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).
Graph plotting the mechanical efficiency of an Alfa-Romeo unit against its RPM.
| Identifier | ExFiles\Box 179\2\ img231 | |
| Date | 4th December 1925 guessed | |
| UNIT ALFA-ROMEO MECHANICAL EFFICIENCY MECHANICAL EFFICIENCY % 95 90 85 80 75 70 R.P.M. 1000 1500 2000 2500 3000 3500 4000 4500 | ||