Those Running Iridium Plugs Please Comment

[TurboGH]

I have researched past posts about Iridium plugs but it seems not many people have actually tried them. Has anyone recently gave them a try? If so, what brand and part number?


Denso shows a 23 Autolite to cross over to their part number ITF20. Those that have tried them, do you think the 20s are the correct heat range for our cars? I see they also make a ITF22 and ITF24. Has anyone tried these heat ranges?


Thanks!!

 

[Ormand]

Iridium?

Are those like the platinum plugs, with a tiny center electrode? If they are, they won't work real well on a Buick because of the "waste spark" system. Three plugs fire from the center to the outer electrode, and the other three fire "backwards". The tiny tip doesn't offer much of a target for the "backwards" spark, so those three cylinders might not fire reliably. Ford used similar ignition on some Taureses, and used three regular plugs, and three platinum.

 

[TurboGH]

Ormond,

That is the first time I have ever heard about the technology you described. I don't think the Densos fire backwards. Their website is www.densoiridium.com in case you would like to know more.

 

[Steve Wood]

Our ignition fires backwards on three cylinders..does not matter what kinda plugs you put in the car.

This all started because some posted that they heard Kenny D had picked up substantial hp with the plugs, I think.

 

[Ormand]

Backwards...

After some more thought (it hurt!) I realized that the current flows through the "backwards" plugs when the "forward" plugs are firing, too. I mean, both plugs fire at the same time. So, if the "backward" plug has some problem that makes it hard for the spark to jump, that would affect the other plug, too. So, using the plugs with the tiny tips might interfere with all cylinders sparking, not just the three that fire "backwards."
I've never liked AC plugs, but I've got them in my Buick. May try the NGKs, is UR5? Anyway, I've seen claims that they might work even better the ACs.

 

[Steve Wood]

UR5s works well as do Autolite 24s which I prefer.