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 fuel consumption figures for Stromberg and 3 S.U. carburetors, along with vehicle test specifications.
| Identifier | ExFiles\Box 98\1\ scan0096 | |
| Date | 14th September 1940 guessed | |
| -2- The figures obtained on the 3 S.U. carbs. are accurate. The following are the figures: Stromberg. 3 S.U's. 20 M.P.H. ... ... 18.27 M.P.G.? ... - 19.44 M.P.G. 30 " ... ... 19.16 " ... - 17.72 " 40 " ... ... 16.33 " ... - 16.57 " 50 " ... ... 15.41 " ... - 15.00 " 60 " ... ... 14.16 " ... - 14.41 " 70 " ... ... 12.63 " ... - 13.12 " 80 " ... ... 11.55 " ... - 11.77 " We also ran the car whilst fitted with 3 S.U. carbs. (Rx3, Rxl, Rx3 needles) over the Ashbourne, Buxton, Glossop, Bakewell, Matlock, Derby route, at an average speed of 47.17 M.P.H. and obtained a consumption of 14.5 M.P.G., the Lagonda over the same route giving 12.24 M.P.G. During all these tests the car was fitted with: 1) E.B.4098 Increased throat cyl. head 6.3:1 comp. ratio. 2) Pistons .030" below cyl. block face. 3) E.B.4512 camshaft, short duration inlet 12. deg. negative overlap. 4) Ignition timed at TDC. 5) Rear axle ratio 3.8:1 6) Tyres 6.50 x 16. All tests run on POOL SPIRIT. Rm{William Robotham - Chief Engineer}/WYM.{G. Harold Whyman - Experimental Manager} | ||