A few weeks ago I sent you a copy of a letter which I wrote to Molyslip, with reference to the latest series of advertisements which they are publishing in your magazine; a copy of this letter was also sent to Loughborough College of Engineering. [Letter reproduced below.—Ed.]
You may be interested to see the attached letter which I received from Loughborough College. [See “Loughborough Replies.”— Ed.] As one would expect, I have not received any comment front the Slip Group of Companies. One can only assume that my points as to the veracity of the complaints made are not without some foundation.
I was interested in the Moly Slip advertisement on page 547 of the July issue of Motor Sport. [Repeated on page 722 of the September issue.—Ed.) It is unfortunate that the name of a highly respected College of Technology be connected with this form of dubious advertising. Such a presentation is more the product of an advertising agency rather than a technical report prepared by a College of Technology.
The following facets of the advertisement should be noted—all of perhaps a small nature but all engendering doubt of the value of such a test.
1. Tests show only a small part of power curve that, by admission, is uncorrected for barometric conditions. No self-respecting engineer would attempt to compare results until this had been done.
2. Over the portion of the R.P.M. range shown, the slope of the power curve is sensibly linear and would not, at full throttle, exhibit the falling off in power shown, particularly in tests 1 and 2. If these are actual brake results they would indicate instrumentation scatter and as this is of the same order as the difference in the “before” and “after” curves one is forced to suspect the accuracy of the test. This is particularly so in view of the elapsed time between tests. Greater confidence would be obtained if the test points were shown.
Try as I might, I cannot obtain an increase of 7.1% in power—at 1,000 r.p.m. the increase is 12.2%, reducing to 8.6% in 1,500 r.p.m. Why not on the basis of this graph claim a 12% increase?
3. The brake r.p.m. quoted is presumably engine r.p.m., with a chassis dynamometer, the wheels are turning at 1/3.77 times the engine speed and the brake turning at presumably some other multiplication factor of this.
4. The scaling of the graph is the product of an artist not an engineer. No one, I hope, who is seriously associated with automobile engineering would adopt a vertical scale of 5/12 b.h.p. per square. This makes both plotting and subsequent interpretation highly inaccurate.
The overall impression is that the Advertising Department has been let loose with the raw data supplied by Loughborough College. A pity, as it brings discredit to both the product and the College.
This type of semi-technical advertising has everything to commend it but it is essential that it is of high quality otherwise its value is completely lost. Motor Sport is read by enthusiasts, all of whom, I am sure, are able to interpret this form of data. If you are continuing this form of advertising with the other cars please stop the advertising boys demonstrating how to “lie with statistics.” I have actively followed the correspondence in the various magazines with regard to this type of additive but it will have to be a better demonstration than this to convince me the cost of Molyslip is warranted by improvement in performance.