Unreliability of acceleration figures and comparing the performance of 'M' series and 'L' series cars.
| Identifier | ExFiles\Box 160\3\ scan0065 | |
| Date | 17th January 1939 | |
| 1379 W/S. {Derby Works / Sales} To Cx. {Major Len W. Cox - Advertising Manager} from Rm {William Robotham - Chief Engineer} /Gry. {Shadwell Grylls} c. LA. {L. A. Archer} Rm {William Robotham - Chief Engineer} /Gry. {Shadwell Grylls} 4/MH. {M. Huckerby} 17.1.39. "M" SERIES ACCELERATION. Cx. {Major Len W. Cox - Advertising Manager} 10/KW.13.1.39. We look on acceleration figures as unreliable and misleading. For instance, we might send you now figures for an "M" series car worse than some which you have (which we have not seen) for an "L" series one. The weight of the cars, the weather conditions or a multitude of errors can so alter the picture. LA. {L. A. Archer} says that on the average an "M" series Bentley in direct gear goes up Ticknall Hill slightly faster (about 1 1/2 seconds less) than an "L" series car. This confirms our contention that due to the 3% lower overall ratio "M" series in direct is better than "L" series by 3%, other things being equal. Our suggestion is to put alongside "L" series figures accepted by Sales and the public, further figures for "M" series 3% better. There will then result no recriminations. Rm {William Robotham - Chief Engineer} /Gry. {Shadwell Grylls} | ||
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).