Overall the trip from Denver to my house, near Madison, was 12.6mpg.
The first 100 or so miles were in snowstorm so 45-55mph and EVIC said 13.7mpg. The rest was on dry roads, I-80, and cruise was set at 75mph most of the way.
It did use IMO, a lot of DEF fluid. Apparently it’s a 5 gallon DEF...