Car Corner
Water 4 Gas, Is It Real or Not

September 1, 2008
By Scott Lewis

I am amazed at how many people are willing to believe in a product that will increase gas mileage by 50-300% just because gas prices are so high. A lot of people have mentioned Water 4 Gas. No, you cannot run your car on water, but devices like this use hydrogen they get from the water to improve the mileage your car gets.

How Does It Work

Let's take a look at this technology to see how it works. Water4gas, Hydro Runner, Hydro 4000, etc. All of these devices work off some basic principals of physics. Water, or H2O, is two parts hydrogen and one part oxygen. Hydrogen can be used as a fuel source. Why not extract the hydrogen out of water and run our cars on the hydrogen. Simple.

Every system I have done any research on does the same basic thing. They use electricity from your car's electrical system (your alternator) to perform electrolysis. Electrolysis is a method of separating chemically bonded elements and compounds by passing an electric current through them. These systems take the hydrogen acquired from the water and channel it into the intake stream of a car's engine. The principal is to have the car burn a combination of hydrogen and gasoline, reducing the amount of expensive gasoline your car needs.

So, does it work? Or is this a scam? Well, it does not work, and it most definitely is a scam.

Sorry to be so blunt, but the process that these people suggest is so close to impossible I find it amazing that so many people would believe it is true.

Let's do a little math. How much hydrogen can we get from water. Well, when we convert water to a gas it take up a substantially larger volume. For instance, 1 liter of water will generate approximately 2,689.7 liters of hydrogen (see this article). This seems like a lot of hydrogen.

The real math comes when we look at how much "air" an internal combustion engine uses. A basic four stoke internal combustion engine (intake, compression, power, exhaust) must make two full revolutions for all its cylinders to go through an intake stroke. Let's late a typical 3.0 liter 6 cylinder engine. At 3.0 liters that means the total of all the cylinders is 3.0 liters. Since it takes two revolution to fill the entire engine we could just say that in 1 revolution it takes in half, or 1.5 liters per revolution.

At highway speeds an engine running at 2,000 revolution per minute (RPM) is common. So, the engine takes in the following:

engine size / 2 * RPM = volume per minute

3.0 / 2 * 2000 = 3000 liters per minute.

So, at highway speed our car with its 3.0 liter engine is breathing in 3,000 liters every minute. The Hydro Runner device mentioned above claims that 1 liter of water will last 3,000-4,000 miles.

Let's take another look at our 6 cylinder car. At highway speed, say 70 MPH, with its engine turning at 2000 RPM. We know that it consumes "air" at a rate of 3,000 liters per minute. How many hours does it take to travel 4,000 miles?

4,000 miles / 70 mph = 57.1 hours traveled

57.1 hours * 60 minutes per hour * 3,000 liters per minute = 10,278,000 liters of air consumed over 4,000 miles traveled.

So we are going to introduce 2,689.7 liters of hydrogen into over 10 Million liters of air. That's 0.026%. A miniscule amount. Yet we are to believe this tiny amount of hydrogen can cause amazing improvements in mileage.

It Can't Work

On any car built after 1996 this can't work. Cars since 1996 have OBD-II (On Board Diagnostic, version 2) which includes oxygen (O2) sensors in the exhaust. If there is oxygen in the exhaust the computer can adjust the amount of fuel to get the engine to run as close as possible to the perfect air/fuel ratio to get the most out of the gas and the least emissions. If you introduce enough hydrogen to upset the balance of oxygen in the "air" going into the engine then the computer would counteract it.

At least with such a tiny amount of hydrogen being introduced you can be sure that you aren't going to damage your car.


The HydroRunner device costs $3500. Even if it could return 50% improvement in mileage, how long would it take for you to get a return on your investment?

12,000 mile @ 25 mpg = 480 gallons @ $4.00/gal = $1,920/year

Add 50%:

12,000 mile @ 37.5 mpg = 320 gallons @ $4.00/gal = $1,280/year

If it worked you would save $640 a year. That means it will take about 5-1/2 years to break even on the investment... assuming it really did work and you kept the car that long.

I really like how they show the results of an "independent" test of the system. The testers used the cars on board mileage display to determine the mileage. And we know how well they use the controls since they had to invalidate two tests because they accidentally turned off the overdrive.

Heaven forbid they do the test accurately and put in a measured amount of gas into the vehicle and see how many miles it travels on a chassis dyno. Of couse people will tell you they don't drive on a dyno. Yes, but on a dyno you can control many more variables, such as terrain, weather, traffic, etc. If it can't work on a dyno how can it work in the real world. And let's not forget the placebo effect. People will sub-conciosly drive will better mileage in mind while they drive with such a device. You can influence you mileage y over 20% just with driving technique alone.

Why not submit the device to the EPA for testing? After all this is what they do. I know the answer the device makers and the supports of these devices will say. They will claim that no one believes the number the EPA puts on cars is real. But what they fail to note is that the EPA's tests are extremely reliable and repeatable. If the device really worked it would improve the mileage during the EPA's testing by the percentage claimed. It's like the chassis dyno test, they don't do it because it will fail.


The Hydro4000 only costs $1,200. A news station actually tested this themselves. They took a vehicle and ran it on a chassis dyno with a measured amount of gas. Hey, we're on the right track here. Then they installed the device and let the owner drive around for a month. Then they tested the car again.

They showed a 10% improvement in mileage. However, their testing was seriously flawed. The biggest flaw was not removing the device and testing the vehicle on the same day with and without the device. Surely if the device were responsible for the mileage increase then removing the device and running the vehicle again would show a reduction in mileage.

Let's assume for a second that the device did provide a 10% improvement. How long before you get your money back on the $1,200 investment:

12,000 mile @ 25 mpg = 480 gallons @ $4.00/gal = $1,920/year

Add 10%:

12,000 mile @ 27.5 mpg = 436 gallons @ $4.00/gal = $1,744/year

That's a savings of $176 a year. That means it will take about 6.8 years to recover the cost of the device. Assuming the 10% was due to the device and not substandard testing procedures. For instance, their testing was done a month apart. Any chance the they didn't perform every step exact the same. They took the owner's word for it that the vehicle was in good condition. Why not take it to a mechanic and have it tuned up to be sure the vehicle was in the best possible state of tune to test the device?

10% is such a small amount that they should have repeated the test just to make sure they could repeat the results. Heck, you can get over 20% improvement in gas mileage through driving better.


There are so many flaws in these systems. They are all scams. If they really worked why wouldn't any car manufacturer want to install them in their cars across the board and have a real advantage over their competition. GM and Ford are losing billions. Surely they would have put their engineers on this to try and save their companies.

None of the devices are being testing by the EPA. Why not? The cost to have the EPA test a device and declare it a success would be invaluable in providing credibility to the device. The only reason not to do it is because it doesn't work.

If you don't believe me read Popular Mechanics report on these type of devices. Even better, read their article on 7 gas saving myths debunked.

Let's face it, there is no magic device that will have your car getting huge improvements in mileage. If there was the manufacturers would use it. Unless you believe in the conspiracy theory that the oil companies are paying the manufacturers to not make cars that get better gas mileage. Yea, that's working. GM and Ford are losing billions because the oil company is paying them under the table. Yea, that must be the reason these devices have never been installed by the manufacturers, because they are making a massive profit to not install them.

Those who say it works are one of two people. 1) They have a vested interest in it... meaning they are trying to make money off of it, or 2) they bought one and are too embarrassed to admit it doesn't work or just too foolish to believe it doesn't work..

Next month we will look at a number of real possibilities for cars to get better gas mileage as well as alternative fuels that promise to relieve our dependency on foreign oil.