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).
Switch from oil trade names to SAE viscosity numbers in instruction books.
| Identifier | ExFiles\Box 145\3\ scan0165 | |
| Date | 24th March 1938 | |
| 1235 To Hs.{Lord Ernest Hives - Chair} from Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls}6/MH.{M. Huckerby}24.3.38. For some time we have been trying to persuade oil companies to use viscosity numbers and not trade names for their oils. Most of the companies now put an SAE viscosity number on the packages in addition to the trade name. We have told all the companies that we propose in our future instruction books to mention viscosity numbers only, so that instruction books for new cars and old cars will always be correct. The reason we have done this is that changes in oil viscosities have been made by the companies usually without consulting us, and with inconvenience to us. The Vacuum Co. have already agreed to our suggestion, and an engineer from the Shell Co. is going to tell his Sales Dept. that unless they agree their oils will not be recommended. We expect the greatest resistance from Wakefields, who consider that the letters 'XL' are the reason for their selling their oil. We want your backing for our suggestion about the instruction books. Attached is a list of the changes made by oil companies that have made us wish to use viscosity numbers only. We expect considerable trouble on P.II cars and 20/25 when they run on the new, much thinner 'XL'. Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} | ||