A feed mixer apparatus that includes a mixing chamber for receiving feed, and having a mixing element situated therein for mixing the feed, a transmission having a plurality of gears and connected with a mixing element, a drive system having a plurality of drive system components, including the transmission, a torque sensor interconnected with at least one drive system component, a control unit having a display and a plurality of user inputs, wherein the control unit is in at least indirect communication with the transmission and the torque sensor, and wherein the control unit receives a plurality of outputs from one or more of the transmission and torque sensor, and based at least in part on the plurality of outputs, provides an output command to effectuate a gear change in the transmission.