So, is it possible to loose that coolant over 60k miles and 3.5 years without ever adding any? Upon initial inspection, I did’t see any sign of leakage.
It can be hard to tell because it's obviously not a big leak since you haven't noticed it until recently and probably only does it when it's hot. Is it better now after topping it off? If so, just monitor it and see if continues to drop. Like I mentioned before, the only common leaks I've heard are from the overflow tank fitting or at the water pump itself. Previous Ecoboosts also leaked at the turbos, but I haven't seen that much in the Gen2