A powertrain (P) for a vehicle, comprising: a body including an engine , and a transmission linked to one side of the engine in a cylinder array direction of the engine ; an exhaust purifier disposed on or near an exhaust side surface of the engine ; a first support having a first end and a second end opposite to the first end, the first end being attached to the body, the first support extending from the first end in a first direction, and the second end being attached to the exhaust purifier at an attachment location on the exhaust purifier ; an exhaust manifold positioned between the exhaust purifier and the engine , the exhaust purifier coupled to the engine by the exhaust manifold , wherein the exhaust manifold has branch passages coupled to respective cylinders of the engine , and a merging structure in which the branch passages merge together, and the merging structure is coupled to the exhaust purifier , characterized in that the exhaust purifier includes a horizontal side portion coupled to a downstream end of the merging structure and disposed immediately below the branch Passages , and a vertical side portion extending in a direction away from the exhaust side surface in an air intake-exhaust direction and containing a purifier , the exhaust purifier is supported via the first support on the body at a corner portion where the horizontal side portion and the vertical side portion intersect, and a downstream side of the exhaust purifier in an exhaust gas flow direction from the attachment location extends in a direction away from the engine , the first support is configured to have a support stiffness smaller in the cylinder array direction than in a vehicle height direction so that the vertical side portion is configured to vibrate in the cylinder array direction, and the merging structure is configured to have a stiffness smaller in the cylinder array direction than a stiffness in the vehicle height direction. a body including an engine , and a transmission linked to one side of the engine in a cylinder array direction of the engine ; an exhaust purifier disposed on or near an exhaust side surface of the engine ; a first support having a first end and a second end opposite to the first end, the first end being attached to the body, the first support extending from the first end in a first direction, and the second end being attached to the exhaust purifier at an attachment location on the exhaust purifier ; an exhaust manifold positioned between the exhaust purifier and the engine , the exhaust purifier coupled to the engine by the exhaust manifold , wherein the exhaust manifold has branch passages coupled to respective cylinders of the engine , and a merging structure in which the branch passages merge together, and the merging structure is coupled to the exhaust purifier , characterized in that the exhaust purifier includes a horizontal side portion coupled to a downstream end of the merging structure and disposed immediately below the branch Passages , and a vertical side portion extending in a direction away from the exhaust side surface in an air intake-exhaust direction and containing a purifier , the exhaust purifier is supported via the first support on the body at a corner portion where the horizontal side portion and the vertical side portion intersect, and a downstream side of the exhaust purifier in an exhaust gas flow direction from the attachment location extends in a direction away from the engine , the first support is configured to have a support stiffness smaller in the cylinder array direction than in a vehicle height direction so that the vertical side portion is configured to vibrate in the cylinder array direction, and the merging structure is configured to have a stiffness smaller in the cylinder array direction than a stiffness in the vehicle height direction. <EOS>