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).
Letter from Vacuum Oil Company Limited advising on Mobiloil equivalencies to SAE grades.
| Identifier | ExFiles\Box 89\3\ scan0023 | |
| Date | 29th July 1939 guessed | |
| COPY. Vacuum Oil Company Limited, Caxton House, Westminster, London, S.W.1. Reference ED{J. L. Edwards}/AUTO. Messrs. Rolls Royce Ltd., Derby. For the attention of W.A. Robotham Esq: Dear Sirs, We thank you for your letter of the 24th inst., reference Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}11/KW. and would advise that Mobiloil Arctic is equivalent to SAE 20 and Mobiloil BB is equivalent to SAE 50. In addition you may be interested to know that Mobiloil A is equivalent to SAE 30. There is also a classification known as SAE 20W which is employed in the United States for cold conditions and Mobiloil Arctic also meets the requirements of this specification. Trusting the above information is what you require. Yours faithfully, VACUUM OIL COMPANY LIMITED. O.T. Jones. CHIEF ENGINEER. | ||