The nail in the HHO coffin.
So I got bored, I have insomnia, so I did a little homework on HHO.
The HHO theory:
An electric current is used to break the chemical bonds in water to separate the hydrogen and oxygen (electrolysis). That hydrogen is then combusted and the additional energy of the combustion of hydrogen is added to the energy from the combustion of gasoline, increasing your MPG's. Here's where I found some variation in the HHO theory. Assumption 1: The alternator in your vehicle produces more electricity than you need so you can use this extra free electric energy for electrolysis. If it didn't, your vehicle would stall every time you turned on another electrical component; OR Assumption 2: The amount of electric energy required for electrolysis is far less the amount of chemical energy obtained from the combustion of hydrogen. Or these assumptions are both used. The assumption that the oxygen needed for combustion is also produced with electrolysis, and that no outside oxygen is need. This means that this is a closed system, more on this later.
Scientific Law: The law of conservation of energy: Energy cannot be created nor destroyed; it can only be changed from one form to another.
An internal combustion engine converts the chemical energy stored in gasoline to mechanical energy. In the presence of oxygen, a spark is used for ignition. Ignition causes the gas to expand (mechanically), forcing the pistons down, turning the crankshaft, which eventually turns the wheels. (This reaction is quick, and the gases produced are ejected before they have completely expanded. So the theory that HHO adds more gas, or more heat making the gases expand more, or more rapidly, is false). This conversion of chemical energy to mechanical energy also produces heat, and light energy, which your engine does not use. So the mechanical component is the only useful component, and the heat and light produced are wasted. Only 30% of the chemical energy in gasoline is actually converted to useful mechanical energy. The other 70%, since it cannot be destroyed, is converted to useless heat and light.
This mechanical energy in turn, is used to spin an alternator, creating an electric field, essentially converting mechanical energy to electrical energy. There are losses here as well. Slipping and/or stretching of the belt, friction of the bearings, and wind resistance (drag) of the spinning components. The alternator efficiency varies by depending on the alternator, but usually has an efficiency of 45-70%.
Here's where the HHO assumptions come in.
Assumption 1: The alternator produces more electricity than is needed. For a second, let's assume this is true. If it is, and energy cannot be destroyed, only transformed, where does it go when it isn't used? Your alternator would be sending out lightning bolts if this were the case, or producing massive amounts of heat. Look at how much heat is produced by gasoline, which has an energy efficiency of 30%. If the were the case with an assumed 70% (best case scenario) efficient alternator, think of the amount of heat that would be produced when this "unused energy" isn't being put to use.
So your alternator doesn't produce extra energy. Where does the additional energy come from when you turn on extra electrical accessories (hint: it's not the battery, your battery is not used as a source of electricity while the vehicle is running. The battery stores electricity, chemically, for use when the alternator is not spinning.) The alternator gets its extra energy from the mechanical energy of the engine, robbing your engine of more efficiency.
Assumption 2: The amount of energy needed to break the chemical bonds is less than the amount of energy produced from the combustion of hydrogen. Remember, this is a chemically closed system with HHO, all the needed oxygen is provided by electrolysis. The only thing entering the system is the electricity. (If it wasn't, this would rob oxygen needed for the combustion of gasoline, which would cause less gasoline to burn causing your engine to run 'rich' and thus lowering efficiency). So you're breaking the chemical bonds of water, only to reform them. Remember, energy cannot be created nor destroyed. What exactly does this do? Essentially it converts electric energy from the alternator, into heat, which we already stated was USELESS in a mechanical engine!
Conclusions: An HHO system decreases the efficiency of your engine by using mechanic energy, which is converted by the alternator into electric energy, to produce useless heat. So why do people think HHO improves fuel efficiency? Because their Scanguage tells them it does. Instantaneous miles per gallon are calculated using information from the computer based on the amount of gasoline injected and the speed (and therefore distance travelled speed = distance/time; you can't have speed without time) of the previous two seconds. So the number you are seeing is the MPG's two seconds ago. Measuring mpg's this way is horribly inaccurate, because the fuel injectors aren't very accurate. So I assume the extra heat generated has some effect on the way the computer measures volume of fuel being released by the injectors.
Why is this a topic for discussion? Well, as with most myths, its based on ideas that sound like science (pseudoscience). Your average person isn't a scientist and doesn't think like one, but that doesn't make them stupid, they just lack an understanding of scientific principle. (I'm trying not to insult anyone.) Being smart, and being intelligent are two totally different things. Being smart is defined as having a ready mental capability (i.e. the ability to regurgitate information). Being intelligent is defined as having the capacity to learn, to reason and to understand facts and meanings.
