A lot of reports of inaccurate fuel level readings, even after the software updates.
I would say that the gauge is not inaccurate - I would say that it is a little aggressive in telling you to "refuel soon" at a 1/4 tank.
I also think the MPG/Fuel Economy estimate system has a bit of self learning going on, and this is what you have heard about.
As you drive, it becomes more accurate.
The gauge itself (not the "Remaining Range" reading ) is accurate as it's driven off a level sensor in the fuel tank, just like every other vehicle. Remaining range will get better with time.
Ive run it all the way to 21.5 gallons - remaining range was 0 and the fuel gauge showed several red bars of remaining fuel. I believe the system has too little data to yet be accurate - especially folks on their first tank or two.
Post: reading stuff on forums is all fine and good, but you really have to take into consideration the author. Most people have no understanding of the automotive industry, only a surface level understanding of cars and often very little experience with new technology.
Do I often see errors about the lane sensing or speed sign reading, auto emergency braking, etc? Sure. It's not a gremlin, it's a dirty windshield - when the camera can't see the road, signs, etc. it tells you certain capabilities are diminished.
This is not unique to the Grenadier - though it may be new to the owner.
For example, my Disco V has many more cameras - and when driving for several hours in salt and snow, things like the blind spot monitor stopped working. There was no error, and once the car was washed, they worked again.
Googling "dirty windshield camera error" will reveal some interesting stories.
I'm not a mechanic, but an active auto enthusiast and hobbyist - I do work in the technology industry, and have spent the last 20 years hanging out in garages and with professional mechanics for Nissan, Infiniti, Mercedes and independent European shops.