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 tests for 25 HP vehicles comparing different carburetter and needle setups.
| Identifier | ExFiles\Box 102\1\ scan0251 | |
| Date | 1st February 1935 | |
| To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to Hs{Lord Ernest Hives - Chair}/CTS.{C. Trot Salt - Carburation} +5080 Hs{Lord Ernest Hives - Chair}/GR.{George Ratcliffe}12/KW.1.2.35. Report on Petrol Consumptions - 25 HP. (1) 20-G-IV. Fitted with EX.15792 Carburetter, (reversed throttle) XB7 needle. GMD-20. Standard, as received from Repair Dept., XB8 needle pulled out .050" from stop. Very weak at high speeds and hesitates badly. Both cars ran together to Leicester and back. 20-G-IV - 15.56 M.P.G./46 M.P.H./57 miles. GMD-20 - 14.13 M.P.G./46 M.P.H./57 miles. --------------------------------------------- (2) 20-G-IV. Fitted with modified Carburetter, LeC.4292, XC2 needle. GMD-20. Standard as received from T. Salt, test bed; fitted with XB9 needle. Very weak at low speeds and hesitations very much worse. Both cars ran together over the Glossop route. 20-G-IV - 15.22 M.P.G./40 M.P.H./117 miles. GMD-20 - 13.87 M.P.G./40 M.P.H./117 miles. --------------------------------------------- (3) GMD-20. After applying cure for hesitations by opening the low speed air passage to floor of casting - 12.7 M.P.G./46 M.P.H./71 miles. This increase in consumption was confirmed on the Test Bed. --------------------------------------------- | ||