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 discussing various motor oils and their viscosities for summer and winter use, and recommending specific grades.
| Identifier | ExFiles\Box 145\3\ scan0063 | |
| Date | 25th November 1936 guessed | |
| Copy. - 2 - recommended - they cannot all be the ideal can they? Take your own case:- Summer. Winter. Price's Motorime C. 250 M.{Mr Moon / Mr Moore} 190 Wakefield's Castrol XL. 240 CW 135 Vacuum Mobiloil D.{John DeLooze - Company Secretary} 300 AF. 200 Shell Aeroshell. 320 Single Shell 148 Variation 240/320 135/200 Mean 280 167 What I am doing is to send you three grades, N.P.1., N.P.2., N.P.3 the 140°F.viscosities of which are:- N.P.1. N.P.2. N.P.3. 115 150 235 but I would like our technical people to have the advantage of your folk's advice before recommending the adoption of N.P.1 for your present or future engines. If you can trace cars which have customarily used Mobiloil Arctic viscosity 110/115, they should provide interesting information. Excuse my verbosity and non-academic language. Yours sincerely, (Sgd) A.Duckham. This delay in dealing with your letter is due to my being away under doctor's orders and I am signing in the country - I am sorry. A.D. | ||