A lightweight suspension assembly for a vehicle includes a suspension upright or knuckle provided with a bearing connection interface for receiving at least part of a wheel bearing, and with a first molded portion made of a first polymeric material; the assembly further includes at least one arm having a second molded portion made of a second polymeric material, and at least one joint member coupling the arm to the suspension upright/knuckle in such a manner to allow a relative rotation between the arm and the suspension upright/knuckle about at least one rotation axis (B); the first and second molded portions are arranged onto a first surface and, respectively, a second surface of the joint member, in such a manner that the first and second molded portions are coupled in a non-releasable manner to the joint member.