Piston ring having a stepped running surface

A stepped piston ring, comprising a ring outer side, an upper ring flank, and a lower ring flank, wherein the ring outer side on an upper edge has a notch that is disposed between the ring outer side and the upper ring flank, wherein the notch forms a step that includes a re-entrant edge and a projecting edge on the ring outer side in an axial direction of the ring so that only a lower portion of the ring outer side forms a contact surface, and wherein the stepped piston ring extends in a circumferential direction and includes a ring gap, and wherein the notch extends in the circumferential direction and terminates at each end thereof short of the ring gap;

• and wherein the notch has a conicity with an angle of between 0.50 to 5° between the re-entrant edge and the upper flank.