Spark plugs for 5.7 Hemi

BadHemi2014

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Greater Cincinnati area
Ram Year
2014
Engine
5.7 Hemi
NGK 92145
Best price usually RockAuto
I also have a 2014 hemi, had these plugs in for 20K miles they look great.
 

Mister Luck

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WEST COAST
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2016/2017
Engine
5.7 V8
Iridium tipped spark plugs
are they OE from the factory?
I’ve heard horror stories for years about the tip dislodging and scoring the cylinder walls and that sales fumbled in Europe among the performance crowd.

I know with other improvements of other Chrysler based engines the spark plug is greatly over looked and one of the last parts to be upgraded/ changed probably from the perspective of profit margins and availability inventory on hand.

The compression ratio was again increased in the 5.7 around 2013

2009–20125.7 L (345 cu in) Hemi V8390 hp (291 kW; 395 PS)407 lb⋅ft (552 N⋅m)
2013–20185.7 L (345 cu in) Hemi V8395 hp (295 kW; 400 PS)410 lb

This should have prompted a study into heat range applications for the spark plugs but the same plugs are being used I believe as early as pre 2009.

Copper center electrode plugs themselves round off from cylinder temps and compression ratios vary depending upon the fuel or additives used.
Iridium and platinum plug tips are only as good as the material they are attached to.

The timing of the 5.7 is controlled by the air intake and in closed loop operation the O2 sensors , and if burning a lower octane fuel retarding the timing is noticeable under load or traveling on long grades.

Adjusting coolant temperatures settings and installing a lower threshold coolant temp sensor is also something to take into consideration when changing heat ranges of spark plugs.

Unless you have dynamometer printouts that are not over corrected for SI or Pa pressure you’re just measuring performance improvements by the seat of your pants.

 
Last edited:

GTyankee

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2016
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3.0 ecodiesel
Rockauto tells you what is OEM & what the current manufacturers recommendations are


Rockauto is also a vendor on this site

 

EdGs

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Location
FL
Ram Year
2015
Engine
Hemi 5.7L
NGK 92145
Best price usually RockAuto
I also have a 2014 hemi, had these plugs in for 20K miles they look great.
^^^^ This^^^^
Should run you $6 and change each at RockAuto.

They should all be pre-gapped, so if you check them, be very careful as the electrodes are teeny-tiny.

Also, get the GearWrench 80546 magnetic swivel spark plug socket from Amazon. Should be about $15. You will be glad you did.
 
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