Replaced original plugs at 83,400 miles today in '00 4.6 engine, and #5 plug had rusty threads. Wonder why? The gaps measured about .006 and looked pretty clean, since I use RXP and Essential Lube (made by Hydrotex). any info is appreciated!

 

.006 ? did you even see light through it? I know it was a typo...the plug was probably from water splash up on front of engine

 

Yep! It's typo. They measure from .064 to .066, maybe not too bad for 83k miles?