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 showing fuel economy at part throttle for a 4 1/4 Litre Bentley engine.
| Identifier | ExFiles\Box 99\1\ scan0020 | |
| Date | 1st January 1933 guessed | |
| 4 1/4 LITRE BENTLEY PART THROTTLE FUEL ECONOMY S. 35 COMP. RATIO 6.3:1 (E.W. 1296) NON. PIPE E.B.3477-8 2 H4 S.U. CARBS ① IDEAL MIXTURE FOR 'ROAD LOAD' ② ACTUAL MIXTURE THROTTLING BACK FROM FULL THROTTLE W M SETTING (NO RESTN) ⓐ 1.000 BALANCE HOLE ⓑ .500 " ⓒ .375 " FULL THROTTLE WEAKEST MAINTAINED CONS. PTS/BHP/HR R.P.M Y-AXIS: 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22 X-AXIS: 500, 1000, 1500, 2000, 2500, 3000, 3500, 4000 | ||