In general I am not impressed by people who quote long lists of qualifications and experience; I prefer to judge people by their work. But since readers of this site have no other way to know why they should believe me and not the makers and sellers of fuel "saving" devices, here is some information about me.

Academically, I have an engineering degree from Cambridge University and am a Chartered Engineer.

I worked for six years at Rover's advanced engines department, the last three of them in close conjunction with the equivalent BMW department. While there I worked on many different fuel-economy concepts, including lean-burn, variable turbulence, exhaust gas recirculation, petrol direct injection, and the system described by BMW as "Valvetronic". I also did some work on diesel engines, including the Land Rover "TD5".

This work involved testing concept engines on state-of-the-art multi-million-pound research test beds equipped with full emissions and fuel consumption measurement as well as in-cylinder pressure transducers to fully characterise the combustion process. We also employed a number of techniques to directly measure the air motion (turbulence) in the engine, including engines made substantially from glass, so changes to the intake system could be assessed. I also personally developed various techniques for researching in-engine processes, and presented some of them at international technical conferences.

From 1999 to the end of 2004 I was employed by Bosch* as a Resident Engineer at Cosworth Technology (now MAHLE Powertrain), setting up engine managment systems in order to meet production requirements for emissions, economy, driveability, diagnostics, etc. This includes cars from a number of major manufacturers, destined for both European and US markets. As well as economical "mainstream" cars, I have also worked on some extremely high performance turbocharged and naturally aspirated derivatives. The name "Cosworth" is of course synonymous with high-performance engine development.

Since 2004, I have continued to work for Bosch, but am now involved in the fuel system design and development for an advanced new high-performance petrol engine at a different vehicle manufacturer.

If any of that sounds like boasting, please accept my apologies. The point is simply this: I know what I'm talking about! With all due respect to motoring journalists, service technicians and members of the general public who frequently say positive things about fuel "saving" devices, only specialists in the field of car engine emissions and economy can fully understand what is an incredibly complex subject.

(It is also worth remembering that many newspapers and magazines, for quite understandable reasons, will print almost verbatim press releases issued by companies. The fact that an article on a particular fuel "saving" device appears in a newspaper does not necessarily mean that the paper has thoroughly researched the story themselves and knows it to be true.)

A good example of what experts call False Authority Syndrome concerns Peter Brock and his "Energy Polariser", basically magnets round the fuel line. Peter Brock was one of Australia's top racing drivers in the 1970's and 80's, and was involved in some quite genuine aftermarket performance upgrade kits. He then discovered "New Age" thinking and became convinced that his "Energy Polariser" would give amazing benefits. The car maker Holden (with whom he had previously had a good working relationship) could not be persuaded and cut their ties to Brock, forming their own performance division. The "Energy Polariser" was never shown to be of any benefit and has long since disappeared from the market.

Now, the lesson is this. Peter Brock was a superb racing driver, with more talent in his little finger than I have in my entire body. But that did not make him an expert on combustion in petrol engines! Just because somebody is an expert in one field, that does not make them an expert in a related but different field. I have tried to stick to my areas of expertise on this site; please accept my apologies where I have stepped outside it. Sadly you will find many people, especially on the Internet, are quick to make definitive statements in areas where they have little or no knowledge.

One more reason to believe me rather than the makers and sellers of fuel "saving" devices is simply this: if you believe them, you will give them money, so it's in their interests to at least "bend the truth" a little. Since I make almost no money from this site (donations do little more than cover the running costs) I have no reason not to be fully honest.

* Please note: the views expressed on this site are entirely my own and are not in any way sanctioned or approved by Bosch, or any other company I am associated with.