It's hard to say. I sit in my car with it parked but running for hours at a time. It is my office. I run a huge variety of roads from interstate at 75-80mph. Back roads at 60mpg. And city streets. I've maxed out around 55 mpgs. I will never complain. My Niros have been good to me so far.What is your typical speed? I ran a new low mpg yesterday at 20 degrees and 75 mph (rare speed for me, I was in a rush for a meeting two hours away) but still well into the 40s. Scary low from my usual summer max of 59 mpg. Still, I'm over 53 mpg over 40,000 miles.