What spark plugs for 95' GT?

[johnny_munyak]

I was planning on changing some spark plugs and the local Ford dealer gave me some Motorcraft SP493 platinum plugs. Problem is that when I went to remove the existing plugs, someone has installed a set of NGK UR45's already. They are a V groove plug. I've heard the NGK's are not a great plug to run in the 5.0?

Anyways, the other problem is that the SP493 plugs are substantially longer than the NGK's?? It kind of scared me a bit.....I wasn't sure if the parts guy gave me the wrong plugs or if they are misbadged in the boxes??

Anyone come across this before?

 

[HISSIN50]

The factory didnt call for plat plugs so I would not use them (Plat does not conduct as well as copper, so ignitions are built to accomodate a plat plug). Also, many folks have issues when running plats. Notably, the idle is a little screwy (lumpy) and there can be a cut-out at about 4K RPM.

Are you sure of the heads on your car? Look for a number on the NGK's and see if you can cross reference them. That might give an idea of what's going on (which is not to say that the NGK's not correct for the heads).

Good luck.

 

[johnny_munyak]

I did look up the NGK platinum V-grooves and the part number is correct for a 95' GT 5.0. The car is BONE stock with 80,000 original miles. The V-groove NGK's look like they were changed very recently because the ceramic is still white. The car seems to run fine on them? I was just really confused by what the dealer gave me. I may have to go back to them and ask them WTF is up. See what they tell me.

So Platinum is not a good idea -- even Motorcraft?

 

[Venom351R]

Ive always run regular copper plugs either Motorcraft or Autolite.


Does not matter if its a motorcraft platinum plug or not, platinum plug is a platinum plug.

 

[FlyBy763]

Why are you changing them if the car is running fine on the NGKs?

 

[SN95StangMan]

sp493 is the part for the Cobra. The copper motorcraft plug for the GT is SP450

 

[HISSIN50]

If the NGK's are the proper plug and the plats you got were longer and not of the correct material, it sounds like you simply might have been given the wrong plugs.

Either way, good work checking them before installing them.

Also, NGK's are not uncommon with 94-95 guys (much more-so than with aero fox guys) and they seem to do quite well. I run NGKs in my bikes and never had an issue. I think they're nice plugs.

 

[RIO5.0]

FWIW...I been running those NGK's for years in mine...never an issue with em and pretty much all my vehicles and toys run NGK...

Plugs are one of those personal preference things.

 

[johnny_munyak]

You are right. They were plugs for a cobra. I was a little pissed at the parts guy behind the counter. I asked him if he realized what would have happened if I would have installed them without checking and fireing the car up?.......potentially an engine job. He looked at me with a dumb look and just said sorry. LOL

Anyways, I took them back and decided to leave the NGK's in there. Will pull a few more out to see how they are fairing and if all is well, I'll leave them alone.

Anyone have a recommendation on plug wires??

 

[HISSIN50]

Anyone have a recommendation on plug wires??

Just wait till Andy posts up his plug wire pics.