Hello everyone,

I wanted to know if anyone knows the original brand and metal (Platinum, Copper, or Iridium) of spark plugs used on a 2004 JAG S-type 3.0 V6?

Much appreciated

 

I replace with Autolite Iridiums.

 

I think the OEM is Autolite double platinum but I used Autolite iridium also a few times.

bob gauff

 

The factory plugs in my 2005 S-Type 3.0 are Motorcraft AGSF22FSM. They are platinum, not iridium. I must say that they continue to perform quite well at just over 92,400 miles....

 

hmm... changed at 70K? (Meant to be.)

(4.2 change is 100K and they are iridium. Cost more, last longer.)

 

The OEM change intervals are quite conservative. Actual serviceable life is probably 2-3x higher.

An acquaintance, just for fun, ran a set of 100K mile plugs till they stopped working and got 400K miles.

 

Wow. They must eventually start misfiring even if you can't tell without OBD / gas analyser.

 

He kept meticulous records looking for signs of increased fuel consumption. Nothing of note ever appeared.

The only sign of difficulty, and what prompted him to change them was hard starting and rough idle on very cold mornings.

 

Sounds like a car with fairly poor mpg no matter what!