Ford 1996 Windstar Manual page 317

Never use:
"Non-Detergent" oils
Oils labeled API SA, SB, SC, SD, SE, SF or SG
Additional engine oil additives, oil treatments or engine
treatments
Engine oils with an SAE 5W-30 viscosity are PREFERRED for
your vehicle. They provide the best engine performance, fuel
economy and engine protection for all climates down to -15˚F
(-25˚C).
Synthetic engine oils which are CERTIFIED and of the preferred
viscosity may be used in your engine. The engine oil and oil
filter must still be changed according to the maintenance
schedule.
Checking and Adding Engine Oil
Since the proper amount of engine oil is important for safe
engine operation, check the oil using the dipstick each time you
put fuel in your vehicle. Remember the engine must be off, the
oil must be warm and the vehicle must be parked on level
ground.
Checking the engine oil level:
Turn the engine off after it has warmed up and allow a few
1.
minutes for the engine oil to drain back into the oil pan.
Set the parking brake, making sure the gearshift is securely
2.
latched in P (Park).
Open the hood. Protect yourself from engine heat.
3.
Locate the dipstick labelled "Engine Oil" and carefully pull it
4.
out of the engine.
Wipe the dipstick clean and put it back into position, making
5.
sure it is fully seated.
Servicing Your Windstar
317