Which should be trusted more??
Well we have a choice of a well built program that is still constantly being improved by a very active member of this forum
something that has been dubbed "guessometer".
hmmm... tough decision??
I think the only confusing thing here is how this is even a question.
As far as your question; I would say...neither.
The gauge on your LEAF dash is ONLY designed to start warning you when you have just under a "¼ tank" remaining. FYI; This NOT even a teeny tiny bit different than how they treat gassers...
So you can take your 100 mile car (or whatever you get) and turn it into a 75 mile car...or not.
LEAF Spy is the answer should you decide on the latter option.
LEAF Spy allows "you" to set a range for your driving based on how much charge is remaining in the battery. Its completely customizable but does require some work.
Your performance changes based on routes, weather, wind direction, congestion, etc. This sounds complicated but you drive the car every day. You would be surprised how quickly you learn what the car can do provided you simply decide to pay attention. LEAF Spy helps you do that.
For me; I set my range to "1%" There are several options including "low battery warning" "very low battery warning" etc. Nearly everything except Turtle which is voltage based and cannot be predicted reliably.
I have 4 different settings I use. One for Summer and 3 for Winter. What can I say? When its clear, dry and Sunny, my performance just doesn't vary that much.
Winter time is a completely different story and I use 3 settings for simplicity. I really should use more but I am lazy so I basically have a "normal" "best case" and "worst case" setting. Strangely enough, "worst case" setting is not temperature dependent. Its wind and rain dependent. My worst performance happens when its actually relatively warm but that is how my weather is.
When its super cold, there is almost never any precipitation.
Finally; The SOC on LEAF Spy is real and its NOT all usable. How much is not usable is completely dependent on the condition of your pack and how well balanced the cells are.
I think you will find the 1% setting to be the ideal if you are interested in knowing where your last mile is. I don't consider "Turtle miles" to be usable. If 1% is too close, there is 2, 3 or whatever available as well.
As far as how accurate the SOC meter is on the car? Check my blog. I have tons of data ridiculing its existence.
In your car, there is basically 3 warnings for low battery.
LBW; Low Battery warning which comes on about 48 GID.
VLB; Very low battery warning which comes on about 24 GID (this is when the GOM goes to "_ _ _"
and finally Turtle. This can happen anywhere from 3 to 9 GIDs. Something in the middle is most likely.
On the 2018, they added another warning I call "SEW" (Static Electricity Warning) which is where the SOC meter (not the GOM mind you) goes to "_ _ _"
IOW, the 2 warning before Turtle were deemed ineffective by Nissan so they added another warning and yes the SOC meter does go to 1% before it goes to SEW (The most robust 1% ever is what I call it...)
Should be enough to scare anyone into pulling over, right? Well, we all know LEAF Spy allows us to ignore that as well
For more info...http://daveinolywa.blogspot.com/2018/08 ... in-40.html
This is only on of many entries about the dash but this does do a decent job of summarizing the comments made in several other blogs so the link is provided for the "quick and easy"
Finally;.... SEW comes on at 40 GIDs. This is just over 3 kwh, of which (on a good day) 2.5 kwh is usable so you can decide how far you can make it on the 2½ kwh or be conservative and only use the 2 kwh...