Owner's manual for my '96 says 3.7 US quarts. I would expect it to be the same. If you don't have an owner's manual and take care of your own car, you really need to get one. They are available on eBay for less than $10. Newer ones are available for download in .pdf format on Subaru's web site free.
The 2002 Subaru Outback has a 5-speed manual.
The 2014 Subaru Outback has a 6-speed manual.
The 2013 Subaru Outback has a 6-speed manual.
The 2011 Subaru Outback has a 6-speed manual.
The 2005 Subaru Outback has a 5-speed manual.
The 2001 Subaru Outback has a 5-speed manual.
The 2008 Subaru Outback has a 5-speed manual.
The 2009 Subaru Outback has a 5-speed manual.
The 2006 Subaru Outback has a 5-speed manual.
The 2007 Subaru Outback has a 5-speed manual.
The 2004 Subaru Outback has a 5-speed manual.
The 2010 Subaru Outback has a 6-speed manual.