Ok, we just got back from our 250 mile trip (ea way). About 85% of it was spend on highway driving. My fuel economy averaged 19.1 mpg. It was on mostly flat terrain (through Texas). I was on cruise most of the time. However, I was doing an average of probably 80-85mph which I don’t think is probably an optimal speed to get the best mileage. I’m going to keep watching it and will post back if I see any improvements.