Comparing performance data (M.P.H vs R.P.M) with a Maybach engine.
| Identifier | ExFiles\Box 170\2\ img013 | |
| Date | 28th February 1938 | |
| 80 M.P.H = 3000 = 2900 Maybach. 80 M.P.H. = 3000 2900 Maybach 80 = 4350 65 = 3500 R.P.M RECEIVED 28 FEB 1938 | ||
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).