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RCS01 10-18-2012 06:39 PM

Spark Plugs for 011' Hemi
OEM plugs in my 011' Hemi apparently are copper core with a recommended replacement interval of about 36,000 miles. I asked the dealer about the installation of platinum plugs but they said their policy was to only install the OEM type plug.
Are platinum plugs that can go 100,000 miles available for the Hemi in the GC? Are there any downsides to using them?

nek121328 10-18-2012 07:15 PM

Re: Spark Plugs for 011' Hemi
Champion makes a 9055 Iridium that works extremely well in the 5.7L. Have them in mine for approximately 8,000 miles without an issue. They have a 7 year/Unlimited mile warranty.

kkreit01 10-19-2012 01:38 PM

Re: Spark Plugs for 011' Hemi
The downside is, if you run any plug longer than Chrysler's 36k spec, and you have an issue, you are on your own (unless you can get the plug manufacturer to pay for it). It probably will never happen, but why take the chance when you are still under warranty. When out of warranty, do as you wish. Chrysler's have always been picky with plugs. If they used copper as OE, typically, copper will run best.

nek121328 10-19-2012 03:20 PM

Re: Spark Plugs for 011' Hemi
Why would it be an issue to run a plug longer than 36k? Hemi owners have been leaving the plugs in way long than that. They suffered from misfire and poor gas economy. Chrysler basically has stayed with copper cored plugs as they cost less times 16 pieces.

berk483 10-19-2012 05:03 PM

Re: Spark Plugs for 011' Hemi
I know on a few Ram/Charger forums there were complaints of coil pack failures due to the difference in resistance between the plugs after switching to plat/iridium. Just a thought that you may want to investigate more. I really don't know enough about it to matter to me so I'll just stick with the copper ones.

ColdCase 10-19-2012 07:07 PM

Re: Spark Plugs for 011' Hemi
I seem to recall a lengthy discussion on this topic a couple months ago, and another one a few month before that.

Bottom line was that there was only a couple plugs that made sense, and extending the change interval doesn't work out on the street. Since you are going to be replacing them every 30-40K miles or so anyway, use the least expensive plugs that work well.

nek121328 10-19-2012 08:04 PM

Re: Spark Plugs for 011' Hemi
Coil packs could be a problem depending on the odometer reading according to the Jeep dealer. Could be whom replaced the plugs and how they removed the boot as well as whether they used a little dielectric grease in the coil boot with the new plugs. 4.7L's have the coil pack issues. I'll fall back on my heritage and enjoy the longer life Iridium plugs. Forget the old wives tales. Fuel economy is nice!

GTREVINOWK2 10-19-2012 11:59 PM

Re: Spark Plugs for 011' Hemi
Engine development enginners used copper plugs for all testing so IMO we should keep cooper plugs as our first choice i however recoomend changing them every 20000 kms....use mopar/champion or the newest version of ZFR plugfrom NGK as prr the latest oem plug being used on hemi engines

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