jmueller065 wrote: ↑Thu Aug 15, 2019 9:26 amActually the owner's manual doesn't really do a very good job of describing all the dash gauges.
The range to empty value of the FFE (commonly called the "Guess-O-Meter") is a calculated average of your driving habits and electricity consumption heavily weighted to your most recent driving. As such the value you see will markedly change: go on the freeway and the value will appear to drop much faster than your moving; drive down a 25mph speed limit street and the range will appear to increase. Turn on the heater and you'll immediately lose 10+ miles. (The A/C is MUCH more efficient than the heater.)
The status value is calculated two different ways depending on weather or not you are using the navigation system:
When not using navigation: At a full charge the FFE will store the range to empty and decrease this value linearly as you drive. The status value displayed is the difference between this calculated value and the current range.
As an example: At a full charge the car shows 70 miles range. Drive for 10 miles on the highway. Now the range displayed is 55 miles (but the internal stored value is 70-10 or 60) the status display will show -5 (55-60). It is a way for the car to "gamify" your driving: If you always have a >=0 value for status you will be driving efficiently.
When you use navigation (e.g. put in a destination and let the car guide you there) the status value will be the difference between the distance to your endpoint and the range display (e.g. if you program in something that is 40 miles away and your range to empty is showing 64 miles the status will be 24). I loved this feature: If I was going somewhere that was on the hairy edge of the range I could program it into the nav and use the status value to determine how fast (or slow) I had to go to make it.
For an accurate measurement you do have to use the heater to run it all the way down from 100% to 0% (per jmueller's instructions). If you drive the car for part of the test you'll end up with a lower-than-actual measurement, because regen braking energy that goes back into the battery while driving gets deducted from the trip meter's measurement of kWh consumed.