My truck had the original champion plats, not bad plug. Tried the autolites, they sucked in my truck. Now have the ngk iridiums, Awsome..... My buddy said he couldn't believe how fast I pulled around him after work one night.

On sparkpugs.com they show a denso iridium plug that also had platinum in them. Sounded like a interesting mix. If anyone ever tries them out, let me know how they work. Their about 2 bucks more a plug.

 

i had both....plugs i just took out were autolites. night and day difference.....

 

So they are worth it then? Might be changing them when I get back to the states.

 

Do they help smooth out the idle?

Denso, NGK, or champion iridium?



LB

 

My truck still shakes a bit. Not real noticeable, but its their.

 

Have any of you out the Iridium plugs in a 4.7 Magnum (non-HO)?

 

well, to avoid them not working properly, I bought the 3923's. I have 5224's and my mpg has tanked for around town driving. I am getting 12.6 mpg and it has no freakin power..

 

With the cold coming and a lot of short stop n go intersections my mpg is plumeting too. Even with only 600miles on the 3923's. A lot may have to do with overdrive not kickin in till the auto warms up. I can't say I've been impressed with 3923's in the HO yet. It's not worse than the factory plugs. Too bad I threw the receipt away already or I'd go ahead and try the irids.

 

I am hoping by the time I am ready to change out plugs you guys will have it all figured out for me I appreciate the hard work and experimentation guys!