Energy screen drive versus consumption inconsistency

[KenC]

Don't know if this helps, but I drove 14.9miles and according to the Energy chart, I was just a touch over the EPA rating.

While on the Consumption screen, looking at last 15miles, I was just a touch under EPA rating. Taken seconds apart. So, they're close.

 

[AlanSubie4Life]

Don't know if this helps, but I drove 14.9miles and according to the Energy chart, I was just a touch over the EPA rating.
View attachment 890180

While on the Consumption screen, looking at last 15miles, I was just a touch under EPA rating. Taken seconds apart. So, they're close.
View attachment 890181

Yep; this is basically what I’ve seen too.

A big part of the confusion was the expectation that the rated line (250Wh/mi in your case, 227Wh/mi in OP’s case) would result in “parity.” Which of course it does not. You have to be 6-7% below it, as explained above; the well understood way this works.

In your case, you’re a touch over the EPA rating of 234Wh/mi on the Consumption screen. (250Wh/mi is the rated line, which converts to 0.955*(250Wh/mi -5Wh/mi))

All very well verified at this point and fortunately this is not something that Tesla has changed for a long time, which leads to stability and certainty…

There may be some residual mismatch due to rounding and the sporadic nature of data dumping, but I think it is small.

The trip meter still appears to be king, in spite of its lack of sig figs (available elsewhere now, fortunately - was not the case for a while).

 

[derotam]

I checked this out a bit more, and it works as expected:

0 for the No trip version (since last charge). Since it has no idea what to expect.

And the baseline expectation for a given weight and set of parameters for any other planned drive. If you don’t match those you’ll do better/worse on the uphills and (most likely) worse/better on the downhills. And the difference vs. that baseline will be displayed.

To get the expectation, subtract second column from the first. (Actual - Expected = Difference, So Actual - Difference = Expected)

——

For the “rated” mode, it does seem that there is a baseline expectation for climate consumption and accessory consumption which is partitioned in the rated result. I wonder how they arrived at this and whether it really reflects EPA test measurements of these contributors (they do measure it during test). And I wonder for different vehicles types whether the % partitioned to each use are different. (For my car it seems to be 8% for climate and ~6.7% for “everything else” category, see above.).

However I don’t think that would be the root cause of the original noted discrepancy here.

Makes sense in theory, but any deviations should really go under driving, or other and not elevation in my mind. Elevation is set, you can't change it...even if you do a navigation route, and then change routes it is going to(haven't verified this for the new drive screen) recalculate the estimates(like it did on the old trip graph).

It may just come down to which bucket you put the various excess/surplus energy usage. Maybe I think that Elevation bucket should be called something else for clarity...

 

[philly4]

Makes sense in theory, but any deviations should really go under driving, or other and not elevation in my mind. Elevation is set, you can't change it...even if you do a navigation route, and then change routes it is going to(haven't verified this for the new drive screen) recalculate the estimates(like it did on the old trip graph).

It may just come down to which bucket you put the various excess/surplus energy usage. Maybe I think that Elevation bucket should be called something else for clarity...

I think of elevation as a sub category for driving which is specifically broken out. If pertaining to "rated" elevation makes a lot of sense to me to show how extra energy going up a hill takes etc. For a "trip" it also can make sense. In therory it should always be 0 in this case, but that assumes the NAV has perfect digital elevation map data...which is does not. I have no idea how accurate Tesla can calculate this. How do they know if it's a headwind, weight in the car, or small evelation gain?...but ideally this number show's you how accurate the NAV elevation data map is vs. reality.

 

[AlanSubie4Life]

but ideally this number show's you how accurate the NAV elevation data map is vs. reality.

And also the weight of the car.

I am curious how they figure out why they get more or less energy usage on an uphill and distinguish that from other vehicle characteristics, though. I guess it wouldn't be that bad, but something like going up a hill where the surface gets wet as you get higher would be pretty tricky to figure out. I guess it's the only thing that would get better on downhills so that should make it possible to figure out. But still a bit tricky to separate contributors and I wonder how they do it, and how well.