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Howdy, fellers!

With all the sometimes drastic and varying differences in reported spark plug gaps from the factory, I decided to check the plugs on my '14 today. Considering all the stories I've read where the factory gaps were all over the place, I expected at least some degree of variance.

Before starting, I decided to set the gap to .028 because folks have reported good performance with it. Lo and behold, every plug was already dead on .028.

Granted, the worst cases I've seen where the gapping was all over the board were from '11s and '12s. However, I've seen several degrees of variance in later models as well.

So, what were your gaps when you checked/changed the plugs, and what did you change them to?

Thankee!
 

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.028
 

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.028
 

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Posted this page 7 of:

Poor Mileage issue on my F150 Ecoboost - Help Please

I did a test with my stock tune truck. Ran the plugs at .035 gap got 22.5 hwy, 18.5 town/country. Ran the plugs at .030 gap, got 20.6 hwy, 15.8, town and country (hand calculated, not computer). I am going back to .035 tomorrow. I will report mileage after couple of weeks. I am starting to believe that plug gap is dependent on tune. .032-.035 is maybe fine for stock, while .025-.028 may be better for a hotter tune. I think possibly that with out the hot tune a cold plug is very inefficient in fully combusting the fuel, leading to poorer fuel economy and increased fuel dilution and a stock tune needs a little hotter plug Time will tell... still testing.
 

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New sp534 outta the box were 0.030. They are working


Sent from my silver iPad Air 1 in a http://www.red.org/en/ smart case using an app called Tapatalky
 

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At 40k miles i changed mine and they were around .035 to .038.. Was getting a surging issue when full throttle.. Gapped new plugs at .030 and truck has been running great
 

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When I bought it, they were:
1x .032"
3x .034"
1x .035"
1x .036"

Now they are all at .030".
 

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My truck has 13k miles now and had surging issues from day one. Checked the plugs over the weekend and all were set at .035. I gapped them down to .030 and the truck feels solid now. Night and day difference!
 

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factory was .38-.49, new plug are at .30
 

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2014 w/ SP-534's after 10K miles were between .030 and .034. I just regapped to .028 I can't check to see if it fixed the slight shudder, roads are all covered in snow.
 

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. 025 tuned with stock 534s
I will be going back with brisk again. I had a set of brisk last over 20k no issues

Tune junky thats addicted to Boost!!!
 
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