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).
Table of chassis starter rolling condition figures for the 20 HP model, comparing Standard, Lucas, and C.A.V. motors.
| Identifier | ExFiles\Box 35\4\ scan 155 | |
| Date | 23th May 1927 | |
| X 4584 CHASSIS STARTER ROLLING CONDITION FIGURES. 20 HP. MOTOR. Standard 20 HP. Design. | Actual. | Lucas. | C.A.V. ENGINE TORQUE. | 560 | 500 | 500 | 500 GEAR RATIO. | 8.4 | 8.4 | 8.4 | 8.4 MOTOR TORQUE. | 66 | 66 | 66 | 66 MOTOR SPEED. | 810 | 715 | 750 | 960 AMPERES. | 137 | 142 | 190 | 153 VOLTS. | 9.26 | 9.16 | 8.4 | 9.0 ENGINE SPEED. | 96.5 | 85 | 89 | 114 E.H.P. | 1.7 | 1.74 | 2.14 | 1.84 B.H.P. | .85 | .76 | .785 | 1.00 EFFICIENCY. | .50 | .435 | .367 | .545 23.5.27. EFC. | ||