Averaging 490Wh/mi what’s wrong?

Averaging 490Wh/mi what’s wrong?

I’ve had my long range AWD M3 for about 3 months now and just started paying attention to the Wh/mi since I only take short trips a few times a week. I only have about 800 miles on the car but something seems off with the Wh/mi range. I just took a short trip (15 mi) and the Wh/mi showed 512.

Has anyone else see anything like this? Could my battery pack be bad? I do have a heavy foot but this trip I was pretty cautious. I went to the average range energy consumption page and it shows 491Kw/mi.

I’ll call tesla service tomorrow but wanted to see if anyone has seen something like this before.


shawncordell | 16 december 2018

Do you have a clubbed foot?

Earl and Nagin ... | 16 december 2018

What is the outside temperature? What is the temperature where the car is parked? How fast are you driving?
All of these issues can affect it.

derotam | 16 december 2018

You have a heavy and cold foot!

Seriously... If the car is cold when you leave and you have the heat on, with short trips you will have issues getting the Wh/m down.

If heat seems the likely culprit, try warming up the cabin using the app a few minutes before you leave. That heating load doesnt get accounted for in the Wh/m and then when you get in the car it only has to maintain the set temperature.

ReD eXiLe ms us | 16 december 2018

Cold weather. Tires not broken in after only 800 miles. Is there ice and snow and rain and sleet and slush to deal with? Do you leave the car sitting for over half an hour unplugged with the heater on blast before leaving?

bluesmanmarlow | 16 december 2018

It’s about 45 degrees fahrenheit outside. Car is parked in a garage averaging about 40-50 degrees. This specific trip I wasn’t accelerating fast. It was all city driving so plenty of traffic (30mi/hr) and no highways.

My clubbed foot is on my non-accelerating foot.

derotam | 16 december 2018

RED, I hope you aren't implying that leaving the car sitting with the heat on is affecting the Wh/m metric. It affects range but as long as you are turning on the heat from the app, there is no Wh/m hit.

bluesmanmarlow | 16 december 2018

No rain, ice slush or anything like that. I’ll do another trip today and preheat the car. Maybe that was all it was. Just surprising heat can affect range that much. I know that was an issue with my Leaf but that car only got 40 miles per charge, max.

derotam | 16 december 2018

@blue, yeah it's most likely your heat use while driving. As I said, preheat your car from the app before you leave. I suspect you will see a difference then.

derotam | 16 december 2018

It's a ~4kw heater and if the cabin is cold the heater will be full on trying to heat the cabin during the short trip.

bluesmanmarlow | 16 december 2018

Thanks @derotam I’ll give that a try.

vishious911 | 16 december 2018

@ bluesmanmarlow Try turning off the heater/AC, no heated seats, switch to "chill" acceleration, and see what the Wh/mile is.
Also, hopefully your battery is warm enough and regen is fully available (no dots on the left screen where you have a line) for this test. One last thing: if you can find a flat area to drive on, even better.

I've personally been getting about 170 Wh/mi in these conditions when it's about 50 degrees out.

vishious911 | 16 december 2018

PS: I don't use chill acceleration anymore but I still get 170 in the above conditions when I'm driving around 60mph average (mix of highway and back roads). And I don't have a super heavy foot, just "spirited" driving to enjoy my car.

batmanasb | 16 december 2018

Tire pressure is another factor, keeping it close to 45 psi should give you the best efficiency.

tim.raymund | 16 december 2018

At almost 1100 miles driven over the last month, averaged 292 Wh/mi.

GotLithium | 16 december 2018

3K miles avg. 284 wh/m on a P3D. Many short trips will affect negatively your efficiency. As mentioned above, preheat cabin then use mostly seat warmers. Monitor tire pressure closer if temperatures are lower. Hope your numbers improve.

coleAK | 16 december 2018

Pre heating dosnt effect Wh/mi only if it is plugged In while you are pre heating. So far I’ve found the largest drain on efficiency is going up hill. And the difference gained going back down dosnt make up for it. I see 600-900+ Wh/mi going back up hill to where I live.

billtphotoman | 17 december 2018

@bluesmanmarlow I suspect the issue is probably cold combined with short trips. There is a big initial cost in energy usage to warm up the interior and that needs to be amortized over the total miles of your trip. So, on short trips you are spreading this over fewer miles which means more energy use per mile. I recently did a 220 mile trip on 45 degree weather in my RWD LR with 18 inch aeros and for the first 10 miles I was in 400+ Wh/Mi range but over the entire trip averaged 248 Wh/Mi into a stiff wind. If you are concerned you could try a longer trip at steady speeds and bring up the energy graph. You should see your energy usage stabilize after 30 miles or so. Otherwise just wait for warmer weather (60+)

sowa.greg | 17 december 2018

You're doing short trips in the city, that's the culprit. The most energy is going to be used to get the car moving from a stop, your cabin heating at the start of the trip is going to eat up a lot of electricity and you're not driving long distances which would give it time to average out to a lower "expense" per mile.

Once you've driven another 800 miles on the highway, I'd venture to guess you'll see your average Wh/mi go down.

Some tips to help:
1) Pre-condition the cabin before you leave (heat in the winter, cool in the summer) so that you're using "shore power" instead of the onboard battery for that task.

2) Use seat warmers and keep the cabin heater at a lower temp (heating the person, not the entire cabin's air is more efficient).

3) Drive a route that doesn't involve a lot of starts and stops (e.g. stop signs, traffic lights, stop-and-go traffic).

M3BlueGeorgia | 17 december 2018

Try the following:
1) Top-up the battery for 30 minutes before you leave. Cold and cool batteries impact power usage
2) A long-ish trip (50 - 80 miles)
3) Optimize the cabin heat settings in the cold: Switch off A/C, set fan to (say) 3, temp to 68F, use seat heaters
4) Always pre-heat the cabin while connected to external power.
5) Don't drive at 79+ mph
6) Make sure your tires are properly inflated (ex: 44 psi )

Vsanva | 17 december 2018

Averaging 320 with my first 500 miles. AWD

Thing is I’ve had long stretches of sub 230.... the car is capable of low output but it’s all about the conditions.

I live in Seattle , lots of hills and traffic I don’t see my overall average droppping much unless I want to hypermile.

Manjushr | 17 december 2018

40 miles per charge in Leaf - that's 27 kWh... 1.48 miles per kWh... which is what I got in my Leaf at 2 Fahrenheit. Sorry friend.... It's you.

derotam | 17 december 2018

coleAK, that is false, If the car is parked and off, then any heating initiated by the APP does NOT affect the Wh/mile even if not plugged in. It does affect battery capacity, but not any of the trip metrics.

coleAK | 17 december 2018

^^^ I see a big “spike” on my Wh/mi graph when I pre heat for 15-20 min before I leave work in the single digits (F). I just parked and my Wh/mi was 429 for the last 30 miles. I’ll check it again when I get back in the car. It’s currently 11 (F)

gmkellogg | 17 december 2018

Tips: Charge right before leaving, heat car before leaving, turn off Auto on the climate, chill mode. I'm still at 300wh/mi but better than what i was seeing.

meni | 17 december 2018

I was also shocked when my stupidly fun P3D averaged ~400 wh/mi after my first week.

But then again it was mostly short trips and one race through the Angeles National Forest (cold and uphill). And even though I live in LA I had the heat on most of the time in the city as it’s December.

Can’t get below 330 wh/mi on short trips either. But all this is to be expected. Longer trips on flat roads with low AC would get closer to EPA estimated range. For example I got 250 wh/mi recently on a mostly highway trip.

So yeah, YMMV.

rsingh05 | 17 december 2018

As others have said, it's the cabin heating.

First month of ownership, I was averaging well above 300. Short trips start with 700-800, with the average for a ten mile trip coming out to 350-400. I was thinking it was because of the 20" summer tires.

Then last week I turned cabin heat OFF and just seat heating on. The average for my commute dropped to ~240-260 right away.

So it's not you, its the cabin heating!

ICEMELT | 17 december 2018

@coleAK where does that graph show up OR is it just a figure of speech?

Wondering if there is a feature I have not explored yet.

nwfan | 18 december 2018

Mild temp's mid 40's in DFW TX. Heat off, seat heater lowest setting.
Averaging 197 wh/mi in my LR RWD 3.
In comparison, my Model S (100D) gets 315 wh/mi on same route and settings.

derotam | 18 december 2018

@coleAK, also you need to define "spike" at what level? Also, go to the 5 mile display and how long does the "spike" last? In any case, any preheating initiated by the app does not count for your running Wh/mile displays, any of them....unless maybe you turned the car on first then it may/will. I turned on my climate control from the app yesterday at noon and left it on till I left work at 3:45pm and while it didn't have to do much because of the 50 degrees and sunny outside, I saw ABSOLUTELY NO spike in energy usage in any display. I NEVER see any kind of spike and with my recent xmas shopping have been pre-heating my car about 10 minutes before I leave any stores. Just make sure that after you get in the car and step on the brake, that you start moving right away because if not, then the heat usage WILL start to count against you. | 18 december 2018

The Model 3 is very efficient. With no heater load while driving one should get 190 - 200 watt hours per mile over relatively flat terrain. Getting into motion requires adding kinetic energy which causes energy use to peak as you start off. This effect averages out over a mile or two. Every stop gets you some regenerated energy but every subsequent start requires more kinetic energy. Stop and go traffic adds to energy consumption. The heater adds about 133 watt hours per mile at 30 miles per hour.

Model S with no heater load should average about 25% or so more under the same conditions, mostly due to added weight. I average under 300 watt hours per mile driving around town with the heater off in a Model X 90D. I would expect the Model S 100D to do a little better than that.

coleAK | 18 december 2018

@SAC. The graph that is in the power usage app in the car. The “spike” is pretty much a line.

Also just to try it out I sat in the car under pre heat and just sitting there and it shows a very slight “white bar” power usage on the display. If you think about it though on the 5,10, 30 mile average it figures a remaining range based on power remaining. So if you are using power to pre heat is reduced the remaining range and there for increases the Wh/mi. Possibly I’m seeing it where others aren’t because I’m in Alaska and it is cold so the heater is working st higher draw for a longer time. Friday high was 2 F and deep unplowed snow on the roads. At times I was “plowing” with the nose. I got 810 Wh/mi for the 16 miles a drive around town.

derotam | 18 december 2018

@coleAK, well yes and no... You sitting in the car, presumably with having pressed the brake pedal makes the car "ON" and in a driving condition, this starts the energy graphs and Wh/mi meters, but they don't actually update until you have moved a certain amount of distance/time.

If pre-heating, don't sit in the car, you will mess up the experiment.

YES, in terms of estimated range left vs miles driven then pre-heating will reduce THAT Wh/mi BUT all the energy metrics in the vehicle don't count expended energy when the car is not in a "drive" mode/"ON".

I thought the same as you in the beginning, that the energy meters accounted for ALL power usage, but it doesn't.

Short drives with heat on are your enemy in terms of your Wh/mile metrics in the vehicle. Try driving your charged and warm car that same 16 miles with no HVAC on.

Your heat usage at your presumably low speeds is the culprit.

coleAK | 18 december 2018

For my geographic location I have the battery meter set to % and use the power app for my estimated range and Wh/mi. I’ve never complained about range or effeciency. Anything I get in the Tesla is better than the 12 mpg in my LX560 or 18 mpg in my E class. From my experience I don’t Think the heat is all that much draw. In the same single digit (F) temps with the heat set to 66 degrees AUTO. I’m at 450-600 wh/mi driving around town and ~320 Wh/mi if I go out of town on the flat’s running 55 mph.

derotam | 18 december 2018

Heater is ~4kW max draw as I said before. With single digit temps it will be drawing a lot more over time than if it were 30-40F outside, also if you don't have recirculate on because it has to heat that single digit air coming in.

It makes sense that your Wh/mi go down on the highway, you are moving faster so the heat used vs miles driven is lower...

Have we beat this enough, it's your HVAC usage.