Trip Screen- Predicted Grey Line (not actual green line) Changed Mid-Trip. Why?

[evupnorth]

On the trip screen, I understand the actual green/yellow line changes throughout the trip, based on using more or less energy than the car estimated it would based on a wide variety of factors around weather, battery temp, etc. What puzzles me is a recent trip I took, where the initial estimated grey line changed. You can see in the first picture at the trip start, it estimates an arrival of 72%. In the second picture, you can see the grey line is now 68% or 69% based on being slightly below the green line of 69%. The trip was an hour long, mostly freeway, I didn't put the car into park or change my destination- what causes the original estimation (grey line) to change?

The only other factors I can think of mentioning is that my car was in the garage at 18 degrees F. When driving, the outside air was -13 F to -16 F. I understand how that could affect the range of the car, but wouldn't that change be reflected in the green line and not in the original prediction line.

Thank you in advance!

 

[bedoig]

Maybe a traffic based re-route or something occurred in the nav plan without you noticing?

 

[evupnorth]

Maybe a traffic based re-route or something occurred in the nav plan without you noticing?

Maybe. Traffic was very light and was 90% the same freeway, and there aren't really other roads that would get me there.

 

[Twiglett]

I've seen this most often when the map data has bad speed limit information so the estimates are thrown off.
Also the same bad map data has me driving off some odd, unneeded detour.
Lots of suspect map data around here

 

[planetary]

I miss the various energy charts and graphs.
- All 3/Y have them
- The old S/X have them
- But the new S/X -- nope!

Dammit, Tesla!

 

[conv90]

I have a similar problem lately not directly linked to yours but related to additional energy needed (AC- heated seats - cold climate ecc) that the navigation is not taking it into account.
I'm NOT able (even with very very efficient drive) to meet the prediction of the navigation simulation in the Energy Screen (trip tab).
Model 3 Performance 2021 :
An example today with the car already preheated by a long previous trip. With temp battery cell around 22-24°C and about 4-5°C outside temp with 20° manual temp selected in car and 1 single heated seat:
I needed to go home and selected "Home" . 33 km of FLAT road to destination and the navigation (Energy screen ) predicted with the grey line: from 38% to 34%. (!!)
WHAT??? only 4% to do 33km?? (4% for 20 miles) Damn ...impossible... expecially if (as already said) with AC on and relatively cold climate and heated seat and with a Model 3 Performance with 20 rims.
Looking at the Energy screen it was precisely 4,1 to 4,2 % needed to do 33 km. This is an efficiency of around 150%! !!
Probably a prediction for a Sr+ with 18" in the spring temp and Ac Off. ...not for a Perfomance with 20" rims and cold climate.
Accidentally I made the trip to home in a very conservative way and I ended with a fantastic average of 119 Wh/km (around 190 Wh/mi!!) but I also ended using about 5% to 5,5% , so the green graph line was always UNDER the grey line on the energy screen.
This is very strange because my old 2019 LR was able to do ALWAYS better than the prediction of the navigation...
Prediction to be at destination at 0% or only 1%??? no problem , I was with no doubt to skip a supercharger because i was sure that during the trip my final % would be way more than 1% and I never been wrong.

Whit this 2021 Performance car I'm afraid to not be able to be at destination if I follow the navigation prediction .