So, here's my take on this. Change your display from range to % and stop worrying about it.
The actual range of my car varies on a day-to-day basis - what's the temperature? Humidity (air density)? Wind direction and speed? Road surface conditions? Tire pressure and wear? You get the idea - there are a lot of factors that affect range. There are days that a 90% charge will get me 150km, like last week in -40* temperatures. There are days when I'd get 440km+, heading downhill with a tailwind. Which of those is my car's range?
Personally I only show percentage, and then I look at how far I drove on the last 10% of my battery and extrapolate that for what my range that day will be. So if I'm in cold weather, stop-and-go traffic, with the heat on and with a cold battery I know I'm not going to get very far compared to if I'm driving in the summer on a moderate day with no AC and no wind on the highway.
I don't know where Youngstown is, but where I live no two days are the same (unlike what I imagine living in southern California to be like), so the error in measurement from the environmental variables washes out whatever the actual degradation effects are. I know my battery will degrade over time and has degraded, but I also know that the impact of degradation is a pittance compared to the impact of other factors that the car experiences every time I drive.
For the record, I believe my car had an original range of around 460 km and the last time I charged to 100% the car figured it could go 440 km. The 440 km is pretty consistent with what I see using my 10% method in near-ideal driving conditions in the summer, and in the winter I know that number will be closer to 330 km unless it's really cold or the roads are really bad. How often do I have to drive that far in a single day without a stop to charge? Pretty much never, so it's usually a moot point either way.
The idea of a single, specific, fixed range that the car has is, to me, not logical. And no different than an ICE vehicle. It's a moving target that depends on that day's circumstances, and unless the car was reporting vastly different numbers under similar conditions I personally don't think about it twice. But I definitely seem to be in the minority on this forum...
