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).
Performance graph plotting RPM against MPH for different gears and two different tyre sizes.
| Identifier | ExFiles\Box 155\1\ scan0156 | |
| Date | 8th August 1934 guessed | |
| J.E.R. HALLS CHASSIS M.P.H. R.P.M. F.D R.P.M. AT 60 M.P.H. 5.50 x 18 TYRES TOP 2609 3RD 3244 2ND 4146 1ST 2635 30 M.P.H. 5.25 x 18 TYRES TOP 2667 3RD 3320 2ND 4240 1ST 2695 30 M.P.H. 5.50" TYRES 5.25" TYRES TYRE CIRCUMFERENCE EFFECTIVE AT 35 LBS 5.50 x 18 = 87.25" 5.25 x 18 = 88.25" ROAD WHEEL REVS MILE 5.50 TYRES = 701.9 ROAD WHEEL REVS MILE 5.25 TYRES = 717.79 AXLE RATIO 11 x 41 = 3.72 : 1 TOP 3RD 2ND 1ST | ||