Here's a car that literally runs on air!
Well maybe not exactly.
While the announcement of its $2,500 Nano four-passenger car by Tata of India may have drawn headlines last week, here's word from the good folk at Autoblog about an even more fascinating (but not to say practical) microcarthe compressed-air-powered Citycat or Minicat.
Now as any engineer (or anyone else with common sense) would tell you, it still takes energy to compress the air to fill the car's tank, not to mention energy losses in the drivetrain. Specs on the fiberglass-foam-body, carbon-fiber-air-tanks, and aluminum-engine Citycat (follow the link above) are given as 68 mph top speed and roughly 125 miles range. Air tank capacity is listed as 52 gallons at 4,350 psi,
So the task for you class (at least those of you skilled in the pneumatic arts) is to dust off the Ideal Gas Law, etc, and vet the given performance (equivalent miles per gallon of gasoline or other measure of energy usage) of these 'cats. Please share your results (and thoughts) on our Forum page.