The debate in Pakistan continues about a water fueled car, where water has been claimed to be the sole source of energy to power a car engine. In various TV shows, the claimant engineer, Agha Waqar has made no attempt to explain the underlying theory that makes the car run on water as fuel. It has been however, stated that the car battery supplies a small amount of electrical energy to a proprietary, custom built electrolyzer that supports the process of electrolysis to extract hydrogen from water. Hydrogen produced by electrolysis is fed to the engine as the fuel, replacing the conventional fuel such as gasoline.The process of water electrolysis has been known for at least 300 years. Depending upon various configurations of the electrolyzers (the electrolysis chamber), it has been reported in the industrial literature that an electrical power of 4 to 5kw is required for the electrolysis of 1 liter of water.Agha Waqar has apparently claimed to have run the car for about 40 km on 1 liter of water. A liter of water has approximately 110 gm of hydrogen. 1 gm of hydrogen has same amount of energy as 2.8 gm of gasoline (petrol). This means, 110 gm of hydrogen (the contents of 1liter of water) can be equated to 2.8 x 110 = 308 gm of gasoline. Since 1 liter of gasoline weighs 760 gm, the volume of 308 gm gasoline would be 0.4 liter this translates to running the car for a distance of 40 km on 0.4 liter of gasoline. This is impossible as the car shown in the demonstration will not be able to run for more than about 20 km on a liter of gasoline, let alone 0.4 liter of gasoline.Furthermore, we have not yet considered the electrical energy required for the electrolysis of a liter of water which is at least 4kw, and has to be provided by the car battery. But the battery of a small car may not even have the capacity of over 500mwh, which is about 1/8th of the energy required to separate the hydrogen which is present in 1 liter of water. There have been two unexplained anomalies associated with the televised demonstrations which are: Hydrogen obtained out of 1 liter of water has been claimed to have run the car for a distance of about 40 km. A lot more of electrical energy is required for the electrolysis of 1 liter of water than a normal car battery has the capability to provide. From the two anomalies, it is obvious that a claim is being made that the demonstration car provides more power than it consumes. In other words, it creates energy out of nothing or the efficiency of the claimed system is over 100 percent. This is a scientific impossibility and clearly the claim violates the 1st and the 2nd law of thermodynamics. On commercial scale, the cost of production of hydrogen through electrolysis of water has been reported to be approximately US$5.00kg. Using the conversion figures given above, 1kg of hydrogen can be equated to 3.68 liters of gasoline. The current retail price of gasoline in the US is about $1.00 liter. At these prices, it is obvious that running a car on gasoline is still cheaper than using hydrogen. JAVED I. CHAUDRY, Lahore, September 17