According to the 1999 Mercury Mystique Owner Guide ( 5W-30 )
With engine oil filter change :
The 2.0 litre four cylinder engine takes ( 4.5 U.S. quarts of 5W-30 )
The 2.5 litre V6 engine takes ( 5.8 quarts of 5W-30 )
According to the 1999 Mercury Cougar Owner Guide : ( 5W-30 ) is used in the 2.0 litre four cylinder engine and the 2.5 litre V6
According to the 1999 Mercury Grand Marquis Owner Guide ( and one of Ford's websites ) ( Motorcraft FL-820-S , engine oil filter )
According to the 1999 Mercury Grand Marquis Owner Guide : ( 5W-30 engine oil , certified for gasoline engines ) With engine oil filter change ( 4.7 litres / 5.0 U.S. quarts )
4.5 quart
According to the 1999 Mercury Sable Owner Guide : ( 5W-30 )
no coolent low oil
10w30
5W-30
According to the 1999 Mercury Mystique Owner Guide : ( 5W-30 ) certified for gasoline engines ( 2.0 and 2.5 liter )
Right next to and above the oil filter.
According to the 1999 Mercury Cougar Owner Guide ( 5W-30 ) With engine oil filter change : The 2.0 litre four cylinder engine takes ( 4.5 US. quarts of 5W-30 ) The 2.5 litre V6 engine takes ( 5.8 US. quarts of 5W-30 )
According to the 1999 Mercury Mystique Owner Guide : With engine oil filter change : The 2.0 litre four cylinder engine takes ( 4.5 U.S. quarts of 5W-30 ) The 2.5 litre V6 engine takes ( 5.8 U.S. quarts of 5W-30 )