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).
Data sheet listing chassis gear ratios, miles per hour at 1000 RPM, and corresponding engine revolutions for various speeds.
| Identifier | ExFiles\Box 75\1\ scan0074 | |
| Date | 29th January 1919 | |
| R.R. 235a (500 T) (S.D. 408. 26-4-17.) Bm. 2/156/13. X. 3426 29.1.19. CHASSIS GEAR RATIOS. Miles per hour at 1000 R.P.M. Reverse. 8.76 1st. 8.76 2nd. 13.43 3rd. 20.08 4th. 29.85 or 17/16 or 9/8 of these in special cases. M.P.H. Engine Revs:- 1st. 2nd. 3rd. 4th. 10 1140 745 498 335 15 1710 1116 747 502 20 2280 1489 996 670 25 2850 1861 1244 837 30 ---- 2232 1493 1004 35 ---- 2606 1743 1172 40 ---- 2980 1991 1340 45 ---- ---- 2241 1507 50 ---- ---- 2490 1674 55 ---- ---- 2740 1842 60 ---- ---- 2990 2010 | ||