Don't forget there are extremes to every trip and or driving style.
I have never reset my "trip B" in the computer my overall average after 4000 miles is 14.1 MPG. Not real impressive but better than the last vehicle I had. 3000 of these miles are highway, but in my case interstate traffic is 75mph. I've gotten 18+ empty with the wind on my back but the overall Trip B is my only true indicator.