THE EFFECT OF ROAD GRADE ON DUMP TRUCK FUEL CONSUMPTION

Abstract

Road grade and mining activities are inseparable. Considering that a mining site is located in a lower elevation, the haul road is usually constructed following the topographic contour. A road grade is likely to affect the speed, travel time, and fuel consumption and is directly proportional to the energy required by dump trucks to overcome resistance. A higher road grade leads to more fuel consumption, while a lower road grade is likely to consume less. This study found that every 1% road grade increase results in 0.482%-0.515% increased engine speed and 2.79% horsepower under laden conditions. It was also found that every 1% road grade increase leads to 21.95% more fuel consumption in CAT 773D dump truck, 23.64% in HD-465-7 dump truck, and 13.29% more fuel consumption in Volvo A40E. Meanwhile, under unladen conditions, every 1% increase in road grade resulted in 7.64% more fuel consumption in CAT 773D, 20.60% in HD 465-7, and 23.75% in Volvo A40E. This study recommends an 8% maximum road grade to save fuel for hauling activities in the mining area.