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).
Request to run a comparative oil consumption test between two different viscosity oils.
| Identifier | ExFiles\Box 159\5\ scan0006 | |
| Date | 18th March 1940 | |
| COPY. Rm{William Robotham - Chief Engineer}/TAS.{T. Allan Swinden} Rm.{William Robotham - Chief Engineer}12/ML.18.3.40. Will you please arrange next time you are running a petrol consumption test, to run a constant speed test at 30 r.p.m. on an s.a.e. 20 oil, and then repeat the test on Castrol XXL, to see whether you can detect any difference in the oil consumption due to higher viscosity. Rm.{William Robotham - Chief Engineer} | ||