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by bdamm 1053 days ago
Right, and the one that is accurate is what you get when you put in a destination. The car can't tell you how far you can go if it doesn't know where you are going, because of all these factors (altitude gain, direction of wind, speed limits on the various roads involved, etc) which have a very significant effect on the range.

The idea of a single value for "range" is fundamentally flawed. Is it Tesla's fault that people don't understand basic physics?

5 comments

Every single other car ever made with a range estimation functionality uses past data to estimate your range. For like a decade Toyota had this on nearly every vehicle despite none of them having GPS integration, and nearly all of them were accurate enough to rely on.

You are bending over backwards to come up with an excuse for Tesla, when they quite clearly made a choice to either be lazy or misleading.

When my gasoline car says "You have 12 miles left", I KNOW I can drive 12 miles minimum, as long as it isn't at wide open throttle. The car has mountains of data at it's disposal, but in reality this technique has been used ever since a car could figure out how much gas was flowing into the injectors. The assumption is that how you have driven for the past ten minutes is a reliable indicator for how you will drive over the next ten minutes, and for most ten minute periods that is an accurate assumption.

Gas cars have had destination-less range estimates for decades, and as far as I know have never based it off of EPA fuel economy. Instead, they use the car’s own recent fuel economy.

Which concept more useful for drivers, the concept of remaining range if you keep driving the way you’ve been driving, or “how many miles the car can get in the EPA test cycle”?

> 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."

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.
Does your Tesla really account for the wind along your route?
Yes.
Wrong. There are leaks saying that the fraud-dumbass himself forced the developers to display the incorrect number because it looks better.