After reading such a glowing review of my book-which means a lot to me knowing your vast experience and knowledge of motoring matters and your critical approach to published works on the subject-it seems churlish to write questioning the basis of your claim that Motor Sport averaged over 100 m.p.h. from Calais to Nice in a 3.0 CSL BMW Coupe during your tour of ten capitals in four days in 1972, but I feel compelled to do so in the interest of historical accuracy, of which there is surely no more assiduous advocate than yourself. Hitherto I have suppressed nagging doubts about this performance which seemed to me too good to be true, but your further reference to it moved me to dig out my copy of Motor Sport for January 1973 and to apply my mind to the facts and figures in your report of that trip.
I have extracted distances and times from your article and summarise the running times as follows:
On the above reckoning the running average speed for the journey was indeed just over 100 m.p.h., but as the crossing of Paris is excluded it is an average speed which relates to the sum of two journeys-Calais to the edge of Paris and the opposite side of Paris to Nice—not the average speed from Calais to Nice. The Boulevard Peripherique from the end of the Al at Porte de la Chapelle to the start of A6 at Port d’Italie is 14 kms. (8.7 miles). My best time for this was 11 minutes in the Double-Six at 6.30 a.m. so that a similar time for the BMW would be assuming pretty spirited motoring at lunchtime. Thus, adding this distance and national time to the figure tabulated above we get 791.7 miles in 8 hours exactly from the Calais to Nice trip, which equates to an average speed of 98.96 m.p.h.
Now if you think I am niggling about decimal points, what about this:
According to your report you left Calais at 11.27, and joined the Autoroute at Dunkerque at 12.19. The direct distance is 24.4 miles, but losing your way in Dunkerque must have added several miles of built-up area and would account for the 52 minutes which you took. Your next recorded time is 12.44 on joining the Al on the southern edge of Lille, thus covering the 464 miles in 25 minutes, i.e., 111.6 m.p.h. Fair enough. From this point on Al to Porte de la Chapelle on the Boulevard Peripherique is 131.5 miles— I have taken this as being the point which you described as entering Paris—and you arrived there at 13.12. Thus the elapsed time from Lille to Paris was 28 minutes which means an average speed of 281.8 m.p.h.beyond even the “unbeatable BMW” I think you will agree! (If you took your point of entry into Paris at Porte Maillot, which might be inferred from your report, then the distance would have been 3 miles more and the average speed nearer 290 m.p.h.) Taking the same reference points outside Dunkerque and Paris, this distance of 178 miles was, according to your report, covered between 12.19 and 13.12, i.e. an elapsed time of 53 minutes (201.5 m.p.h.) including the pave of Lille. Clearly the average speed of 117.7 m.p.h. from Calais to Paris indicated in the above summary (including an unplanned tour of Dunkerque) is impossible in any car in any circumstances.
Unless my reading of your published figures is incorrect, there is something wrong somewhere. Could it be that the change of time crossing the Channel caused confusion and you lost an hour somewhere in your reckoning? An extra hour of elapsed time would give credibility to the Lille/Paris section of the journey, i.e. 1 hour 28 minutes, which would give an average speed in the region of 91.7 m.p.h. including the Peripherique to Porte Maillot. An extra hour would bring the claimed Calais/Nice average down from “over 100 m.p.h.” to a mere 87.97 m.p.h.! That I could believe and give credit to the driver(s) for no mean performance.
I should appreciate it if you would look into this and let me know where lies the truth. If indeed an arithmetical or timing error was inadvertently committed, I have no doubt that you would wish to publish this letter if only to ensure that “the BMW 100 m.p.h. average” does not become wrongly enshrined in the annals of motoring.
Cobham STANLEY SEDGWICK
[At this distance of time the log has been disposed of and I would be the last person to query the findings of Mr. Sedgwick. The points he makes are noted. There is clearly something amiss with the Lille-Paris times and while I think the Calais-Nice average of 98.96 m.p.h. not impossible, I will accept the 87.97 m.p.h. which now seems more probable. Of course, our aim was, as stated at the time, a gentle tour embracing ten European capitals in five days, which the BMW enabled us to reduce to four days, to commemorate the entry of Britain into the Common Market, and we were consequently less concerned at the time with average speeds from one place to another.—Ed.]