21 gal.
refer
http://www.fueleconomy.gov/feg/noframes/25116.shtml
http://automobiles.Honda.com/odyssey/specifications.aspx?group=epa
The gas tank on the 2008 Honda Odyssey holds 21.0 gal..
Honda Civic 2008 has a gas tank size of 13.2 gallons
20.0 Gallon
20 Gallons http://www.edmunds.com/used/2003/honda/odyssey/100178649/specs.html
I just read the the gas tank size of the 2008 Honda Civic (including the LX) is 13.2 gallons.
The gas tank on the 2014 Honda Odyssey holds 21.0 gal..
The gas tank on the 2007 Honda Odyssey holds 21.0 gal..
The gas tank on the 2012 Honda Odyssey holds 21.0 gal..
The gas tank on the 2010 Honda Odyssey holds 21.0 gal..
The gas tank on the 2011 Honda Odyssey holds 21.0 gal..
The gas tank on the 2001 Honda Odyssey holds 20 gal..
The gas tank on the 2005 Honda Odyssey holds 21 gal..