The 2001 Ford Windstar Owner Guide shows :
With engine oil filter change ( 5.75 quarts )
Personally I would try 5 quarts first and see where it is on the dipstick
According to the 2002 Ford Windstar Owner Guide : With engine oil filter change ( 5.0 quarts )
( 26.0 ) U.S. gallons in a 2001 Ford Windstar gas tank
The fuel tank holds ( 26 gallons ) on a 2001 Ford Windstar
The 2001 Ford Windstar has the ( 3.8 liter ) over head valve / pushrod V6 engine
According to the 2002 Ford Windstar Owner Guide : With engine oil filter change : The 3.8 liter V6 engine takes : ( 5.0 U.S. quarts of 5W-20 )
On a 2001 Ford Windstar : The 3.8 liter V6 engine has ( 6 engine cylinders )
According to the 1996 Ford Windstar Owner Guide : With engine oil filter change : Both the 3.0 and the 3.8 liter V6 engines take ( 4.5 U.S. quarts of 5W-30 )
15 quarts
I was looking at the 2001 Ford Windstar Owner Guide and it shows : With engine oil filter change : ( 5.44 liters of 5W-20 ) * but the 2002 and 2003 Ford Windstar Owner Guides show 4.7 liters of 5W-20 is used *
( 6 quarts ) with engine oil filter change
Every Windstar ever built was equipped with a V6 engine (3.0 or 3.8 liter), so the answer is 6.
6 quarts WITH FILTER CHANGE