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 results for car 1.EX, a 4-seater open touring body, comparing high and low compression setups.
| Identifier | ExFiles\Box 29\3\ Scan105 | |
| Date | 13th September 1922 guessed | |
| Particulars of car 1.EX - 4-seater open touring body - windscreen and hood - all accessories - weight complete 46¾ cwts. during tests. 14 X 52 axle ratio. Tests were taken to prove that ignition and mixture were set to give the best results. Max. speed for one lap. TESTS. | | High compression. 23¾ cu.ins. Exhaust cut-out | Low compression. 26 cu.ins. Exhaust cut-out | |---|---|---|---| | | Open. | closed. | Open. | closed. | | Max. speed for one lap. | m.p.h. 71.4 | m.p.h. 65.5 | m.p.h. 69.4 | m.p.h. 65.74 | | Max. speed for ¼ mile. | 67.4 | 63.5 | 65.22 | 62.7 | | Acceleration. | secs. | secs. | secs. | secs. | | 10 m.p.h. to 65 m.p.h. | 37¾ | 50 | 47 | impossible | | 20 " " 65 " " | 34 | 46¾ | 41 | to | | 30 " " 65 " " | 29 | 35 | 38 | get | | 40 " " 65 " " | 26¾ | 32 | 32¾ | | | 10 m.p.h. to 60 " " | 30 | 37 | 34 | 42¾ secs. | | 20 " " 60 " " | 27 | 31 | 32 | 36 | | 30 " " 60 " " | 21 | 25 | 28 | 32 | | 40 " " 60 " " | 17 | 19 | 20¾ | 23 | | 10 " " 50 " " | 21 | 23¾ | 23 | 25 | | 20 " " 50 " " | 17 | 19 | 20 | 22¾ | | 30 " " 50 " " | 12 | 14 | 15 | 17 | | 40 " " 50 " " | 7 | 7½ | 8¾ | 10½ | | ¼ mile acceleration test. | | | | | | starting at 10 m.p.h. | 40 | 43 | 45 | 47½ | | 20 " | 36 | 37 | 38¾ | 40 | | 30 " | 33 | 33 | 36 | 37 | | ||