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).
Petrol consumption of a 20 HP model in relation to its thermostat setting and engine running temperature.
| Identifier | Morton\M13.2\ img009 | |
| Date | 16th December 1930 | |
| To R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} c. to SG.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. to F.{Mr Friese} Da.{Bernard Day - Chassis Design} c. to PH. HV. Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson}12/MJ.16.12.30. THERMOSTATICALLY OPERATED SHUTTERS 20 HP. X3499 X5250 We were concerned about the consumption of the 20 HP. 18-G4, in France. This car was sent over with a thermostat which gave a mean running temperature of about 70°C. The average over-all petrol consumption was coming out at about 13 1/4 m.p.g. We asked them to increase the temperature at which the car ran to 80°C. and in the Daily Report of 14.12.30 you will see that the consumption has risen by approximately one m.p.g. We think the improvement would have been greater if the carburetter had been re-set to the higher temperature. The 20 HP., having a much more effective hot spot than the 40/50, is not so sensitive to water temperature. The results obtained, however, are sufficient to shew that we must expect to use more petrol on both cars, particularly the 40/50, if we keep the radiator temperature down. Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} | ||