HHO seems an out-dated technology that I fell it is not worth the effort.
Theoratically it's very simple, but to implement an engineering device for
automotive applications, a lot of issures must be considered or solved ----
space to install a big can; battery power to consume; battery get drained;
fuse get blowed; electrical connection; on/off control; pipe connection;
maintain liquid level; low liquid level will reduce current; higher liquid level
will be sucked into the engine, chock engine to die.... a lot of headaches
and hard works yet you get tiny result, and sooner or later, the plates get
corrupted and you need to rebuild the cells.....
DCD with its fully electronic control, has opened a new erea for automotive
fuel economy retrofitting. Once it's installed, it would last forever. The high
reliability of modern electronics will serve you unlimited time.
Therefore, I'd like to recommend that Ecomodders stop playing HHO, turn
to advenced DCD technology instead. Spending less efforts with DCD, yet
you could gain much more than HHO. DCD will absolutely worth the effort.