I have filled my car up twice, and keep a spreadsheet of fuel consumption, since buying it. My vehicle is the 1.6 Hybrid. The first tank of fuel, which I filled up after 520 miles calculated out at 69mpg, and the 2nd tank full calculated out at 64mpg. A typical run to, or from, work of 22 miles is usually displayed between 65 and 70mpg.
I live in the UK and most of my commute is via the M6 and M42. All of my cars have been plodders, not racing cars, and the Ioniq is another plodder. With a smaller fuel tank than my previous 1.6 Astra Estate I am getting better than 1.5 times the mileage out of the Ioniq and I am pleased with it.