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 and comparing the performance of old and new carburetters on 20/25 HP cars.
| Identifier | ExFiles\Box 102\1\ scan0228 | |
| Date | 20th November 1934 | |
| 45050 W/S - C. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}7/KW.20.11.34. Petrol Consumption on 20/25 HP. Cars. Replying to C1/C17.11.34, we went into this question very thoroughly when we introduced the new carburetter, because Wor.{Arthur Wormald - General Works Manager} complained that his car was down in petrol consumption when we fitted the new carburetter. This gave us a good instance that it is possible for a customer to get the wrong impression. We took his car and fitted the old carburetter and then fitted the new carburetter, and when in each case the cars were driven at identical speeds the consumptions were exactly the same. He could of course drive his car faster with the new carburetter; when he did so the petrol consumption deteriorated. It is of course possible to set the old carburetter so that it is weak. The net result of this is that acceleration suffers and that the carburetter pops and bangs for some time after starting up. Some people are so keen on an economical petrol consumption that they will put up with this, but we hardly think we ought to cater for them. We send you three sets of carburetter tests which we took on two separate cars with the new and the old carburetter, indicating what sort of consumption may be expected. The only thing we should query about Br's note. Br.6/S.15.11.34, is that the gentleman's previous car which was 18 months old gave 18 to 20 miles to the gallon when driven in the ordinary way. The only possible way of settling the point would be to get hold of the car and see whether it does what he says and if so whether the carburetter is set correctly. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||