Larry Hull, my friend who owned an NC700 (manual clutch version, IIRC) and I rode together on one long ride. We left here and rode through Loveland and Estes Park, over Trail Ridge Road in Rocky Mountain National Park, then over Willow Creek Pass and up to Walden for lunch. That was 162 miles from here, reaching an altitude of 12,200+ feet. Riding through the Park, the speed limit has been lowered to 35mph, and high altitude seems to help gas mileage. But after we got on CO-125 from just west of Granby and rode it up to Walden, I was riding "briskly." I was surprised that when I'd pass a slower vehicle, Larry stayed right with me. After lunch we stopped at a gas station in Walden to fill up the 130 mile ride home.
As I was calculating my mileage, I remember feeling pretty cocky when it turned out to be 58mpg. But then Larry walked over and his had been 73 mpg. So, if I could have kept the 58mph average, I would have had a range of 302 miles. And if Larry could have kept his 73mpg average, his range would have been 270.
I have to admit, I was more impressed than I expected to be. But I still haven't ridden an NC700. One of these days, maybe I'll throw a leg over the NC750.