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 40/50 R-R model competitors' specifications and prices.
| Identifier | Morton\M21\ img029 | |
| Date | 19th September 1922 | |
| 40/50 R-R COMPETITORS. Make. | Chassis Price. | Bore and Stroke. | No. of cylinders. | Cubic Capacity. | Chassis price per cubic inch. | Treasury Rating. | Price per h.p. Treasury rating. 40/50 Rolls-Royce. | £1850. | 4½ x 4½ | 6 | 453.3 | £4. 1. 6. | 48.6 | £38. 1. 4 " R-R Long. | £1900. | 4½ x 4½ | 6 | 453.3 | £4. 3. 9. | 48.6 | £39. 1.10 40/50 Napier. | £1750/£1850. | 4 x 5. | 6 | 377.0 | £4.12.0. | 38.4 | £45. 3.0 * Napier Long. | £1734/£1834. | 4 x 5 | 6 | 377.0 | £4.17.3. | 38.4 | £47.15.2 40 hp Lanchester. | x£1895. | 4 x 5 | 6 | 377.0 | £5. 0. 7. | 38.4 | £49. 7.0 40 hp Hispano Suiza | £2100. | 3.9x5.5 | 6 | 401.0 | £5. 4.8. | 37.2 | £56. 9.0 45 hp Daimler. | £1275. | 4.33x 5.1 | 6 | 438.0 | £2.18.2. | 45.0 | £28. 6.8 30 hp Daimler. | £1000 | 3 35/64 x 4 7/32 | 6 | 303.1 | £3. 6.0. | 30.1 | £33. 4.5 x Allowance has been made for accessories that they include and we do not. | ||