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 data table for 33 x 6.75' tyres at 35 lbs/sq.in pressure.
| Identifier | ExFiles\Box 45\1\ Scan384 | |
| Date | 30th November 1926 guessed | |
| -2- 33 X 6.75" TYRES. Pressure 35 lbs/sq.in. Tach: revs. | Gear. | R.P.M. | Lbs. | Equiv: H.P. ---|---|---|---|--- 1240 | Top. | 1500 | 142 | 63.0 1440 | " | 1750 | 132 | 68.0 1650 | closed | closed 2000 | 116 | 68.5 | | open 2000 | | 1240 | 3rd. | 2250 | 155 | 68.7 1400 | " | 2500 | 132 | 66 1540 | " | 2750 | 97 | 54.0 | ||