There's actually a bogus way for the bad designs to work on old vehicles, this would be by running very hot and producing a mist of water, steam and powdered electrolyte, typically lye, this goes down a hose draped into the airbox... does it get sucked into the engine? Yes... by the crankcase vent... whereupon it reacts with oil mist and vapor in the crankcase due to various catalytic processes, a combo of hydro cracking, thermal and catalytic cracking (Lye is a good catalyst for reforming oils, ask the biodiesel folks) and comes back out the PCV valve as a mixture of hydrocarbon vapors... and finally into the combustion chamber. Due to copious blowby and pre-existing oil high consumption, it kind of escapes notice that the motor is sucking a quart a hundred miles now. For similar reasons PCV jars show larger gains on these vehicles, but don't create extra oil consumption. Typically though if the blowby was caused by stuck rings, the removal of liquid particulate oil from the induction stream will mean that the motor can clean itself up over a period... Then you get results like "I was getting 12mpg, then I used HHO and it went up to 24mpg, but after a while it went down to 18mpg, and I took it off, and I still get 18mpg"
Have you been laid up- injured from that stretch?
Old EPA 23/33/27
New EPA 21/30/24