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).
Oil consumption differences between oil types ('Mobil-arctic', 'Castrol XL') and the impact of mild weather.
| Identifier | ExFiles\Box 144\3\ scan0139 | |
| Date | 11th January 1937 | |
| C220 W/S. Cx.{Major Len W. Cox - Advertising Manager} from Rm.{William Robotham - Chief Engineer} Rm{William Robotham - Chief Engineer}7/R.11.1.37. Thank you for Cx{Major Len W. Cox - Advertising Manager}5/KW8.1.37. The information is interesting, but we should be glad if you would add the type of oil the cars are using. There may be as much as 25% difference between the oil consumption when using 'Mobil-arctic' or 'Castrol XL'. There is no doubt that the present extremely mild weather makes the oil consumption problem increasingly difficult, as obviously, a customer must run on thin oil in case there is a cold snap, and yet with the present atmospheric temperatures summer oil would be perfectly all right. Rm.{William Robotham - Chief Engineer} | ||