They probably switched for CAFE or factory commonality reasons, but according to the manual, you can use either. I'm not aware of any changes to the engine post -2012 that would change the oil viscosity requirement.

For you 2014 Pentastar owners, note that the oil filter changed:

http://www.200forums.com/forum/10-chrysl...ter-change.html
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2014 Dodge Challenger 100 Yr Anniversary Ed.
2014 Jeep Patriot Limited
2012 Jeep Grand Cherokee
2007 Crossfire Limited Roadster