luvboost

Got oem plugs which are gapped around .039-.040.

ive looked everywhere and the best info i could find is in this thread. Doesn’t seem like there is anything more informative on the forums or Google for the M156.

https://mbworld.org/forums/c63-amg-w204/414257-brisk-sparg-plugs-m156-weistec.html

QUOTED
Quote:
Originally Posted by Muskoka_AMG
What do you guys gap your plugs to?
I got this instruction straight from Weistec:

"
Failure to properly gap spark plugs will cause misfiring or pre-ignition. Please follow instruction carefully and use best mechanical judgment.
5. Gap new spark plugs to .032"-.038" depending on power Level.
• Stage 1 .038"
• Stage 2 .035"
• Stage 3+ .032"
6. Reinstall spark plugs, coils, and air boxes. Be sure to plug all wiring in. "


Question is: Does anyone know if this holds true for an oem plug that is not one step colder?

I’m running said tune in title with advanced timing for Ethanol.

luvboost

I’m guessing .035.

for reference it looks like the previous plugs were gapped around .032 - .034.

thebug44

I’m running stock plugs with no issues. Never replaced them

luvboost

are you on an advanced timing map with e85?

PeterA90

That gap is from weistec a site. Your n/a. Run .40 gap.

hachiroku

for a non boosted non nitrous engine factory gap and factory heat range plugs are what you should run.

luvboost

.040 oem gap it is