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).
Comparing petrol consumption results between an old and a new type of carburetter for a 25 HP model.
| Identifier | ExFiles\Box 102\1\ scan0246 | |
| Date | 16th January 1935 | |
| X5080 To Hd.{Mr Hayward/Mr Huddy} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}6/KW.16.1.35. Re Petrol Consumption - 25 HP. Hd{Mr Hayward/Mr Huddy}/WT.1/HR.16.1.35. Attached is a copy of a complete series of tests which were taken comparing the new type carburetter with the old type when this was first introduced. As further evidence, we have the results of a number of 10,000 miles tests in which the petrol consumption of our cars with the new carburetter has not been materially different to that of the old type carburetter. As an indication, the last 10,000 miles test done with the old carburetter gave an average petrol consumption for 15,000 miles of 14.96 m.p.g. On the present car running with the new carburetter which has completed 15,000 miles, the average petrol consumption for this distance is 15.2 m.p.g. Taking two days in these 10,000 miles tests where the average speeds of the cars were identical, i.e., 47 m.p.h., the old carburetter did 14.9 and the new carburetter 15.39 m.p.g. We do not claim that the new carburetter should give a better consumption than the old one; we claim that the consumption will be the same if the cars are driven at the same average speed. In the circumstances we can only assume that the carburetter which you have of the new type is not functioning satisfactorily, and we suggest that you take the matter up with the Test Dept. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||