I searched but only found 1 opinion on this. Has anybody run several different plugs to see if any of them give better gas mileage. I was told to only run the copper plugs as thats what was best although I am a long time modder of hondas and acuras and I know with those, the NGK Iriddiums give the best mileage. Does irridium work well in out ram or should I stick with the coppers?

Chris

 

You'll get a LOT of people saying "save the money and go copper", as there's no difference between them and Irridums. That might be true for performance.
I've run the NGK Irridiums for well over 46K now and all is good.
I think I'll get more miles before I need to replace them than the cheap coppers.
If you've ever changed out the 16 plugs on a Hemi.....It's a bear and if you can eek out another 15-20K or more miles from Irridiums......well lets just say I'm a bit lazy ha ha ha.
Al.
PS don't forget I run dual fuel and I haven't had a hickup yet!

 

I'm just looking to squeeze a few more MPG out of this beast. I know with my old honda I swapped to a full MSD and got almost 8 or 9 MPG total. I wonder if I swap in the MSD coils for the hemi if it will make much of a difference.

Chris

 

I took the stock Champions out of my Hemi and replaced them with NGK. There was nothing wrong with the ones I took out, But I don't like Champions. I saw no difference in MPG at all. It's only my opinion But I think with the two plug heads , There going to burn hot enough to burn off the same amount of fuel no matter which plug you use..
This might not be the case ,?

 

Swapped stock Champions out for colder NGK 4306 due to performance reasons not mpg.

 

You will not see a MPG increase going to Iridiums. The only benefit they will give is being able to go 100K on 1 set of plugs vs having to do 3 sets of coppers( 30K change intervals )in that same time frame( i.e. 100K ). As the other member said changing plugs on the 5.7L Ram's is a PITB. 1 set of Iridiums will run you about the same $$$ wise as 3 sets of coppers. So the savings comes on the labor end as you are only changing the plugs once in 100K w/ Iridiums vs changing them 3 times in 100K w/ coppers. That is ALL the benefit you will see. No MPG and no HP gains either.

Plugs do not give MPG gains. Don't buy the hype any plug mfg tries to sell you that their plugs will do so. BULL! The only thing plugs will do for MPG is give you back any lost MPG due to old worn plugs. A new set of plugs will return the efficiency of the engine to where it should be so while you may see a slight MPG gain what you are really seeing is a return to what it should be anyway.

 

I'm interested in the explanation for this as relating to performance...

 

Not performance per say but to run safer and help avoid detonation with my mods.

 

Ok... now I see. I agree with avoiding detonation, but when you mentioned for performance, I got curious. Thanks for the clarification.

 

The feedback I got about the irridiums was that they or platinums didn't really do anything for efficiency just more a longevity thing. I usually change my plugs between 30K and 40K anyway whether I run iriidums or planitnums and obviously sooner with coppers. But thanks for the feedback y'all.

Chris