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Comment by galangalalgol | Hacker News Reader

I had an uber driver that said his 3 had less than half the range when temperatures got over 100F (38C). I imagine that is just the increased load from the cooling system. My Y sounds like a combustion car the ac runs so loud the past couple months. I leave the display on battery percentage because the range counts down very quickly in this heat. But it doesn't when it is nice out. Cold decreases the range because the battery heater has to work hard.

My point is that it isn't as simple as an average due to the massive temperature sensitivity. It applies to ICE cars too, but it certainly isn't as noticeable as the engine allows a wider range of temperatures. Ironically the EV is proposed as something to battle climate change, but it is much more susceptible to it's effects.

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On a lot of ICE cars there's definitely a hit to running the AC.

https://www.fueleconomy.gov/feg/hotweather.shtml

Personally my ICE goes from ~22-23mpg to ~19 when it's like 100F outside. That's a 17% drop in mileage. My EV has had a bit of a hit but not nearly as much, <10%. I can even offset that a bit more by ensuring I plug in and precondition before I leave, meanwhile my ICE will always burn it's gas to cool down even if I had remote start.

Heating is usually "free" energy-wise though since the gas motor is just leaking massive amounts of heat all the time.

17% is about what you would expect when the temperature goes from 72F to 100F. Inlet temperature is also a major contributor to fuel efficiency. Hot air isn't as dense so the ECU will add more fuel and retard timing to compensate to help cool the cylinder and avoid pre-detonation.

It knows about how much power is in the battery and it can measure the distance, and power use so why not an estimate based on a windowed average of the last two - three days of actual distance/power?

It ought to quickly adapt to weather pattern changes quickly enough while not being too "jumpy".

My ICE car can display MPG and distance to empty it seems to do something like that instead of displaying some random preconfigured metric.

Everything coming out of the battery is a huge thing. In cold temperatures, the heating is just waste heat from the ICE. In EVs, you are using the battery to heat the interior and the battery performance is itself low from the cold, so you get a double whammy.

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