http://www.fiat500usa.com/2010/02/inside-fiat-500-spark-plugs.html For the 1.4 L 16V version of the Fiat 500, NGK’s DCPR7E-N-10 has been selected as Original Equipment. This 12mm spark plug has been developed specifically for the FIRE MPI engine family. It is also a nickel alloy plug with a gap setting of 1mm.
One of the reasons Fiat chose the DCPR7E-N-10 plug is because its small diameter makes for easier installation in multi-valve small displacement engines. Another reason is its good ignition quality without requiring the costs of precious metal and its robust ground electrode design.