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 comparing part throttle fuel economy against engine RPM for two different induction systems on a 4 1/4 Litre Bentley.
| Identifier | ExFiles\Box 112\1\ scan0012 | |
| Date | 15th June 1938 guessed | |
| 4 1/4 LITRE BENTLEY PART THROTTLE FUEL ECONOMY S.37 COMP. RATIO 6.3:1 (E.W. 1296) ① STD. WRAITH INDN. SYSTEM (SINGLE D.C. 42 STROMBERG) ② B.II. INDN. SYSTEM (2 W4 S.U. CARBS.) IDEAL PART THROTTLE MIXTURE FOR 'ROAD LOAD' PTS / B.H.P / HR R.P.M. | ||