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).
Table correlating car speed in M.P.H. with the R.P.M. of various components for an axle ratio of 4.25.
| Identifier | ExFiles\Box 173\3\ img064 | |
| Date | 26th October 1933 | |
| CAR SPEED vs.{J. Vickers} ENGINE R.P.M., ETC. - 40S - AXLE RATIO 4.25 Car Speed M.P.H. Factor | Engine R.P.M. | Camshaft Distributor R.P.M. .5 | Generator R.P.M. 1.51 | Water Pump R.P.M. 1.3 | Rear Wheel R.P.M. .82 5 | 271 | 135 | 409 | 352 | 59.9 10 | 542 | 271 | 819 | 705 | 119.1 15 | 813 | 406 | 1228 | 1057 | 178.7 20 | 1084 | 542 | 1637 | 1410 | 238.3 25 | 1355 | 677 | 2047 | 1762 | 297.9 30 | 1627 | 813 | 2456 | 2114 | 357.5 35 | 1898 | 949 | 2865 | 2467 | 417.0 40 | 2169 | 1084 | 3275 | 2819 | 476.6 45 | 2440 | 1220 | 3684 | 3171 | 536.2 50 | 2711 | 1355 | 4094 | 3524 | 595.8 55 | 2982 | 1491 | 4503 | 3876 | 655.4 60 | 3253 | 1626 | 4912 | 4229 | 715.0 65 | 3524 | 1762 | 5321 | 4581 | 774.5 70 | 3795 | 1897 | 5731 | 4933 | 834.1 75 | 4066 | 2033 | 6140 | 5286 | 893.7 80 | 4337 | 2168 | 6550 | 5638 | 953.3 82 | 4445 | 2222 | 6714 | 5779 | 977.1 * No account is taken of slippage. 10-26-33 | ||