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Comment by paxys | Hacker News Reader

This is key, because not every mile driven is the same. If you see "Model Y has a range of 300 miles" and set out to drive 300 miles you are going to have a problem. The temperature, wind speed/direction, humidity, pressure, cloud cover, altitude, uphill/downhill driving, vehicle weight, battery quality, tire tread, AC use, average speed... all make a huge difference. The nav system does take these into account and gives you a much more realistic number.

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It's impressive how well these estimates work, given the outsized impact many of these factors can have. These things are more negligible in an ICE as the denominator of energy stored in a gasoline tank is 4-5 times more than an EV. I believe a typical EV has to make do with the equivalent of just 2-3 gallons of gasoline in energy on a full battery charge.

The energy density of the fuel isn't an apples-to-apples comparison. The chemical energy stored in gas is much harder to use. ICE cars typically get around 20-40% efficiency. Electric motors typically get 80-90%.

In some sense, they do that by moving the losses to before the battery/tank; so this isn't as big of a gain in terms of total energy usage. However, in terms of the effective capacity of the energy storage device, we don't really care about losses in refilling it.

Do we know it doesn't cheat?

We know the range estimates used to (?) be gamed[1], I don't see why this part wouldn't be, too.

[1] https://www.reuters.com/investigates/special-report/tesla-ba...

If I say I want to go to X destination the car says I will arrive with Y battery percent left.

This is accurate to me within about 5% of the battery, even driving at fast highways speeds and in cold weather.

If it was "cheating" I think I'd notice an issue when the car said I had 5% left but the real battery charge was empty.

It would hurt the brand to cheat the sat-nav based range, it would mean the car wouldn’t make it to a charger when it said it would. You’d have a lot of unhappy customers.

Think of the sat-nav range as closed-loop and the other testing based ranges as open-loop.

Claim: "The nav calculated estimations tend to be very accurate"

> Do we know it doesn't cheat?

Then the nav won't be accurate then would it? Also: https://www.linkedin.com/in/gregory-pannone-3a414610/

> I believe a typical EV has to make do with the equivalent of just 2-3 gallons of gasoline in energy on a full battery charge.

The 57.5 kWh battery in the base Model 3 has the same energy content as just ~1.18 US gallons (4.46 liters) of pure gasoline. Electric motors are a lot more efficient than combustion engines, though.

It's much more like the range on a small private plane. It might be rated for 500 miles on a tank, but that involves so many factors that you have to take into account, because there aren't gas stations in the sky.

Once you learn how to take the factors into account, you get a "feel" for what you can and cannot do.

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