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).
Graph plotting vehicle speed in M.P.H. against engine speed in R.P.M. for 19' and 17' wheels.
| Identifier | ExFiles\Box 90a\3\ Scan114 | |
| Date | 21th May 1912 | |
| M.P.H. 80 70 60 50 40 30 10 R.P.M. 1,000 2,000 3,000 4,000 5,000 21-5-12. X.76 / 19" WHEELS. 17" WHEELS | ||