A drive unit includes a speed reducer that includes a plurality of gears having helical teeth and rotatably supported by bearings, and transfers rotation of a drive motor to rear drive wheels of a vehicle. The maximum value of torque to be generated by the drive motor during rearward travel of the vehicle is set to be lower than that during forward travel. Under such a precondition, the size of a bearing that receives a load during rearward travel, among the bearings which constitute the speed reducer, is smaller than the size of a bearing that receives a load during forward travel.