Evaluation of new agricultural tractors engines by using a portable dynamometer

Official agricultural engineering testing aims to determine torque and power, which are important information for decision making when buying an agricultural tractor. In this research the torque and maximum power values provided by manufacturers with the dynamometer tests values, were compared. Forty new agricultural tractors commercialized in the brazilian market were used. Tractors were classified according to the power range in: Class I (less than or equal 22.1kW); Class II (between 22.1 and 51.5kW); Class III (51.5 and 73.5kW); Class IV (73.5 and 117.7kW); and Class V (117.7 and 183.9kW). Variables were analyzed with the statistic t-Student test (P≥0.05). Class IV tractors engines power is bigger in comparison to the values specified by manufacturers. As for Class III tractors engines, torque values observed were bigger when compared to the specified, while for Class V was presented smaller values. As conclusion, with respect to the maximum engine power, it was verified that 67.5% of the evaluated tractors meet the information provided by manufactures.