Experimental study on the energy consumption of gasoline engine lubricating pumps in standardized driving cycles

Abstract

This paper aims to evaluate the potential of lubricating pumps to reduce the fuel consumption of passenger cars under the standardized driving cycles conditions. The transient parameters of lubricating pump in a gasoline engine are measured based on the test bench, and a quasi-steady-state model is brought forward to calculate the matching work state of lubricating pump and engine lubricating system. The result shows that a certain amount of excessive hydraulic power is needed under low speed condition to meet the step increase of lubricating requirement. In the range over piston spray cooling speed, the excessive hydraulic power of lubricating system is proportional to engine speed, and this part of driving power can be saved. The duration of acceleration conditions in driving cycles and the lubricant temperature are the most critical factors affecting the lubricating pump’s driving power. At 100 °C, the lunricating system driving energy costed in the Urban Driving Cycle (UDC) is 60.2% lower than 25 °C, but it is 42.1% in the World-wide harmonized Light duty Test Cycle (WLTC) due to the increase of acceleration condition. With a fully variable lubrication pump, the driving energy levels can reduce by 5.76%, 8.96%, 32.1% in WLTC, Extra-Urban Driving Cycle (EUDC), and UDC, respectively.