4mpg is quite high if thats actually true. Computers are misleading quite large margin then. However would you then feel that RTP2017 computer is just being honest or there is something odd going on because ultimately thats what we are trying to do. Lol perhaps his computer is under estimating and mine is overestimating. I think its perhaps a little low or again maybe he has one honest computer reading.^^^ Eggszactly.
As I stated earlier, people tend to lie (by addition or omission either maliciously, accidentally, or due to ignorance) and/or exaggerate to impress the world or themselves. That's why I generally disregard reports from "Chicken Littles" complaining about only getting 12 MPG or bragging about getting 28 MPG - those are outliers. By now, there have been enough Fuelly reports to establish reliable enough data that individual reports can be dismissed. According to real-world data, the 2017 averages 4 MPG more than the 2014 so far - which matches my personal experience.