How Much HHO Should I Use?

I frequently get asked about how much HHO will yield the best mileage gains for a particular car or truck. Well I have a very precise formula for that.  I got this formula from Bob Boyce directly when I met him at an HHO show in Florida a few years ago.  You need 1/4 liter per minute for each liter of engine size.  For example, if you have a 2 liter engine, you need .5 LPM of HHO. 

Now you have to watch our for something.  If your measurement (or your supplier's measurement) is truly honest and accurate, and you're not over-driving your cell so that it's making a bunch of steam, then the .5 LPM will be plenty for our example 2.0 liter engine.  But some hobbyists (and unfortunately, some suppliers) try to drive up their cell's statistics by using too much electrolyte for their cell.  These cells will then run very hot, and most of the apparent "volume" is due to the heat of the gasses, as hot gas has more volume than the same amount of cooler gas.  Also, the steam content that's included with the HHO further inflates the figure.  So in that case you would need twice as much volume, and in our example it would be 1.0 LPM instead of .5 LPM.  However, it's really the same amount of HHO in both cases.

More Is Better, Right?

People new to this subject think that if some HHO is good, more is always going to be better. Others believe that the electricity used to make the HHO is actually "free energy" since the engine is turning anyway. Both of these statements are false, as I will describe below.

First lets look at the alternator. When the engine is running it transfers rotational energy, via a belt to the alternator, which then generates electricity. This energy is actually a measurable drag on the rotational energy of the engine, and it costs fuel to counter this drag. Even if you're coasting down hill, the distance you will coast will be less before you have to add gas again to maintain your speed. The bottom line? The electrical energy from your alternator costs you gas to create.

Now lets look at the gas. HHO, when burned, does not give back as much energy as the energy that was used to create it. There are several energy conversions involved. Since there is no such thing as 100% efficiency, energy is lost at each conversion. The conversions are: mechanical to electrical (alternator), electrical to chemical (electrolyser), and chemical to mechanical (burning the HHO). By the time all 3 of these conversions have taken place, when the HHO burns you'll get back about 20-25% of the energy used to create it. But don't despair just yet. Awesome gains in mpg are still achievable using this technology.

Where we get our gains is the fact that the HHO causes the gas to burn more efficiently. The majority of the energy in our petroleum fuel is wasted due to incomplete combustion during the power stroke. The HHO causes some of this waste to be used in the combustion process. We're not actually getting it all back either. It's just that there's so much waste, that even getting part of it recovered makes a large change in our mileage. This is what makes HHO so valuable in our engines.

However, only so much HHO will give us more efficiency in this way. If you add more HHO after that, you'll then start to lose mileage because of the efficiency losses described above. Now, as you add more and more HHO, your mileage gains will start to dwindle away.  Now you'll be drawing more and more horsepower to make amperage, than you get back when the HHO burns.  Since you've already tapped the latent power in the petroleum fuel, and since more HHO doesn't help you recover any more of the petroleum fuel's power, the overall result is that your mileage will diminish.

Summary

So, by trial and error of many years, Bob Boyce, and many other researchers in the HHO industry have adopted the formula above.  I hope I have helped you in your quest to get the best mileage from your vehicle. If you have more questions on this subject, please post them at www.fuel-saver.org.