mlg

putting champion IRIDIUM plugs in my 06 c350 sport
manual calls for gap of .031 , but my friend told me they come pre gapped and dont mess w gap. they seem to be gapped now at 036 who is right

thanx, mike

happiness is the next corner!

ncmudbug

My understanding is they are pre-gapped. I measured one or two of mine and they seemed close at least so I didn't change them. I haven't had any problems with them (but then, I doubt I'd be able to tell ). I read someone said that the gap shouldn't be changed. I'm not sure I really believe that. If you're really worried about it, you can gap them to whatever gap spec you find or if you're not, you can leave them.

Moviela

Iridium is rather rare so not much is on your plugs. If you gap them, chances are you will remove the material that resists the corrosion and high temperature.

dwpc

If you're buying the plugs locally, take a feeler gauge to the parts store and check them for proper gap before taking them home. Here's what NKG says:

https://ngksparkplugs.com/en/resourc...d%20electrode.

Handalw211e55

BF_JC230

I’ve changed mine with OEM (m271) plugs every five years since new. Never gapped them. Never had an issue.

paste

Did you raise or lower the bumper support when adjusting the four bolts?