I recently ordered Motocraft SP-537 (CYFS-12Y-2) spark plugs for our 2.3 EcoBooost. They are Iridium fine wire on the firing portion only, the ground appears to be nothing special. I just found it interesting that these plugs are made in Japan for Motorcraft. I wonder if they are Denso or NGK made. I wonder if the factory plugs are the same.
Whimsey
Whimsey