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 comparing steering wheel torque to rocking shaft torque using different lubricants at various temperatures.
| Identifier | ExFiles\Box 154\3\ scan0042 | |
| Date | 9th June 1927 | |
| Torque on Rocking Shaft in lbs. Torque on Steering Wheel in lbs. 1000 2000 3000 4000 5000 100 200 300 400 500 600 700 Iso-Vis (160°F) (Room Temp.) Motorine C (160°F) (Room Temp) Amber Gear Oil (160°F) (Room Temp) KEUFFEL & ESSER, CO., NEW YORK, NO. 359-12G. R.{Sir Henry Royce} JMH 9/6/27 | ||