Schulzie

I've got a 2012 EcoBoost, Lariat, 4WD with a Livernois Tuner. I've got over 29,000 miles on her now, and I haven't pulled the plugs to check the gap. I figured I'd pull them and just replace them.
What plug are you guys using as a replacement. I've searched, and found that some are using MotorCraft SP-534. However, I've had a hard time locating them. I asked Livernois, and they want to sell me a set for $90. That seems a bit high. Thoughts?

jmvdigital

Personally, I went with the NGK 9509 Iridium IX plugs. I found them at Advanced Auto for about the same price as here:

http://www.stage3motorsports.com/LTR...ark-Plugs.html

You have to gap them down to about 0.030, they come at around 0.040 I believe.

Schulzie

I finally changed the plugs. My truck was manufactured early 2012. I've got 29,500 miles on it now, half of them tuned. I pull a 5500 lb boat occasionally, with the remainder of the driving 75% town, 25% highway.
I never did any of the TSB's. The only changed on it are a LMS tuner, Airaid intake, and one size larger BFG tires. It would start to miss occasionally when I'd get on it and it was tuned. Not all the time, just some.
I ended up ordering the MotorCraft SP-534's from O-Reilly. They arrived at the store next day, and priced at $3.99 each. I checked them, they were all exactly .030. I pulled the plugs from the truck, they were .037-.039. They didn't look worn, just gapped wide. I attribute the stumble from blowing out the spark under certain conditions. So far, no problems.

TJPlatinumEB

Motorcraft SP-534's gapped at .030-.032 at the highest. You will be good for another 25-35k miles after that

I haven't bought any for my 13 yet, just regapped the stockers. I did buy the 534's for my 2011 when it had about 30k miles on it. Got them from Amazon. I couldn't find any auto parts stores local that carried them.

torinalth

did the exact same

Stu Cazzo

Did any of you notice an increase in fuel mileage as a result of replacing the plugs?

Schulzie

I did not notice an immediate gain. However, it's too early to tell.

Just 5

NGK's for me too...no noticeable gain or loss, but I feel better because they are all now gapped the same instead of 6 different gaps on my original one's.

EcoBoostJake

I did mine about 2 months ago with the motorcraft SP-534s. I noticed an immediate jump in mpg by almost 2 miles per gallon. I do a mix of city and highway and am currently running between 17 and 18 mpg.

Stu Cazzo

anyone install the autolite iridium plugs?