Why Miracle Fuel Savers Don't Work

Sexed up with pseudo-science, miracle fuel savers promise the earth, albeit with the underlying credibility of Roger Ramjet's proton energy pill. They use magnets, ceramics, catalysts – anything quasi-technical. What’s really going on is this: They’re preying on vulnerable consumers willing to believe a miracle is just a mouse click – and a credit card number – away.  

Sorry, but if this really is a fuel saver it's time to buy into that swampland redevelopment projectFirst let’s introduce two experts who know more about engines than just about everyone. Emeritus Professor Brian Milton specialises in thermodynamics, fluid mechanics and the processes inside internal combustion engines. An academic at the University of NSW since 1967, he was Nuffield Professor and head of mechanical and manufacturing engineering for a decade. He’s the author of Thermodynamics, Combustion and Engines (not especially light reading) and numerous related academic papers. Simon Cassin is the manager of Holden's Powertrain Group. He oversees 36 engineers who manage all of Holden’s engine design, development, durability and compliance – including meeting the fuel economy and performance targets for local engines and those exported to the US, Europe, the Middle East, Korea and China.

They concur that miracle fuel savers don’t work. Here’s why.


Miracle fuel devices often promise miraculously to enhance or refine fuel or air using, magnets, ceramics, etc. But since there’s nothing really wrong with either fuel or air, devices that purport to bolster the chemistry (by, for example, ‘de-clusterising’ fuel molecules – whatever that means) are pulling your leg.

Typical claim: “Fuel conditioned by a strong magnetic force carries more energy and mixes more readily with air resulting in more complete combustion.” – www.ecomagnets.com.

Milton: “The energy driving the engine comes from breaking molecular bonds in the fuel during combustion. In modern engines, combustion is pretty well complete. And for a magnet to boost performance it would have to add energy … magnets just don’t operate that way.”


Car companies compete intensely. With engines, they all try to do more with less fuel. If you could really deliver that, why sell it to the masses in boxes of one when you could sell millions wholesale to the global car industry?

Milton: “If you had a device that delivered even a one per cent efficiency increase, they’d be in it like a flash! It would really have to work, however...”

Cassin: “When 20 or more global manufacturers all spend tens of billions of dollars, and independently reach the same conclusions about the future technologies that will deliver efficiency improvements – and these are expensive to develop – well, it just wouldn’t happen if there were cheaper, simpler solutions.”


For as little as $35 you can pick up an aftermarket fuel-saving ‘vortex generator’ for your engine’s inlet air plumbing. It might be like asking your engine to inhale athsmatically through a straw, however.

Typical claim: “The Turbonator’s airflow dynamics can produce a swirling, fast-burn effect in the combustion chamber. This can create finer particles of atomized fuel, allowing better flame propagation and more complete combustion.” – www.turbonator.com

Milton: “Modern petrol engines inject right on the back of the inlet valves, which delivers excellent fuel atomization. Most turbulence is generated by the air flow through the inlet valves and subsequent in-cylinder motion. Upstream turbulence will have no effect on combustion or atomisation, but anything placed in the inlet air stream could easily restrict airflow … and the limiting factor on the power output of engines is their air-swallowing capacity.”

Cassin: “All manufacturers devote much effort to mixture preparation and flow within the cylinder – for both emissions and thermal efficiency. What dominates both fuel atomization and mixture motion is injector design and targeting along with very precise inlet port and valve throat shapes. Small details within the head make all the difference and far outweigh any upstream effects in the induction system. Additionally, owners need to be aware that there are profound warranty implications that could flow from engine modifications, including those to the inlet air system.”


Catalysts are used to kick off hard-to-start chemical reactions. Unfortunately, combustion is already relatively uninhibited. Some catalyst-based fuel-saver systems even purport to introduce platimum – a good catalyst – into the combustion chamber. At around $55,000 per kilo, however, platinum is one of the more expensive elements to start saving money with…

Typical Claim: “With platinum in the flame zone, you increase the percentage of fuel burning in the engine from 68 to 90 per cent.” – www.nationalfuelsaver.com

Cassin: “I won’t comment on the effectiveness or otherwise of specific products, but it’s worth visiting the US EPA website, www.epa.gov/otaq/consumer/reports.htm, which has a compendium of impartial test reports of (in part) fuel saving devices – interesting reading.”

Milton: “The only time a combustion catalyst would help is if the spark energy was insufficient to start combustion. Combustion is easy to start. We tested higher energy spark plugs against normal ones – years ago. It made no difference to a well designed engine.

“Internal combustion is one of the most studied and optimized processes on earth. It’s been going on since at least 1876. Since then, the best ideas have come to light, and the bad ones have been thrown out.”