1997 Mercury Grand Marquis Owner Guide 1st Printing - Page 210

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 Never use: u "Non-Detergent" oils u Oils labeled API SA, SB, SC, SD, SE, SF or SG u 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. 211