it does in fact seem like that.
and when the battery is low is "runs out" faster than reality and then if you keep going it slows down and "catches up" with itself (so it might say 6 miles left you go 2 miles and it still says 6 miles left)
I wish it would just give me a solid linear reliable value.
if pushing it I just use leaf spyi and use kwh remaining as my guide (just remember 0 is .5kwh NOT 0kwh !! the battery will hard disconnect at around .5kwh
The GOM run down "catches up" is probably due in part to the natural intelligent user response to being so low, driving better. A big part of this is forced on Nissan by our society that demands money back on major car investments for little things that bother them and the fear of being stranded. No one is going to sue Nissan for a car that their program said could do 6 miles but actually went 8 but they will sue and ask for a full refund on a now used car when it said 8 and went 7.5 and claim that Nissan endangered their family by leaving them on the side of the road .5 miles from where they thought they could go. Also the GOM especially at those low numbers is designed to make you search for a charging spot within the range given, it has to be extra cautious because even a short hill at a low battery SOC can make the difference between getting there and not. At full range a hill can never go on for 84 miles so they can make the assumption based on a tighter avg consumption.
It would be impossible to give a solid linear reliable value since no human can drive that way, no wind will ever blow that way and no road will ever be level in that way. I personally like the way the spark ev does it with a high/low and current use GOM and future cars should be programed with topographical information to give more accurate GOM when a destination is put in the GPS. I've heard the BMW active hybrid will do this when in cruise control to calculate if the electric assist should be boosted to maintain speed up a hill or give it more gas and or downshift.