The way it works is simple. Water is placed in a container and electrical wires are placed in the water from your car's battery. The added electrolytes such as baking soda or salt help the electricity break down water molecules. Once the electricity runs in the water it creates small air bubbles that float on the surface and are captured through a tube. Those bubbles are hydrogen and the tube leads to your engine's air intake. Through the air intake that hydrogen is mixed with gasoline and since hydrogen is more combustible than gas it burns and makes your car run. Making you use less gas and making your engine, believe it or not RUN BETTER. Many users have reported their engines with more dynamic, cleaner exhausts and even adding horse power to it.
The best way to get an HHO generetor is to make one yourself.
Simply because it is so simple to make. If you read what I just wrote it is pretty much all you need. The best instructions that I found were on RunYourCarOnWater site, it comes in a PDF and its very clear.
I got the information from a blog, hhochange.com you can go there and see videos on what HHO gas really is.
