BMW developed a super sleek race car that runs completely on liquid hydrogen. Under the hood is a 6.0-liter, V-12, 232 hp hydrogen-powered engine. This slightly modified gas engine can propel the car to 187 mph. Hydrogen has a few advantages over gas.
1. Hydrogen is very abundant
2. Hydrogen burns clean, when it burns it is combines with oxygen to produce H20 or water, this water can be reused to make hydrogen again.
3. Hydrogen weighs less than gas and produces more power.
4. Hydrogen burns faster and cooler than gas.
The BMW H2R set 9 international speed records
In response to Josh's question in episode 798, and maybe saving Molly a little research work (I guess my email last Friday didn't get through), there actually is research being done on running internal combustion engines on hydrogen gas. According to the latest research, such an engine can be as efficient as the best diesel engines. It's also thought that a hybrid car with a hydrogen-powered IC engine would have the same mileage as a hydrogen fuel cell car, but at a fraction of the cost (see http://www.abc.net.au/science/articles/2008/06/16/2273538.htm )
There were also several papers presented on storing and using hydrogen in IC engines at the recent 17th World Hydrogen Energy Conference. Of course, the problem of safely storing hydrogen in a car for use in an IC engine is exactly the same problem as storing hydrogen for use in a fuel cell car. See http://www.whec2008.com