From page 237 of the owner's manual:
Engine Oil Change Indicator System
Oil Change Required
Your vehicle is equipped with an engine oil change
indicator system. The “Oil Change Required” message
will flash in the EVIC display for approximately 10 seconds
after a single chime has sounded, to indicate the
next scheduled oil change interval. The engine oil change
indicator system is duty cycle based, which means the
engine oil change interval may fluctuate, dependent
upon your personal driving style.
Unless reset, this message will continue to display each
time you turn the ignition switch to the ON/RUN
position or cycle the ignition to the ON/RUN position if
equipped with Keyless Enter-N-Go™. To turn off the
message temporarily, press and release the MENU button.
To reset the oil change indicator system (after
performing the scheduled maintenance) refer to the following
procedure.
From page 445 of the owner's manual:
NOTE:Under no circumstances should oil change intervals
exceed 10,000 miles (16,000 km) or twelve months,
whichever occurs first.
Engine Oil Selection
For best performance and maximum protection under all
types of operating conditions, the manufacturer only
recommends engine oils that are API Certified and meet
the requirements of Chrysler Material Standard MS-6395.
I personally change mine every 3000-4000 miles, or every 6 months. Whichever comes first.