I would like to dispel a myth for the readers of these humble pages. There is no such thing as a car that runs on water unless your talking amphibious vehicles. You cannot burn water and you cannot oxidise it to produce energy. You can run a car on Hydrogen such as BMW’s Hydrogen burning Car (I think it’s the 7 series).
http://en.wikipedia.org/wiki/Hydrogen
http://www.bmwgroup.com/cleanenergy/ http://www.wired.com/cars/energy/news/2006/11/72100 http://www.spiegel.de/international/spiegel/0,1518,448648,00.html
The exhaust gas from burning Hydrogen is water. Combine 2 Hydrogen atoms and 1 Oxygen atom and you get 1 molecule of water. There are two main ways that the energy from converting Hydrogen and Oxygen to water is used. One is through a fuel cell which uses this reaction to create electricity and the other is to use it in a internal combustion engine. The second option is almost like burning LPG in a car. You just need different internal bits in the car to stop corrosion by high temperature water.
There are websites out there that purport to let you run your car on water. You will not be able to convert your car to run on water. If you inject water and only water into the cylinder of your car instead of petrol/diesel you will not be able to produce any power. Most of the systems seem to be a small container of water that is electrolysed (split) into its component atoms of Hydrogen and Oxygen. Then these are injected into the cylinder and burnt to form water. Then big problem here is that it takes more energy to split the water into Hydrogen and Oxygen than you get back by burning it and producing water. This is because of the second law of Thermodynamics. http://en.wikipedia.org/wiki/Thermodynamics. The second law of Thermodynamics is a basic law of the universe Suns, black holes everything in the universe abides by this rule. So if you put a kilo of water in and get a kilo of water out mass is conserved so energy must be reduced, necessitating an input of energy other than the water. If you could affect mass to energy transfer (such as in matter anti-matter collisions) you would produce enough energy from a kilo of water to power a car for several lifetime. Unfortunately we don’t have this technology yet (or in the foreseeable future).
