I agree with bbunt302, and Corey. I was using my dads truck one day. Its a 1997 F-150, and it started to run like crap, and the check engine light came on. So I limped it to the Ford dealership, and it turned out that the problem was my dad had gotten the spark plugs change about a year ealier, and they used champion spark plugs. The people at the Ford dealership said that you should only use autolite plugs in Ford products because Ford own Autolite. They told me that Dodge owns Champion, and the plugs that they make that fit F-150's doesn't work the same as the Autolite plugs intended for the F-150. I can't remember what spark plug company they said that GM owns, but I believe they did tell me. The spark plugs didn't hurt the truck I don't believe, they just burnout prematurely.