We have the 2019 PHEV Niro and just finished an 800 mile trip! Obviously, mileage depends on speed and conditions. We averaged 43-44 mpg averaging near 80 mph. When we got into the 60-65 mph driving, it was up near 48 mpg, but there were some stop lights involved too
What sort of mileage did you get in hybrid mode on the highway (not considering EV range)? And at what speed?