2008 Mustang Spark Plug Guide, Brenspeed info on spark plug identification
 

Just wanted to take a minute and post a helpful picture on identifying which spark plug your 2008 Mustang has. When ordering plugs you will need to know this. From 2005 to mid 2008 Ford uses what we call "old style" spark plugs. In mid 2008 Ford changed over to the "new style".

Common aftermarket old style plug part numbers are...
Autolite HT1 (standard heat range)
Autolite HT0 (one step colder)
Brisk 3VR17 (standard heat range)
Brisk 3VR14 (one step colder)
Brisk 3VR12 (two step colder)

New Style Part Numbers
Brisk XOR14 (one step colder)
Brisk XOR12 (two step colder)

There are lots of other brands of plugs as well. Here is a link to the spark plugs we keep in stock. Hope the picture below saves some of you time when ordering plugs for your Mustang.
Spark Plugs[/URL]

http://i759.photobucket.com/albums/x...BOOTSCOLOR.jpg

Yes - starting in Dec 07 ("Job 2" I think). Mine was built 1.9.08 and has the new heads/plugs/brown boot.