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
2014 Dodge Challenger 100 Yr Anniversary Ed.
2014 Jeep Patriot Limited
2015 Jeep Grand Cherokee
2007 Crossfire Limited Roadster