2011 5.7 ...any recommendations or experiences with NGK Iridiums, or others folks have tried?? I believe they have NGK 92174s in there had em bout 80k no issues, not for sure haven't physically seen em. I know Coppers are recomended but dont care for interval

 

From my experience the hemi doesnt like the "precious metals" in sparkplugs. They seem to run the best on copper plugs.

 

I replaced the NGK R 's that v have been in there for 80k not 1 problem out of my truck, ruthenium, is what is used its an alloy after copper, they had gaps of anywhere from 45 to 49, my mileage dropped off so i knew they were past there prime....but damn, were expensive, $22 for 4

 

You call 22.00 for 4 plugs expensive? You should live in canada,,, I tried the iridium plugs in my 09 an they were 16.00 each so was a 300.00 with taxes,,, My 09 never did like them didnt run smoothly at all, so went back to the original copper ones and all smoothed out

 

Ouch that is pricey...