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I've been wondering the following:

The range displayed varies depending on one's driving history (expressed by the ECO bar) and the battery charge level, oh and the current AC/Heater setting.

Apart from the AC/Heater setting, and perhaps any other small loads on the system, can one say that the range is a function of only the SOC and ECO reading?

In other words, will the display always show the same range given the same SOC and ECO readings? Or are there other factors that influence range?
 

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It's more complicated.

In my experience, the range estimate doesn't appear to use the ECO meter at all (good thing, too!), but it does look at recent energy efficiency (miles/kWh). The two don't correlate. It seems to look at the time since the last reset of the "reset" odometer, but weighs more recent data higher than older data.

The effect of heat/AC setting is odd, but straight-forward: It uses only fan on or off, AC button on/off, and external temperature. It completely ignores what temperature you set the dial to, but instead assumes some fixed setting (whatever the engineer who developed it was comfortable at).

It also seems to use recent speed: drive side roads at low speed for a while and then go on the highway: Range estimate drops rapidly. Do the reverse, and you can go lots of miles with the remaining range not dropping at all, or increasing. This is independent of the energy efficiency effect: I have a stretch of highway that goes downhill for the first mile. The remaining range drops sharply while I get 5 miles/kWh.

It uses battery temperature to give you a more accurate (lower) estimate in the winter, even before you turn the fan on. And it keeps track of the estimated battery capacity.
 

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The ECO rating is a joke.

It simply likes you to drive at a consistent speed.

If you maintain a steady 60 MPH on the highway, you'll get 90%+ (I've gotten to 100%) ECO rating. Your range will stink driving a steady 60 MPH.

Conversely, driving in the city with lots of stops and starts, your ECO Rating will suffer, but you can get well into the 70s or even 80s in range.
 

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Conversely, driving in the city with lots of stops and starts, your ECO Rating will suffer, but you can get well into the 70s or even 80s in range.
Actually, I find the ECO rating only dings your for sudden stops, where you peg the recharge over the limit. But overall I agree: The ECO rating thing needs more tweaking to make it at all realistic. It may help standard car drivers get a better idea of how to change some of their habits to be more efficient (longer breaking/regen). But it misses just as many opportunities as it catches.
 

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It is very easy to reach 100% Eco rating by just maintaining a constant speed (any speed) on the highway for the majority of your battery's SOC.

I achieved it just yesterday going between 70mph and 75mph indicated.


What sucks is the estimated range is affected by the Eco rating and the Eco rating isnt very accurate as far as correctly calculating under all driving conditions (Stop-n-go traffic hurts the Eco rating most, when in fact it actually helps as long as you efficiently utilize the regen and drive with plenty of gap between you and the car in front of you to allow for adequate stopping/slowing via regen. Even when using this eco driving strategy the Eco rating doesn't seem to show any improvement. My mileage per charge (MPC) indicates an improvement, so I would gauge your actual range using traditional calculations and mileage logs. Even still, the SOC meter leaves much to be desired when trying to get an accurate SOC reading in order to track your milege. The Smart ED app does provide an exact number, but the apps reliability makes me feel like I should be questioning its accuracy as well. In either case, something is better than nothing.
 

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Actually, I find the ECO rating only dings your for sudden stops, where you peg the recharge over the limit. But overall I agree: The ECO rating thing needs more tweaking to make it at all realistic. It may help standard car drivers get a better idea of how to change some of their habits to be more efficient (longer breaking/regen). But it misses just as many opportunities as it catches.
Accelerating quickly seems to hurt it as well. It seems that anything over about 50% power dings you - sometimes quite a bit - too. And using the friction brakes, as you pointed out, does too.

The 50% thing can also mean maintaining speed up a steep hill, or not starting like a grandmother trying to hypermile. :) Sometimes it's easy to hit 50% even without a lead foot.

A constant 75 MPH isn't great at all for range, but you can get 100%, as the poster above pointed out. That's why I'm saying ECO is "okay" but really it's kind of crap as far as what it is actually measuring.
 
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