On Thin Air Students at the University of Washington and the University of North Texas claim to have built cars that run on thin air. It turns out they re for real. F. Exposed to ambient temperatures, the liquid turns to a gas and expands. Make this happen inside a pneumatic motor, and you can power a car, albeit not much faster than 20 mph at the moment. Although nitrogen is free, it takes energy to liquify.
Proponents envision someday using solar power to chill the gas.
What s more, liquification also removes airborne matter and undesirable gases, including carbon dioxide. The Internal Revenue Service has announced a 1998 national per-mile driving rate of 32.5 cents for the U.S. taxpayer. The rate for 1997 was 31.5 cents.