Polar.C43

Probably a stupid question but do you have to change your spark plugs more often if you decide to go with a stage 1 tune? Any of my stage 1 guys can chime in on this one? How often? Definitely a cost to think about. Thanks.

stockbmw

$10 from Rockauto or $15 from MB. Not cheap compared to some popular $5 Japanese makes, but easier to change then some transverse mounted v6.

Polar.C43

Thank you. Would you say you have to replace your spark plugs more frequently though? Thanks.

mau108

Not really. I'd say you're good 80-100K miles. The Iridiums in there are rated for 100K miles. Now if you idle more then drive thats going affect the plug life as well. I'd say change it around 80K. I was on stage 2 and now back to stage 1 and car is perfect.

Polar.C43

Thank you 🙏

MatthewJ

MB change interval is 46k miles. With the multi-spark ign that they use i wouldnt push them to 80k+. They are easy to change and at $12 each not a big cost. Adding basic bolt on mods wouldnt really effect spark plug longevity.

munis

Dunno about the labor cost though. The plugs need to indexed too.

MatthewJ

If you buy into that making a difference...

munis

Well I read a Mercedes maintenance pamphlet that wrong orientation would and can cause a lot of issues with combustion. I would definitely buy into what the manufacturer has recommended, because you know, they designed the freaking thing.

MatthewJ

I get that in theory you can get slightly more power from combustion and better efficiency at low load. I dont see it causing any problems by not indexing them unless by some miracle of a chance all 6 line up where the electrode points towards the intake. In which case each combustion starts at a slight disadvantage to make its way out of the cylinder.
They index them from the factory and if you have the ability to do it it certainly wont hurt. Im just saying not doing it isnt going to make a noticeable difference. I didnt do it on past 2 MB motors ive done plugs on and saw zero difference in how the car ran or MPG. If you order them from MB they should indext automatically just from applying the proper Tq on them. If you get OEM mfg plug chances are they thread them the same way and they too will index correctly.

munis

I heard that one. so apparently if you torque them OEM spark plugs to correct spec, it will be indexed automatically?

jonathan358

Sorry to bring up a dead thread but there is literally 2 with this being the most recent:

What is the correct torque spec for the spark plugs in our M276 DE 30 LA?

From what I have read, torquing them to the correct specs will automatically index them ^^.

mau108

23Nm and toruqing them will auto index it as per the factory manual