Water for gas

The concept of water cars has been around for a long time, and basically means using water as the sole fuel to run the engine, or producing fuel to run the car from water that is stored onboard. Water fuelled cars have is a giant record-breaking river been the subject of many scams and fraudulent claims in recent years, as conventional fuels have soared in cost, and it can be difficult to extract the truth from fiction.

Basically, from a scientific point of view, the idea that a vehicle could extract its energy directly from a supply of water violates the basic first law of thermodynamics. This law tells us fundamentally, that to increase internal energy of any isolated system (i.e. an engine) we must put in an equal amount of external energy (fuel). In thermodynamic terms water is not fuel. True fuels such as gasoline, wood and coal do not create energy, but instead release it when they are heated, converting unstable bonds into stable bonds during the process. Water is made of stable bonds that resist most reactions (hence the reason is an abundant and useful chemical compound), therefore is does not contain the content of unstable combustible bonds like gasoline does, which are essential for the thermodynamic energy release process. Basically when you heat water you get steam, and this can power machinery, but with steam power you are merely transmitting the existing energy of the heat source to the pistons, not creating a release of higher, more effective energy that can drive sophisticated modern engines.

According to the principles of the first law of thermodynamics, the only way that water could take part in a reaction that produces higher energy would be to add higher energy compounds in to start with. For example acetylene is a combustible fuel made by adding calcium carbide to water, and this still technically means that water is not a fuel - it is the calcium carbide that is providing the reaction, the water is merely the vessel.


The only theoretical way to extract energy from water is with nuclear fusion, but with current technology this is not practical or cost effective method and has not been developed.

Some claims of water-fuelled engines are actually powered by the process of electrolysis. Here an electrolysis cell must be fitted to the vehicle, and these are powered by an electricity supply. The cell extracts hydrogen and oxygen from the water tank and this can then be heated to provide the power. The efficiency of such engines are restricted as the electrolysis cell requires more energy to power than can be extracted from the resulting hydrogen mix on its own.


The Japanese company Genepax has recently developed a type of car that runs on water and air, which has been dubbed a "water fuelled car". However the company has not revealed the core structure to this new design and it has been speculated that in actual fact metal hydrides are added to the water which are processed through an onboard generator. This would mean then that the metal hydride is the reactive source of energy, rather than the water, making it a hydride-fuelled car and not a water-fuelled car. Until the company releases the specifications of their design however, this cannot be confirmed.

There have been other claims of water-fuelled cars over the years, none of which have ever been independently verified, and until someone finds a way of breaking apart the laws of thermodynamics, it seems that true water-fuelled cars will always just be a concept, and never a reality.