Only tip I can add is to always but a little anti-seize on the threads the some dielectric grease on the tip of the plug where the coil boot slides over. It makes it so much easier to change them out next time.

I went with the stock plugs (NGK) when I swapped mine out. Found them the cheapest on Rock Auto actually.

 

My 2014 Manual says change them at 100,000. They must have went to different plugs in 2014.

http://www.dodge.com/en/owners/manuals/

 

Been a Chrysler tech for the entire life of the gen2-3 hemi, never seen or heard of a Hemi plug breaking in the hole. Unless it dropped a valve seat and got mashed in place of course. Lots and lots of 5.2 and 5.9's broke plugs

 

Regular old copper core on the Hemi, every 30,000 at least through 2012. I found either Champions or NGK performed best. Know for a fact the Hemi (at least the pre MDS) hates platinum plugs.

The rear two are a biotch, I use a piece of cut garden hose to get to them. Never had a plug break in a Hemi yet.

 

Changed the plugs on the wife's 300 C 5.7 at 75,000 miles and I did have two plugs that were stuck in the alum. head. The other 14 came out just fine. Tried using WD-40 and let sit for two hours but no luck so I gave them a shot of carb & brake cleaner and within 15 min. they came right out? The plugs looked perfect but the gap was at .055". I have a plug blaster (cleaner) so I cleaned them and set the gap at .043" and screwed them back in with spark plug never-seize on the threads. Lots of smoke on start up and now the engine has 87,000 miles on the original plugs. Cost to change plugs "O". Oh, and I am still getting 22 miles per gallon at 70/80 mph. .


Auggie

 

How and where you drive has a to do with plug wear. I have to admit on my old '04 Hemi, I pulled 4 to look at at 28,000 miles. Gap was off but condition was excellent. Pulled and regapped them all and checked again at 36,000. Condition was still very good but gaps were already a little on the wide side. Since I was going to have to pull them anyway, I popped for new Champion Copper plugs which were about $1.50 each in boxes of 8. Sold the truck last year with 68,000 miles and that 2nd set of plugs. BUT, my driving other than hunting and fishing was 90% interstate from my home in Florida to my farmland in Georgia.

I've tuned up Hemi trucks used for daily in town commutes where the plugs were in need of replacing at 30,000 miles. Same with the EGR valve. I replaced mine at 50,000 miles and it was just slightly dirty, coulda gone 100k, cleaned it and kept it as a spare. Seen them pop codes and be gonzo at 30,000 miles...

 

All good info, thanks! I'm hoping when I change them my gas mileage will go back up. I was getting 17ish (combo city/hwy, mostly hwy to work), and now can't seem to get past 14.9. I have the Hypertech too...

 

I tend to run in the high 13's to very low 14's for combined driving according to the onboard computer. which I have found to average about 0.75 mpg over real world mpg.

however, that is easily 75% city driving, which means ERS and no MDS cylinder cut out and I remote start each morning for at least 5-10 minutes. so I'm fine with that mileage.

I thoroughly coated the plugs with both anti-seize and dielectric grease (in the proper areas) when I changed mine. the Police Package plugs were about $18 after tax from the dealer so the total was around $350.

you can find them slightly cheaper online. I had a $150 certificate from D/C for getting recall work done so I bought them from my local dealer.

 

$350 for spark plugs? That's crazy... I'm happy my current truck ain't got no plugs...

 

HammerZ71, they're still "plugs", they just glow instead of spark.

So what is the benefit of the police package plugs over a by-application Iridium spark plug that can be found for $7 each?

-Rod