kg, almost 12 times greater than compressed air.

On the only published test they did, the car got only 4.5 miles on a full tank of air. In order to get the range of a normal car, the air tanks in such a car would have to be the size of a moving truck. Even then, the filling up process will take hours, which, like electric cars, means that they will not be practical solutions for transportation. As for heating the car, well I?m not sure how you heat a car with compressed air, but if you can, you will need to drain the energy from the tanks to do it. With fossil fuel cars, heat is a waste product so no energy penalty is required to heat the vehicle. This is a significant, perhaps fundamental, stumbling block to all-electric or all-air cars in cold climates, range and power aside."

Aha! But I only commute 31 miles each way! It would be perfect for me…except for this little budget shortfall of mine…

You’re right, your friend is wrong, and the conspiracy theory is off base. There is no way the oil companies could keep anything concealed; especially considering the vast number of things they’ve been accused of hiding.

That guy in France (Negre) is a huckster who came up with this about 15 years ago and the idea has been around for a 100 years.
The guy in France was looking for shareholders to invest and become a license holder based strictly on his word that “it works”. Since he could never produce a verifiable working model that would do what he claimed not one person bought into it.

Thanks to the internet, many people read claims by people who are not mechanically inclined, do not know the gentleman, never have seen the car, etc. and blindly defend the idea simply because it sounds good.
It’s no different than gas line magnets, acetone treatments, overly priced spark plugs, or whatever. Throw some gibberish out and X number of people will buy into it.

Anything isn’t possible, except for heated air fights. I heard that somebody got beaten to death with a shovel when they were discussing Hank Aaron and Babe Ruth. Nobody wanted to look up the facts about which hit the most home runs. Somebody should have had a book handy. I had a book handy when one of my friends thought that Apollo 13 burned on the launch pad. I wasn’t even threatened when I showed him the true information.

Yea it’s costs OVER 100k.

Your friend sounds like the perfect candidate. They want people dump enough to believe it to invest. Does your friend buy all the stocks from the E-Mails too???

It’s NOT possible.

You Don’t See Any Perpetual Motion Cars Driving Around

They are all locked up and stored away with $100 new-condition military Jeeps and crashed UFO’s in a remote mountain vault, managed by Elvis.

But think of the money I’d save in gasoline!

Not to mention the issues of cabin heat and A/C. I would think in NM you might want A/C in the summer and I certainly need heat where I live in the winter. What % of the total power budget does that consume???

I’m in NH. Good question. I wonder if the designers have considered using the heat from the lithium ion cells to help…

How does your friend plan to compress air without fuel? I would love to hear his idea.

Thanks, I didn’t think I missed the memo on the suspension of the laws of physics. I think it is just as someone said, people want to believe it is possible for a car to run on something as readily available as air or water and don’t understand the dynamics involved. It is kind of the mechanical equivalent of a Ponzi scheme: if you make it sound feasible, someone will buy into it. I got a good laugh out of several of the responses. I will pass them along to him, maybe he will see the light. Thanks to everyone for reassuring me that I am not insane.

And you thought black holes were only theoretical.

Actually, I bought the patent to the perpetual motion air car so I could suppress the technology and leave a bigger market for my perpetual motion electric car with a windmill on the roof to recharge the batteries as you drive.

Good one. A former Brother-in-law around 1969 informed me of the new Jeeps, still in the cosmolene, for $50 in those days. I scoffed, and he insisted it was true. I ordered 15, I think it was. I told him no matter how much time passed, I was good for the money. I am still waiting.

Every generation comes into the world pretty much the same. Unlike Jean Auel’s fictional Neanderthals, humans do not pass on a whole body of memories. So in each generation, there are people who must learn again there is no such thing as a free lunch, nor perpetual motion, and that not all that looks great is great. And, in each generation, there are those who are incapable of learning.