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).
Two graphs illustrating the acceleration performance of different 20 HP engine configurations.
| Identifier | ExFiles\Box 77\5\ scan0049 | |
| Date | 19th November 1926 guessed | |
| Top Graph: ACCELERATION ACCELERATION Ft/Sec/Sec. ROAD SPEED M.P.H. LEGEND: HIGH COMP. 20 H.P. HIGH COMP. 20 H.P. CUT OUT OPEN STANDARD 20 H.P. Bottom Graph: ACCELERATION HIGH V LOW COMPRESSION RATIO 20 H.P. VELOCITY M.P.H. TIME SECONDS LEGEND: HIGH COMP. 20 H.P. 5.4 HIGH COMP. 20 H.P. CUT OUT OPEN STANDARD 20 H.P. 4.6 | ||