This seems like a silly question even to me but I thought I would get your opinion. I have a 2012 Ford Fiesta S that has 65k miles and thought maybe its time for new plugs as the service manual calls for them at 60k. Today I pulled 1 to get the part # and to check its condition. They are iridium made by NGK with a Ford PN on them. It looks clean and in good condition other than the gap has opened just slightly from .031 to .0335. With a normal copper plug I would just regap but copper plugs dont normally stay this long in a motor. If they were $2 ea I would just replace but the Ford part is 11.50 and the NGK part is 10.65 that and I dont know how long they can stay in before I start risking them seizing if ever.
Do you think I should just run them till I notice a problem or replace them by the book. NGK calls them 100k plugs.
Do you think I should just run them till I notice a problem or replace them by the book. NGK calls them 100k plugs.