40 years ago .043 rings were "race only". Now days there are mass production cars with rings thinner than that. Car manufacturers had to search for advanced ways to improve fuel economy and reduced friction was one of the first ways. This put higher demands on the rings and forced them toward steel base materials and other improvements. Riken , NPR, and Mahle are all producing cutting edge rings already, Hastings is just getting into it although they do have the best oil ring around.
