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).
Continued analysis of speed and distance instrument accuracy based on tyre revolutions and speed.
| Identifier | ExFiles\Box 59\2\ Scan036 | |
| Date | 4th June 1930 | |
| EFC2/ADL4.6.30 contd. -2- indication when driven at 600 R.P.M. would be 45.8 miles per hour. Since the minimum drive speed corresponding to the largest tyres used is 801 revolutions per mile (with possibly a slight reduction in this figure at higher speeds due to centrifugal force) and the corresponding miles per hour at 600 R.P.M. at this drive is 44.9, it will be seen that both the counter miles and speed indications of this instrument at all temperatures will be reasonably correct with a reasonably small amount of positive error. EFC. | ||