5 w 30 ( according to the owners manual )
10w-30
( 5W-30 ) according to the 1999 Ford Mustang Owner Guide
5 quarts ( 4.7 liters ) WITH FILTER CHANGE - according to the 1999 Ford Mustang owners manual
The 1999 Ford Mustang 3.8 liter V6 engine takes : ( 5 quarts with engine oil filter change )
According to the 1999 Ford Mustang Owner Guide : With engine oil filter change ( 5.0 quarts / 4.7 liters of engine oil )
Try above oil filter
It's on the bottom of the engine where it belongs.
( 5W-20 ) according to the 2004 Ford Mustang Owner Guide
The recommended oil is SAE 5W-20
It came from the factory with ( 5W-30 )
5W-30 ( according to the Owner Guide )
The 2003 Ford Mustang Owner Guide shows ( 5W-20 )