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 vehicle acceleration, one for different compression ratios and another comparing the 20 HP and 40/50 models.
| Identifier | ExFiles\Box 77\5\ scan0048 | |
| Date | 19th November 1926 guessed | |
| Top Graph: ACCELERATION HIGH V LOW COMPRESSION RATIO 40/50 VELOCITY M.P.H. TIME SECONDS ________ 10 E.X. WT. EMPTY 2.27 TONS COMP. RATIOS 5.2/1 ---------- 98 N.K. WT. EMPTY 2.34 TONS COMP. RATIO 4.1/1 10 E.X. 1.5 CWT. LIGHTER THAN STANDARD TOURER. Bottom Graph: ACCELERATION 20 H.P. V 40/50 VELOCITY M.P.H. TIME SECONDS ________ STANDARD PHANTOM ---------- 20 H.P. | ||