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).
Two graphs comparing the rolling resistance of different tyre types under machine and road test conditions.
| Identifier | ExFiles\Box 158\1\ scan0015 | |
| Date | 14th January 1927 guessed | |
| contd :- -6a- FIG 1. MACHINE TESTS ON ROLLING RESISTANCE SPEED 50 M.P.H ROLLING RESISTANCE LBS WT/TN. INFLATION PRESSURE LBS/SQ IN. 33 x 6.75 TYRE 33 x 5 TYRE FIG: 2. ROAD ROLLING RESISTANCE TESTS DISTANCE ROLLED FROM REST YDS INFLATION PRESSURE LBS / SQ. IN. 33 x 6.75 TYRES 33 x 5 TYRES | ||