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).
Petrol consumption test results for Twin S.U. carburettors under high-speed conditions.
| Identifier | ExFiles\Box 1\8\ B001_X100 Engine Chassis-page250 | |
| Date | 22th March 1933 | |
| X4027aW. 3.Per.II. 22.3.33. Petrol consumption test on Twin S.U. carbs. fitted with No.5 needles over 342 miles. Brooklands and return, high speed conditions - is 15.3 m.p.g. | ||