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).
Comparison of speedometer readings and acceleration tests between R-R, Marmon, and 2.EX cars.
| Identifier | ExFiles\Box 32\5\ Scan144 | |
| Date | 8th February 1921 | |
| X 1692 EFC File X.3743. X/1692 8.2.21. RECEIVED FC FEB 18 1921 R-R Car Speedometer Reading. Marmon Car Speedometer Reading. 10 M.P.H. 12 1/2 M.P.H. 20 M.P.H. 28 M.P.H. 30 M.P.H. 36 M.P.H. 40 M.P.H. 45 M.P.H. 50 M.P.H. 61 M.P.H. 60 M.P.H. 65 M.P.H. Marmon Car Acceleration Tests - London Rd. M.P.H. at start. | M.P.H. finish. | Secs. Time taken. | Distance. | Remarks. 10 | 50.5 | 33 20 | 54 | 27 30 | 61 | 22.8 40 | 62 | 21 2.EX Car Acceleration Tests - London Rd. M.P.H. at start. | M.P.H. finish. | Secs. Time taken. | Distance. | Remarks. 10 | 50.5 | 30.8 | | Air Piston undrilled. 20 | 54 | 26.8 30 | 55.5 | 23.8 40 | 56 | 21.2 2.EX Acceleration Tests M.P.H. at start. | M.P.H. finished. | Secs. Time taken. | Distance. | Remarks. 10 | 54 | 31.2 | | Std: Air Valve 20 | 55 | 26.5 30 | 57.5 | 24.4 40 | 60 | 21.0 | ||