2013~2016 Skyactiv Spark Plug Question

Back in early 80s, a co-worker had a Chevy Monza. I was told the engine had to be removed to have it tuned up, no independent confirmation. Speaking of a GM V-6, I bought '82 Buick Century new, needed carburetor overhaul at 36,000 miles. Shop charged me 4 hours of labor for tune-up. The list of break downs are more than a few pages during first 3 years of ownership.

The last GM car for me.
There's a reason GM went bankrupt.
(And Chrysler went bankrupt twice!)
 
Back in early 80s, a co-worker had a Chevy Monza. I was told the engine had to be removed to have it tuned up, no independent confirmation. Speaking of a GM V-6, I bought '82 Buick Century new, needed carburetor overhaul at 36,000 miles. Shop charged me 4 hours of labor for tune-up. The list of break downs are more than a few pages during first 3 years of ownership.

The last GM car for me.
Yes, the Chevy Monza! Although the engine is not transverse mounted, when equipped with an optional Buick V6, it would have problem to get to the last 2 spark plugs, and require the engine lift-up too.

Also during 1980’s, GM also came out the “innovational” 8-6-4 V8 with cylinder deactivation and it’s a total disaster! It proved that the cylinder deactivation simply doesn’t work!
 
It proved that the cylinder deactivation simply doesn’t work!

Well, my 2015 Acura MDX also has cylinder deactivation (called VCM for Variable Cylinder Management), many had problem with it but mine works so flawlessly, I really can't tell when it's activated. Some brilliant engineer figured out how to disable the VCM in Acuras with aftermarket gizmo, so should with Mazdas, I thought.
 
Well, my 2015 Acura MDX also has cylinder deactivation (called VCM for Variable Cylinder Management), many had problem with it but mine works so flawlessly, I really can't tell when it's activated. Some brilliant engineer figured out how to disable the VCM in Acuras with aftermarket gizmo, so should with Mazdas, I thought.
I've heard horror stories about the VCM failing and causing massive oil starvation issues. This was mainly in the first gen of that system though. By 2015, they probably figured out all of the bugs.
 
I went with the NGK OEM replacements at about 77k miles and couldn't tell any difference. But Mazda uses the plugs to measure ionization in the cylinder predicting pressure and that can predict spark knock and cylinder pressure at various crank angles. Since these engines emulate Atkinson Cycle, knowing the pressure is valuable. How much info Mazda uses is known only to Mazda, but clean plugs should give better info. Mine were certainly clean enough to have run to 100k miles in most other engines.
 
I think most want to forget the 1980's "feedback carburetors"

yrwei52: I just bought plugs from here


I was more interested in ensuring they were OEM than fakes and from years of experience with company I know that is all that they sell.
 
EDIT: I should have checked.. this was previously recommended by yrwei52

Plugs came today... might change this weekend but not sure yet.

This 14mm thin wall socket I used on my '07 G35x holds these plugs nicely.


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I've heard horror stories about the VCM failing and causing massive oil starvation issues. This was mainly in the first gen of that system though. By 2015, they probably figured out all of the bugs.
I have a 12 Pilot with basically the same V6 with VCM they've used since 2009 and through '22 models. VCM eventually cokes oil and compression rings of the shutoff cylinders, causes excessive oil consumption and plug fouling later in service life, hammers on the engine mounts, and of course many (especially with AWD) experience a variety of vibration and shudder, especially in cold weather.
Honda doesn't enable VCM operation until coolant temp reaches 167F. The Honda VCM disabler device simply keeps the REPORTED coolant temp to the PCM below 167F. If the actual coolant temp exceeds 220F or something like that, the disabler device reports the actual temp so overheating can be detected properly. My'12 runs flawlessly with the disabler.

I don't think Mazda uses the same strategy for VCM and thus can't be disabled as elegantly. And Mazda uses continuously variable intake/exhaust cam timing, which Honda does not.
 
Just a quick glance they looked exactly the same. I'm just shy of 68k miles. So an early swap but it will probably be another 8 or so years before replaced again as it appears I am only doing about 8-9k miles a years.
 
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