Nothing official but rumor has it that the MKC should come in somewhere in the low-twenties for a combined fuel economy rating. That is for the MKC's base 2.0-liter turbocharged four-cylinder. There isn't much to go off of for the 2.3-liter turbocharged in-line four.
I have a 2011 MKX, 3.7L 2WD. Have not touched the MPG average since it was purchased. The average for highway and city is 24.2. therefore, i would expect the MKC, smaller and lighter and assumable more efficient engine, to be more that 24.2.