Why do people call HHO generators perpetual energy?

A 9 volt battery would work to create electrolysis but not enough for a car. Perpetual it is not, but it makes the gasoline burn faster so therefore more power to the punch, meaning it has overcome the alternator issue of using an extra 10 HP or whatever it is, because it gave you more HP than that by using HHO. You cannot store Hydrogen, oxygen mixed HHO they call it. Its a bomb. Therefore it has to be made on demand and not stored. 12 volts 20 amps is about what it takes to make 1 liter per minute using the basic methods. Not enough to run a car by itself, but it aids in the gas exploding to bring up its efficiencies. You can argue until your blue in the face, but the fact is, it works. some claims almost double, others probably 50 % increase more or less. probably because the designs are all different, and nothing to base it by. Just more miles per gallon of gas, no matter how much more power it takes, If i can go a few miles farther using water why not?