[Rodney King]

Most of these miracle, alternative energy vehicles are what I would call "displaced energy" vehicles.

Right, they transfer energy from one form to another, and then ignore the orignal source of energy. That is exactly what this is all about.

[aligncare]

Would it make you feel better if the electricity used to compress the air into the tanks was derived from nuclear power? You know, no air pollution issues, low cost of energy production, and so on?

Or how about hydroelectric source for the electricity?

Or what if you're generating your own electricity in some fashion in the near future. How would that change the equation of why the air car is a stupid idea?

[LeGrande]

The point that everyone seems to be missing is that the air after it exits the high pressure tank has to be heated in a chamber and then heated again in the piston. That is why it takes 8 hours to go 120 miles just using the ambient air temperature. If the air is not heated up to ambient temperature then it probably has a 5 - 10 mile range.

Now that I am thinking about it the best solution is probably a hybrid with the heat from a small gasoline or diesel engine used to heat the compressed air.

About efficiency. A gasoline engine is very inefficient less than 20% or so. A coal fired electrical plant can reach about 40% efficiency and the price per Coal BTU is much cheaper than Gasoline, apx 40%. So the cost of electricity with the same energy value of gasoline is about 1/4 the cost (including transmission costs).

If we had a perfect battery to store the electricity in, electric cars would be the way to go : ) We don't though. Compressing air is not very efficient because it produces a lot of heat (Remember the heat that is needed to help it expand?) but if it was used to heat your house then it might not be that bad.

The bottom line is that a compressed air car should be much cheaper to operate and run, it will just be very slow.