Save gas by adding water?

There was an article in the July 16th Jamestown Sun about a couple of brothers in Duluth, MN who have come up with a device that is supposed to save gas in your car by adding water. The writer (Jana Peterson of the Duluth Budgeteer News) doesn't offer even a hint of skepticism or scientific knowledge.

Basically, what Jay and Rick Plante have done is come up with an electrolysis machine. It passes electricity through water, which breaks it down into hydrogen and oxygen. The hydrogen is then piped into the fuel/air mixture, where it is burned as regular fuel. The brothers have a kit available for a few hundred dollars to set up your car to run on hydrogen.

The device should work fine, with one major problem that anyone with a basic science background should know: you won't save gas. Yes, we can produce hydrogen by electrolysis. This hydrogen can burn in an engine (I have no idea how efficiently in engines not designed for hydrogen). The hydrogen only produces water as a product, no carbon dioxide or other pollution. Hydrogen has a reputation as a clean fuel, maybe the fuel of the future.

So what is the problem? The second law of thermodynamics tells us that we can't get energy from nothing. Useful energy is always lost. Are the brothers in fact getting energy from water? Water has almost no usable energy in it. The problem is in the source of the energy for electrolysis. What isn't made explicit in the article is that the electrolysis runs off of the car battery. Drawing a charge from the battery requires more energy to recharge the battery. Just as you get fewer miles per gallon when you run your air conditioner off of the battery, you will get fewer miles per gallon if you run your electrolysis machine off of the battery.

You get some of that energy back when you burn the hydrogen. But the second law tells us that some will always be lost. The energy you get back by burning the hydrogen is necessarily less than the energy used to make it in the first place. Ultimately, this device will not save gas, it will decrease your fuel efficiency and it will increase pollution. Amazingly, no place in the article is there any indication that the brothers have ever attempted to measure their fuel efficiency.

There are several other interesting points in the article. At one point, it refers to the water in the electrolysis machine as a brownish liquid. I suspect the reason that it is brown is because they are using steel wires, and these will oxidize during electrolysis. The wires are slowly rusting away, and would have to be replaced frequently. To prevent this, you would need to use a metal that won't oxidize, such as platinum, which would obviously be much more expensive.

Jay is quoted as saying "at $1.29 a gallon for distilled water, it's a lot cheaper than gas". He seems to believe that they are getting as much mileage for each gallon of water as for each gallon of gas. Even if the machine didn't lose energy, there would be no reason to assume this.

Jana Peterson made no attempt at all at skepticism. If science education were up to standards, anyone with a high school degree should realize there are problems here. At the very least, she could have asked an engineer whether this should work, or just asked the brothers what their mileage is before and after they added their device.

The brothers seem to really believe in their device. I don't think it is deliberate fraud. But it is fraud nonetheless, and this article will probably help them sell more of their devices, especially in the current energy climate.

At least I got one thing out of this article. I can now assign it to my students after our section on thermodynamics and see if they can spot the problems.