Hi priusCpilot:
Yeah, the Prius c is a highway and city eating animal and would break either the Elantra or the Cruze in half when it comes to measurement at the pump.
The Cruze and Elantra however have other redeeming features including larger driver/front passenger size, higher quality interior materials, better handling and their get up and go go was not too bad either.
Here are two shots that did not make it into the Shootout...

Cruze ECO F&R seating positions - A little tight in the back.

A bit more room and my head was almost touching the headliner.
The c was a bit tighter as expected given it is a smaller car....

Tight and my head was touching the headliner in back.
As you know, trunks can hold a lot of stuff but hatches are so much more versatile, convenient and larger
Wayne