Originally Posted by vansnxtweek
does anyone know how to tell if the plug is a platinum or a double platinum? the guy at the place said what he gave me is a double plat. and i thought that would be like a double electrode or something,
Double platinums have small but visible platinum coated lumps on both the center and side electrodes. Single platinums have a single lump on EITHER the center OR the side electrode, depending on which cylinder the plug is from.
The correct single platinum plug is installed at the engine factory to work with the the coil pack polarity for that cylinder. Ford sells the double plats for replacement since they can be used in any cylinder, avoiding any possible errors in field service replacement.