NGK 4644s or Autolite 3923s are one heat range cooler; it seems to help the 4.7l smooth out if it has a slightly rough idle.

Otherwise I would just go with the stock Champion. Autozone should have the number in their system.

 

Autolite 3923's best plug IMO cause they've never gotten me anything but results and decent mileage out of them! also they are a colder plug so you'll see the truck idle smoother as well!

 

I have an 05 with 3.7L. The factory plug is an NGK which I thought was strange since like everything else dodge seems to be champion. When I changed my plugs I went with the NGK iridiums. When I first installed them it ran a little rough. I found that my truck actually had the wrong gap listed on the sticker. (there was a service bulletin on this for certain vin numbers) I re-gapped with proper gap and it ran smooth! Even got slight increase in mileage but that was because when I changed them at 30,000 miles they were shot. I now have 58,000+ and the truck still runs great.

I was told by the parts store to not touch the gap on iridium plugs because I would damage them. You do have to be very careful with them but in my case it made all the difference in the world with proper gap.

If you have the 3.7 do check the service manual for proper gap as you might have the one with the wrong one listed like I do. The plugs on the sticker are correct just the gap is listed wrong. They should be NGK.

 

What did you do with the old coils? I may be interested in them for a project idea I have.

 

Not to speak against any of the members here....

but regardless of the spark plug type: copper, platinum, etc, they all work in these trucks. No spark plug would cause a blinking check engine light and an extremely rough idle.

I would bet my last dollar that when you installed the new plugs and coils, that one of the coils did not seat correctly, or was not plugged back into its harness correctly, because you are describing what sounds like a miss or dead cyl.

When you put the coppers back in, you probablly corrected the coil without even knowing it....

Things get a bit blown up on the internet...if the part # is correct, it works. You think these companies don't test there plugs for QA? Some companies like NGK will list a slightly wider gap for different metals used in the plug, and some do not. If gapped correctly and installed right, the truck should run smooth regardless of plug type. Dodge uses copper cores in there 3.7 and 4.7 because there cheap, and keep you coming back for service, period.

Ive been running doulbe plats for 30,000 miles. The truck runs EXACTLY the same as it did with its factory coppers.

I will agree that one particular plug may perform better then another, because that may very well be. But I am arguing that there is no way a spark plug type is causing that sort of problem. Lets not jump the gun fellas.

 

Trust me, when you use the dielectric grease you will thank yourself the next time you change the plugs, makes life easier. Plus as rengnath mentioned it keeps the moisture out.

 

Im not shure what im gonna be doin with them, I onily replaced 5 of them tho cuz one of my coils broke last week and needed to be replaced.

 

Thank you for all of the helpfull info guys.
I just went back to autozone and exchanged the plugs with the autolite 3923s sence so many of you guys run them and stand by them.

MonkeyWrench4000 you are right. It turns out that one of the plugs broke and that was causeing the missfire the intire time.

However I still exchanged them for the autolite copper cores because so many ppl on hear are saying that I will feal the difference. Hopefully this helps my gas mileage problem also.

As far as the dieletric greese. I am deffently going to be useing it due to the fact that I actually had water puddled around one of the coils causeing it ground out for 3 days intuil I fixed it by letting the truck sit in a heated garage. And ever sence then the engine would missfire every once in a while and eventually the coil completly failed about 6 months later.

And I cant forget how much I enjoy flying over puddles eather.

Thanks again for the info and experence guys. I will let you know how it goes.

 

You may want to replace the o-rings that seal up against the spark plug wells. I know mine were pretty bad when I replaced my plugs, but I didn't replace them because the hardware store wasn't open and I don't go through water that much. You may need all the protection from water you can get though

 

[The autolites are in my truck and I can feal the difference. U can feel it has more power when coasting, and also when you step on the gas you can feel the engine pickup faster.

I can tell the truck is running alot more lean cuz it used to smell like exaust bad when it started up and now it doesent thanks to the new plugs. I am hopeing this is going to fix my gas mileage problem.

Also I had a cel which gave me the code that the catalayic converter is bad and now after I cleared it and purt in the new plugs the cel is not coming back on.

When I bought the new coils they came with new o-rings.
Also I loaded them and all around the coils with dieletric greese to make shure water will not get past them any more.

Thanks everyone so much for the help.