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).
Diagram illustrating the stages of wear on front tyres over mileage.
| Identifier | ExFiles\Box 82\1\ scan0305 | |
| Date | 7th December 1933 guessed | |
| Front Tyres XU5532 1st stage outside tread. outside tread. 5000 miles wedge shape wear Outside treads 2nd stage 8000 miles 3rd stage. slight tread. smooth slight tread. 9,533 discarded | ||