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).
Performance test report detailing car speed and lap times under various configurations.
| Identifier | ExFiles\Box 160\2\ scan0043 | |
| Date | 8th July 1925 guessed | |
| CONDITION OF CAR. CORRECTED SPEEDOMETER. 98-NK. 15 X 52 2 passengers. Wt. of car complete - no passengers - 2 tons. 7 cwts. 1 qr. Best time for one lap | Equivalent speed. | Best speed held on most favourable straight for wind. | Max. speed off member banking. No side curtains. C.O. closed. Hood up. | 2 mins. 20 | 71.15 | 73 | 74 Side curtains. Hood up. " " | 2 " 17 2/5 | 72.5 Hood down. " " | 2 " 14 2/5 | 74.13 | 76.0 | 78 Hood down ++ Top wind screen panel open. Spare wheel carriers off. " " | 2 " 13 | 74.89 Ditto ++ C.O. open. | 2 " 10 | 76.62 | 78/79 | 80/81 The number of laps in conditions marked ++ were hardly sufficient to ensure that the best possible lap had been attained. contd :- | ||