Check your plugs

[jwuonog]

How often are people changing plugs? On the Focus ST (2.0 Ecoboost), plugs get worn out pretty quickly. Many recommend changing them at every oil change, or at least checking the gap.

They're not as easy to access on the 3.0, I'm hoping we can go longer intervals.

What is the consensus on the best plug? Bosch? NGK? Brisk?

Do you recommend staying with the stock heat range on the stock tune?

 

[Cdubya]

I changed them at 60k. Nothing too unusual about the ones i took out. Gap looked enlarged but that's a given. You could probably regap them at 30k but taking them out is a minor pain, not worth it to just inspect the plugs IMHO... just replace them. Maybe every 30k if you are concerned about it. I'm a pretty conservative driver so every 60k is fine with me. I got Motorcraft, the latest stock replacement (iridium) SP594

 

[TMac]

Back in the day of carburetors, machining problems, and iron heads, yeah, 5k miles was very possible for plugs.

I think 30k miles is not a problem with a direct injected engine with aluminum heads. As far as "best plug", the newer ruthenium or iridium plugs are going to last longer, but copper still works fine.

For temperature range, stick with the factory spec. See post here

 

[TMac]

And just because I'm sometimes mystified, bewildered, and flummoxed by certain things, why would anyone running an ethanol tune use a colder plug?

 

[Lightning Struck]

I changed mine this weekend at 57K. The factory does not use anti-sieze, and mine were he-man tight. The sounds they made as they broke free were definitely not re-assuring. I went with Bosch 96315. Idle quality improved, as did mileage.

This thing made me miss my old fox body mustangs, and Gen 1 Lightning. I could do plugs in them in about 5 minutes. The back plugs on the ST used just about every wobble extension I own. And do not discount the value of a 1" extension! I think this was the first time I ever used it, but it was a life saver.

 

[DetroitST]

Are the Bosch 96315 the same heat range as OE? Or one cooler? Running e85 here I want to make sure I'm not going cooler. I don't know where the heat range specs are for stock or these are. Anyone else better informed? Thank you.

 

[G’sCGST]

Are the Bosch 96315 the same heat range as OE? Or one cooler? Running e85 here I want to make sure I'm not going cooler. I don't know where the heat range specs are for stock or these are. Anyone else better informed? Thank you.

96315 are 1 step colder plugs

 

[bavarianblessed]

96315 are 1 step colder plugs

Spark plug heat ranges don't translate 1:1 between manufacturers


https://www.ngk.com/heat-range-conversion-chart-2

 

[Cruising68]

Just an fyi. I replaced my plugs at 25K and they were completely intact and looked normal. I did notice a little smoother idle on the new colder plugs. Used to have a very subtle miss sometimes.

 

[MrBigglesworrth]

Just an fyi. I replaced my plugs at 25K and they were completely intact and looked normal. I did notice a little smoother idle on the new colder plugs. Used to have a very subtle miss sometimes.

Same