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 carburettor recommendations for a 25 HP car, model GMD-20.
| Identifier | ExFiles\Box 102\1\ scan0254 | |
| Date | 4th February 1935 | |
| To Hd{Mr Hayward/Mr Huddy}/WT. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}24/KW.4.2.35. 25 HP. petrol Consumption - GMD-20. Replying to Hd{Mr Hayward/Mr Huddy}/WT.5/HR.4.2.35. We recommend that the customer should have his standard carburetter back. If he is keen on petrol consumption he will certainly be able to get a better figure by using his mixture control on the standard carburetter than he can without any mixture control on the new carburetter. There is one thing about Spink's car which has shown up on our experimental tests, and that is that it does 2 m.p.g. less than our experimental 20/25 when fitted with the same carburetter, i.e., a carburetter which gives 15.2 m.p.g. on our 20/25 gives only 13.0 m.p.g. when fitted to GMD-20. Under these circumstances we are sending you an adaptor and a standard carburetter which you can fit to Spink's car and get a consumption figure over the same route. Even if when set correctly for the best performance this carburetter is no better than the new one, we shall still recommend that the customer reverts to the old carburetter if his major concern is petrol consumption, as he will always get an advantage out of the use of the mixture control. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||