2013~2016 Anyone install Ruthenium Spark Plugs yet?

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
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Plano, Texas, USA
Mazda would not be the first and might be the last to use spark plugs as a combustion chamber sensor. Since coil on plug systems came into use that has been possible. Why else would the coil have 4 connectors when it need a 2 to fire? For that reason, I'd be a little slow to change types.
Good point! Why there’re 4 wires if the spark plug has no other functions such as ion sensing than just firing?
 
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2010 CX-9 GT
Lots of OEMs use 4 wire coils. In general, the 4 wires are:
1 - +12v
2 - ground
3 - trigger
4 - diagnostic

The only mystery there is the "diagnostic" wire, and different OEMs use it for different things. Some coils pulse that after successful firings to signal to the ECU that "all is well". What Mazda is doing with it I can't say, and unless someone hooks an oscilloscope to an injector while it's running we won't ever know.
 
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16.5 CX-5 Tour/AWD
Looks like the coils do have ION sensors.

1607208626431.png


So after determining that the coil has ION sensing capabilities built inside, I guess my question would be, does it really matter if we use an aftermarket spark plug such as Ruthenium?
 
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2010 CX-9 GT
If the resistance of the plug and the gap size is similar to the OEM, it's probably ok. Otherwise, the sensor behavior is not going to be what the ECU expects.
 
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16.5 CX-5 Tour/AWD
If the resistance of the plug and the gap size is similar to the OEM, it's probably ok. Otherwise, the sensor behavior is not going to be what the ECU expects.
I actually had some luck trying to measure the resistance of the Ruthenium's prior to installation. Shame that I used a crappy Harbor Freight multimeter and not something of better quality but I think it was somewhere between 3.1 - 3.3 kOhms. The issue was that the spark plug center electrode tip is so small because it has a double electrode design with both sides sticking inwards and I had trouble touching the center due to the clearance. As for the gap, both are gapped at 0.044" and I did confirm the gap with a wire gauge tool.

However, if someone else wants to take a shot at measuring the resistance, I would recommend one end of your multimeter leads to have an alligator clip or something that can clamp onto the terminal nut.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
I actually had some luck trying to measure the resistance of the Ruthenium's prior to installation. Shame that I used a crappy Harbor Freight multimeter and not something of better quality but I think it was somewhere between 3.1 - 3.3 kOhms. The issue was that the spark plug center electrode tip is so small because it has a double electrode design with both sides sticking inwards and I had trouble touching the center due to the clearance. As for the gap, both are gapped at 0.044" and I did confirm the gap with a wire gauge tool.

However, if someone else wants to take a shot at measuring the resistance, I would recommend one end of your multimeter leads to have an alligator clip or something that can clamp onto the terminal nut.

Mazda CX-5 Spark Plug Inspection_03.jpg
 
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2010 CX-9 GT
The resistance is on the lower end of acceptable, but that may be because spark plug resistance tends to drift upward over time.

From what I can gather, the ignition coils are sensing ionization current and feeding that information back to the ECU. Depending on how advanced Mazda's implementation is, the ECU can determine if the combustion event occurs "as planned" vs. a misfire or a preignition/detonation based on the current flow across the plug gap and how it varies over time. This info can then be used to adjust timing on a per cylinder basis rather than on all cylinders in bulk.

Other OEMs have been using this technique since the 1980's, with varying levels of capability. If you want to experiment, be on the lookout for misfire check engine lights and a code reader might be a good idea to check for misfire counts (record this before and after swapping plugs).

I'd probably just stick with OEM spec plugs.
 
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16.5 CX-5 Tour/AWD
The resistance is on the lower end of acceptable, but that may be because spark plug resistance tends to drift upward over time.

From what I can gather, the ignition coils are sensing ionization current and feeding that information back to the ECU. Depending on how advanced Mazda's implementation is, the ECU can determine if the combustion event occurs "as planned" vs. a misfire or a preignition/detonation based on the current flow across the plug gap and how it varies over time. This info can then be used to adjust timing on a per cylinder basis rather than on all cylinders in bulk.

Other OEMs have been using this technique since the 1980's, with varying levels of capability. If you want to experiment, be on the lookout for misfire check engine lights and a code reader might be a good idea to check for misfire counts (record this before and after swapping plugs).

I'd probably just stick with OEM spec plugs.

Good points. I'll probably report back every 10-20k miles but I'm hoping nothing bad will happen. I changed to Ruthenium at 68,233 miles and I haven't really noticed much change in MPG. Start up wise, it feels better but that could also be attributed to being a new spark plug so I'm neutral in terms of that aspect. As of right now, no ill effects or misfires but YMMV. One thing I can say right now is that I wouldn't hesitate to use Rutheniums again if OEMs are too expensive or sold out though.
 

Pitter

Pitter
Contributor
:
2020 CX-5 Signature Azul Metalico
I hail from the days when spark plug changes were at 12,000 miles so whether the change interval for a new plug is 75,000 or 70.000 really makes me no never mind. If a new plug type can really provide a perceivable acceleration increase I'd be interested. But wouldn't it be necessary for the plug to somehow provide increased horsepower output to increase acceleration times? If the plug could do that I would think that would be banner news.
 
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2011 CX-7 i Sport
I installed the Ruthenium plugs on a 2015 with the 2.5L several weeks ago. I did so without hesitation, as I believe that NGK, as the maker of the factory Iridium's, wouldn't be likely to engineer a plug that didn't meet the needs of the car. Plus, they are actually now slightly less expensive as the Iridium.
 
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16.5 CX-5 Tour/AWD
I installed the Ruthenium plugs on a 2015 with the 2.5L several weeks ago. I did so without hesitation, as I believe that NGK, as the maker of the factory Iridium's, wouldn't be likely to engineer a plug that didn't meet the needs of the car. Plus, they are actually now slightly less expensive as the Iridium.
Would you say you noticed any perceivable differences between OEM and Ruthenium's?
 
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