Lincoln 1997 Continental Owner's Manual page 227

Engine Oil Recommendations
We recommend using Motorcraft oil or an
equivalent oil meeting Ford Specification
WSS-M2C153-F and displaying the American
Petroleum Institute CERTIFICATION MARK on the
front of the container.
The API Certification Mark
226
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.