Influence of Tyre Inflation Pressure and Wheel Load on the Traction Performance of a 65 kW MFWD Tractor on a Cohesive Soil

The choice of tractor configuration is of primary importance in tillage operations for the optimisation of traction performance, i.e. for limiting slip which involves energy loss. To a great extent, this aspect affects the fuel consumption and the time required for soil tillage. Tyre inflation pressure and wheel load are both easily managed parameters which play a significant role in controlling the traction performance of a tractor. The present study aimed to investigate the influence of tyre inflation pressure and wheel load on the traction performance of a mechanical front wheel drive MFWD tractor (65 kW engine power) on an agricultural clay (C) Vertic Cambisol on the basis of results of traction tests and simulations with a semi-empirical soil-tyre interaction model adapted for MFWD vehicles. The traction tests were carried out using four tractor configurations with two tractor weights (40.8 kN and 50.2 kN) and two tyre inflation pressures (60 kPa and 160 kPa). Traction performance was considered in terms of drawbar pull, traction coefficient, tractive efficiency, power delivery efficiency and specific fuel consumption in relation to wheel slip. A decrease in tyre pressure and an increase in wheel load resulted in higher drawbar pull however, only the former produced improvements in terms of coefficient of traction, tractive efficiency, power delivery efficiency and specific fuel consumption, while the only significant benefit resulting from the latter was a reduction in specific fuel consumption at a tyre pressure of 160 kPa and a slip of under 15%.