Tuesday, 17 November 2009

More Snake Oil

Carmarthenshire County Council's website now includes the detailed report on Fleet Management which went to yesterday's meeting of the Executive Board. The section about the magic magnets which they have been installing on vehicles includes some interesting details.

Firstly, they have repeated the claim made by the manufacturers about how the device 'works' ("realign the carbon molecules allowing the fuel to burn more efficiently") with no qualification or challenge whatsoever. There is absolutely no scientific evidence to substantiate this claim.

Secondly, by stating that "some results have been skewed by the effect of operating conditions", they are effectively saying that, although they have measured some change in fuel efficiency, they have absolutely no means of knowing whether that is attributable to the devices fitted or to other factors, which they were unable to exclude from the trial.

Thirdly, after removing the 'outlying' vehicles from the results (I take that to mean those vehicles which showed the greatest variation – in either direction), they are left with a set of results which is a long way away from the claimed level of savings. The most common result seems to be that the effect is, at best, 'negligible'. Rather than concluding from the overall set of results that this product simply doesn't do what it's claimed to do, they have instead concluded that it only works on some vehicles and are, apparently, setting out to fit it to vehicles which seem to fit the pattern of 'working'. There seems to have been no questioning as to why a device would only work on 'some' vehicles.

Fourthly, the endorsement from the council carried on the company's website quotes only one result - showing a 14% saving. Interesting that that result is considered good enough to use in an endorsement, but not good enough to be included in the evaluation report given to councillors – I assume that it's been disregarded as an 'outlying' result.

Fifthly, the point which they really seem to have missed is the huge variation in mpg between vehicles of the same type – much wider than any effect of any magic device. All of the 'improvements' measured are smaller than the variation which is occurring between vehicles of the same type anyway.

Finally, they proudly state that "Carmarthenshire was the only council in England and Wales to trial the product". Still no alarm bells ringing anywhere?

P.T. Barnum may have been wrongly credited with his famous phrase, but that doesn't mean it was wrong.

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