Thread: Spark plugs gap
View Single Post
      06-15-2020, 12:34 PM   #2
thejeremyman9's Avatar

Drives: 2015 BMW 335i
Join Date: May 2019
Location: Cali

iTrader: (0)

I am not 100% sure if the B58 is the same as N55, but for N55 some people say run OEM plugs OEM gap (MHD recommendation), some people say go two step colder NGKs at 0.022 (BM3 recommendation). I ran stage 2+ MHD tune with FBO up until 45k miles on OEM plugs. Never any misfire issues, just a little inconsistent timing which i attribute to California fuel quality. Just two days ago i replaced with new Bosch plugs (same as OEM). They are supposed to be 0.032 out of the box, and the general advice is to NOT adjust the gap. However, you should check all of them to make sure they are within spec and consistent. Mine were all 0.030 out of the box and that is how i installed them.

See more info here:

Specifically these posts: