ive researched this quite a bit and I believe it does work..
but from what i've read the powerstroke isnt the best vehicle for it, something to do with how the powerstroke injects the fuel in two stages??
dont know how accurate that is..
hho is pretty neat stuff, have a guy i work with that was messing around with a generator just slapped together and was producing hho.. he wanted to see if it was producing gas so he filled a small soda bottle with it and threw it in a fire.
big boom..
myth busters tried to use hho solely as fuel not as supplemental fuel witch is where hho is the best right now..