Which sparkplugs are the best to use in my 03 Mach 1...I havent changed em yet & Im gonna be dynoing my car on sunday so I figured now (43k miles) would be a good time to do so...I am getting mixed answers from people, & I pretty much only used stock motorcrafts when I changed them on my other stangs. Most people said i should go one heat range colder, but I am getting different opinions as far a platinum, Iridium, & copper.. I want whatever is gonna make my car run the best...
should i use...
-stock motorcraft platinum
-autolite platinum
-autolite copper
-NGK iridium
-Denso iridium
Any help or suggestins would be much appreciated & part #'s would help too....thanks
should i use...
-stock motorcraft platinum
-autolite platinum
-autolite copper
-NGK iridium
-Denso iridium
Any help or suggestins would be much appreciated & part #'s would help too....thanks