Just changed out my old Bosch Platinums with some regular NGK coppers. I noticed on the old sparkplugs, the platinum tip is further "in" within the insulator. Is that normal? Thanks for any insight.

 

dont worry about it its because the platinums have a smaller tip. (I think thats what your talking about).

 

Well, when they were new I can see the tip clearly. But now it's like a small portion of top is burned off. I'm not too worried about it, engine is still running great

 

oh, i get what your saying, hmmm
my dads platinums had 80,000 on them when i pulled them, it was almost like some crap was built up on top of the tips, and alot of it broke off when i went to check the gap, kind of strange.

on a side note, dont let even platinums go that long, his were in bad shape (melted).

 

hmm, guess it's normal wear-and-tear. thanks for the replies