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).
Specification sheet for India Tyres 5.50 x 18, detailing the effective rolling circumference.
| Identifier | ExFiles\Box 157\6\ scan0006 | |
| Date | 10th February 1936 guessed | |
| x1336 India Tyres 5.50 x 18. Effective rolling circum. 90.25" | ||