Effects of Tire Size and Inflation Pressure on Tractive Performance

Abstract

The dynamic traction ratio and tractive efficiency were compared for a tractor equipped with three different size rear tires (18.4R42, 18.4R46, and 12.4R54) each operating at three different inflation pressures 55 kPa (8 psi), 83 kPa (12 psi), and 124 kPa (18 psi) and on two different surfaces (wheat stubble and plowed wheat stubble). In general, lower drive tire inflation pressures increased tractive performance. On a firm soil and at a given inflation pressure, the larger diameter tires perform better than the smaller diameter tires. On the soft soil surface, the smaller diameter tire had the lower performance of the three different size tires with an interaction with the two larger diameter tires.