Yes, you can run your car on water. All it takes is to build a "water-burning hybrid" is the installation of a simple, often home-made electrolysis cell under the hood of your vehicle. There's even a Japanese company, Genepax, showing off a prototype that runs on nothing but water.
Similarly, you may ask, can you run a car on hydrogen?
Unlike conventional vehicles which run on gasoline or diesel, fuel cell cars and trucks combine hydrogen and oxygen to produce electricity, which runs a motor. Because fuel cell vehicles are only beginning to enter the U.S. market, interested drivers should ensure they live near hydrogen refueling stations.
Can water be used as fuel for cars?
To fuel a hydrogen car from water, electricity is used to generate hydrogen by electrolysis. The resulting hydrogen is an energy carrier that can power a car by reacting with oxygen from the air to create water, either through burning in a combustion engine or catalyzed to produce electricity in a fuel cell.
How does a hydrogen car engine work?
Like an internal-combustion engine, they make power by using fuel from a tank (though the fuel is pressurized hydrogen gas rather than gasoline or diesel). But, unlike an engine, a fuel cell doesn't burn the hydrogen. Instead, it's fused chemically with oxygen from the air to make water.