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).
Lubricating oils used on 3½ Litre Bentley cars.
| Identifier | ExFiles\Box 145\1\ scan0041 | |
| Date | 29th September 1933 | |
| X1588 Hs.{Lord Ernest Hives - Chair} from Mx.{John H Maddocks - Chief Proving Officer} Mx{John H Maddocks - Chief Proving Officer}15/T29.9.33. 3½ Litre Bentley - Lubricating Oils. Reference to my Mx{John H Maddocks - Chief Proving Officer}16/T12.9.33. In the absence of any information with regard to the above, we have used on the 14 Bentley Cars which have been back to the Works for modification, the following oils:- Engine - Motorine "C" Gear Box - Amber "A" Steering Box - Amber "A" Axle - Whitmores Compound. With regard to the axle, you will remember that you agreed to us substituting Whitmores Compound for Gear Ease, as we have had several cases of "cutting in" Mx{John H Maddocks - Chief Proving Officer} [Signature] | ||