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).
Results of fuel consumption runs and average speed tests.
| Identifier | ExFiles\Box 147\5\ scan0156 | |
| Date | 29th October 1938 | |
| -2- Results of consumption runs. Average Speed Tests (72 Miles at 60 M.P.H.) TABLE DATA: Column Headers: 6.B.IV., 7.B.V. ROW 1 6.B.IV. Carb. features: Standard 1 3/4" carbs. (L.B.1 needles) M.P.G.: 14.2 7.B.V. Carb. features: 1 3/4" carbs with B.J.A. needles. M.P.G.: 13.35 Remarks: B.J.A. needles were best available at time of testing. They were just too weak for full throttle pick up 10 to 30 M.P.H. ROW 2 6.B.IV. Carb. features: 1 3/4" carbs. with B.J.A. needles. M.P.G.: 13.8 7.B.V. Carb. features: 1 3/4" carbs with Lbl needles. M.P.G.: 13.1 Remarks: Carburetters complete interchanged between the two cars. Little change in relative petrol consumptions, but the weakness follows the carburetters making 6.B.IV much too weak. ROW 3 6.B.IV. Carb. features: Same as previous test, but with rear wheels interchanged. M.P.G.: 13.8 7.B.V. M.P.G.: 14.05 Remarks: Interchanging rear wheels gives a reversal of consumptions due to 1" difference in tyres size. Allowing for slightly better consumptions due to a slower run the reversal is almost exact, giving 1/4 M.P.G. better cons. for 7.B.V. 6B.4 is very weak. | ||