2023 Mazda CX-9 Sparkplugs

[pbm]

no I don't have Ruthenium plugs, you could take a multimeter, set it to ohms and measure the resistance if your daughter isn't too far away to test it, or she could if she had a multimeter. You measure between the top electrode (above the white porcelain) and the center electrode.

I just looked at the Mazda CX-5 service manual it said the measured resistance should be between 3000 and 7500 ohms or 3.5-7.5k Ohms.

yes keep us updated on how it goes.

I don't have a multimeter but the NGK Ruthenium plugs list a 5000ohm resistance right on the Rockauto site. Interestingly, so do many of the other plugs such as Denso Iridium TT's so I should be fine with the Rutheniums.

 

[researcher]

I don't have a multimeter but the NGK Ruthenium plugs list a 5000ohm resistance right on the Rockauto site. Interestingly, so do many of the other plugs such as Denso Iridium TT's so I should be fine with the Rutheniums.

oh ya, no problem, as long as they listed that, they are telling the truth and would measure right around 5k. It'll be interesting to see how these perform compared to the originals.

 

[Urshurak776]

https://www.amazon.com/Sephile-BKR5EIX-11-Temperature-Resistant-Compatible/dp/B0DGLDPTNM/ref=sr_1_6?af=eyJ2ZWhpY2xlTmFtZSI6IjIwMjIgTWF6ZGEgQ1gtOSIsInZlaGljbGUiOiIyMDIyLTgwLTU4NjMtLS0tLS0tLS0tLS00In0=&crid=30IUMUZQUR2TH&dib=eyJ2IjoiMSJ9.07X34douJE7yf8XSFto47sevbbGNh7wfJF0M4zzOIcmH05aGEmxjGRXA8Yvs-fqQVUudqnSS6S5KYv9P8pEwrYptAgdeRmuvtm4omVNGbqwZ7w-qaWJPnJNHOJGyWzu7qMy6k21P9xRcx807sHjz8w.bA_ot4FHbm1Sko7f5LPIf_i94IOV79r-gjD3S_WnXJo&dib_tag=se&keywords=Mazda+CX-9+OEM+spark+plugs&qid=1749418367&sprefix=mazda+cx-9+oem+spark+plugs,aps,182&sr=1-6&vehicle=2022-80-5863------------4&vehicleName=2022+Mazda+CX-9

I respect that you have a Super Bowl ring, but no........

 

[pbm]

oh ya, no problem, as long as they listed that, they are telling the truth and would measure right around 5k. It'll be interesting to see how these perform compared to the originals.

I went on the Autolite website and supposedly the Autolite Iridium plugs I installed in my in-laws 2015 CX-5 a few years ago have a resistance of 4000 Ohms. At any rate the CX-5 is still running well with approx. 65K* on those Autolites.
* In post #5 in this thread I said the Autolites had approx. 50k on them but when I looked at my records they actually have approx. 65k on them.

 

[kschachn]

I don't have a multimeter but the NGK Ruthenium plugs list a 5000ohm resistance right on the Rockauto site. Interestingly, so do many of the other plugs such as Denso Iridium TT's so I should be fine with the Rutheniums.

Well the tip material is irrelevant in terms of the overall resistance of the plug, that is far more determinant on the internal resistor.

I still don't really understand this Mazda restriction, does the owner's manual give you a dire warning to not use anything other than what's listed?

 

[dubber09]

I'd sure double check on NGK website what plug they recommend for the application before buying.

 

[researcher]

Well the tip material is irrelevant in terms of the overall resistance of the plug, that is far more determinant on the internal resistor.

I still don't really understand this Mazda restriction, does the owner's manual give you a dire warning to not use anything other than what's listed?

Here's my post #9 in this thread.. it helps explains why Mazda is saying what the resistance of the spark plug should be.

R

Post in thread '2023 Mazda CX-9 Sparkplugs'

Jun 8, 2025

I need to change the spark plugs on my wife's 2023 Mazda CX-9. I prefer using the OEM sparkplugs but they want $35+ each for them. Any reason not to use NGK from RockAuto?

Thanks!

I ran into this with my friend's 16 CX-5. Here's what I found.. Mazda's plugs are much more expensive than the NGK aftermarket. Yes NGK was what was installed at the factory. In the service manual, Mazda talks about making sure the resistance is between a certain value. Why? Because Mazda does something unique in that they use the spark plug as a sensor, it measures the ionic charge inside the...

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[kschachn]

Here's my post #9 in this thread.. it helps explains why Mazda is saying what the resistance of the spark plug should be.

R

Post in thread '2023 Mazda CX-9 Sparkplugs'

Jun 8, 2025

I need to change the spark plugs on my wife's 2023 Mazda CX-9. I prefer using the OEM sparkplugs but they want $35+ each for them. Any reason not to use NGK from RockAuto?

Thanks!

I ran into this with my friend's 16 CX-5. Here's what I found.. Mazda's plugs are much more expensive than the NGK aftermarket. Yes NGK was what was installed at the factory. In the service manual, Mazda talks about making sure the resistance is between a certain value. Why? Because Mazda does something unique in that they use the spark plug as a sensor, it measures the ionic charge inside the...

• researcher

• 
• 

So the owner’s manual only recommends Mazda OEM plugs or does it give a “traditional” spark plug designation?

 

[nthach]

Because Mazda does something unique in that they use the spark plug as a sensor, it measures the ionic charge inside the combustion chamber. It allows the computer to calculate the performance/efficiency more accurately. All SkyActic engines have this feature and it's not marketing, it's an actual thing.

holy Saab flashback. Saab was the first to use ionization to detect combustion events and used that to control the engine. They boasted that they didn’t need a knock sensor. I knew someone who worked on Saabs, and he said he always used Bosch or NGK on them without issue.

 

[researcher]

So the owner’s manual only recommends Mazda OEM plugs or does it give a “traditional” spark plug designation?

In both the service manual and the owner's manual it only recommends the Mazda part number for the spark plug. Nowhere does it say anything about aftermarket.

I ended up using the Mazda part number to cross reference to NGK. Bought the Laser Iridium version. They've been working very well.

 

[researcher]

holy Saab flashback. Saab was the first to use ionization to detect combustion events and used that to control the engine. They boasted that they didn’t need a knock sensor. I knew someone who worked on Saabs, and he said he always used Bosch or NGK on them without issue.

thanks for that info, I never knew that Saab was the first to use that. very cool idea to use!