Effects of tire ply construction (radial and bias-ply) and tire arrangement (singles and duals on the rear axle) on the performance of a medium-powered tractor were evaluated on a concrete surface for three gear levels. Performance evaluations were identified in terms of maximum drawbar pull, maximum drawbar power, overall tractor efficiency, and specific fuel consumption. The use of radial tires provided a small advantages on the evaluation criteria compared to the bias tire. The use of dual tires instead of single tires and the increase of ground speed provided considerable advantages with respect to the evaluation criteria, particularly on the maximum drawbar power. The best results in this study were obtained with radial tires and dual configuration at the highest speed level used in the study. In this configuration, the maximum drawbar power and overall tractor efficiency increased by about 12 % and 4 %, respectively, while specific fuel consumption decreased by about 4 %.