Tables of box ratios and overall ratios for a 'D' style gearbox, noted as 'Bentley old'.
| Identifier | ExFiles\Box 104\3\ scan0244 | |
| Date | 16th October 1937 guessed | |
| D Style Gear Box (Bentley old.) Box Ratios Top | 3rd | 2nd | 1st & Rev Constant mesh 1.81 1 | 1.33 | 1.63 | 2.64 Overall Ratios Top Axle Ratio | 3rd | 2nd | 1st & Rev 3.3 (50/15) | 4.39 | 5.38 | 8.7 3.533 53/15 | 4.70 | 5.76 | 9.33 3.785 53/14 | 5.03 | 6.17 | 9.99 3.923 51/13 | 5.22 | 6.39 | 10.35 4.23 55/13 | 5.63 | 6.90 | 11.16 P. Box Ratios Top | 3rd | 2nd | 1st & Rev Constant mesh 1.72 1 | 1.357 | 1.823 | 3.364 Overall Ratios Top Axle Ratio | 3rd | 2nd | 1st & Rev 3.533 53/15 | 4.794 | 6.44 | 11.885 3.785 53/14 | 5.136 | 6.9 | 12.732 3.923 51/13 | 5.323 | 7.151 | 13.197 4.230 55/13 | 5.740 | 7.711 | 14.229 | ||
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).