From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
'Autocar' magazine road test results and the methodology of speedometer testing for a Bentley.
| Identifier | ExFiles\Box 160\3\ scan0191 | |
| Date | 14th February 1939 | |
| S/W. Rm.{William Robotham - Chief Engineer} C. to Bly{B. W. Bleaney - Bentley Sales} "Autocar" Road Test. Cx{Major Len W. Cox - Advertising Manager}7/KW14.2.39. Thanks for Rm.{William Robotham - Chief Engineer}1/R14.2.39, but I am afraid you have taken rather an erroneous view of the contents of my previous memo on this subject, at least I got that impression from your reply. You say you deprecate the practice of judging a car's performance by an unchecked speedometer reading to which has been added a hypothetical allowance. The Autocar road test official never judges a car by its speedometer, as one of the things he does to check up his figures is to test the speedometer for its accuracy and make due allowance for any error. The figures they have published in the past have always been after this due allowance has been made and are proper timed speeds. Bearing that in mind the speeds published by the Autocar in May 1936 were as under :- Mean maximum timed speed over ¼ mile .... 90.91 Best timed speed over ¼ mile ........... 94.74 In November 1937 the Autocar did another Bentley test and showed - Mean maximum timed speed over ¼ mile ...... 88.02 Best timed speed over ¼ mile ............ 91.84 I have not the official figures of the recent test by Mr.Linfield of the Autocar, but from what he told me on the telephone they are not as good as the last occasion. I am hoping to get these figures from him possibly tomorrow, and will let you have them. You say that B-2-MR is up to standard, but you do not say how we are to explain away to Mr.Linfield, and of course to the Public, the fact that the figures are worse each time during the last three tests. Quite apart from all this, and with regard to the speedometer reading itself on this particular (cont) | ||