Are these spark plugs still good?

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Trying to feel out everyone's opinion. I got someone saying they look great, don't know why I bothered to pull them. This is a representative image.

20190305_180207.jpg
 
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You never mentioned how long they were in service. They don't look bad but if you go through the trouble of removing them, I would just replace them.
 
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FL
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100k miles in service. Manual calls for 60k change intervals. Spark plug itself is rated for 120k. Replaced all 6 with Rutheniums and noticed a huge difference. Idle became glass smooth. Fuel economy went up 1-2 MPG overall and that's with me stomping the pedal harder than ever. I was getting like 18 driving conservatively. After changing I was getting 19-20 and that's with a bunch of 0-60 sprints just to get a feel for the new plugs.
 
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Is the ignition a waste spark type? If yes, 60K with a second wasted spark would be equal to 120K in a non waste spark engine. Electrodes with sharp edges require 25-40 percent less voltage than ones with rounded edges. May be the reason for the improved idle and mileage.
 
Dare I say they look "Tony the Tiger" Greaaaaat? Are they Iridiums? I had a set of AC Delco Iridiums that I pulled at 180,000 miles. The threads were corroded so I won't do that again. Meanwhile, interesting post on the Ruthenium's. Here is my a representative photo of my Iridiums with 180,000 miles that are "Not so great" but they still ran fine. The other shot is a new Iridium AC Delco plug.

E1B29D8A-7B9E-4AAF-96A1-8E170DB672FA.jpeg


D308E26E-69BB-4B60-AD26-8E6FC4CCBBEA.jpeg
 
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Will you put the original plugs back in ? If not, it really doesn't matter.... What if the majority of folks say they look fine ? When I replaced plugs in (2) of our cars recently, I kept the old plugs for a few weeks just in case we got a bad one with the new plugs. After that, I kept (2) plugs for each car as back-ups, just in case.
 
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Originally Posted by hallstevenson
Will you put the original plugs back in ? If not, it really doesn't matter.... What if the majority of folks say they look fine ?
If they weren't looking so good it would indicate a short change interval for the future.
 
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FL
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Originally Posted by shanneba
Is the ignition a waste spark type? If yes, 60K with a second wasted spark would be equal to 120K in a non waste spark engine. Electrodes with sharp edges require 25-40 percent less voltage than ones with rounded edges. May be the reason for the improved idle and mileage.
I don't think it's a waste spark type. 6 cylinders, 6 coil packs. Electrodes with sharp edges require less voltage...is that why Autolite/Fram loves advertising their "proprietary V-trimmed" ground electrode?
 
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4,102
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They lasted 100k miles. The OP did notice an improvement after changing them but didn't indicate they were changed for any performance related reasons.
 
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Pennsylbammyvania
Originally Posted by Deontologist
Replaced all 6 with Rutheniums and noticed a huge difference. Idle became glass smooth. Fuel economy went up 1-2 MPG overall and that's with me stomping the pedal harder than ever. I was getting like 18 driving conservatively. After changing I was getting 19-20 and that's with a bunch of 0-60 sprints just to get a feel for the new plugs.
I just replaced my 18K mile (NGK made Motorcraft Iridiums shrug ) factory plugs with the same heat range Rutheniums as well. The idle is MUCH smoother, but no long trips yet to check the fuel mileage, and I have not been able to drive it in 'anger' yet to see if there is any difference in that realm.
 
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Spark plugs have internal resistors that degrade over time. That's why a plug that looks good on the outside might be firing very weakly when it's under compression. Most plugs have a resistance of about 5K-8K ohms that's easy to check with a multimeter. If a plug tests substantially over the resistance of it's mates, then it's time for replacement...
 
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The Garden State
Originally Posted by dailydriver
Originally Posted by Deontologist
Replaced all 6 with Rutheniums and noticed a huge difference. Idle became glass smooth. Fuel economy went up 1-2 MPG overall and that's with me stomping the pedal harder than ever. I was getting like 18 driving conservatively. After changing I was getting 19-20 and that's with a bunch of 0-60 sprints just to get a feel for the new plugs.
I just replaced my 18K mile (NGK made Motorcraft Iridiums shrug ) factory plugs with the same heat range Rutheniums as well. The idle is MUCH smoother, but no long trips yet to check the fuel mileage, and I have not been able to drive it in 'anger' yet to see if there is any difference in that realm.
Just curious, how worn was the gap on the factory plugs @18,000 miles compared to installed recommended gap? My wife has a 2017 2.3 EB Explorer with ~45,000 miles. I'm going to change them soon with the same Motorcraft iridium plugs that I got from RA for ~$4.50/ea. Ford says they're 100,000 mile plugs. Currently it's smooth running and still gets the same or very similar mpg as after break in. But I have to guess that the DI Turbo in a smaller engine in a heavier vehicle takes it's toll on the plugs. I look at is a cheap preventative maintenance rather than failing on the road while she's driving. Thank goodness for inline 4 cylinder engines grin2. Whimsey
 
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Alabama
Originally Posted by hallstevenson
Will you put the original plugs back in ? If not, it really doesn't matter.... What if the majority of folks say they look fine ? When I replaced plugs in (2) of our cars recently, I kept the old plugs for a few weeks just in case we got a bad one with the new plugs. After that, I kept (2) plugs for each car as back-ups, just in case.
Originally Posted by hallstevenson
Will you put the original plugs back in ? If not, it really doesn't matter.... What if the majority of folks say they look fine ? When I replaced plugs in (2) of our cars recently, I kept the old plugs for a few weeks just in case we got a bad one with the new plugs. After that, I kept (2) plugs for each car as back-ups, just in case.
I do this too. Especially seeing as the NGK platinum plugs for my civic are $24 a piece. Granted I don't pay that and get them off rock auto for around $13 a piece.
 
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7,658
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MI
Originally Posted by Deontologist
100k miles in service. Manual calls for 60k change intervals. Spark plug itself is rated for 120k. Replaced all 6 with Rutheniums and noticed a huge difference. Idle became glass smooth. Fuel economy went up 1-2 MPG overall and that's with me stomping the pedal harder than ever. I was getting like 18 driving conservatively. After changing I was getting 19-20 and that's with a bunch of 0-60 sprints just to get a feel for the new plugs.
Do you think that the Rutheniums actually improve performance vs. OEM plugs or are your differences due to comparing new plugs to old, maybe worn out plugs?
 
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