How much hydrogen in 15 gal of water

Question

if you put 15gal of water in like a gas tank and you use thy car the car eletrical system to help make the hydrogen into a storage tank for hydrogenthats on board can you make enough hydrogen to keep the car or truck to go 400 miles and how often would you have to change the tank water in the 15 tank to keep the car going

Answer 1

Water expands up to 18000 times it's volume

Answer 2

I would be much more worried about the batteries needed.. the car's electrical system does not have enough power to produce the hydrogen needed for your theory..  

Answer 3

13.77 pounds of hydrogen.

All else varies as to size of engine, efficiency, energy loss due to a number of factors, etc.

Answer 4

one part oxygen two parts hydrogen so i guess 10 gallons of hydrogen