Wait.... the 5.7L has 16 spark plugs?!

 

Yup, twin plug ignition

 

I use NGK iridium, however I honestly think I got the best MPG with the OEM copper plugs that are needed for 4.7l. I just got iridium because I researched that it lasts longer then 30k. 30k is the manuf... schedule A to replace copper plugs. Good luck with whatever you choose! And I have heard many bad reviews with bosch plugs on 3rd Gen Dodge Ram engines.

 

Well I think I'll go with the Iridium ones, but damn... at 16 bucks for a pair, this is going to be expensive.

 

i put champion platinums and it does seem to idle better and maybe a little better throttle response.

 

This info if from the 08 RAM brochure. (also mentioned above)
The 4.7L has 2 plugs per cylinder. The top ones are copper plugs and need to be changed every 30K miles. The bottom ones are platinum and need to be replaced every 100K miles.

Yes, the Hemi has dual plugs as well, side by side under the coil packs on the 08. Older ones had a coil pack over one plug and a plug wire that ran to another. Not sure when the Hemi plug wires ended. Never made sense to me.

Use copper plugs in the Hemi. You get the best performance and have to change them every 30K anyway, why waste the money on gimmick plugs.

 

The every time a coil in the hemi fires, it fires the plug directly underneath it for the primary spark on that cylinder (normal compression stroke firing), and it also fires of whatever other cylinder it is connected to via a spark plug wire for a secondary spark (firing during power stroke). best i can figure is that its doing it for emissions reduction to burn off that extra bit of fuel. that won't get you any power, but will cut down just a little bit on hydrocarbons?

I don't think it needs it. The 6.1 fires both plugs at once, as do the newer hemis.

I've had short spark plug wires so both plugs fire at once and platinum plugs sitting for a few months now waiting for me to get a chance to put them in.

 

before spending money on 16 new spark plugs
why not sharpen up the tips of the factory plugs
set new gaps of your choosing
and index their ground strap position
for best growth of the
'flame kernel' ?

 

we wouldn't be able to sharpen them precisely enough, wouldn't know what gaps to choose or what to index the ground strap to because we don't know what affect any of it would have on the flame prolongation, nor do any of us have the equipment to check/test/confirm the effects.

that and cuz new plugs are $3. hell most talking about going plat or iridium are doing so because they don't want to change as often, including myself. why the hell would we want to do all ^^

 

Refurbishing used plugs properly is harder then it sounds, the most critical part of a standard plug is the sharp edge around the electrode, when you buy a new plug it is always nice and sharp, and the edge is the first thing to wear if you look at your old plugs you will notice they have rounded edges. trying to get a nice sharp even edge all the way around with a file would be difficult and very time consuming. Buy new plugs