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 of performance and fuel consumption between a new and old type carburetter, including acceleration test data.
| Identifier | ExFiles\Box 102\1\ scan0338 | |
| Date | 25th June 1935 | |
| -3- From the above figures it can be seen that driving under all normal conditions one can obtain a petrol consumption of approx. 16 m.p.g. with the new type carburetter with of course the outside balance pipe fitted. With regard to the performance of the 2 types of carburetter, the following table shews the new type carburetter to be definitely better at the higher speeds, actually 7% better from 40 to 50 m.p.h., 10% better from 50-60 m.p.h., 28% better from 60-65 m.p.h. and 34% better from 60-70 m.p.h. Acceleration Tests on Shardlow Road, using G's Car GAE-19. Average time for 6 runs. 3 in each direction. | | New Type Carb. | Old Type Carb. | | :--- | :---: | :---: | | 10 - 20 m.p.h. | 5.73 secs. | 5.90 secs. | | 20 - 30 m.p.h. | 10.97 secs. | 11.15 secs. | | 30 - 40 m.p.h. | 5.87 secs. | 6.00 secs. | | 40 - 50 m.p.h. | 7.27 secs. | 7.80 secs. | | 50 - 60 m.p.h. | 10.15 secs. | 11.30 secs. | | 60 - 65 m.p.h. | 7.60 secs. | 10.60 secs. | | 60 - 70 m.p.h. | 21.00 secs. | 31.90 secs. | Thus we arrived at the position where, using the same car, the new carburetter had a better performance, but a heavier petrol consumption of approx. 1.25 m.p.g. | ||