The gas tank on the 2008 Toyota Highlander-Hybrid holds 17.2 gal..
http://www.fueleconomy.gov/Feg/noframes/24629.shtml
19 Gallons.
The gas tank on the 2011 Toyota Highlander holds 19.2 gal..
The gas tank on the 2004 Toyota Highlander holds 19.1 gal..
The gas tank on the 2005 Toyota Highlander holds 19.1 gal..
The gas tank on the 2009 Toyota Highlander holds 19.2 gal..
The gas tank on the 2006 Toyota Highlander holds 19.1 gal..
The gas tank on the 2012 Toyota Highlander holds 19.2 gal..
The gas tank on the 2013 Toyota Highlander holds 19.2 gal..
The gas tank on the 2001 Toyota Highlander holds 19.8 gal..
The gas tank on the 2003 Toyota Highlander holds 19.8 gal..