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).
Tables detailing tyre performance characteristics including load, pressure, and use on different surfaces.
| Identifier | ExFiles\Box 114\4\ scan0018 | |
| Date | 29th January 1937 guessed | |
| Table 1. Various Tyres carrying maximum tyre load of 4.75/16 (6½-cwts). Inflation pressures. Tyre size. lbs./sq. inch. Use. Ellipse Area sq. inch. Contact Pressure. lbs./sq. inch. 4.75/16 28. Roads. 20.2 36. 4.75/16 24. Hard sand. 21.9 33. 6.50/16 8. Very soft sand. 37.5 20. Table 11. Various tyres carrying maximum tyre load of 6.50/16 (11¼-cwts). 6.50/16 30. Roads. 30.7 41. 6.50/16 22. Hard Sand. 37.7 33. 7.00/16 18. Hard sand. 41.6 30. 9.00/16 13. Soft sand. 58.5 21. Table 111. Various tyres at 10-lbs./sq.inch Inflation Pressure. Size. Load. (cwts.) Use. Ellipse Area. Average Contact Pressure. 4.75/16 3½. Very soft sand. 21.2 19. 6.50/16 7. Very soft sand. 36.5 21. 7.00/16 8. Very soft sand. 41.6 21. 9.00/16 9½. Very soft sand. 60. 18. Table 1V. Tyres with approximate load used in Mr. Symon's Desert Tours. Size. Load. Inflation Pressure. Ellipse Area. Av. Contact pressure. 6.50/16 10. 20. 36.7 31. 6.50/16 10. 26. 30.9 36. 7.00/16 16** 20. 54.0 33. 7.00/16 16. 35. 39.0 46. ** This is a greater load than we should normally recommend at this pressure. | ||