Produces hydrogen during vehicle operation through electrolysis of water using the power generated from the vehicles electrical system. A small amount of hydrogen added to the vehicles intake air/fuel mixture allows the engine to operate with less fossil fuel. Ronn Motor Company will use this technology in its revolutionary Scorpion to achieve lower emissions and vastly improved fuel economy.
There are two main kinds of Hydrogen Hybrid automobile. These are fuel cell vehicles and Hydrogen internal combustion engines, (HICE) like our first automobile "The Scorpion". Fuel cell vehicles are electric cars. Hydrogen is pumped into a tank in the car, just as gasoline. The hydrogen gas is then fed into the fuel cell where it is electrochemically converted into electricity--with no combustion, no moving parts and no emissions other than water vapor. The electricity is used to power the vehicle.
Hydrogen ICE vehicles use a regular combustion engine modified to use gaseous hydrogen instead of liquid gasoline (much like a natural gas vehicle is modified). They burn hydrogen or a combination of gasoline and hydrogen, but since there is no carbon in hydrogen, there are no or almost no CO2 emissions and only trace amounts of NOx (oxides of nitrogen). Hydrogen ICE vehicles are typically about 30-50% more efficient than comparable gasoline vehicles.
Apparently the first paragraph is about the onboard HHO supplement systems that some here experiment with, the second is about hydrogen fuel cells (requiring you to fill up with hydrogen), and the third is mainly about burning hydrogen that's filled up instead of made onboard.