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 acceleration performance graphs comparing different engine configurations and car models.
| Identifier | ExFiles\Box 21\2\ Scan036 | |
| Date | 3rd January 1927 guessed | |
| ACCELERATION HIGH V LOW COMPRESSION RATIO 40/50 VELOCITY M.P.H. TIME SECONDS OPEN TOURING CARS 10EX WT. EMPTY 2.27 TONS COMP. RATIO 5.2/1 92 N.K. WT. EMPTY 2.34 TONS COMP. RATIO 4/1 10 EX. 1.5 CWT LIGHTER THAN STANDARD TOURER ALSO MORE SPORTING LINES ALL FIGURES DIRECT DRIVE C.O. CLOSED ACCELERATION 20 H.P v 40/50 VELOCITY M.P.H. TIME SECONDS OPEN TOURING CARS STANDARD PHANTOM 2.34 TONS 20 H.P EMPTY WT. 1.56 TONS. | ||