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).
Data table showing the amount of petrol not drawn from a 12-gallon Bentley tank at various gradients and positions.
| Identifier | ExFiles\Box 95\4\ scan0193 | |
| Date | 20th December 1935 | |
| -4- Hs{Lord Ernest Hives - Chair}/Wym.{G. Harold Whyman - Experimental Manager}17/KW.20.12.35. 12-Gallon Tank. Bentley. Petrol not drawn from tank Tank on level .250 pts. 1 in 10 upward gradient .250 " 1 in 8 " 1.00 " 1 in 5 " 2.250 " Tank in position of R/S camber of 1 in 10. Level 5.00 pts. 1 in 10 upward gradient 5.50 " 1 in 8 " 5.750 " 1 in 5 " 6.500 " Tank in position of O/S camber of 1 in 10. Level 2.00 pts. 1 in 10 upward gradient 2.25 " 1 in 8 " 2.50 " 1 in 5 " 3.250 " | ||