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).
Table of test results logging vehicle stability and control at various tyre pressures.
| Identifier | ExFiles\Box 28\4\ Scan285 | |
| Date | 17th August 1925 guessed | |
| Tyre press: lbs/sq". | ADVANCE M.P.H. | RETARD. M.P.H. | TOE IN. | WHEEL BALANCE. | PIVOT LEAN. .125 / .150" | REMARKS. 60 | 66 | 66 | 1/8" | 1 lb. out. | " | Not very violent, fairly easily controlled. 55 | 65 to 68 | 68 to 66 63 to 60 | " | " | " | Intensity same as previous. 50 | 62 to 63 65 to 67 | 67 to 65 63 to 60 | " | " | " | Violent - just under control. 45 | 61 to 63/65 | 65 to 61 61 to 54 | " | " | " | Shade more violent than previous. 40 | 59 to 61 | 61 to 53 | " | " | " | Dangerous - still more violent than previous. 35 | 57 to 59 | 59 to 48 | " | " | " | Very dangerous. Ha/Rm.{William Robotham - Chief Engineer} | ||