[ImperialCrown]

5W-20 is recommended and safe if the oil filler cap says so.
Oil change intervals depend on climate and driving habits. At under 25K, this van doesn't see much driving. Every 8 months or 4000 miles should be good. .

 

[ImperialCrown]

When measuring modern Chrysler engine parts for wear, many specs are given for an ambient shop temperature of 70 deg F (21 deg C). In this way, tolerances can be more consistently done down to 1/10,000 of an inch (.003mm).
The thinner viscosity oils not only reduce the viscous drag for better fuel economy, but the world engines, Pentastar and the MDS Hemis (since '09) use VVT (variable valve timing) that requires very fast hydraulic cylinder deactivation/cam phaser reaction times that heavier oils would slow down too much. Heavier-than-recommended viscosity oils can turn on a 'ck eng' light and store a fault code.
Older, high mileage engines driven in warm weather with oil use issues may benefit with a slightly heavier grade.