In order to evaluate tractor performance, axle torque and speed are required to calculate axle power. The ability to develop torque in drive axles of agricultural tractors is dependent on dynamic axle load, the tire-surface interface and surface conditions. The factor limiting tractive performance could be any one of the forementioned variables. In large four-wheel drive tractors, equal torques in the front and rear drive axles are desirable under normal tractor operations to insure favorable drive train life.
Presented in this paper is a summary of axle torques observed during operation of front-wheel assist and four-wheel drive agricultural tractors during performance evaluations on several different soil surface conditions.
