4.6.... breezed right on over that little piece of info...

 

I'm curious as to why you didn't put platinum plugs back in .

 

Didn't know the originals were platinum. Also when I went to check my year and motor for Motorcraft plugs I wasn't going to spend 5x the amount for a different plug. Plugs just produces a spark for the ignition process. Platinum doesn't provide a better spark, just last a lot longer. As in my case changing the plugs only took me an hour and 45 minutes. Next time it will be quicker for me. But 30K is a long way from know since I really don't put a lot of miles on it. Maybe 6K a year.