Consensus sucks, but when it comes to expert opinion about fuel saving devices and additives the jury is in.
From hydrogen generators to magnets, ignition enhancers to ionizers and even water injectors – who would have thought! – tests prove most devices not only do nothing, they could damage your vehicle.
Money-saving gadgets will always be popular among cost conscious drivers. But a closer look at how they work and whether they live up to their claims, paints them in a whole different light.
And, with price tags ranging from under $50 to more than $500, they can hit your hip pocket hard.
Are You Selling has examined the most popular categories and have come to the same conclusion – give them all a wide berth if you’re driving a modern car with a well maintained engine.
Designed to reduce the amount of unspent fuel that gets blown through an engine’s exhaust, this type of device is little more than a supercharged spark plug that never misfires.
Modern engines with computer controls and electronic ignition are so efficient, misfiring is more or less a thing of the past unless there is something radically wrong with the engine.
VERDICT: There’s no longer any need to enhance ignition.
Installed in diesel and petrol powered cars between the fuel pump and injectors, makers of these devices claim they create an ionic field to separate molecules in fuel making it burn more quickly and cleanly.
Modern fuel injectors already do this so well, there’s little if anything to be gained even if the makers’ claims are correct.
VERDICT: In old cars – very old cars, with old engines – perhaps they can improve fuel efficiency. In new models, forget it.
Fuel Line Magnets
Hailed as being capable of increasing power, improving fuel economy and reducing emissions, spruikers claim they help fuel burn more efficiently by “breaking apart clusters of fuel molecules.”
VERDICT: Tests conducted by Popular Mechanics show no impact on performance or economy.
The science of internal combustion engines is pretty simple. They act as large air pumps, sucking in a mix of air and fuel to be ignited and expelled through the exhaust.
The HowStuffWorks website makes no bones about the effectiveness of these devices: “This fuel saving quackery plays off misunderstandings about this process.”
In modern engines, writer Matt Cunningham argues, computers control the mix of fuel and air. “Alter this,” he says “and you’re more likely to hurt performance than improve it”.
VERDICT: Don’t risk it. Stay away from these.
Onboard Hydrogen Generators
Hydrogen, like fuel, burns. Introducing hydrogen into the fuel mix, so the thinking goes, reduces fuel consumption. The only way to produce hydrogen to save fuel is by using an onboard generator. But there’s the catch. The energy required to generate the hydrogen onboard uses more fuel, thus eliminating any gain.
But there is hope for this idea. Generating the hydrogen outside the vehicle and storing the gas onboard has potential. According to Autoblog experiments are taking place in India with blending hydrogen with natural gas to produce more efficient fuel.
VERDICT: One to watch but if saving money is the goal, the costs of generating the hydrogen might outweigh the savings it produces.
Developed during World War II, this technology was designed to increase power in turbo charged planes. At altitude, with less air for cooling engines, turbo engines heat up quicker and stay hot, reducing power and increasing fuel consumption.
Popular Mechanics explains: “Spraying a water-alcohol mixture directly into the air intake lowers the combustion chamber temperatures. This permits substantially more power for brief periods.”
At sea level, however, one of these devices fitted to a car generated less revs at a 20% reduction in fuel economy.
VERDICT: Get your head out of the clouds. This technology doesn’t work.
Fuel Vapour Injectors
Vaporized petrol burns efficiently enough to power a modern engine. This is exactly what modern engines already do. And they do it while monitoring the correct fuel-air mixture all the while.
HowStuffWorks warns that vaporizing the fuel any more risks engines running rich, sapping performance.
VERDICT: A great big hoax! They’re not worth the words we’ve just written about them.
Fuel and Oil Additives
They don’t cost much, but most of these don’t make a blind bit of difference to how your car performs.
HowStuffWorks sums it up well: “Some additives may indeed work. But understanding which ones can make a difference for your car or truck requires a thorough understanding of both the engine and the additive.”
VERDICT: Of all the options, some experimentation with fuel and oil additives might produce some elusive fuel consumption savings. Your guess is as good as ours as to which ones work in what cars and why.
These little rippers add pieces of various metals into the fuel as it travels between the pump and the injectors, supposedly producing a catalytic reaction to remove impurities from the fuel.
This may have worked in old carburettor models but has little value in assisting the combustion process in modern vehicles.
VERDICT: They’re expensive and they only produce minimal changes in the properties of fuel. Even if they do work, would you ever get your money back?