Cars
Fuel saving devices
Introduction
It would be nice if we could snap something on to our engines, get instant fuel savings and have more power too. Several products make promises like this, but we had trouble finding proof to backup the claims.
While researching fuel savers we found some extraordinary claims - magnets that pull molecules apart; stickers that generate resonant frequencies; and a lab report that was discredited in Britain years ago.
Talk is cheap
It's easy to promise the world in ads, but it's illegal to make claims you can't prove. We asked eight sellers of fuel-saving devices to justify the claims they made in their advertising.
Several sellers offered us a free example of their device so we could test it ourselves. Their offers were generous, but the testing should come before the advertising. It's not our job to prove their claims. If the products haven't been proven under rigorous scientific tests, then sellers shouldn't be making claims about their effectiveness.
What about testimonials?
Most of the fuel-savers are promoted by testimonials from satisfied users. But that's not the same as objective, third-party lab tests. For example, you can't be sure about the relationship between the importer/manufacturer and the writer. And you don't know how many letters were received from unhappy customers.
The US Federal Trade Commission looked at fuel-saver testimonials: "few customers have the ability or equipment to test for precise changes in gas mileage after installing a gas-saving product. Many variables affect fuel consumption, including traffic, road and weather conditions, and the car's condition."
And then there's the placebo effect. Anyone who's concerned about fuel consumption and fits a fuel-saving device is also likely to back-off on the accelerator too.
We're not trying to knock happy customers. But for these and other reasons, we suggest you ignore testimonials and ask for objective proof before parting with your money.
Does your engine need help?
If you grew up fiddling with carburettors and distributors, you'll be surprised how efficient a new car can be. Modern engines use computers to maximise fuel efficiency while reducing exhaust emissions.
The computer constantly senses the engine's speed, load, the volume of air entering it, and exhaust emissions. It then adjusts the amount of fuel released by the injectors to match the work the engine is doing at that instant.
Adding any additional devices could cause problems. The computer might not be able to make sense of the readings it's getting and makes inefficient adjustments to engine operation. If your car has fuel injection (and most cars built after 1995 do) then you're probably operating about as efficiently as you can. Replace your spark plugs and air filter regularly and see our recommendations.
The products
Magnetic devices
The claims
Ecoflow - "Ecoflow products are proven to increase power, save fuel and reduce emissions into the atmosphere as tested by the British Government's environmental laboratories. Fuel savings average between 8% & 25% on all petrol & diesel engines."
Evodrive - "The molecular structure of the fuel is altered by the rotating magnetic field as it passes through the unit. Changes the polarity of the hydrogen molecules of the fuel into a form that can be incinerated more efficiently and more completely."
Magnetic gas saver - "When gasoline remains in your tank, the fuel molecules start to cluster. Magnetic gas saver field breaks up clusters of hydrocarbons in your gasoline for more complete burning."
The evidence
Ecoflow presented a lab report prepared in Britain in 1992. But ads quoting this report were the subject of complaints to the UK Advertising Standards Authority in 2002. After taking expert advice, the ASA concluded the report's "testing procedure was flawed and therefore the results did not prove the efficacy of the Ecoflow fuel economiser. It considered that the letters, testimonials and articles sent by the advertisers to support their claim ...did not constitute rigorous scientific evidence." Ecoflow promised to stop quoting this report in its British ads, but it still uses it here.
Neither Evodrive nor Mega Accessories (distributor of the Magnetic fuel saver) provided any evidence to back up their advertising.
Our recommendation
Avoid Ecoflow, Evodrive and Magnetic gas saver.
Mechanical devices
The claims
Hiclone - swirls the air flowing into the engine. "Hiclone's swirling effect makes fuel particles finer and therefore burns up to 85% of the fuel as opposed to 65% in the best conventional systems. Will not only decrease your fuel consumption but will also give you up to 10% more power."
Jassco fuel economiser - Diesel is heated by water from the radiator hose. "The working principle is based on thermal cracking of the hydrocarbon molecule in diesel fuel. This is achieved by heating the fuel through the unit to a level closer to flashpoint. We have carried out extensive road and laboratory testing in NZ and overseas."
Ramjet Fuel Saver - a valve takes air from the crankcase when the engine is under load. "Expect better gas mileage, more engine power, faster acceleration, less harmful carbon build up, and cleaner crankcase oil which means less engine wear and tear."
The evidence
Hiclone sent us many pages of information, but there was no evidence that Hiclone will increase the proportion of fuel burnt.
Jassco's importer said the New Zealand testing referred to hasn't been completed. We were given a report produced in Thailand but it didn't say if it used the same type of diesel sold in New Zealand. Heating the fuel makes it expand and can have a similar effect to lifting your foot off the accelerator slightly. This can give fuel economy benefits, but do you really need a device to do it for you?
Ramjet has several tests which appear to back up the claims. But the tests were conducted in the 1970s on carburetted engines. Ramjet is unlikely to help a modern engine. The US Environmental Protection Agency has tested the Ramjet and found it did not decrease fuel consumption or pollution.
Our recommendation
Avoid Ramjet, which is obsolete and unproven. Wait for Jassco's local lab tests. Hiclone may produce some benefits but doesn't seem to do everything it claims.
Other technology
The claims
Power Pill - chemical fuel additive. "Prevents knocking. Cleans injectors, carburettors, and entire fuel system. Promotes more complete fuel combustion, lubricates and conditions valves, pistons and rings."
Biopro QX-3 - We really don't know what this one is! It seems to be a self-adhesive disk to stick to the fuel tank. "The QX-3 is charged with a proprietary blend of resonant frequencies. The QX-3 transfers these frequencies onto your vehicle's fuel, which changes the structure of the fuel molecules." Does that help explain it?
The evidence
Neither Power Pill nor Biopro provided any evidence at all.
Our recommendation
Some additives can provide benefits, but there's no evidence to support Power Pill. Don't waste your money on Power Pill or the Biopro QX-3.
We recommend
Consumer recommends two fuel-saver devices. They have a proven record, and we even know how they work.
Tyre pressure gauge
The simplest way to keep your car running efficiently is to keep your tyres inflated correctly. Under-inflated tyres create friction and that uses extra fuel. Keep your tyres at the recommended pressure, which you should find in the handbook or on a sticker inside a front door. Regular wheel alignments will also help.
Cost - $10-$50
Right shoe
The Right shoe is a multi-purpose tool that can cut fuel consumption by as much as 100 percent! When used alone, the Right shoe is the key to smooth acceleration and braking, the secret to economical driving. Just apply your Right shoe gently to your accelerator and brake pedals and watch the savings! Don't apply too firmly or the Right shoe can actually cause fuel wastage.
When combined with the Left shoe, the Right shoe makes a fun and exciting alternative vehicle which can be used without a car on short journeys! Fuel savings = 100 percent!!!
Cost - $10-$500. Buy now and get Left shoe for FREE! (Instructions not included.)
Report by Martin Craig.