are these the recommended colder plugs for stage 2 EC tune

NGK 95770 ILZKBR7B8DG Laser Iridium Spark Plug

I’m running NGK 1555 in mine. They can also be found under NGK SIZKBR8A8HS

Since we're on the topic - how involved is DIY plug replacement? I'm due and would prefer to do them myself - but haven't poked around much to see if it's a bear.

With the proper Mercedes tool/Socket it’s not that hard. You can find it online for like 30 bucks.

I want to do this myself..I have all the basics tools .flex thin wall 6 point 12 point. TQ wrench..what are the special tools needed. I did plug on W211 63 no big deal
Thank You

there is a how to on here. It's not that bad just follow what they are saying.

you’ll need this socket, can it be done without it? Yes. Do you want to do it without it? No

CTA Tools 1061 Spark Plug Socket with Swivel (14mm x 12 Pt)

Each coil pack have 2 bolts holding it down, they are fairly easy to reach. However, the back 2 coils packs are very close to the fire wall making it near impossible to put a socket/wrench/screwdriver on to take it off.
I took all the bolts and coil packs off in like 15 mins my first time doing it, the back two screws took me close to 30 mins just to take off (mainly cause I dropped the socket like 59 times trying to reach that bolt at the back)
long story short, a 1/4 inch swivel joint would have made my life sooooo much easier. A 3/8 or 1/2 would be too large as it’ll touch the firewall. I would have paid a 100 bucks for it at the time but it was 11pm when I started the spark plug change lol

MAXPOWER 3-Piece Universal Joints 1/4", 3/8" and 1/2" Industrial Grade Spicer Coupling for Angled Socket Wrenching

so which were the correct NGK 1-step colder plugs is it the 95770 or 1555 for the M157 thats tuned?

I would also like to know which one is correct or if both will perform the same function.

myself and few others are running them tuned stage two no problem. They are considered a step colder than stock

SAMz - thanks a bunch. Do you recall if the NGK 1555 plug is exact size as the MB OEM stock? I saw a post that the NGK 95770 plug was same size but I thought the 1555 plug was 2 mm shorter vs Stock MB plug which I say based on what I read on NGK site with the specs.

im alll for an NGK 1-step colder plug if it’s the same size as the MB OEM plug but just not sure which NGK plug that would be (1555 or 95770).... will prob just buy one of each on EBay and verify before making a decision.

thx al for the feedback.

no problem, glad I can help.
If my memory serves me right I believe they were the same length.
If you are not in a super rush, I’m switching from NGK plugs to Mercedes OEM GTS plugs, according to my tuner they should be a step colder. So I’ll be taking the NGK out when I receive them and throwing OEM GTS plugs back in to test them. Once they arrive I can take detailed pictures comparing stock M157’s to NGK 1555 to GTS plugs (pretty much any M177 engine, not necessarily GTS).

I did not have any issues with NGK, I’m switching to GTS for fine tuning/data logging consistently and not needing to gap my plugs every time as OEM ones come pre gapped.
a local member here is making 650whp I think and over 800wtq on his 2012 E63 with NGK 1555 no issues.
my current set of NGK have less than 2k km on them. I’ll be selling them for cheap if you need to try them.

@SAMzE63s who is your tuner? Do you have a part number for the plugs?

DTK, the most hated lol
Part number A 000 159 05 00

thanks SAMz - would be great to see pics of the NGK 1555 vs MB OEM vs GTS plus and see how they compare size wise and how that factors into correctly indexing them. Appreciate all your feedback bud!

J

Side by side view of MB OEM plug and NGK 1555 plug



for those interested here’s a side by side view of stock MB OEM plug (heat range 6) with 8k miles and the NGK 1555 plug (heat range 8).

As you can see they’re very similar size and dimension to OEM (not identical) and from what I’m told by my MB tech buddy you can pretty much index properly with spec 23 NM and using a line to guide on your socket.

Typo on the images below. Its M177 not M178









The M177 plugs are slightly narrower than the M157 and NGK plugs, the boot still grabs it just not as firm as the OEM ones, so I just wrapped one roll of electric tape around them for a snugger fit, even though I doubt its needed since the coil is held by two screws that keeps them from moving, I just wanted an oem like fit.

Looks like a recipe for disaster. I hope not for your sake

how so?

Proper indexing.

The factory 157(278/276) plugs index via different thickness copper washers at the specified install torque (23nm). The different thickness washers compensate for minor production variations. The 178 plug washers are significantly thicker in those pics and the coil end is completely different. Coming from almost 20 years of MB experience these engines WILL melt down if not indexed properly. There is a built in tolerance of 45° in relation to the injector but I wouldn't risk catastrophic failure if it were me, or my customers. That doesn't mean don't mod, but I don't buy into aftermarket plug swaps on these engines...I've seen them go horribly wrong.

My personal s63 coupe has the eurocharged stage 2 tune with OEM plugs gapped to .022 and runs like a champ.

Specifically 157, 278, and 276 engines

TECHNICIAN - great feedback thanks.

Question, should an experienced MB master tech (not just any MB tech...) be able to properly index a 1 step colder NGK plug (1555's are what some use for m157) for stage 2 tuned cars as a option to help reduce misfires since they colder than the OEM plugs ??? i get that the aftermarket plugs arent 100% exact same size as OEM but have heard an experienced MB tech should be able to properly index those in cases with stage 2 tuned M157 motors.