I do not understand. Even your graphs show that it is impossible. I’m thoroughly confused unless you were driving 20 mph downhill for 25-30 miles.
If you have followed my other posts about these graphs it was explained in their proper context. My point was I've been collecting data, very observant with my Volt and I am insulted if someone calls out my observations as BS when I provided proof against their disbelief.
These graphs were for normal driving, such as level roads, more or less maintain constant speed, and then analyzed statistically for the patterns when using your Volt normally.
I was pushing limits of the Volt, beyond the confines of these graphs. In fact Ari Collins was able to do 122 miles on a charge driving less than 25 mph along an elliptical stadium for hours. I pushed it further on my first try by finding elevated charging stations and slide down from there and I have achieved 186 miles to a charge.
I then took up the challenge of beating the record in VoltStats for number of electrical miles driven in a day, and I have studied those graphs to aid me in the optimal speeds to use. I then have a fully charged Volt starting out at the highest elevation that I can find, and then driving level road at optimal speed to deplete the battery then slide downhill until battery is near fully charged and then drive level road again to deplete it and continue the process. I achieved nearly 200 miles to a charge. This is a record achievement run, not your normal use of the Volt, the same reason why Tesla drivers would crawl drive to establish the longest distance records with Tesla, or why would someone climb the peaks of the mountains...
So I used various hypermiling techniques. I've even calculated the expected recharge rates for regen from downhill elevation changes. Did some tricks with mountain mode and normal mode... In many of these instances between recharges, I achieved at least 90 miles to a full charge, going as high as 199 miles. That's when I noticed why the GOM for the EV Range seemed to max out at 86 miles. Normally, the EV Range in the GOM reflects your performance the previous charging cycles, and all my previous charging cycles were over 90 miles to a charge and yet, the display for the start of the next run never exceeded 86 miles for me, and that is why this post. So I'd be the first one to actually confirm this limit on the display if no one else can show me.