[340irckt8683]

Hi
My car is currently at 52k miles
And I'll be replacing my spark plugs
I ordered the genuine Bmw spark plugs
From ECS tuning , I'm currently running
MHD stage 1 91octane , it's a 340i 2016 with a b58
Not sure if I should stay with the original recommended gap or a different gap because of the tune,thanks.

[thejeremyman9]

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: https://f30.bimmerpost.com/forums/sh....php?t=1709198

Specifically these posts:
https://f30.bimmerpost.com/forums/sh...5&postcount=10
https://f30.bimmerpost.com/forums/sh...5&postcount=15
https://f30.bimmerpost.com/forums/sh...3&postcount=35

[chowser51]

Any recommendations for b48/b46 running bm3 stage 1?

I was just going to get oem spark plugs.

[thejeremyman9]

Originally Posted by chowser51

Any recommendations for b48/b46 running bm3 stage 1?

I was just going to get oem spark plugs.

The general concensus and my recommendation is go for new OEM plugs at OEM gap, especially only for stage 1, then only go to colder plugs with smaller gap if you find that you have issues with OEM. The colder plugs and smaller gap can cause cold start and/or idle issues in some cases, so only use if necessary.

[3FortyI]

If it helps.. I was on OEM plugs when I had stage 1 and 2 on MP tune. Stage 2 is with downpipe.

Recently went with NGK and gapped them, and it rides much much better. I'm switching to MHD soon and will re-gap/assess every 10k miles or when oil change happens.

[340irckt8683]

Originally Posted by thejeremyman9

The general concensus and my recommendation is go for new OEM plugs at OEM gap, especially only for stage 1, then only go to colder plugs with smaller gap if you find that you have issues with OEM. The colder plugs and smaller gap can cause cold start and/or idle issues in some cases, so only use if necessary.

thanks

[chowser51]

I’m looking at NGK 94201. It says B58/B48.

[ooshnoo]

If you get them from FCP Euro, the come pre-gapped and have a lifetime warranty

[thejeremyman9]

Originally Posted by ooshnoo

If you get them from FCP Euro, the come pre-gapped and have a lifetime warranty

That's where i got my Bosch OEM ones, just installed last weeked. Even though they are pregapped, check them before installing for consistency. You dont really want to have to adjust these type of plugs, but if one is dramatically off you should correct it. Mine were all 0.030 out of the box, installed like that.

[Asvplee]

Went bm3 stg 2 91, had oem champion plugs for about 500 miles, then switched to ngk. Car ran much better with oem plugs. Going to put a new set of oem champion plugs in but closing the gap to .025