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Popular Mechanics senior automotive editor Mike Allen has debunked the myth that you can increase your fuel economy by burning the hydrogen from water in your car.
I've been tinkering with a couple of homemade and commercial HHO generators. I have instrumented several cars with HHO generators I can switch on and off, flow meters, scan tools and instantaneous mileage displays. I've tested them on the road and on chassis dynamometers, and have never seen any improvement. None.
I've been working with NBC's Dateline to debunk the whole hydrogen-on-demand industry. The show's producer bought a car, an ordinary five-year old Honda Accord, to perform our tests. I checked the car over to make sure it was up to spec. Then we did some over-the-road and steady-state dynamometer testing to establish base-line fuel economy numbers. NBC followed my testing up with additional testing at an EPA-certified emissions lab, which wasn't cheap. The lab used its climate-controlled emissions dyno to establish fuel economy numbers in our Accord with the same protocols the EPA uses to generate the numbers on the window sticker of new cars. They're accurate and reproducible to well under 1 percent.
Then we took the car to a specialist who installed, for nearly $1900, a hydrogen generator and a system of other enhancements. There was a fuel heater, fuel-line magnets (which I debunked here), and several inscrutable boxes full of electronics designed to fool the car's computer into using less fuel. There was even a bottle of acetone to add to the fuel. (This is something that I've mentioned doesn't work here and here). The specialist guaranteed major improvements in fuel consumption. One week and nearly two grand later, the producer from NBC (who still hadn't identified himself as anyone except a guy who was tired of spending $50 to fill up his tank) picked up the car. He got a gas receipt proving the installer had seen 96 mpg, nearly triple the original economy.
We took the car straight back to that same EPA lab for another round of testing. It was followed shortly by a week's worth of road testing, dyno testing and general poking about to see what we could discover.
You can guess, right? The total improvement in fuel economy after $1800 plus of expenditure? Bupkis. Too small to measure. Nada. In fact, if you look at the EPA tests with the system switched on and then off, there's a tiny increase in fuel consumption when the system is turned on. I attribute this to the 15 amps or so of current the electrolysis cell consumes to produce hydrogen. That current uses horsepower to spin the generator, and that consumes gasoline. The hydrogen "boost" couldn't even compensate for its own losses.
And that is exactly what I've been saying for years. These systems don't work. Popular Mechanics
Water-Powered Cars: Hydrogen Electrolyzer Mod Can't Up MPGs
Looking For A Miracle: We Test Automotive 'Fuel Savers'
THE MORAL OF THE STORY
We've tested nowhere near all of the fuel-saver gadgets on the market, and I'm sure purveyors of others will be waiting in our lobby soon. But not one of the items we tested worked. At all. There's no ignoring the laws of physics, people. Your vehicle already burns over 99 percent of the fuel you pay for. Less than 1 percent is squandered as partially burned hydrocarbons and carbon monoxide before the exhaust hits the catalytic converter for the last laundering. Even if one of these miracle gadgets could make the combustion process 100 percent complete, the improvement in mileage resulting would be 1 percent. Any device that claims quantum-level increases needs to be examined with considerable skepticism.
We say caveat emptor (let the buyer beware). But there are plenty of people out there who say: "There's one born every minute." Prediction: Within a few weeks after the appearance of this article, there will be gas-saving gadgets on the market that tout themselves as "Featured in Popular Mechanics.
More than once, Popular Mechanics senior automotive editor Mike Allen has debunked the myth that you can triple your fuel economy by burning the hydrogen from water in your car. Now, he's teamed up with Dateline NBC and an EPA-certified emissions lab to test hydrogen generators, fuel heaters, fuel-line magnets and acetone fuel additives, once and for all.