It is difficult for people outside the engineering fraternity to appreciate the level of expertise needed to design a modern vehicle. It takes four years to get an engineering degree in this country, but most students do it in five. Then it takes at least as long again before he or she becomes a really productive member of a team. These design teams, consisting of a number of engineers who are experts in various disciplines, such as thermodynamics, stress analysis, vibration, production, and many others, use computer-aided modelling and visualisation to design the various components that make up a car. These parts are then tested, individually and as assemblies, and even as complete vehicles, to ensure that they perform as envisaged. This is the process that most parts that you can buy for your car have to go through.
Alternatively, there are devices and products being hawked around that have never been tested scientifically. All the so-called fuel savers that we’ve come across belong in this category, as well as most fuel and oil additives. Some of the sellers genuinely believe in their product, but many are well aware that they’re conning the public, and they use a range of techniques to persuade you that the device works.
Many of these products appear to work in the initial stages, because of the powerful psychological effect that comes into play whenever you’re testing a product. You tend to drive more steadily, cruising at exactly 120 km/h, for example, and accelerate more sedately, because you want to give the product a fair trial. You’ll get good results, seldom as much as the seller claims, but enough to keep you happy for a while. Eventually, you lapse into your old driving habits, the fuel consumption falls to previous levels and, if you’re honest with yourself, you end up admitting that it doesn’t work. Of course, some people will never admit that they have been fooled, and end up writing glowing testimonials.
Let’s look at some of these devices:
A magnet around the fuel line
This one has been around for at least 30 years, in various parts of the world, under a number of different names. The magnetic field is claimed to affect the fuel, making it burn more easily, so that fuel consumption is improved. The truth is that the combustion efficiency of most engines is close to 98 per cent, meaning that there is only a two per cent waste in liberating the energy from the fuel during the combustion process. If the magnet had any beneficial effect, it might result in a 0,5 per cent improvement in fuel consumption, instead of the over 30 per cent claimed for most magnets. Scientists we’ve spoken to do not know of such an effect, and the magnets we’ve seen are so weak that they wouldn’t even cling to a fridge door…
One of my favourite stories about these magnets was told by a well-known engine tuner. His friend had raved about the improvement in fuel consumption to such an extent following the fitment of the magnet, that the tuner was forced to take a look at the device, only to find that it was clamped over one of the heater hoses!
Another insight into magnets concerns an American TV station’s consumer investigator, who fitted two different brand-name magnets around the fuel lines of two one-ton trucks belonging to the AAA (American Automotive Association). The third truck only received some household tape around the fuel line. The fuel consumption change, monitored for 24 000 km, resulted in a three per cent worsening in consumption for one of the magnets, and a five per cent worsening for the other one. The tape scored a six per cent improvement!
Should we all start putting tape around our fuel lines? No. The scientific conclusion is that longer-term fleet tests usually ignore the weather and atmospheric effects, so they can only pin-point really significant changes in fuel consumption.
An air bleed in the intake manifold
A number of local “inventors” are selling such a device, and the obvious result is that the mixture is leaned out. It may result in a fuel saving at small throttle openings – as well as a flat spot – and some dirt getting into the engine. However, over a period of time the lean mixture may cause damage to the valves and pistons.
An impeller inside the intake manifold
This is supposed to induce swirl in the mixture, and it may do so at low engine speed, but is bound to form an obstruction to airflow at higher engine speed, thus reducing the maximum power output. It is claimed to improve fuel consumption by improving combustion, but this device faces the same problem as the magnet over the fuel line: you cannot improve significantly on 98 per cent combustion efficiency. Fitting this device to a car with an electronic mixture control may upset the air mass measuring sensor.
A spark-intensifier
This comes in a plastic casing, and fits in the high-tension ignition cable running from the coil to the distributor. It has been on the market for at least 60 years. The casing covers a gap inside the device that’s bigger than the spark plug gap, forcing the build-up of a higher-than-normal voltage in the coil. This increases the spark voltage, so it will fire through oil or carbon build-up that would normally result in a misfire. You could achieve the same effect by interposing a rubber tube between the HT cable and a spark plug that has oiled up. It will not make any difference to an engine that is in a good condition, but will mask ignition faults, and eventually lead to a breakdown of insulation in the coil and other ignition components.
Aftermarket fuel additives
These appear from time to time, catch some people out, and then vanish from the scene. At the moment, a platinum “catalyst” is doing the rounds, which is added to the fuel in liquid form. It is supposed to improve combustion and save fuel, but the American Environmental Protection Agency tested a version called the Platinum Vapour Injector, and found no fuel saving.
Aftermarket Oil additives
Oil from the major oil companies is carefully tailored to cater for the needs of modern engines. It contains a number of additives that are carefully blended to obtain and retain the required anti-friction and other properties. It also has to pass a number of tests prescribed by the API (American Petroleum Institute), and any of the other classification societies that ensure the oil meets the need of engine manufacturers and the end-users of their products.
Aftermarket oil additives are claimed to reduce friction and wear inside the engine by modifying the oil that is already in the sump. However, modern oil is so slippery that any change that can be made by a mere additive would only result in a very small difference in frictional coefficient, not a measurable improvement. In addition, modern oil is such a well-balanced mix that any additive is bound to disturb the mix, and may well have a negative effect on some of the constituents of the oil.
METHODS USED TO SELL THE PRODUCT
Most of these gadget merchants put up what looks like a strong case for their products, with certificates from laboratories, glowing reports from users, and a lot of clever-sounding “scientific” words and facts. But only too often these credentials do not stand up to close scrutiny.
Let’s look at the selling methods in more detail:
Laboratory reports
These reports often turn out to be false, or from a laboratory in a country that is not easy to contact. In the past, we’ve been given a test report in Polish, and a certificate from what purports to be a governmental organisation, only to find that the department concerned does not test automotive equipment. A certificate purporting to come from the governor of one of the states in the USA had so many spelling mistakes that we could not believe that it was genuine. Sometimes the reports are incomplete, with a minor advantage for the product highlighted, but the final conclusion is left out.
Dynamometer testing
A “before and after” test on a chassis dynamometer sounds like a good way to test a fuel consumption improvement gadget, but it’s not. This is because it is extremely easy to influence the readings on such an instrument. The readings depend on under-bonnet, oil and water temperature, as well as the tyre pressure of the driven wheels, and the atmospheric pressure. Since a test run usually takes not much more than 40 seconds, all these factors can be manipulated by the operator to give low readings before a test and favourable readings afterwards. Just about the only test that we will accept as solid evidence for an improvement is an engine dynamometer test, because on a good engine dynamometer set-up one can control all the above factors, so that you can compare results taken at different days and with different components.
User testimonials
These are seldom reliable because very few organisations are able to test vehicles under strict scientific conditions. The average fleet owner has no chance of doing it correctly, because his personnel have not been trained to behave like scientists. In fact, fleet trials using the same vehicles over a period of months are notoriously difficult to control scientifically because of different driver habits, the effect of seasonal ambient temperature variations, and incomplete data or haphazard data collection. There is also pressure on the fleet manager to come up with favourable results, especially if he was involved in making the decision to try the product.
Scientific explanations
These are often hilarious, because the so-called explanation of how the gadget works usually refers to phenomena that no qualified scientist has ever heard of, or else well-known phenomena are used out of context. In fact, we believe that if the seller cannot explain the scientific terms in his own pamphlet in plain language then it’s a sure sign that the gadget is a scam.
HOW DO YOU KNOW A PRODUCT IS FAKE?
Each one of the following facts should make you suspicious. Any two should be sufficient to encourage you to walk away.
The product is not standard equipment on any new vehicle
The salesman usually volunteers that the product is not fitted to any new vehicles, but company XYZ is testing it at the moment. Your response should be that, since they haven’t decided yet whether the gadget represents a worthwhile improvement, you should also remain sceptical. The truth is that all the major automobile manufacturers are aware of the foregoing products. They get bombarded by salesmen, or hear about the products from their dealers. If any of them showed any promise, the “inventor” would become a multi-millionaire overnight, because the large improvements claimed are much greater than those an honest engineer could design into a vehicle.
It has not been tested by any well-known university, laboratory or technikon
The salesman usually confirms that it has been done, and then shows you dubious or incomplete lab reports, as already explained.
The salesman can’t explain the theory behind the gadget in plain English
If the salesmen’s explanation doesn’t make sense to you, then the product is likely to be worthless. You don’t have to know any science, because all weird scientific terms are shorthand for phrases consisting of everyday words. These scientific terms have been included to make the product sound genuine, and confuse you.
The claimed improvement in fuel consumption, engine wear, or whatever else, exceeds single figures
Such an improvement is extremely unlikely, because engineers know that it costs a lot in research time and money to make even a five per cent improvement.
If you’re still sceptical about the way we dismiss these gadgets out of hand, please consult the following websites: www.fuelsaving.info/debunk.htm and www.ftc.gov/opa/2001/11/gadget.htm
The last-mentioned website is that of the federal trade commission in the USA. This body prosecutes companies that make false claims, and has debunked the advantages of several products that are still being sold here.
Finally, as a consumer, you should guard against fairy tales. In fact, it makes sense to adopt CAR’s philosophy: There are no fairies at the bottom of the garden.
TESTED OR NOT…
CAR magazine has often been attacked for saying a device doesn’t work without having tested it. We feel that it is a waste of time to test something that is not scientifically sound. We have two engineers on the staff, and contacts at four universities, to say nothing of what one can learn from the Internet, so it is quick and easy for us to find out whether any device makes sense.
Another reason for not testing is that even if a short-term test shows an improvement in some aspect of performance, it is often the case that there are long-term negative effects, and these may only become apparent after six months or longer. This makes it dangerous to declare an improvement after a short test.
