According to the Owner's Manual:
If your climate is colder than usual you'd use 5W-30, but in most instances and in warm climates you are just fine with 10W-30.
You can use synthetic engine oils provided that the recommended oil quality requirements are met. And do not put any other meterials in the motor oil.
R134a
Green.
The 2001 Dodge Grand-Caravan has a 4-speed automatic.
The 2004 Dodge Grand-Caravan has a 4-speed automatic.
The 2005 Dodge Grand-Caravan has a 4-speed automatic.
The 2010 Dodge Grand-Caravan has a 4-speed automatic.
The 2006 Dodge Grand-Caravan has a 4-speed automatic.
The 2002 Dodge Grand-Caravan has a 4-speed automatic.
The 2007 Dodge Grand-Caravan has a 4-speed automatic.
The 2009 Dodge Grand-Caravan has a 4-speed shiftable automatic.
The 2004 Dodge Grand-Caravan runs on regular unleaded.
The 2012 Dodge Grand-Caravan has a 6-speed shiftable automatic.