[Danny Richie]

I looked into doing stuff like that years ago. It was even looked at from a standpoint of a drag racing application as a lot of compressed air can be dumped all at once.

It really doesn't make that much power though and it is extremely inefficient (as Jules already mentioned).

That car really doesn't run on air at all. Air is just being used as an energy storage device. And air is not a good way to store energy. It takes a lot of electricity to compress a lot of air (especially when pressures get high) and it won't get you very far especially if you really open up the valve.

[Russell Dawkins]

Just for the record, my father used to own an Amphicar and I drove it a couple of times.

Fun watching faces on shore as I "drove" on water up to the ramp at twilight (with headlights on) and straight out onto the road!

[atmasphere]

If you have ever let the air out of a tire then you know the difficulty with this concept. Releasing compressed air causes things to get frozen. In a nutshell this idea is impractical.

Now if you want something practical that actually exists, electrics do work. I have an EV that I built up from an older Ford Ranger. It has a 100-mile range on a single charge. I could not afford anything but lead acid batteries for it (its a hobby after all...) but if I had NimH the range would be 200 miles (with 4 hour recharge) and with LI batteries about 300 miles. There is a battery that one of our customers is working on that can recharge in 5 minutes...

Considering that most of my driving is around town and under 30 miles on most days, this is a very practical machine. Let's see how I feel about it in 2 years...

[Funnehaha]

If compressing the air takes up too much energy, what about using liquid nitrogen? It could be carried in fairly light insulated "bottles" in the car. Then when it is needed to drive the car, a measured amount could be injected into a "piston" chamber, warmed enough to vaporize it with some sort of "glow plug", and the expanding nitrogen vapor would drive the "piston" down....

[geezer]

If compressing the air takes up too much energy, what about using liquid nitrogen? It could be carried in fairly light insulated "bottles" in the car. Then when it is needed to drive the car, a measured amount could be injected into a "piston" chamber, warmed enough to vaporize it with some sort of "glow plug", and the expanding nitrogen vapor would drive the "piston" down....

Making liquid nitrogen involves compressing air.