I have a 2013 Accent GLS and, like my son's old Elentra GT, this has a
running average MPG calculation. It definitely has some correlation to
reality since I can influence it one way or the other if I either am
heavy on the gas or try to speed up down hills and slow down up hills -
I was wondering how accurate it tends to be over a few hundred miles. If
I am very careful and do more steady state driving with not a lot of
traffic and only some stop and go I can coax it to over 40 MPG. Careful
driving in town (not huge city) with some traffic drops it down to 36
MPG. That includes fairly slow acceleration. My wife says if she had
known it was so easy to get me to drive gently/slow down she would have
found a car with that ages ago.
Funny thing is that in ECO mode my mileage drops - probably because my
light-footed driving is conflicting with the fuel saving algorithms.
During test drives the ECO mode seemed to cut down on my wife's ability
to accelerate hard, etc. It shifted earlier, etc.