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.