Yeah even if you could get enough energy from the HHO to power the entire car, it's still not perpetual motion because you're still inputting fuel (the water). Some people are getting confused between free fuel (as in water) and free energy (as in perpetual motion). Just because the fuel is plentiful and free does not make it *free energy*.
Now using just a little bit of energy to make a fuel additive (hydrogen) that will improve the low combustion efficiency of diesel or gasoline to the point where you're improving efficiency enough to more than offset the amount of energy you're using to produce the additive... well calling that unrealistic is just not thinking things through IMO.
Now using just a little bit of energy to make a fuel additive (hydrogen) that will improve the low combustion efficiency of diesel or gasoline to the point where you're improving efficiency enough to more than offset the amount of energy you're using to produce the additive... well calling that unrealistic is just not thinking things through IMO.