I'm assuming you're referring to the XP's which are platinum. A few guys on here have tried platinums on theirs and it seems our engines don't like them much.

 

Nope, we like them about as much as, well Honda Ridgelines.

 

Ok coolness guys, thanks for the help. I'm gonna slap a set of 3923's on this weekend and let you know how it turns out.

 

Phew that was a close one

 

My Yami Raptor runs an NGK plug. No turbo on it.

 

I didn’t mention that the factory Champions plugs pulled out all where under gaped? Between 036 to 037. Not one was even close to 040. I installed the Autolites 3923s at 0.38 each (a compromise).

 

I forgot to update that I put 3923's in last weekend. I really haven't seen a noticable improvement. Maybe a bit smoother, but nothing to write home about. It took freaking forever to change them though with the positon of a few of the plugs. I had to disconnect and remove the AirRaid intake tube and dismount and move a few AC lines to get to the front 2 plugs.

The one thing I DID notice though was that my factory plugs were fffffried. The electrode on every plug had about a 1/6 or more of the tip burned off at an 45 or so degree angle. It also seemed like they might have been a little hot. There was that whitish/yellowish scorching on the ceramic and electrode onalmost every plug.

On a side note, speaking of hot plugs, a gearhead buddy of mine is into Mustangs bigtime, and when I told him I changed to Autolite 3923's he says I probably should have went with 24's. His '91 Stang with 400 or so HP has 25's in it and he thinks the 23's are going to be too cold, so I told him I'd pull one in a few weeks and see if they're black.

What is everyone's opinion (or at least the guru's opinions) on going with a little hotter plug than the 23's in our 4.7's?

 

Mine where not burnt they looked good though only at 16k. The pin like electrode on the Champs. are weird but they where in good shape. Some with white powder that was about it. Some plugs are a bitch to remove. I did torque them to spec. The 3923s do run a bit smoother and I'm getting a few tenths better in millage driving as I always do.

 

Forgot to add that mine had 36K on them. Gaps were way over .040 but that makes perfect sense with the electrodes being burned.

 

NGK makes lots of copper core plugs. Most Mitsubishi cars, turbo and non-turbo use NGK plugs from the factory. Some are copper core, some are platinum, and some are iridium.