Here's a good example of different oil for different applications.....
10w30 Valvoline DuraBlend in the 4.6L Bullitt / 23k miles
5w20 Motorcraft Synthetic in the 4.6L Roush / 7k miles
5w30 Valvoline in the 4.0L Sport Trac / 49k miles
But always Motorcraft Filters