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 following adjustments to the carburettor's tilt and fuel level.
| Identifier | ExFiles\Box 92\3\ scan0347 | |
| Date | 1st January 1938 | |
| To By.{R.W. Bailey - Chief Engineer} c. to Mx.{John H Maddocks - Chief Proving Officer} 300a Rm{William Robotham - Chief Engineer}/GR.{George Ratcliffe}1/JH.192.38. 35.EX PETROL CONSUMPTION TESTS. Carburettor fitted with forward tilt of 4½° total fuel level not altered and checked at .750". Original jets .058 main and .060 byepass retained. The .058 main jets are essential for performance with the lower level, which in turn gives freedom from flooding on a maximum gradient of 1 in 5 cold. This gradient is reduced to 1 in 6½ with the fuel level at .625" cold. Newark route of 84 miles. 40 miles at average of 60 M.P.H. 44 miles at average of 40 m.p.h. Normal top gear consumption 10.0 m.p.g. Overdrive 11.0 m.p.g. Rm{William Robotham - Chief Engineer}/GR.{George Ratcliffe} | ||