Any additional days over 100 degrees that we may have had this year over normal, only would extend the heat exposure by 1 day each. So, say there were 10 extra days over 100 degrees so far this year (I have no idea if this is even close to accurate), the decrease in range and the bar-loss that we are seeing may have been postponed by those 10 days (I'm guessing here). Not 3-4 years...
I do not find your reasoning persuasive.
Did you actually expect, that most Phoenix LEAFs would not lose a capacity bar, until "3-4 years" after delivery?
The additional capacity deterioration and/or BMS restriction on charge levels, caused by high temperatures, is overlaid on the underlying capacity deterioration every LEAF is experiencing, due to other factors.
For example. IF
the southwest high temperature anomaly over the last two "hot seasons" (AFAIK, winter temperatures are largely irrelevant) has caused each of the 37 LEAFs with reported loss of one or more bars, to each have lost one more bar on average, over that which would have occurred under "normal" temperatures
, and we had experienced those same "normal" temperatures, we might now have a list of only nine LEAFs with lost bars, only two of which would have lost two bars.
Most of the other 28 LEAF owners would probably be oblivious to their significant, but less-than-one-bar loss, of available capacity.
I would not be surprised if that rate of Leafs with bar disappearance by this time, under a dozen rather than several dozen, was about what Nissan was expecting.
And I also expect that Nissan is now trying to figure out the most cost-effective response to the unexpectedly large number of early bar losses, and to the hysteria that it has caused.