Bought my 2016 CC 4x4 just after Christmas and finally had a chance to put some miles on it. Took it from So Cal to Las Vegas and made a few side trips - about 560 miles. The computer said 18.1 mpg when I got all the way into Vegas and by the time I got home, it said 18.5. That was driving an almost empty truck (except for fuel). That's with 3.31 rear end, driving between 65 - 75 and using cruise control as much as I could.
I was expecting about 14 to 15, so this is a nice surprise. Gets better mpg's than my FJ Cruiser plus fuel is cheaper.