EcoBoost spark plug life
Wanted to let you guys know that around 47,000 miles I noticed my milage had dropped by a couple of points. Around this time I installed a 5 star tuner so I thought the tune was the cause of the milage drop. I also noticed a full throttle miss. 5 star suggested I check the plug gap and sure enough they were .040 to .043. The Fomoco replacements were all .035. Did the factory plugs come with that big of a gap? I don't believe so, I think center electrode eroded widening the gap. After their replacement, the full throttle miss was gone and my milage is back up to where it used to be. There have been a lot of threads regarding spark plugs, but based on my experience you can plan on having to replace them every 50,000 miles.