A powertrain 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.