Quote Originally Posted by SlowNA06 View Post
FAIL. Coppers work best in modified GTPs. and should be changed every 15,000 miles. They are on or below par with iridium in functionality.
Iridiums are good in stock base, stock GT, and stock GTPs for 100,000 miles.
I'd rather change them at 15,000 anyway, and most people on here will say coppers are the best for any 3800...