How hard do you drive the car? How often do you change the oil, and what type do you use? If you drive hard and change the oil every 10k miles or more I'd shorten up the oil change interval.
If you're using recommended oil (meets Fords spec), viscosity, and oil change intervals, well sometimes stuff happens. Good luck.
It's my wife's car and she does not drive it hard(drives like a old lady, LOL). Oil changes have been about every 5000 - 6000 miles and the oil used is Ford recommended 5w20 synthetic