Since the mileage on my 2012 EB has sucked since day one, 13-14mpg, I've read the posts on this subject, especially the ones about the plugs and incorrect gaps. Since it was an easy thing to try I pulled out the originals and replaced them with new Motorcrafts.

I checked the gaps on the originals and what I found was: 1 at .028, 1 at .029 and the remaining 4 at .030. I gapped the new ones at .035.

Another thing I saw was that the ones that came out were CFYS-12-YT3 and the new ones were CFYS-12-Y3. I don't know what difference that T makes but I verified the numbers and found that the T's were for a 2013 Taurus and Lincoln MKS / MKT. The non-T's were for the 150 along with a few others.

Checked the mileage as I ran out to work to change them and I got 13.6. Checked the mileage as I ran from work and I got 19.8.

Now I know that the mileage after was not a valid test and I'll have to run for awhile to get actual but I thought it all was pretty interesting.