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 showing the effect of tyre size on power loss during dyno drum tests.
| Identifier | ExFiles\Box 158\2\ scan0048 | |
| Date | 17th May 1939 | |
| 9 TESTS ON 2 REAR WHEELS ON DYNO DRUMS EFFECT OF TYRE SIZE ON POWER LOSS DUNLOP TRACK RACING @ 44 LBS/IN² CURVES TAKEN AT FULL THROTTLE AXLE LOAD 1920 LBS APPROX. H.P. LOST IN TYRES M.P.H 6.50 x 19 6.50 x 16 | ||