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).
Vehicle road tests, detailing hill-climbing performance, fuel consumption, and transmission behavior, accompanied by illustrative diagrams.
| Identifier | ExFiles\Box 156\4\ scan0088 | |
| Date | 2nd September 1938 guessed | |
| 11 standard clutch and gears; and, though acceleration was lively, it was always smooth and progressive, the torque ratio decreasing gradually as road speed increased. Inasmuch as with the transmission there is neither declutching nor gear changing, optimum performance is achieved without involving gear changing skill on the driver’s part. Passage from the ratio of 1 to 1 to drive at higher ratios, and vice versa, is controlled solely by the accelerator, so that even at very low speed the car is driven at the ratio of 1 to 1 when acceleration is not needed, The author has carried out also a prolonged road test to ascertain the fuel consumption of the car fitted with the two-stage transmitter as compared with the fuel consumption of the same model when fitted with the standard clutch and gearbox mechanism, which latter consumption is given by the makers as “from 18 to 20 m.p.g.”. The weight of passengers and other load carried in the car during this test was approximately 6 cwt. The route was chosen to include some of the most typical and hilly country in the British Isles and was as follows: Sheffield, Scotch Corner, FIG. 21. FIG. 22. FIG. 23. while torque increase takes place, whenever needed, the moment the accelerator pedal is pressed hard. The hill-climbing performance of the vehicle was particularly impressive. This particular feature should prove of great advantage in heavy lorries, caterpillar tractors and the like. A special hill-climbing trial was made on the 1 in 4 portion of the Brooklands Test Hill. The car was loaded with progressively greater weight until the final test, when a net load of 22 cwt. was put on the car. The car was then driven on to the 1 in 4 portion of the hill, was stopped and then re-started without difficulty on the same gradient, and was driven to the top of the hill comfortably without resort to any kind of mechanical gearing (other than the said standard back axle gear). Brough, Appleby, Carlisle, Lanark, Stirling, Perth, Blairgowrie, over the top of the Devil’s Elbow on the road to Braemar, and back again by the same route to Sheffield. The car was driven at an average speed of approximately 38 m.p.h. over the whole distance, a speed somewhat higher than would be maintained on this route by the average driver. The total distance covered was 761 miles, and the petrol consumption over this distance proved to be 21 m.p.g. Throughout this long run the temperature of the liquid medium in the transmitter gave no signs of rising unduly, although the transmitter tested was of comparatively small size (13 in. outside diameter) and had no fan or cooling fins on its outer face, or any other cooling device whatsoever. The liquid medium used | ||