Bosch suck. They may work alright for you, but never as well or as reliably as Motorcraft/Autolite double plats.
Everyone should run Autolite double plats in their Duratec! You may or may not see a difference, either good or bad, with other plugs, but it's not worth a lot more money (NGK, Denso) or a chance they may hurt performance or wear out quickly. Just shell out $24 at any auto parts chain for 6 new plugs!Originally posted by FAQ:
The Duratec requires double-platinum plugs for proper operation. Single platinum or copper plugs will fire but will wear prematurely. Appropriate stock replacements are Motorcraft AGSF32PP/AGSF32PPM or Autolite APP764 (essentially the same plug). The Motorcraft plugs may be hard to come by in your area; the Autolites are perfect substitutes in that case. Don't forget to set the proper gap on your plugs (.054) even if the manufacturer claims they are pre-gapped.
Note that Bosch +4 or NGK Iridiums are hit-or-miss for many Duratec owners. Some people have reported great performance, while others have experience ignition problems. Other kinds of plugs, like Splitfires, are mostly snake oil and should be avoided altogether.
