2012 Ford F-150 Ecoboost Crew cab XLT
What Motorcraft Spark plug number should I use?
SP-534 CYFS-12Y-T3
SP-534 CYFS-12Y-T4
SP-580
or some other

 

Go to www.fordparts.com (Ford's official parts site) and look it up by your VIN.

 

Thank you.

 

...or look on the VECI label under the hood.

(phone app link)

 

use the ford plugs...gap them properly i think there was a new spec on that, i don't remember if it was .028 or .030. torque them as well to spec. use anti-seize on the threads.

 

Ford specifically says to NOT use anti-seize on the threads if you use Motorcraft plugs. The updated plug is the SP-580. Local parts stores have stopped carrying the others.

 

strange cause the original plugs i removed had anti-seize on them. So i reapplied it lightly, had no issues with it yet.

 

gap numbers keep changing. owners manual gives .033-.037 range.
been told that the motorcraft plugs come pregaped.
been told not to try to regap iridium plugs because you might brake them.
things are getting confusing

 

You probably wont but its easy to over-torque them with any type of lubricant on them. My stock plugs did not have any kind of anti-seize on them when I took them out recently.

The SP-580's I got were pre-gapped to .032", verified with feeler gauges.

 

Virtually guaranteed to have been superseded by a service part number.