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).
Graph plotting oil and top water temperatures against miles run under various car operating conditions.
| Identifier | ExFiles\Box 12\7\ 07-page089 | |
| Date | 25th June 1930 guessed | |
| GRAPH IV 62 M.P.H. C.O. CLOSED ATS TEMP 20°C CAR OPENED FULL OUT C.O OPEN 83 M.P.H. OIL TEMP TEMP C° 100° 90° 80° 70° TOP WATER VENTILATED UNDERSHIELD ALL BONNET SHUTTERS OPEN MILES RUN 25 30 35 | ||