Actually, according to the Owner's Guide, the scheduled maintenance for the NA 2.0 Duratec spark plugs is 100,000 miles. As with the 10,000 mile oil change interval, I won't wait that long, maybe 50,000-70,000 miles or if the car starts running rough or I see a significant drop in fuel economy. If someone wants to change out their plugs before the scheduled mileage, that's up to them, just doesn't seem necessary.
The FL910S is the same filter used on my 2010 Fusion, 2.5L Duratec, it's been around a while.
2014 C-Max Energi