Spark Plug Gap for x166 - MBWorld.org Forums

Dec 30, 2021 | 12:35 AM

Steven Lim

Thread Starter

Junior Member

Joined: Dec 2020

Posts: 15

Likes: 4

GLS450

Spark Plug Gap for x166

Looking for spark plug gap please. Thanks!

Dec 30, 2021 | 03:34 PM

chassis

Out Of Control!!

Joined: Sep 2018

Posts: 14,714

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From: unbegrenzt

2017 GLE350 4MATIC

No need to gap, take them out of the box and install them, if you are using OEM plugs from the dealer.

Jul 8, 2022 | 07:33 PM

clarkpittman

Junior Member

Joined: Feb 2021

Posts: 70

Likes: 33

From: Aubrey, TX

GLS550, GLE450 Coupe

$720 seems like a bargain to me. Genuine MB parts installed correctly... on a V8!? Hell yes! I'd pay that in a second. But, I'm the guy that cracks the porcelain on the plug that goes into one of the back cylinders, or breaks off something plastic in the engine bay when a plug breaks loose when extracting it. No way I would try to change the plugs. Now, my Miata MX-5? Done in 5 minutes...😁

Jul 8, 2022 | 10:01 PM

John CC

MBWorld Fanatic!

Joined: Jun 2021

Posts: 1,967

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From: New Hampsha

'17 GLS450, '14 GLK250, Grandpa's Roadster

Quote:

Originally Posted by chassis

No need to gap, take them out of the box and install them, if you are using OEM plugs from the dealer.

That's how it's supposed to work, but I'd never install them without checking them first.

The answer to the question is 0.7mm or 0.028"

Aug 10, 2022 | 01:07 AM

bkdc

Senior Member

Joined: Dec 2008

Posts: 378

Likes: 114

2015 S550, 2017 GLS450

These days, no need to gap. If you have the right plugs, they have the correct gap, and they are also indexed to be rotated at the appropriate position when torqued down.

I used aftermarket OE NGK-95875 SILZKFR8D7S spark plugs. Perfect fit and performance. Indexed and gapped appropriately.

Last edited by bkdc; Aug 10, 2022 at 01:13 AM.