Nissan recommends the use of any good quality 5w-30 motor oil. Conventional or synthetic will do. Make sure the brand you buy is certified by the American Petrolium Institute and the mark (a gold starburst symbol) is printed on the bottle. The API rating should be SL or higher.
The 2014 Nissan Xterra has a 5-speed automatic.
The 2008 Nissan Xterra has a 6-speed manual.
The 2003 Nissan Xterra has a 5-speed manual.
The 2005 Nissan Xterra has a 6-speed manual.
The 2002 Nissan Xterra has a 5-speed manual.
The 2006 Nissan Xterra has a 6-speed manual.
The 2001 Nissan Xterra has a 5-speed manual.
The 2010 Nissan Xterra has a 6-speed manual.
The 2013 Nissan Xterra has a 5-speed automatic.
The 2011 Nissan Xterra has a 5-speed automatic.
The 2004 Nissan Xterra has a 5-speed manual.
The 2007 Nissan Xterra has a 6-speed manual.