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).
Comparison of fuel consumption increases at various speeds and gear settings for two vehicle models.
| Identifier | ExFiles\Box 93\2\ scan0214 | |
| Date | 16th November 1937 | |
| -2- Rm{William Robotham - Chief Engineer}/GR.{George Ratcliffe}6/MH.{M. Huckerby}16.11.37. Consumption M.P.G. 35-EX 37-EX. Increase with .056 jets at 45 MPH. 0.8 0.2 " " " " " 60 MPH. 0.7 0.4 " " " " " Overdrive 2.0 -- " " .058 " Overdrive -- 1.4 Tests carried out with the overdrive included acceleration to 50 MPH. in top gear and then up to a maximum of 70 MPH, this maximum being adhered to for the top gear test, in order to get a direct comparison of economy. RM{William Robotham - Chief Engineer}/GR.{George Ratcliffe} | ||