Which Spark Plugs To Use MB or Bosch
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2001 S600 V12 Sold, 2011 Jaguar XFR Sold, 2017 S550 4-Matic, 2018 S63 AMG Sedan
Which Spark Plugs To Use MB or Bosch
I'm going to change plugs and coils, hopefully this upcoming weekend. I'm going with MB coils, already on the way.
But, I'm trying to decide between MB OEM plugs: https://www.fcpeuro.com/products/mer...des-0001590500 and Bosch plugs:
It's clear from MB's site that they don't recommend the NGK plugs so they're off the table. But what about the Bosch plugs? Does anybody have experience with using those? Bosch Part#96347. What would you do?
But, I'm trying to decide between MB OEM plugs: https://www.fcpeuro.com/products/mer...des-0001590500 and Bosch plugs:
It's clear from MB's site that they don't recommend the NGK plugs so they're off the table. But what about the Bosch plugs? Does anybody have experience with using those? Bosch Part#96347. What would you do?
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2025 AMG G 63 SUV /// 2025 AMG GT 63 S E Performance 4 Door Coupé
I have no experience with Bosch plugs but considering most of the fuel systems on AMG’s are Bosch I’m sure they’ll be fine.
On the other hand, you obviously can’t go wrong with OEM.
On the other hand, you obviously can’t go wrong with OEM.
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With all of the very specific guidance around indexing and proper installation, I would go MB branded just to be sure. 100 bucks buys a little peace of mind.
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My only concern with the Amazon sourced Bosch plugs is their authenticity. Then Chinese are really good at making something look like the real thing on the surface, (but far inferior in quality), then selling it on sites like Amazon.
Personally, I'd go with non MB branded Bosch. Today's application specific plugs will already be threaded to be indexed correctly at the called for spec. Yes, I see those plugs can also be used in some other bands, but these are the same plugs/part number that Mercedes shipped the 63s with. I change my plugs out every 15K miles anyways, so there is that.
The coils, I'd certainly go MB branded.
Edit. Edited the Edit after the Edit to Edit.
Personally, I'd go with non MB branded Bosch. Today's application specific plugs will already be threaded to be indexed correctly at the called for spec. Yes, I see those plugs can also be used in some other bands, but these are the same plugs/part number that Mercedes shipped the 63s with. I change my plugs out every 15K miles anyways, so there is that.
The coils, I'd certainly go MB branded.
Edit. Edited the Edit after the Edit to Edit.
Last edited by Sathinas; Aug 18, 2025 at 10:42 PM.
Thread Starter
MBWorld Fanatic!
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From: Pacific Northwest
2001 S600 V12 Sold, 2011 Jaguar XFR Sold, 2017 S550 4-Matic, 2018 S63 AMG Sedan
My only concern with the Amazon sourced Bosch plugs is their authenticity. Then Chinese are really good at making something look like the real thing on the surface, (but far inferior in quality), then selling it on sites like Amazon.
Personally, I'd go with non MB branded Bosch. Today's application specific plugs will already be threaded to be indexed correctly at the called for spec. Yes, I see those plugs can also be used in some other bands, but these are the same plugs/part number that Mercedes shipped the 63s with. I change my plugs out every 15K miles anyways, so there is that.
The coils, I'd certainly go MB branded.
Edit. Edited the Edit after the Edit to Edit.
Personally, I'd go with non MB branded Bosch. Today's application specific plugs will already be threaded to be indexed correctly at the called for spec. Yes, I see those plugs can also be used in some other bands, but these are the same plugs/part number that Mercedes shipped the 63s with. I change my plugs out every 15K miles anyways, so there is that.
The coils, I'd certainly go MB branded.
Edit. Edited the Edit after the Edit to Edit.
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There are several forum threads about indexing. Here's one to start with.
https://mbworld.org/forums/e-class-w...-indexing.html
https://mbworld.org/forums/e-class-w...-indexing.html
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I suspect a lot of people who have issues with their "Bosch" plugs purchased them on Amazon and ended up not receiving real Bosch plugs. Why would someone who is (rightfully) trying to save money by not paying the "Mercedes tax" not try to save even more money by buying from Amazon instead of FCP Euro (don't like them myself), or other established online Mercedes parts vendors? Those unscrupulous Amazon sellers price their wares a couple of dollars cheaper throw in with free shipping, and Voila! People will buy from the Amazon seller(s).
Now, I'm not saying that every Amazon seller of plugs (in this case) is an unscrupulous ***** who preys on us "stupid Americans". Amazon can be great for the hings you know are legit and there are legit parts sellers on there. Trick is, sorting and finding those sellers. I give Amazon props for trying to protect brands and trademarks, but they can only do so much.
Now, I'm not saying that every Amazon seller of plugs (in this case) is an unscrupulous ***** who preys on us "stupid Americans". Amazon can be great for the hings you know are legit and there are legit parts sellers on there. Trick is, sorting and finding those sellers. I give Amazon props for trying to protect brands and trademarks, but they can only do so much.
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2001 S600 V12 Sold, 2011 Jaguar XFR Sold, 2017 S550 4-Matic, 2018 S63 AMG Sedan
There are several forum threads about indexing. Here's one to start with.
https://mbworld.org/forums/e-class-w...-indexing.html
https://mbworld.org/forums/e-class-w...-indexing.html
I'm placing the FCP Euro order today.
Last edited by carlosinseattle; Aug 19, 2025 at 03:28 PM.
Thread Starter
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2001 S600 V12 Sold, 2011 Jaguar XFR Sold, 2017 S550 4-Matic, 2018 S63 AMG Sedan
Exactly! And the coils are made by Delphi. Both things are true but I'm not sure if I want to be the guinea pig in the "will it explode" experiment. The coil packs for the S560 cost around $80 each, but the coils for the S63 cost at least $200 each, and my local dealer wants over $600 each. I was quoted $3866 for coil and plug replacement. Pretty sure I can do it in under 6 hours, hoping for 3 hours, and for less than $1K in parts. I did a trial run on the driver's side to access the coil packs and feel confident that side will take less than an hour. The other side requires moving some vacuum lines and the ECU out of the way.
Main deciding factor about using MB plugs vs Bosch branded plugs is the gap. You can easily check for the gap on any plug, but the iridium tip is super small and I don't want to risk it if I need to increase the gap, better to be sure they're gapped properly. The price difference will be less than $90, I think that's worth the peace of mind.
Main deciding factor about using MB plugs vs Bosch branded plugs is the gap. You can easily check for the gap on any plug, but the iridium tip is super small and I don't want to risk it if I need to increase the gap, better to be sure they're gapped properly. The price difference will be less than $90, I think that's worth the peace of mind.
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From: Pacific Northwest
2001 S600 V12 Sold, 2011 Jaguar XFR Sold, 2017 S550 4-Matic, 2018 S63 AMG Sedan
The bosch plugs are available locally for a decent price, so I might just buy one for that purpose. The other thing is the internal resistance and temperature rating. Some plugs run hotter and some cooler, that kind of thing is outside of my knowledge base. Maybe tuner guys know the difference and why it matters. I plan to keep my car bone stock for as long as possible so.
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Exactly! And the coils are made by Delphi. Both things are true but I'm not sure if I want to be the guinea pig in the "will it explode" experiment. The coil packs for the S560 cost around $80 each, but the coils for the S63 cost at least $200 each, and my local dealer wants over $600 each. I was quoted $3866 for coil and plug replacement. Pretty sure I can do it in under 6 hours, hoping for 3 hours, and for less than $1K in parts. I did a trial run on the driver's side to access the coil packs and feel confident that side will take less than an hour. The other side requires moving some vacuum lines and the ECU out of the way.
Main deciding factor about using MB plugs vs Bosch branded plugs is the gap. You can easily check for the gap on any plug, but the iridium tip is super small and I don't want to risk it if I need to increase the gap, better to be sure they're gapped properly. The price difference will be less than $90, I think that's worth the peace of mind.
Main deciding factor about using MB plugs vs Bosch branded plugs is the gap. You can easily check for the gap on any plug, but the iridium tip is super small and I don't want to risk it if I need to increase the gap, better to be sure they're gapped properly. The price difference will be less than $90, I think that's worth the peace of mind.
?
Thread Starter
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From: Pacific Northwest
2001 S600 V12 Sold, 2011 Jaguar XFR Sold, 2017 S550 4-Matic, 2018 S63 AMG Sedan
If you want a little more detail it says that the OEM plugs have threads that will automatically "index" the plugs so the electrode is in the correct orientation inside the cylinder, while others might not.
Other points for consideration:
Robert Bosch invented the spark plug
OEM plugs have the correct temeperature rating and are pregapped corrrectly.
Use diaelectric grease
Don't use Anti sieze on the threads
Use a spark plug socket that will properly grip the plug. And preferable one that has a built in swivel for ease of installation.
Last edited by carlosinseattle; Aug 22, 2025 at 02:15 PM.
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@carlosinseattle , thank you. I was just being a smartarse because... well, just because.
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2001 S600 V12 Sold, 2011 Jaguar XFR Sold, 2017 S550 4-Matic, 2018 S63 AMG Sedan
@carlosinseattle , thank you. I was just being a smartarse because... well, just because.
I thought it was like when I posted some info on Top Tier gas: https://mbworld.org/forums/s-class-w...100-wrong.html
