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).
Table comparing petrol consumptions from tests conducted at Brooklands with different axle and compression setups.
| Identifier | WestWitteringFiles\I\September1922\ Scan72 | |
| Date | 9th September 1922 guessed | |
| COMPARATIVE TESTS OF PETROL CONSUMPTIONS TAKEN ON BROOKLANDS. Condition of test. | 15 tooth axle. high comp: | 15 tooth axle low comp: | 14 tooth axle high comp: | 14 tooth axle. low comp: Car run at 30 m.p.h. on Track. | 16 m.p.g. | 15½ m.p.g. | 14½ m.p.g. | 14½ m.p.g. Car run at 50 m.p.h. on Tract. | 14½ " | 14½ " | 13½ " | 13½ " Car run 1 lap 20 " " " " 30 " " " " 40 " " " " 50 " finish at 60 " | 15½ " | 14½ " | 14½ " | 14 " Run from Brooklands to Derby (140 miles) average speed 31 MPH. | 14 " | - | 13.75 " | - Run from Derby to Brooklands - 140 miles. | - | 13.5 " | - | 14 " | ||