Well, actually it’s clean cold air that is the only (!) exhaust gas produced by this CAT (compressed air technology) car.

It can run solely on compressed air, making it a true zero emission car. In fact, as the air produced is completely clean and cold (between 0°C and -15°C) it can even be used to provide air conditioning.

Of course, energy is needed to compress the air and this energy is usually provided in the form of electricity. So the question to ask is whether it is actually more energy efficient than an ordinary electric car. The manufacturers don’t really say anything on this issue (so the answer is probably “no”), but there seems to be big advantage in terms of the “battery”: you can quickly refill your compressed air tank within 2-3 minutes, while it would take much longer for a battery to recharge.

Whether it is more ecological or not ultimately depends on how you produce your electricity. In any case, it claims to be a lot cheaper to operate, running about 100km with €1.50 worth of electricity.

If you’re interested, also check out the video on the Discovery Channel Canada or the recent story on the Tagesschau.

Oh, in case you’re surprised by the fact that the exhaust air is cold rather than hot, then maybe you’ll be interested to read up on the ideal gas law.