[jcranmer]

> The car can't tell you how far you can go if it doesn't know where you are going

But the car can use your recent driving experience to get a good estimate. After all, if you've spent the past 10 minutes driving at 70 mph into a strong headwind, there's a decent chance that your next hour will be spent doing that. (Although this does get amusing on I-68 where my range estimates are markedly different after cresting the hill versus bottoming out in the valleys).

Sure, it's not the best estimate possible. But it's trivial to implement "assume recent past", and it's a far better estimate than "synthetic estimate that relies on a weighted average of two very different driving conditions."

[bryanlarsen]

According to the article, that sounds like what they do. When the battery hits 50% they switch to estimating the range based on your driving on the top of the battery.