According to the computer, that I reset before the wife and kids went to Atlanta, the beast got 19.2.
Granted, I didn't get to fill it up and do the "actual math".
And at the risk of being a smart ass...can you say "gearing"?
My Excursion is barely turning 2000 RPM at 70 MPH. Hell, it only turns about 2200 at 80MPH.
The only things hard to love about it are the low-speed handling, and rearward visibility. Especially when being followed by cars that are "un-tall".
My son's Lumina is almost the same height as the hood.

And the whole rig is only about 7.75 feet tall.