FredB

I posted this on the V6 board but not sure how many view that board.
Question is this, 2015 2.7 ECO is currently gapped at .30 as per Ford Specs, I am thinking of trying a gap of .28 to see if that will improve MPG and Performance
Has anyone tried a tighter gap on a stock engine.
It seems the first time I changed the plugs there were gapped tighter than the stock .30 gap as I checked and a .30 feeler gage would not fit, did not try any lesser gap though
Does Ford set the gap tighter from the Factory to give these engines a bit more pep. Would this have an adverse effect on the engine, predetonation knock, etc.
Thanks in advance

PUT-IT-IN-4L

It’s .030” not .30. Huge difference. As for changing the gap by .002”, you will not notice a thing. All of you current plugs probably vary .004 to .006” as is.

rngtrtl

I dont think you are going out engineer the motor designers that spec'd 30 thousandths on a stock motor.

engineermike

.030 is pretty tight for a stock spec. They tightened it up since the first eb f-150’s came out. I’m not sure I’d go any less than .028 but no, you won’t notice a difference unless it happens to fix a misfire problem.

autoworker

I’m curious why you’re changing the plugs. Due to miles? How did they look? Did the gap grow from the factory settings?

Bubbabiker

Ford spec is 0.028-0.030" for the 2.7L. Personally I always set the gap to the tight side for forced induction engines.

NASSTY

My H.O. 3.5 takes Motorcraft SP550. They come pre-gapped @ .028. I check the gaps before installing them, but they've always been right on.

white15lariat

More power = wider gap, not smaller.

You close the gap to correct misfire/'blowout' problems. For instance, you up the boost, you may have to close the plug gap (pretty typical). You may also have to run a 'colder' plug in some applications.

If anything, go to the top end of the factory spec. If you basically never go WOT, you can play with larger gaps -- but I wouldn't. It's not going to yield any appreciable gains, honestly. In a racecar, definitely. Truck? No way, Jose.

Buy stock plugs, install. Done.

FredB

Thanks all for the replies. I have 100K on the engine and have changed the plugs @ 45K. I didn't see any wear on the plugs I did pull out but they were not gapped @ 0.030, they seems tighter as feeler gauge would not fit @ .030. May be its just a mind thing but it did seem to idle better/smoother, and pep was better after changing them
Anywho, thanks again all