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 comparing acceleration performance for different 20 HP engine configurations.
| Identifier | ExFiles\Box 21\2\ Scan034 | |
| Date | 3rd December 1926 guessed | |
| 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. 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 | ||