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).
Comparison table of car data for Phantom, S.S., 20 HP, and Chrysler models.
| Identifier | ExFiles\Box 125\2\ scan0033 | |
| Date | 16th April 1929 guessed | |
| CAR DATA. CAR. | Cubic capacity. | Average weight. | Gear Ratio. | Revs. per mile. | Litres/mile per ton. Phantom. | 7600 c.c. | 50 cwts. | 3.72 | 2300 | 3500 S.S. | 7600 c.c. | 47.5 cwts. | 3.73 | 2310 | 3670 20 HP. | 3127 c.c. | 33 cwts. | 4.54 | 2980 | 2820 Chrysler. | 4080 c.c. | 32 cwts. | 3.9 | 2708 | 3450 | ||