+19

# Explain consumption difference between TeslaFi's "Drive Details" and car's display

MarcMMueller 3 years ago updated by potato 2 years ago

Yesterday I made a 35 minutes drive to home. After that, my Tesla's display showed up 181 Wh/km. But TeslaFi's "Drive Details" gave me 241 Wh/km for this route. How this difference can be explained? I feel much better, when I'm able to beat 200 Wh/km (~322 Wh/mile) with my X90D ;-) Thanks (I'm new to TeslaFi)

I'm still curious as to why there is ever a difference between the the Wh/m from the car vs. TeslaFi. It seems to me that they should be the same. Could this be due to TeslaFi sampling the battery state (i.e. some dynamics) vs. the car measuring actual (current)*(voltage) consumption? If this is true, I would expect errors due to sampling by TF vs. integration of power by the car... not to mention energy efficiency when the battery is drained.

It also seems logical that energy storage in the battery is the best way to measure power consumed since it would reflect all power consumed by the car, losses, etc. If the car is only measuring power consumed by certain parts of the system (e.g. power train, climate control), a complete picture will not be obtained (any unmeasured subsystems, battery discharge inefficiencies, etc.).

+1

Actually yes, I received this response by email. Forgot to repost here, sorry:

The wh/mi is not provided by the Tesla API and has to be calculated. You can adjust this calculation if it appears to be off in settings->account->vehicle->kWh & Wh/m(km) Factor:. In this case you could try .777 (335/431).

Was there an answer given to anyone for this?

I just noticed this as well. Yesterday, TeslaFi reported a 128 mile round trip at 428 Wh/mi while my car's display showed 319. For the return trip, TeslaFi reported 431 Wh/mi versus 335 displayed by my car.

Same here. Does TeslaFi account for accessories that Tesla may not be?

I've been seeing TeslaFi reporting high as well.

+1

I would also like to see the usage as reported by the car in the log.