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).
Guidance on interpreting the red engine warning lamp in various weather conditions.
| Identifier | ExFiles\Box 15\1\ Scan346 | |
| Date | 2nd September 1930 | |
| Hs{Lord Ernest Hives - Chair}/Rd/AD2.9.30 contd. -3- (3) On Continental roads, benefit can be derived from running with the cut-out open. The main point to bear in mind is that the periodic lighting of the red lamp in exceptionally warm weather (30° C.) does not indicate that any damage or likelihood of any damage being done to the engine. Naturally, if the red lamp lights in cool weather (atmospheric temperature below 20° C.) it is a warning that something is wrong (short of water etc.) Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} | ||