Skotares bränsleförbrukning
In published studies it is found that the fuel consumption on a forwarder is relatively constant, on time basis. A certain variation between different sizes of forwarders occurs as well as between different working elements.
The aim of the study was to establish a forwarders comparatively fuel consumption when driving on road and in the terrain, loaded and unloaded, with high and low gear and with high and low speed as well as with hydrostatic and hydrodynamic transmission. A hypothesis was that low rpm gives lower fuel consumption on distance basic, at all trials.
The test driving was made with a Hemek 750 which is a three geared hydrostatic machine and with a Hemek 700 which is a hydrodynamic machine with six gears. Both the machines were equipped with the same kind of engine, Iveco, 6 cyl, 145 kW.
The machines were tested with a load of 12.5 (metric) tons. The study took place on a pine moor near to the Tigercat´s industry in Hede, Härjedalen, Sweden. The driving was done on a measured terrain course on 200 meters and on a section of 100 meters on a level road.
The result shows that the fuel consumption is as lowest on certain optimal revolutions and gears. A higher gear showed throughout a lower fuel consumption which a higher speed on the same gear, in most cases, also showed. On average, the fuel consumption increased with about 14 % when the machines are loaded. It was not possible to find any major difference in fuel consumption between the two machines.
When driving unloaded on the terrain course the fuel consumption varied between 2.0 and 4.0 l/km. The corresponding values for loaded machines was 2.5 and 4.5 l/km. Driving on road and using a high gear made the fuel consumption to vary between 0.7 and 2.2 l/km, with and without load.