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Spark plug change

Sean R.

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#1
Who had changed to a heat range cooler plug and who hard is it to the the plugs on the ST... Thank you for any advice.
 

UNBROKEN

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#2
It’s not too bad. Take the strut brace off for extra room. Pull the cover off the HPFP and toss it...it’s just a sound dampener and take the bolts out of the hard lines across the top of the engine so you can move them out of the way. After that it’s all standard stuff.
 

OP
Sean R.

Sean R.

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Thread Starter #3
It’s not too bad. Take the strut brace off for extra room. Pull the cover off the HPFP and toss it...it’s just a sound dampener and take the bolts out of the hard lines across the top of the engine so you can move them out of the way. After that it’s all standard stuff.
Nice.. And thanks.
 

DChute

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#4
What is the general recommendation for spark plug upgrade for the ST?
 

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Dallas, TX, USA
#5
It’s not too bad. Take the strut brace off for extra room. Pull the cover off the HPFP and toss it...it’s just a sound dampener and take the bolts out of the hard lines across the top of the engine so you can move them out of the way. After that it’s all standard stuff.
There is really no need to take off the strut brace.
 

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Las Vegas, NV, USA
#8
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92
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Location
Virginia
Vehicle
2020 Explorer ST
#9
Hey guys, I was about to replace the plugs in my 2020 as they are the original with 50,000 miles on them. I picked up a set of Motorcraft from the dealer “part SP-594” and I noticed this thread and basically the NGK plugs are the ones most recommended. My question is about the temperature range, what is the benefit of running one step colder? This is something I have never been concerned with and just wanted to know if a step colder is better than what Ford has spec for the vehicle. I have a Tune but am currently running stock to help MPG, I have a VERY HEAVY FOOT with the tune on. If anyone could answer this I would be greatly appreciative…. Wouldn’t need a long explanation, just a short to the point type explanation please. Thank you in advance
 

TMac

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#10
Hotter or colder has to do with the average expected temperature of the plug. It doesn't have anything to do with spark energy so it won't have any impact on MPG. A plug should be hot enough to burn off deposits and cold enough so as to not burn up the electrodes, insulators or cause detonation. Some prefer a colder plug in a high performance vehicle, but practically speaking if they're not causing detonation or they aren't burning electrodes the stock setup is absolutely fine.
 

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2020 Explorer ST
#11
TMac, thank you for the info, well written and just what I was looking for.
 

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Location
Minneapolis, MN, USA
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2022 Ford Explorer ST
#12
Just installed the NGK Ruthenium HX spark plugs a few weeks back, great little upgrade so far. The install isn't bad, the hardest ones are the back (towards the driver/passenger side) but if you take your time and have the righ tools it's a simple job.
 

TMac

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#13
If I could add a bit to my last post in this thread. Consider the engine as a "system". If you're running high ethanol blends, I would not be running colder plugs. The latent heat transfer of ethanol is higher than that of gasoline which lowers the heat range of the plug, altering it's ability to burn off deposits. Another example of hot-rodding "lore" that might have made sense 40 years ago. I don't have any opinion on ruthenium vs copper vs platinum vs iridium but running "colder" plugs is not a performance enhancement.
 

Cruising68

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#14
I found straight copper plugs ran best in my CTSV. I believe all the precious metal tipped plugs do so only for longevity and do nothing for performance. Just my opinion of course.


Sent from my iPhone using Tapatalk
 

Messages
72
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28
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Location
Fort Lauderdale, FL, USA
Vehicle
2022 Explorer ST
#15
What’s the torque spec for the spark plugs? Haven’t seen that mentioned in the forum
 



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