motorcraft 820 S
( 5 quarts ) with engine oil filter change ( according to the 1996 Mercury Grand Marquis Owner Guide )
According to the 1998 Mercury Grand Marquis Owner Guide : With engine oil filter change ( Motorcraft FL-820-S ) The 4.6 liter V8 engine takes ( 5.0 U.S. quarts / 4.7 litres of 5W-30 )
According to the 2002 Mercury Grand Marquis Owner Guide : With engine oil filter change : The 4.6 liter V8 engine takes ( 5.0 U.S. quarts of 5W-20 )
According to the 2001 Mercury Grand Marquis Owner Guide ( 5W-20 ) ( with engine oil filter change , 5.0 U.S. quarts / 4.7 litres of 5W-20 engine oil )
According to the 2000 Mercury Grand Marquis Owner Guide ( 5W-30 ) ( with engine oil filter change , 5.0 U.S. quarts / 4.7 litres of 5W-30 engine oil )
The 2006 Mercury Grand Marquis owners manual shows : The use of synthetic or synthetic blend motor oil is not mandatory - the oil just has to meet Ford specifications
5w-30 is what I use in my 2000 grand marquis, in 2001 ford started saying 5w-20.
Another member has informed me of what oil to use (Mobil 1 10-40), the appropriate oil filter wrench (0420-0577) and the oil filter (Onan 122-0836, NAPA 7398, WIX 57398).
For a 2005 Mercury Grand Marquis : " regular " unleaded , 87 octane According to the Owner Guide
According to the 1997 Mercury Sable Owner Guide : For the 3.0 liter " Vulcan " V6 engine ( Motorcraft FL-400-S engine oil filter ) For the 3.0 liter " Duratec " V6 engine ( Motorcraft FL-820-S engine oil filter )
According to one of Fords websites : For the 1972 Mercury Cougar , 5.8 liter / 351 cubic inch V8 engine : ( Motorcraft FL-1-A engine oil filter )
For a 1991 Mercury Grand Marquis : " regular " unleaded gasoline , 87 octane is used for both the 5.0 and 5.8