Depends a bit on the climate where you live and the general condition of the engine. In a cold climate, I would use 15-40 W oil. In a hotter climate, a 20-40 W or 20-50W. In case of very worn engine use single grade 40 W oil as this will give maximum protection. An oil additive increasing viscosity is in order if the engine burns a marked amount of oil between regula roil changes.
The 2013 Honda Odyssey has a 5-speed automatic.
The 2014 Honda Odyssey has a 6-speed automatic.
The 2011 Honda Odyssey has a 5-speed automatic.
The 2012 Honda Odyssey has a 5-speed automatic.
The 2002 Honda Odyssey has a 5-speed automatic.
The 2004 Honda Odyssey has a 5-speed automatic.
The 2010 Honda Odyssey has a 5-speed automatic.
The 2003 Honda Odyssey has a 5-speed automatic.
The 2009 Honda Odyssey has a 5-speed automatic.
The 2006 Honda Odyssey has a 5-speed automatic.
The 2008 Honda Odyssey has a 5-speed automatic.
The 2005 Honda Odyssey has a 5-speed automatic.