Graph showing the variation of horsepower consumed by a tyre over time as its temperature increases.
| Identifier | ExFiles\Box 160\2\ scan0020 | |
| Date | 1st June 1923 guessed | |
| 3.15 HP HP CONSUMED VARIATION OF HP. WITH TIME OF RUNNING i.e. TEMPERATURE OF TYRE. Normal running temp. 1.2 HP. Test on drum. Load 1050 lbs. 80 lbs. sq.in. 50 m.p.h. 895 X 135 cord (magnum). Equivalent to standard load on road of 1,700 on axle TIME IN MINS | ||
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).