Use 10-30
The book on my 1998 Ford E350 says to use 5W-30.
It takes 75W140 SYNTHETIC
The Ford motor company recommends you use 10W-30 weight motor oil in the 1998 Ford F1 50 truck. A heavier weight motor oil can be used in extreme climates.
Ford uses the Motorcraft blended oil (part synthetic).
In your owners manual , page 302 , comment # 5 shows that it is NOT MANDATORY to use synthetic or synthetic blend motor oil in your engine as long as the motor oil meets Ford specifications and the API " certified for gasoline engines "
Will it go fit a ford
5W-30 is the preferred oil ( according to the Owner Guide )
My 2000 Ford Focus owner's manual lists 5w-30 as the correct weight motor oil. Any modern brand of motor oil should be fine. 5w30 oil for ZETEC engines
The ( 1997 ) Ford Expedition Owner Guide shows ( 5W-30 )
Use the manufacturer's suggested oil. If you have a turbo charged vehicle, synthetic oil will make it run cooler.
10w30. The brand is a personnal choice. I use Pennzoil.