“Motor Mouth’s” FAQs and Tips Page
Happy New Year to all you doubters out there, watch my lips, are they moving?
I must be telling the truth!!!
The last 2 articles have involved fuel and not enough already with fuels, 2 more articles covering the BIG QUESTION to come.
Q: How can I improve my fuel consumption?
A: Drive sensibly!!!!!!
At every Motor Show or in every Motor Magazine you will find some poor salesman trying to sell you some type of fuel saver, These savers can take 2 forms, either a liquid additive or some gadget to fit to your fuel system. Let’s have a look at additives this month, next month the turn of the gadgets.
Fuel additives
Some of these products are of course intended to meet genuine needs. For example, old engines may require a valve seat protector when used with unleaded fuel, or very high performance engines may require an octane enhancer when "ordinary" petrol is used. I would generally prefer to buy a "pre-mixed" fuel that already meets these requirements, rather than trust a possibly sub-standard additive, but there are certainly plenty of good quality and effective additives available for this kind of work (please do not ask me to recommend one, though). Another potentially useful product is an additional stabiliser, for vehicles that are only used infrequently and where the fuel could otherwise "go off".
Where I am far more sceptical is with additives that claim to enhance the combustion process in some way. Typically these supposedly make the fuel vaporize better, burn more quickly or more completely (a catalytic effect), or clean deposits. In all these cases, I am highly doubtful that large benefits can really be obtained in this way, as you will see from the links above. Especially critical is that using these additives may add 5 or even 10% to the cost of a tankful of fuel ( you have to pay for the additive), so unless very large improvements in economy can be obtained, the overall effect is an increase in cost. Although the products vary greatly in their supposed effects, two particular claims are very common:
An engine cleaning effect. The oil companies already add a detergent to all fuel available in South Africa. They do this at the correct fuel to additive ratio and this means the additive gets burnt off, If you add more to the fuel there is a chance that you wont find all the additive burning off and land up with it being wasted via the exhaust, or worse forming a build up in your combustion chamber.
A more complete / faster burn. Typically makers of these products suggest that a large proportion - 10% or more - of the input fuel escapes unburnt from the engine, to be either released into the atmosphere as pollution or uselessly burnt in the catalytic converter. This is just not true at least for any reasonably modern car in good condition - the true loss is only about one or two percent, so the potential for improved economy is equally small. A related claim is that the burn is "faster" or "hotter"; without evidence, I am sceptical that this enhancement in burn rate really takes place, but in any case the critical point is that the engine is already optimised (ignition timing, etc) for the "normal" burn rate. A faster burn, even if theoretically beneficial, is likely to make economy worse unless engine parameters are optimised to suit.
Especially suspicious to me is that virtually every product I have come across claims to be equally effective on petrol and diesel engines, which given the radically different combustion processes strikes me as unlikely.
It's also worth pointing out that many, if not most, of these products are sold through Multi level marketing which immediately triggers warning bells among sceptics. Some perfectly good and effective products are sold through MLM, but it is also a common method employed by scammers and snake-oil salesmen to maximise revenue from ineffective products. (Commonly, the "early adopters" make much, if not most, of their money by recruiting lower-level sales people rather than directly through product sales.) This sales method also means that there is an army of thousands of bottom-level sales people, all with a financial stake in the success of the product, who will pop up whenever it is discussed on Forums and newsgroups and say how marvellous their product is or write glowing "independent" reviews of it. Some, or even most, of these people do genuinely believe in the product, but their lack of financial independence means that any testimonials you see should be taken with an even larger pinch of salt than normal.
An additional problem with MLM products is the "Chinese whispers" effect - a company may make quite modest claims for their product (say up to 5% economy gain) but as the message travels down through the "pyramid", the claims become more and more exaggerated. By the end, some people selling the product to end customers may be claiming 50% economy gain. Or a company may mention that the product is being tested on a small scale by a particular institution, which somehow turns into an endorsement of the product by that institution. This isn't the fault of the selling company, of course, though some do seem reluctant to correct the misconceptions. Ask for a SABS stamp of approval or for test results from SABS (don’t hold your breath while waiting though).
To avoid any doubt, I am equally sceptical about all the other fuel "saving" additives I have come across, but do not have the time to write complete critiques of all of them.
Please read this page again, to understand my concerns about all products of this type. The UK TV program 5th Gear tested a few well-known brands in 2007 (admittedly in quite a limited way) and could not find any benefit.
From me, don’t believe in additives; take your whisky neat “Motor Mouth” and make the best of the New Year.
Roger
082-557-6060