Gas Savers and Hot Air

Want to save some gas? There’s a sucker born every minute!

When gas prices climb, the crazy people and swindlers come out of the word work. Since we are well on our way towards gas prices going above four dollars a gallon all across the country and not just on the coasts, consumers are grasping at straws. They are doing anything they can to try and save fuel including spending money on contraptions that come with big promises. Many cheats, thieves, and charlatans are pushing all sorts of products to try and tell you that you can save fuel by installing their revolutionary device.

Most of these devices are either doing something to change airflow into the engine, or they are doing something to try and affect the combustion process, or they try to enhance the ignition source. The devices that change the airflow into the engine probably end up blocking the flow of air into the engine more than anything else. This will actually lead to a loss in power and possibly a decrease in fuel economy. The gadgets that claim to affect combustion probably don’t do anything at all to the combustion process, and in some cases might even be harmful to some of the things that make the vehicle run right, such as O2 sensors. If the device adds any kind of fluid to the air fuel mixture it is possible to hurt the O2 sensors which are installed in the exhaust pipes.

They all claim an increase in fuel economy somewhere around 20 to 30 percent. The problem with this is that modern engine control systems are so accurate and so efficient that only a tiny fraction of the fuel that is injected doesn’t get consumed. When fuel is not fully burned in the combustion chamber it comes out the exhaust as carbon monoxide and hydrocarbons. Looking at the emissions from a modern vehicle, before the catalytic converter, the amount of CO and HC’s is very low. CO is likely to be less than .009% and HC levels will be less than 1 part per million. How on earth can it be possible to increase your car’s fuel economy by 20% by burning this unburned fuel, when we are only talking about the possibility of burning such a tiny amount?

Most of these devices take a theory that applies to something else in the engine function or controls, and misapplies that theory in the name of saving fuel. The following is a bit of information about a few of these devices from different manufacturers. These are not necessarily the most popular ones but they are representative of the different types of devices that the consumer can waste their money on in a bout of wishful thinking.

Tornado Fuel Saver

This is a little device made from small metal fins arranged together in a circle that are supposed to create a swirling motion in the intake air. One of these contraptions will usually cost you about $50. This swirling motion is supposed to increase volumetric efficiency or something like that. The fact of the matter is that most engine designs and intake manifold setups are already designed to create turbulence or a swirling motion in the air stream that enters each cylinder. This helps to atomize the fuel as it leaves the injectors and flows into the combustion chamber, and it is supposed to help the fuel mixture fill the combustion chamber evenly so that it gets burned more thoroughly.

The Tornado installed

Swirling the air as it enters the intake manifold is useless since the air splits into the various intake ports as it goes into the engine and how is it supposed to keep this swirl? Automotive engineers have been studying air flow and volumetric efficiency for over a hundred years now and they know what works and doesn’t work when it comes to making the air behave properly in the intake manifolds and the combustion chamber. If efficiency could be increased so easily every engine designer and manufacturer would immediately be integrating their own version of this design or process into their product, and if they didn’t it’s very likely that the EPA would mandate that they do so. This notion really applies to all of the gas saver devices.

Platinum Gas Saver

This item will set you back about $150 plus installation. Many companies build something along these lines; they are all about the same thing. Manufacturers claim that it might take 1,500 miles before it starts to become effective. This is another common claim from the people that make just about every fuel saver. They also claim that you might need to replace your oxygen sensors. This is silly because no good reason exists for doing so just because you are now running tiny amounts of platinum through your engine. The real reason that they recommend this is because most O2 sensors on cars that have been on the road for a while, sat for 100k miles or so, probably have O2 sensors that have lost some efficiency anyway.

Magic platinum fluid. If the solution in the bottle really is platinum, it can't be cheap.

Any gas saver that uses platinum has some kind of reservoir where a solution is held that contains some form platinum. A vacuum line from the engine’s intake manifold connects to the reservoir where the solution is sucked into the intake manifold. Once inside the manifold it goes into the combustion chambers of the engine, or at least into the combustion chamber that is closest to the vacuum line.

The theory is that when combustion takes place in the presence of platinum, the combustion will be more complete. Platinum is one of the elements found in catalytic converters to act as a catalyst to trigger the complete oxidation of any of the carbon monoxide and hydrocarbons that didn’t get used up in the combustion process. The definition of a catalyst is something that triggers a chemical reaction but does not get consumed in the process. Dribbling platinum into the intake manifold and then letting it run down into the combustion chamber is not the same as coating a ceramic element inside of a catalytic converter. This does nothing to save fuel.

Fuel Doctor

This device retails for $50 and is super easy to install because you just have to plug it in to your cigarette lighter or accessory socket. The device has a couple of LEDs that light up as you drive down the road. The manufacturer claims that this electronic device cleans and conditions the electrical power running through the vehicle’s electrical and electronic systems as you drive. With this “conditioned” electricity the electronic control systems become more efficient which helps the engine become more efficient and thus use less fuel.

This is pure quackery and very insulting that these people think we should believe this drivel! Conditioning the electrical power? What nonsense! How is the condition of the electricity affecting engine output, and how would something plugged into the power outlet change the electricity flowing throughout all of the vehicles systems?

On their website they show a video of a power supply attached to an oscilloscope and on the scope you can see some electrical noise. They say that this noise represents the noise from the battery of the car. The problem is that a DC battery doesn’t put out any noise, not even on a car that is 2 years old or older. This is just not true, and combined with the fact that when your engine is running the system voltage comes from the alternator, their demonstration is useless. Some noise can occur from the alternator but it doesn’t have the effect on the computers and control systems that these people claim.

With the alternator turning typical electrical system voltage is going to be in the neighborhood of 13.5 to 14.5 volts. The voltage must be higher than the 12.6 volts of the battery so that electrons will flow into the battery recharging it. The alternator actually produces 3 phase A/C electricity but everything in the car runs off of D/C, and of course the battery can only store D/C. Because of this the electricity produced by the alternator must be rectified from A/C to D/C.

This occurs in a device called the rectifier bridge which is made up of six diodes, 2 for every phase of alternator output. What actually occurs during the rectification process is the alternating current that switches from positive to negative gets cut off from going negative. These negative waves get rerouted and become positive. This happens to all three output phases so that the end result is a fairly direct flow of current into the vehicle’s electrical system.

Looking at this output up close using an A/C coupled oscilloscope you can see a bit of what is termed A/C ripple. If there is too much A/C ripple then things like the engine control module can be damaged. The maximum amount of ripple that the system can have before problems start is about 500 mV peak to peak, high to low.

Normal A/C ripple. This is harmless and normal on every car. This is the top of
the A/C sign waves that come from the alternator.

On the video that the Fuel Doctor shows on their website they show some noise that could be compared to A/C ripple, then they plug in their device and the noise goes away. Big deal. The noise to begin with appears to be around 100 mV. So even if this was true A/C ripple from an alternator, or some other such electrical noise, which it is not, the oscillation that they say is a problem isn’t even high enough to affect anything.

These computers are digital devices. They are either on or off, they either work or they don’t. The A/C ripple will cause them to shut down, or it won’t. Middle ground or gray area is not something that occurs with the function of a digital control mechanism.

Like so many of the other fuel saving devices, the Fuel Doctor people say that you have to drive your vehicle for a while before it will work, but they don’t really say why. Probably to blow out all of the carbon or some such thing. The real reason that they say this is because the device won’t work ever, but if you keep trying then I suppose you hang on to the hope that you really didn’t waste your money, or maybe with some time you will become bad at math and will not be able to properly calculate fuel economy.

Ignition Enhancers

These devices usually claim that they can save you gas by increasing the power of the spark that is responsible for igniting the air/fuel mixture. The claims vary and the setup of these devices follow a few different arrangements. Some of them are meant to be attached to the spark plug wires, and some consist of special voltage enhancer that installs in series with the coil wire. This thing is just another air gap for the spark to jump.

Those that claim to increase the voltage say that more voltage in the secondary ignition means that the fuel will burn faster, or more efficiently. This does not happen because the controlled burn of the air/fuel mixture occurs once it is lit, and the voltage of the spark does not affect the rate of combustion. The only thing that’s important is that the duration of the spark be long enough to get a good burn. Spark duration will usually go down if the firing voltage in the secondary goes up.

Clip these ionizers (little rubber blocks) to your spark plug wires and you too
can save save save!

In many high performance applications increasing this voltage is necessary because these engines have higher compression ratios which makes ionization of the air molecules in the spark plug gap more difficult with lower voltage. In these cases a more powerful ignition coil is used, and/or higher voltage is used in the primary side of the ignition coil in order to produce higher voltage in the secondary.

Increasing the secondary voltage only helps in special applications, and really does nothing to help any situation on the average vehicle of today, and most especially does not save you any fuel. Increasing the secondary voltage can have a slightly negative effect in that it can cause spark plugs to wear faster than normal. This extra voltage causes more metal transfer between the electrodes of the plug which is how spark plugs wear out. The other thing that can happen is that as resistance increases in secondary ignition components, the increased voltage will make it more likely that the spark will leave its normal path. This will cause a cylinder to misfire.

Fuel Line Magnets

These have been around for a very long time and come with all sorts of different names printed on the package. Sometimes these devices are referred to by their manufacturer as a fuel ionizer. This is usually the case when they want the buyer to think that they are getting something special, something that is not just a couple of magnets. An ionizer sounds like something high-tech. An ion is simply an atom that is missing an electron or has and extra electron. What does this have to do with combustion? Nothing.

Fuel line magnets in action.

They all work (don’t work) the same way. You attach them around your fuel line that is going to the fuel rail where the injectors are located. This allows the magnetic flux that emanates from the magnets to affect the fuel as it flows to the injectors. Much of the time these fuel lines are metal so attaching magnets to it wouldn’t even allow the field to reach the fuel since the metal line would actually deflect the magnetic lines of flux.

The claims all vary from one magnet maker to the next. Some claim that the hydrocarbon molecules that make up the fuel are grouped in big clusters that when injected don’t get consumed all of the way. This leads to inefficiency, more fuel used, less power output, and higher emissions from the tailpipe. Some others claim that the molecules are strewn about haphazardly as they enter the injectors which causes inefficiency in the burn. Passing through the magnets forces the molecules to line up in nice even rows, facing the same direction. Aligning molecules has nothing to do with combustion efficiency. Furthermore, if aligning molecules somehow did contribute to combustion efficiency, how would you keep the molecules aligned after they passed through the magnetic flux? Everyone knows that molecules are always moving around bumping into each other even when they are just sitting there.

You can tell that they work well based on this picture.

So the magnets are supposed to rearrange the molecules, which then causes the fuel to burn faster, or more completely. No matter what the claim is about the hydrocarbon molecules and how they are behaving or not behaving, the fact of the matter is that magnets or fluxes don’t have any effect on gasoline. Magnets only affect things that are electrical, or at least somewhat ferrous, like iron or steel. Everyone knows what magnets stick to and what they don’t stick to, but never the less people buy into the supposed power of magnets and claim that they work miracles for all sorts of different things.

Hydrogen Generators

If anything has a chance to work it this, but sadly it still falls short. These devices tout the use of hydrogen (H2), or Oxyhydrogen (HHO), as being something that can be mixed with your intake air to increase your fuel economy. This may be true in theory and this is why many people who don’t believe in any of the previously mentioned fuel savers will continue to come back to these devices as being legitimate. The problem here is a matter of scale.

A typical HHO generator.

Engineers have developed a number of different alternative fuel prototypes that run on hydrogen. Most of them use hydrogen fuel cells which use the single proton and the single electron of the hydrogen atom to produce electricity that runs an electric motor. This is totally unlike using hydrogen to produce combustion. Some auto companies however, have built vehicles with normal internal combustion engines that will run on straight hydrogen instead of gasoline. These engines work very well and produce very little pollution, much less than an internal combustion engine because there is no carbon in any form getting wrapped up in the combustion process.

In these engines a large volume of hydrogen is stored in a very large and rather specialized tank onboard the vehicle. While these vehicles work very well the problem they have is the process of sourcing the fuel. While hydrogen is the most abundant element in the universe it does not occur naturally anywhere on planet earth, so it is usually rendered from splitting water molecules or breaking down hydrocarbon fuels. This process takes a tremendous amount of electricity.

Hydrogen fuel saver mounted under the hood.

The hydrogen generator type fuel savers use a very small fuel cell in which electrolysis is used to split the water molecules that are stored in a small onboard tank. The hydrogen that results is drawn into the intake manifold, and it does get burned with the gasoline. The total amount of hydrogen that is used is tiny, certainly not enough to make a difference in fuel consumption. If you were to install more fuel cells to produce more hydrogen then you would have to have more electricity coming from the vehicle’s alternator to produce the extra hydrogen. This would place an extra load on the alternator and on the vehicle’s engine. If the engine is working harder, then obviously it would be using more fuel.

Someday maybe we will have cars that run on hydrogen in some way or another, but that day will not come until we figure out a way to produce massive amounts of electricity in a manner that is relatively cheap and does not pollute. Which is not to say that we couldn’t do this now.

When Will We Learn?

If you want to save fuel get a smaller car. Many people insist on driving cars that are bigger than they need or have bigger engines then they need. If they want to drive this kind of car then that’s fine, but they shouldn’t expect to have 300 horsepower and 40 mpg. Other things that can help save fuel are simple things like obeying speed limits, and avoiding jack rabbit starts every time the light turns green. Most cars will also get better fuel economy if speed limits are obeyed.

Vehicle maintenance also helps to save fuel. If your check engine light is on, get it fixed because there is a good chance that the failure will cause a reduction in fuel economy, because it most certainly causes an increase in emissions. Remember simple things like replacing spark plugs at recommended intervals, and keeping all services current. These things are not difficult to remember, all you have to do is follow the manufacturers recommended service schedule. This can always be found in the owner’s manual or through some searching online.

What about tire pressure? Some politicians in Washington like to tell us that we should just check our tire pressure every time the price of gas starts to jump up. Does this really make a difference? It does make a difference but it is pretty slight. Somewhere in the neighborhood of .03% for every PSI that you are low. This adds up eventually but keeping your tires inflated properly is more about making sure they don’t wear out too quickly, or about keeping the car safe, then it is about fuel economy.

So if you want to save money at the pumps the most important things are: drive a smaller car, drive with a little more self-control, and take care of your car. Whatever you do, don’t buy any crazy device to hook up to your engine, or to plug in here or there. None of these work because if they did, everyone would have them.