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 comparison charts for Open Touring Cars, one comparing high vs low compression ratios and the other comparing 20 HP vs 40/50 models.
| Identifier | ExFiles\Box 113\2\ scan0112 | |
| Date | 19th November 1926 guessed | |
| ACCELERATION KIT. 25 HIGH V LOW COMPRESSION RATIO 40/50 VELOCITY M.P.H. ALL FIGURES DIRECT DRIVE C.O. CLOSED OPEN TOURING CARS - 10 E.X. WT EMPTY 2.27 TONS COMP. RATIO 5.2/1 ------ 98 N.K. WT EMPTY 2.34 TONS COMP. RATIO 4/1 10 E.X. 1.5 CWT. LIGHTER THAN STANDARD TOURER. ALSO MORE SPORTING LINES TIME SECONDS ACCELERATION 20 H.P. v 40/50 VELOCITY M.P.H. OPEN TOURING CARS - STANDARD PHANTOM 2.34 TONS ------ 20 H.P. EMPTY WT 1.88 TONS TIME SECONDS | ||