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 car related to its thermostatically operated shutters and running temperature.
| Identifier | ExFiles\Box 39\4\ Scan212 | |
| Date | 16th December 1930 | |
| To R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to SE. Mor. c. to E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} c. to PN.{Mr Northey} HY.{Tom Haldenby - Plant Engineer} 83499 Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}12/MJ.16.12.30. THERMOSTATICALLY OPERATED SHUTTERS 20 HP. X.3499. X.5250. 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 then 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 show 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}/Rm.{William Robotham - Chief Engineer} | ||