According to the 2002 Mercury Cougar owner Guide ( 5W-20 )
With engine oil filter change :
The 2.0 litre four cylinder engine takes ( 4.5 US. quarts of 5W-20 )
The 2.5 litre V6 engine takes ( 5.8 US. quarts of 5W-20 )
near the oil filter
14mm
For a Mercury Cougar , 2.5 litre V6 engine : According to the 1999 to 2002 Owner Guides : ( Motorcraft FL-820 engine oil filter )
According to the 2002 Mercury Cougar Owner Guide : The 2.5 liter V6 engine takes : With engine oil filter change : ( 5.5 litres / 5.8 US. quarts of 5W-20 engine oil )
5w 20 ======================================================== The above answer of 5W-20 is correct if it is a 2001 or 2002 model year according to the Mercury Cougar Owner Guides ( 1996 , 1997 , 1999 , 2000 guides show 5W-30 from the factory )
On a 1991 Mercury Cougar : The oil pump is INSIDE the oil pan ( the oil pan is bolted to the bottom of the engine )
According to the 2002 Mercury Cougar Owner Guide : With engine oil filter change : The 2.0 litre four cylinder engine takes ( 4.5 U.S. quarts ) The 2.5 litre V6 engine takes ( 5.8 ) * 5W-20
It came from the factory with ( 5W-30 )
Use Super Premium SAE 5W-20
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
5w30
5w 30