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 performance, one for high vs low compression ratios and the other for the 20 HP vs 40/50 models.
| Identifier | ExFiles\Box 19\7\ Scan093 | |
| Date | 16th November 1926 guessed | |
| Top Graph: ACCELERATION HIGH V LOW COMPRESSION RATIO 40/50 VELOCITY M.P.H. TIME SECONDS Legend: Solid Line: 10 E.X. WT. EMPTY 2.27 TONS COMP. RATIO 5/1 Dashed Line: 98 N.K. WT. EMPTY 2.34 TONS COMP. RATIO 4/1 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 Legend: Solid Line: STANDARD PHANTOM Dashed Line: 20 H.P. | ||