Jbrew

100,000 miles is what they say.

To have good performance the ladder half of those miles isn't going to happen BUT, the engine will run.

Spark plugs to Mileage. That's just a piece of how that works.

There's a few drive it until it dies attitudes here, that's okay. These Fords are some what resilient to that type of abuse lol. For those who are intawested, - pick a good question.


snowman3, - between 50 - 60,000 miles for plats. After that it's down hill slowly...that's the fact. Your engine is running, but it DEFINITELY will run better longer, keeping that regimen within your frame of mind.

snowman3

Thanks everyone for the info. I normally do maintenance religiously: fluid changes, fuel filter, air filter, etc. 12yo and dang thing runs like a champ! (knock wood cross fingers). Love my truck! Still looks showroom.

But something about spark plugs scares me to replace. And I dunno why. I swap out fluids + filters all the time, seems like right thing to do and gives me piece of mind. But for electrical I seem to think that the coils, wires, plugs, cylinders, etc have all aged together. And putting a new hot spark in the middle of all that old stuff gives me the jeebies. I don't want to break something that was working OK! Irrational?

Anyone ever heard of new plugs CAUSING a problem? Maybe you guys can convince me it will all be OK. For some reason I seem to think that replacing them will end up creating more problems.

(Mechanic will be doing the plugs. I thought about pulling one myself and checking the gap, but those things are buried in there! 5.4L)

Are the stock plugs dual tip platinum?

And aside from worse MPG, what else can go wrong if the plugs are too worn out? I pass emissions, MPG is still good. Power is OK (Actually I really dunno since AZ isn't hilly and I drive easy).

Warspite

This forum contains many posts about spark plug choices; most would shy away from aftermarket Platinum plugs that could strip out the threads on the heads due to higher heat. I went with stock Motorcraft ones. The originals all wore evenly and no difficulty in removal (other than the position and location) as some have run into.

MDJ1993

I used denso platinums and no problems so far after about 1,000 miles on em

jdinner

If you wait too long you will end up with catalytic converter damage. A spark plug change is cheap maintenance.