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 horsepower loss in new versus worn Dunlop Fort tyres at various speeds and pressures under load.
| Identifier | ExFiles\Box 158\2\ scan0024 | |
| Date | 2nd May 1939 | |
| 3 DUNLOP FORT TYRE LOSSES. COMPARISON OF TYRES NEW (SHEWN _____) WITH TYRES HAVING 1/3 THE TREAD REMAINING (SHEWN -------) CURVES AT FULL THROTTLE UNDER LOAD. WEIGHT ON 2 TYRES TESTED 1920 LBS APPROX. H.P. LOST IN TYRES M.P.H. 53 LB/IN² 33 LB/IN² 33 LB/IN² 43 LB/IN² 21 LB/IN² 27 LB/IN² RM{William Robotham - Chief Engineer} / TAS{T. Allan Swinden} / 2 - 5 - 39 | ||