Speed efficiency

Veritas1980 7 years ago updated by vasvas 2 years ago 21

I was thinking it would be nice with a speed efficiency overview in the same way as with temperature. So within a certain interval we could what the average usage was:

100 - 110 km/h: 195 wh/km

110 - 120 km/h: 207 wh/km

Something like this.I would love to know how the energy usage against speed would look for my car.

Speed Efficiency is calculated based on the AVERAGE speed of the whole drive and not on the instant speed. A more usable statistic will be efficiency/instant speed. Probably done by comparing consecutive data points....

I've got the same problem as MrTemple here. My graph only goes up to 75kmph. I think that it says kmph but actually showing in mph


with data up to 110 km/h I am missing 40% of my trips data. Logged 11000 Km, but Speed Efficiency total is 6500 Km.

I notice that my data seems to show my battery use is most efficient when traveling at about 50kms/hr...   im wondeing if this is because when I travel at that speed Iam usually slowing down ...  I usually accelerate through 50-60km/hr range pretty quickly.. but when im slowing down I usually coast and spend more time in the 50-60km/hr speed range ?  Just a thought


Would love to see the option up to 110km/h  Rather than stopping at 80.


Great feature! Thanks for the amazing work.

One UI bug though... Everything in my TeslaFi is set to km, and the Speed Efficiency page shows km for everything, but the actual seed numeric values are presumably in mph.

I've definitely driven more than 37km at 80kph!

I'm  in doubt as well. I have the same feeling. Burt don't have enough kms drivent to be sure /

Great feature (thank you!) but the chart only shows speeds up to 110km/h. Is this correct?


How many kilometers/miles does a car has to record in each speed range to show data in this window? My account is new and my commute is very short so I have a few kilometers logged in it, but I recently had a 26 miles drive with an average speed of 28 mph and a top speed of 63 mph, in which I had a stretch of 5 miles driving at 58 MPH but my speed efficiency window only show data up to the 25 to 30 MPH range. Do I need to log more miles in those range for the data to show up? Thank you for this implementation.

I'm looking for the answer to this exact question .. did I miss something ? 


This can be found in Drives->Speed Efficiency.

Thank you so much!


We are starting to implement this new page at https://www.teslafi.com/speed.php.

It's only been through a few revisions so far but please let me know any thoughts.


Hi James,

Great work!

Two requests and a question :-)

1. (most important) please make it an option to show Wh/km instead of %efficiency

I really cannot relate to the efficiency number whereas Wh/km is the number I see in the car every day.

2. (would be cool) please add statistical data from other users for comparison (like in the battery beta graph)

Apart from being a cool feature, this could also make data at speeds that we normally do not travel by more statistically significant.

In my graph, I see that the efficiency drops significantly after 115 km/h which totally makes sense. but it seems like there are no data above 120-125 km/h which seems strange as the speed limit is 130 km/h on my primary highway - and even though I do not always run at that speed, I do it quite often. So - myy question is - could it be that the graph have been shifted on the x-axis? it could also support my feeling that the big punishment for speed comes after 120-125 km/h...


I'll look into 1, it shouldn't be a problem.  2 is something we'll add later, it's in the works throughout the site on graphs.

The data is coming from the average speed of the drive so it won't show individual minutes at a certain speed.  Unfortunately it's not really possible to pour through each drive and break it down minute by minute or mile by mile.  It would be a really slow report trying to process all of that data and the data wouldn't be accurate.  
Tesla doesn't provide any kWh data in the API so it has to be calculated based on the rated miles used.  The rated miles used only updates periodically and TeslaFi only obtains data 3-4 times a minute when driving.  It's accurate enough to calculate a whole drive but not tons and tons of individual segments of a drive.  Mostly because the odometer value updates on each data point but that rated miles used may only update once a minute.


This unfortunately makes it very misleading - at least for my drives.

Can we get this added please?

I'd like to have this as well. Would prove valuable when planning trips and charging stops. I did this recently with my own data that I downloaded. Used 742 drives over the last 6 months. The below grid shows wh/mi in 5 MPH increments and my estimated range at each speed. I drive a '17 MS 100D

I like to this this and the same data over time. I wonder if the Tesla get better efficiency or worse efficiency as the battery ages. 


Since temperature and weather (ex. rain) has a huge impact on range, I would suggest that the graph should be a heat map. 

one axis should be a selection between temperature and weather. The other the driving speed. The colow coding should indicate the efficiency with a mouse over-function that shows the actual wh/km and number of km driven in that condition.


totally true, we could decide the speed to use based on efficiency