PETROL CONSUMPTION.

Greymouth Evening Star, 7 September 1934, Page 3

PETROL CONSUMPTION.

EFFECT OF HILLS AND WIND

So many things have a bearing on fuel milage that it is almost impossible to fix an actual rate of consumption that will apply in all working conditions. However, some particularly interesting facts were recently made available as the result of road tests conducted in England. Special fuel measuring equipment was installed on a 20-horse-power sixcylinder car weighing 32cwt., by means of which accurate details were obtained of the petrol used when the car was driven at touring speeds on the level, up gradients, and in congested traffic conditions. Travelling in top gear at a steady speed of twenty-five miles an hour on a level main highway, the average result of two runs in opposits directions was twenty-two and a-half miles a gallon. At forty-five miles an hour the average was nineteen and a-half miles a gallon. On a slight down grade, at forty-five miles an hour, the figure rose to twenty-three miles a gallon. In suburban light traffic, with speeds ranging (on top gear) from twenty to thirty miles an hour, the consumption dropped to eighten and a-half miles a gallon. Travelling through heavy city traffic on top and third gear, at speeds ranging from fifteen to twenty-five miles an hour, brought the consumption down to thirteen miles a gallon. On a long ascent (1 in 15 to 1 in 10 gradients) in top gear, at thirty-five to forty-five miles an hour, the figure! dropped to ten* and a-half miles a gallon. Climbing the same hill in | third gear at forty to forty-five miles an hour gave a result of nine and ahalf miles a gallon. Therefore, about double the fuel was used travelling uphill, as against the same speed on the level. Throughout these tests a normal carburetter setting was used, and no deliberate effort was made to reduce the quantity of fuel. The figures show clearly how petrol consumption increases as the speed rises. The effect of wind resistance was revealed in a striking manner during one of the tests. There was a fairly strong wind during the runs on the main roads, which made a pronounced difference in the figures obtained. For example, at forty-five miles an hour with the wind, the consumption was twenty-one miles a gallon, but against the wind only eighteen miles . a gallon. The influence on fuel consumption, of temporary checks, followed by acceleration in thick traffic, is also remarkable. It is of interest that the , average monthly petrol consumption of the car used in the lests, based on ; mileage travelled and quantity of‘fuel used during that period, was 18.2 miles a gallon. ,