Popular Mechanics just ran the tests and reported on the results:
I have told people not to waste their money, but that is just based on the science: It takes more energy to electrolyze water than you get back out of it. In theory, injecting hydrogen could allow you to run at a different compression ratio, which could allow you to derive more useful work out of the engine. Or, it could allow you to run at a different fuel/air ratio. So I don’t necessarily reject it out of hand until I have seen the data, I am just highly skeptical. Popular Mechanics provides some data. The background:
Water-powered cars continue to be the largest single topic taking over my in box—and the Comments section of this Web site. And it’s not just my recent column on the truth about water-chugging prototypes. This trend has become an obsession with many backyard inventors, and some of them have become quite strident, insisting that if I knew anything at all about cars, I’d be embracing this technology. They say it could help change the world as we know it. They even say it could eliminate the energy crisis altogether.
So, last month I received an electrolyzer, fabricated by my old Monster Garage partner, Steve Rumore at Avalanche Engineering out in Colorado. Steve cleverly designed the device into a steel toolbox, making it portable—just the ticket for someone tinkering with HHO/water/hydrogen/Brown’s Gaspowered conveyances. The unit consists of eight plastic bottles with stainless-steel electrodes, connected up in series—parallel to the vehicle’s battery. The cells are filled with plain ol’ water and a small amount of potassium hydroxide electrolyte to conduct electricity. A hose conveys the HHO output to the engine.
It took me a few days of puttering around in my shop to get the electrolyzer up and running. I’m using an HKS Camp 2 onboard computer, hooked into an LCD monitor that’s suction-cupped to the windscreen, to check things like mass airflow, fuel-injector pulse width, battery voltage and, of course, fuel economy.
But guess what? My fuel economy is exactly the same, whether the HHO generator is turned on or not. And that’s exactly what I expected. This isn’t anecdotal evidence from several tankfuls of gasoline. It’s steady-state, flat-road testing, and I don’t even pretend to have actual economy numbers. I’m using fuel-injector pulse widths directly from the OBD II port. That means I’m measuring the actual time the injectors are open and delivering fuel. When the HHO generator is toggled on, there’s no change. And when it’s turned back off, there’s no change. Well, the computer’s system voltage sags a couple of tenths of a volt, indicating the current drain to run the electrolyzer.
This is not a great surprise, but it didn’t take long for someone in the comments section following the article to invoke the oil conspiracy charge:
As an owner of an auto repair facility that installs and configures HHO Cells i have to disagree with your findings. I am not surprised by your results considering your methods and your obvious opinion going in that it would never work. It does in fact work when installed and configured correctly. Your article brings to mind the weak attempt Mythbusters described on their show. Needless to say my high opinion of Popular Mechanics and MythBusters is not so anymore. By the way, i wouldn’t be surprised if the oil companies financed your obviously biased experiment.
Of course I have to point out that since the commenter installs and configures HHO cells, he has a vested interest in claiming that they work. One good accusation deserves another.