I got a 2017 Niro in May 2017. I live in NE. There are times in nice weather, w/o running AC or heat, I average as low at 28 mph, especially on longer drives. My first couple months I was getting 46-50 mpg. Then it changed in Sept. I started complaining 3 months after I bought it. They came up w/every excuse under the book: cheap gas, wind, hills, my driving, using cruise, not using cruise, driving over 55 mph. You name it, I heard it. I kept complaining with each oil change. “I’m reading Niro drivers in Wisconsin in winter with hills driving 75+ getting over 50. You promised me 49/51.” They asked me to keep track of my mileage and gas. So I did. They asked me to buy premium, so I did. They asked me for screenshot stories of these great mpg stories. So I did. The ONLY reason I purchased this Niro was the promise of 49 - 51 mpg in NE with regular gas. Kia finally did a 3 day long series of analysis/tests. Their results were the same as mine. Yes, driving under 55 mph does increase the mpg. But I drive 60 miles each way almost all interstate, 5 days a week. The typical speed on I80 for this stretch is 82-85 mph. No way can I drive 55 mph to get closer to their mpg Kia claimed, advertised and promised. Kia explained there are so many variables and that even in nice weather, I should expect 37-38 mpg on my interstate drive. And much less in winter. I was livid. If that’s the case, then Kia shouldn’t promise 49/51. Such a bait and switch. Felt like I’d been lied to. Then, over two years later, I’m finding improved mpg. 44-50 this summer, with hills, wind, driving 80 mph, ac on both sides, ethanol gas. It’s like after passing 55,000 miles/odometer, it finally started delivering near its promise. Still, I endured 2 years of disappointments, every excuse in the book, and much experimenting in how I drive, my speed, AC, heat, tires, cruise, etc. I have no idea if this better mileage will continue as the weather changes, but for now, I’m happier. However, next time around, I’ll be driving a Prius.