MAHLE Original plasma-moly steel top rings provide the ultimate in tensile strength, hardness, and fatigue resistance. The MAHLE Original SAE 9254 steel is combined with proprietary plasma face coating to extend life, eliminate ring breakage, reduce side wear and minimize groove pound out problems. The smaller cross-section of the steel ring allows the top ring groove to be moved closer to the top of the piston. This reduces the crevice volume portion around the top ring land for reduced unburned fuel. Smaller cross-sections mean lower ring mass; this lighter ring design will better tolerate inertial forces and thus seal against the bottom of the ring groove more effectively. The smaller cross-section permitted with higher strength material greatly improves the ability of the ring to conform to cylinder bore distortion often found in today's high output, high RPM engines.