According to the 2005 Mercury Grand Marquis Owner Guide :
With engine oil filter change :
( 6.0 U.S. quarts / 5.7 liters of 5W-20 )
According to the 1996 Mercury Grand Marquis Owner Guide ( 5W-30 is the PREFERRED engine oil )
According to the 1996 Mercury Grand Marquis owners manual ( 5W-30 engine oil ) is the PREFERRED oil weight
According to the 1996 Mercury Grand Marquis Owner Guide : ( 5W-30 is the PREFERRED engine oil weight )
According to the 1997 Mercury Grand Marquis Owner Guide : ( 5W-30 )
A 1992 Mercury Grand Marquis came from the factory with ( 5W-30 )
( 6 quarts with engine oil filter change ) according to the 2003 Mercury Grand Marquis Owner Guide
5w 30 if it's new, older engines need straight 30 weight.
According to the 1997 Mercury Grand Marquis Owner Guide : ( 5W-30 ) is the PREFERRED oil
5w-20
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
According to the 2006 Mercury Grand Marquis Owner Guide : With engine oil filter change : ( 6.0 U.S. quarts / 5.7 litres of 5W-20 engine oil )
According to the 2004 Mercury Grand Marquis Owner Guide : With engine oil filter change : ( 6.0 U.S. quarts of 5W-20 )