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 of standard vs high compression 20 HP models.
| Identifier | ExFiles\Box 113\2\ scan0114 | |
| Date | 3rd December 1926 guessed | |
| TOP GRAPH: 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. BOTTOM GRAPH: 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 HANDWRITTEN TEXT: Wt of 20 H.P. car empty 1.58 Tons | ||