[zroger73]

Does your Tesla lie? No.

Do people misunderstand the information the vehicle is giving them? Yes.

The kWh and Wh/mi shown in the vehicle represent the amount of energy used by the vehicle while it was being driven. It does not reflect energy that is used by the climate control, electronics, pumps, and fans used for Camp/Dog/Keep/Sentry Modes while the vehicle is parked.

Also, it does not account for the losses associated with converting 120/240 VAC to 400 VDC by the PCS to charge the battery or power the vehicle.

The energy indication in the vehicle accurately displays how much energy the vehicle used while driving.

The energy indication in the mobile app shows you how much energy went into the battery while charging.

The energy used by the vehicle while plugged in is not shown in the mobile app for the Mobile Connector. It is for the Wall Connector, but even that number doesn't (and can't) account for losses between your electricity meter and your Wall Connector.

 

[zroger73]

To give a current example:

At 38,220 miles, my car shows a Total Energy of 10,243 kWh or 268.0 Wh/mi.

The mobile app shows a Total Charged of 2,066 kWh for 2025, 6,070 kWh for 2024, and 3,827 kWh for 2023, which is a total of 11,963 kWh or 313.0 Wh/mi. This number will be higher because unlike the Total Energy shown in the car, the Total Charged shows how much energy went into the battery to replace what was used while the vehicle was parked along with efficiency losses that occur during the AC to DC conversion for charging the battery.

I don't have complete statistics on the actual total amount of energy used by my vehicle because I charge from a variety of sources including Mobile Connector, Wall Connector, other L2 charging stations, Superchargers, and other DC fast chargers.

On some days, I have charged exclusively at home using a Wall Connector, so I have accurate data that can be used to extrapolate.

Date
Total Charged (mobile app) / Charge History (Wall Connector)

3/4/25
11 kWh / 12.3 kWh

2/13/25
13 kWh / 15 kWh

1/21/25
27 kWh / 29.7 kWh

1/8/25
29 kWh / 30.3 kWh

1/6/25
38 kWh / 39.8 kWh

10/10/24
27 kWh / 28.3 kWh

9/14/24
25 kWh / 26.2 kWh

8/30/24
37 kWh / 39.2 kWh

8/27/24
34 kWh / 39 kWh

8/24/24
26 kWh / 27.2 kWh

8/6/24
12 kWh / 13 kWh

8/5/24
10 kWh / 10.3 kWh

8/4/24
6 kWh / 6.8 kWh

7/19/24
16 kWh / 17.1 kWh

7/18/24
8 kWh / 8.8 kWh

7/9/24
0 kWh / 0.2 kWh

6/29/24
51 kWh / 54.2 kWh

6/26/24
14 kWh / 14.7 kWh

5/30/24
25 kWh / 27 kWh

The mobile app rounds down, so 8 kWh, for example, could be anywhere from 8.0 to 8.9 kWh. I accounted for this error by adding 0.5 kWh to the Total Charged displayed in the mobile app for each charging session for my calculation below.

TOTAL
418.5 kWh / 439.1 kWh = 4.9% more energy was delivered to the vehicle than went into the battery

This represents charging losses and the energy used by the vehicle during charging.

So, I end up with three different numbers, which are all accurate for what they are measuring.

10,243 kWh (268 Wh/mi) shown in the vehicle (used by the vehicle while it was being driven)
11,963 kWh (313 Wh/mi) shown in the mobile app (energy that went into the battery during charging)
12,549 kWh (328 Wh/mi) delivered to the vehicle (energy that was delivered to the vehicle before conversion losses and overhead)

That last number still doesn't account for losses between the metering point, which determines how much energy you actually pay for, and the charging equipment, but those losses are generally small unless there is a large distance between your meter and the charging equipment and/or undersized wiring.

Let's assume a 1% loss, so the amount of energy I would have paid for would be 12,674 kWh (332 Wh/mi).

In this example, the amount of electricity that was purchased would be 23.7% more than what the vehicle indicates was used while it was being driven. This 23.7% accounts for all charging losses, overhead, and other uses while the vehicle was parked.

This number for me will be higher than most users because my use and charging habits include extensive use of Camp Mode where the climate control is running while the vehicle is charging. Because I am a tightwad, I regularly take advantage of free-to-me public charging so I spend a lot of time sitting in my vehicle. To pass the time, I'll often play games, watch a TV show, take a nap, and/or get some work done using my laptop and $25 unlimited mobile hotspot. Most people will plug in at home and exit the vehicle or spend only minutes at a Supercharger instead of hours at an L2 charging station.

To conclude and restate, the vehicle is not lying about its energy use, but you have to understand what it is telling you.

 

[zroger73]

I understand your answer, but it doesn't absolve my car from lying. A gasoline-powered vehicle will show miles per gallon which includes idling and other information. The true efficiency MUST include any losses while the vehicle sits, or it is useless information.

Your vehicle is not lying. You appear to not understand the information it is presenting to you.

A gasoline-powered vehicle's trip computer:

• Does not account for fuel leaks, fuel evaporation, or fuel theft. It only accounts for the amount of fuel used using pulse counts from a flow sensor or injector on-time and an assumed injector flow rate.​
• Typically overstates the actual fuel economy.​

The trip computer on the 2021 Ridgeline that my 2023 Model Y replaced indicated 5.3% higher over 30,575 miles than the actual fuel economy.
The trip computer on the 2019 Ridgeline that I owned before that indicated 7% higher over 16,979 miles than the actual fuel economy.

On the other extreme, I had a 2020 CX-5 that indicated 1.1% lower over 11,403 miles than the actual fuel economy.

The most accurate trip computer in a vehicle I have owned was in a 2018 Accord that indicated 0.6% higher than actual.

Your assumption that there is loss in the wall connector is not true. The amperage and voltage figures which I use in my calculations are what the car is actually receiving as shown on the car's screen.

The amperage and voltage shown on the car's screen only show you how much power is going into the PCS (approximately, because the vehicle indicates these readings using whole numbers, so your calculations can be off by more than 0.2 kW. It does not show you separate indications for:

• AC-DC conversion losses
• Power going to the battery
• Power going to the heat pump compressor
• Power going to the DC-DC converter used to charge the LV battery and operate coolant pumps, fans, computers, etc.
• Losses upstream of the vehicle, although you can estimate this*

*To estimate losses upstream of the vehicle through the EVSE and circuit back to your metering point, you can calculate that using the voltage drop.

For example, if the vehicle indicates 240 volts at 0 amps and 230 volts at 48 amps, this is a loss of 480 watts. Over two hours, for example, the vehicle will receive 22.08 kWh, but you pay for 23.04 kWh. The other 0.96 kWh is lost as heat in wiring and through devices like your EVSE and circuit breaker.

 

[zroger73]

Has anyone else noticed an uptick in daily new forum members joining and immediately posting over the top or controversial open ended questions?

For example
vision impaired child has had FSD revoked for a week?
Is your tesla lying to you?
Targeted for speeding?

You forgot the one about the shrimp farmer who purchased a Cybertruck that was ran off the road by a Dodge.

https://www.teslaownersonline.com/threads/dodge-driver-caused-a-rollover.35241/#replies

 

[zroger73]

The trip computer is lying, plain and simple.

No it isn't - you just don't understand the information the vehicle is presenting to you. We've been through this already. Extensively.

 

[zroger73]

My issue is that the car "knows" how much power has been delivered to the car, and chooses to ignore the internal loss of the charging process when stating the energy use per mile. I think that the power which the car receives, not the power which is stored in the battery is a better gauge of the car's total efficiency.

Which EVs indicate usage based on energy delivered rather than energy used?

A quick search reveals that the next two most popular brands of EVs behind Tesla including Ford and Hyundai report energy used by the vehicle - not energy delivered to the vehicle.

 

[zroger73]

The estimated range provided by my 2019 M3 has been getting worse over the six yard of driving it. In that time the standard range batteries have degraded from a maximum of 220 miles to 202 miles over 57,357 miles. I did not expect the degradation of the range to be so quick.

It looks like your battery retention is tracking exactly where Tesla reported.

My 2023 Model Y has 10.6% degradation at 2 years and 40K miles - still with the standard deviation. For the first 30K or so, I kept the state of charge within a 15% band around 50% for daily driving and only charged to 80% just before longer trips in an attempt to minimize degradation. It didn't help, so I now just charge to 80% every day like Tesla suggests.

 

[zroger73]

Yes, it was to rebalance the BMS. So presumably the remaining range the batteries have will be more accurate. I only did the 100% charge after five years of driving the car, so the overall benefit may be small. I will probably charge to 100% one time per year to see if that helps. Making things a bit more complex is my consideration of trading the M3 in on the purchase of a Hyundai Ioniq 5 or a KIA EV6, if I can find either one on sale.

The first time I charged to 100% was when a saw a huge drop in indicated range. Until then, I thought I was somehow exempt from reality. I've since charged to 100% a few more times before long trips and the "lost" range never returned.

It is my understanding that cell balancing occurs without the need to charge to 100%. Charging to 100% can change the indicated range (usually lower, but sometimes higher). The most accurate way to evaluate the battery's health and calibrate the range indication (which, of course, is still "EPA" range and not real range) is to run a battery health test that discharges then fully recharges the battery. This can now be done from the Service menu without the need to enter Service Mode.