[jmc]

I posted this when I first found out they updated the OEM plugs and got a set ...

http://www.mercedescla.org/forum/32-cla-performance/18593-m270-spark-plug-updated.html

For future easter egg hunts, try the "search" function ... I typed in "spark plug" and found the above post ...
The one you found at Amazon *is* the OEM plug ... made by NGK specifically for the M270 engine. Price is about
right.

The Bosch one has an Iridium ground plate "inlay" instead of platinum which the NGK has ... this will remind me
to look at the ground plate vs the spark tip on the NGK when they come out at 20K ... if the tip surface quality is
much better than the ground, then the Bosch ones may be worth a try?
Though I need some data on the thread start point and insertion depth of the gap ... the M270's are rather picky
which way the ground metal faces, and how deep the gap is within the fuel charge.

 

[jmc]

Thanks for the info. I had seen your original thread. But I guess what I was looking for was if anyone had ever discussed which is the best spark plug since there are several options.

Last question, I am about to hit 30K miles. Do you suggest I should change the plugs? Last thread I read had conflicting opinions. It's not an expensive investment. Just want to make sure I am not wasting my money either.

The "best" is somewhat subjective though if the oem unit is designed for the engine thats usually a good first choice especially in this case with purposed oem development.
Now until I see technical proof an aftermarket (bosch etc) plug puts the spark exactly where it needs to be (gap depth) and does not disturb the designed flame front propagation (ground arm orientation and shape) I feel more comfy with the oem.
As for maintenance again thats a personal flavor ... stick with the 60k service mark and hope for the best, or maintain a performance and efficiency advantage by replacing somewhat earlier (30k in your case, 20k for mine) since as you pointed out its not a severe expense, and considering the multispark operation (accelerated aging) and the tons of spark counts on limited lifetime consumable metal electrodes ... I personally am not going to tolerate misfire codes cuz I was too lazy to execute a simple replacement. But again thats just me.
Hopefully my original plugs will seem good enough to keep as spares ... just in case. ?

 

[jmc]

why bother with changing spark plugs if you can do without it...

Next Mazda SkyActive Engine Will Have No Sparkplugs - Gas 2

Its funny you bring this up ... just had a (friendly) yelling match with some cohorts on this very subject ?
Reminds me of the glow plug r/c model engines ... should be interesting to see a production engine with this in action.
I wonder if they can merge 20:1 c/r with turbos? That will be a hoot!