Hydrogen is a perfectly good motor fuel if you follow appropriate safety and storage protocols, but in case you haven't heard, there ain't no free lunch. Electrolysis is a very inefficient way to generate hydrogen, and if you think you can use electricity from your alternator to generate while you are driving, you will be very disappointed with the results. People who claim big mileage gains are not measuring their entire energy budget. The only way these systems make any sense is if you have a "free" energy source like solar or wind to plug into and generate hydrogen while the car is idle.
