So i know it does sound crazy but yes you can use water for fuel... well not water per say in this instance but hyrdogen rather or more specifically HHO or Browns Gas (because is brownish... clever eh?)
so heres the run down, first you need an HHO Generator, theres tons of ways to make em they way i made it was using two mason jars with electrode towers and air intake/ gas expellsion fittings, relief valve and of course the positive and negative for your battery connection on both which you wire in series. i can get some pictures for you guys, my set up is a little more sophisticated then some out there, trust me theres a lot! what you are doing is using a electrolosis to seperate your two hydrogens from your oxygen, the displacement from your engine creates the vacuum that sucks the HHO gas through vacuum hoses first from your generator then through a bubbler then into your air intake/ throttle body. so now the myths, no it doesnt suck water into your engine, hince the bubblers purpose, no its not just tap water, its distilled water with a teaspoon of baking soda, and no your not wasting energy trying to create it, it takes a very minimal amount of voltage (less than a stereo) and no doesnt make your engine run harder to keep up with production (alternator) HHO is about 300X more effecient than gasoline/crude oils, you you only need to add about an 1/8 inch of water to tap it off at fill ups (even if you have to) you creat it based of consumption, so your not storing compressed hydrogen (Hindenburg) and better yet its byproduct of combustion readily returns to h20 when released back into the ozone. its very easy on a carb'd vehicle but not impossible on fuel injected ECU'd vehicle, this man (a jeeper and liberty owner
http://www.madcosm.com/index.htm ) sells the box to control your 02 sensor as well as has tons of free information on how you can build your own HHO generator, and controller and other info, youtube also has some interesting videos (and i know youtube is about as good as wikipedia BUT) if you dig enough you can find theres alot of truth. Matter of fact the original patent was bought out in the late 70s by big oil... this deosnt replace gas, but it does supplement allowing you to use less gas, save some money and hopefully make way for some newer technologies for more sutainable energies.
i will try to get some pics.
by the way the us military has contracted a Humvee to run on Gas and HHO, Cali's Arnold is currently driving an HHO hummer i believe and Mazda has some HHO rotary technologies in the works that are straight up amazing shown at the 08 detriot auto show. just my 2 cents but hey, it might save you a whole lot more eh?