One of the reasons for the incredible efficiency of these engines lies in the fact that piston rings account for nearly 40% of all engine friction. That makes piston rings the number 1 source of friction in an engine.amsbottom invented the piston ring in 1852, and he did it for steam engines. So before we had cars or gasoline, the industrial revolution brought us steam locomotives. Prior to Mr. Ramsbottom’s stroke of genius, steam engine pistons featured grooves packed with hemp or cotton to imp