My '05 GT has a Kenne Bell supercharger, so needs colder plugs than stock. This setup is hard on plugs, as they only last about 12-15k miles. However, the Autolite's hold up for about 50% longer than the Ford Racing equivalent. They're pre-gapped and ready to go, and I haven't had any trouble with seizing like with the original stock plugs. I recommend these for forced induction applications.