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 engine overheating symptoms, the function of the red warning light, and acceptable operating temperatures.
| Identifier | ExFiles\Box 105\1\ scan0078 | |
| Date | 1st August 1930 | |
| -4- Hs{Lord Ernest Hives - Chair}/Bm.l/MJ.1.8.30.Contd. with a louvred bonnet should be free from over-heating up to an atmospheric temperature of 30° C. and if trouble occurs at a temperature below this the car is not up to standard. Incidentally, owners should be told that the red warning light is a device provided to prevent them forgetting to open their radiator shutters and not an indication that the car is overheating badly and cannot be driven further. Actually, the car can be driven all day with the red lamp on and the thermometer shewing 98° C. - 99° C. and yet only lose 6 or 7 pints of water which causes no harm whatever. HS{Lord Ernest Hives - Chair}/Bn.{W.O. Bentley / Mr Barrington} | ||