What is your Wh/mi? Do 20” wheels really make that big of an impact? My 2023 RWD only has 19” wheels but it has a smaller battery pack and the energy app estimates (pretty consistently) that I’d get between 290 and 320 miles of range if charged to 100%. I’m currently at 56% and energy app estimates I’ve got 178 miles or range.
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100% range on new Model Y LR with 3 miles on it calculates to 301 miles
- Thread starter CoolBuddy
- Start date
dont use the main display mileage/percentage
use the energy app to see whats going on vs what the LR is rated for wh/mile
my bro bought his MYLR and he came back to me and said, WTF
we looked in his energy app and saw 600wh/mile for his drives....hes a serious lead foot
I educated him on the energy app and now hes averaging the rated number of 280-300
There are a couple of things to know about bigger Tesla wheels. The bigger wheels are heavier, so take more energy to move. But the 21 inch wheels on the MYP are also larger in the back, and bigger (wider) tires also use more energy to move.
The reason to use % is it dissuades people from relying on the false precision of the mileage. Thats because the battery capacity is only estimated (based on voltage), and the consumption is variable.
Assuming those 2 things are perfectly known — eg “this car will cover 150 miles no matter what” — do you know the exact distances to the hotel then the game then the restaurant than the hotel anyway?
If you knew that distance to be 147 miles, would it have been useful to know the hypothetical range of 150 mi? No, because most people wouldnt rely on that single charge to do the full drive anyway.
So in the real world, you’d plug the first few far destinations in the computer. If computer tells you to charge, you charge. If computer tells you arrive with 10-30%, you’d probably plan to charge for remainder of destinations. If computer says you land at 40-50%, you know you have sufficient buffer for additional runs.
The point is that all the components in the equation have uncertainty (exact route, traffic, weather, driving style, vehicle load, etc), so having a range readout with single-mile precision isnt that useful
To be clear, I don't think going off percentage is really bad or anything. I think what most people end up doing is just fudging in a lot of safety margin to avoid doing too much math, so the rest of the discussion below is really just about those margins where one ends up needing to calculate.
Why wouldn't it be useful? Let's say I know there's a EPA rated range of 150 mi left in the battery, and we all know the EPA rated miles are optimistic. I like to have some built in fudge factor and safety buffer, so I'd probably want another 75 miles of range in the battery on top of that.
I suppose if you don't know that the number is a fixed conversion of kWh to EPA rated miles, then sure, percentage might prevent you from making a mistake. But for anyone that DOES know that, EPA rated miles have the advantage of making you do one less conversion in your head and also of staying the same as the battery loses capacity.
Why wouldn't it be useful? Let's say I know there's a EPA rated range of 150 mi left in the battery, and we all know the EPA rated miles are optimistic. I like to have some built in fudge factor and safety buffer, so I'd probably want another 75 miles of range in the battery on top of that.
That sounds like a false dichotomy ... sure, single precision miles isn't necessarily that useful, but miles is still the unit in which we have to think about in terms of distance to a place. All of the variable factors you mentioned are just multipliers on top of that number ... which is still at the end of the day, can I go X miles, not X percentage of my battery.
AlanSubie4Life
Efficiency Obsessed Member
Folks, use the energy screen method. Usually it is correct (except it provides a capped value above a certain amount, a good problem to have). There have been software errors before which caused it to be wrong. But exception rather than rule. My dad’s 2024 Model Y shows 79.5kWh or so, with about 304 miles at a full charge. This is incorrect (310 miles is correct), but energy is approximately correct.
I suspect at some point software will be updated to reflect the new EPA values but have not been tracking it closely. Maybe it will never happen and Tesla is going to change the way they do things - no idea.
What matters is total energy capacity, not how many miles your car displays.
Miles could be 30, or 1 million. It doesn’t really matter. Just different units.
There is tons of information around here on why this (available energy) matters and how to calculate it (or just use a CAN reader).
As usual, trust but verify. If the answers don’t make sense, change wheel selection and see whether the software is broken. Anything is possible and the method can break if the software is buggy.
I suspect at some point software will be updated to reflect the new EPA values but have not been tracking it closely. Maybe it will never happen and Tesla is going to change the way they do things - no idea.
What matters is total energy capacity, not how many miles your car displays.
Miles could be 30, or 1 million. It doesn’t really matter. Just different units.
There is tons of information around here on why this (available energy) matters and how to calculate it (or just use a CAN reader).
As usual, trust but verify. If the answers don’t make sense, change wheel selection and see whether the software is broken. Anything is possible and the method can break if the software is buggy.
For example, the method for this vehicle gives a rough (only 56%, could be more accurate) 69.6kWh, correct for the RWD.
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Prospective new MYLR owner here. Can someone confirm for me how many WALL kWh goes to putting in 100 battery kWh in real life?
I know what the manual says it should do and it sort of tallies with the other range and usage numbers I have seen but it's not a number I have seen mentioned.
I think I am sold on the "charge to 80% maintenance level" which would do me for a day without any anxiety and leave room for an unexpected trip to only need a charge to get home.
I know what the manual says it should do and it sort of tallies with the other range and usage numbers I have seen but it's not a number I have seen mentioned.
I think I am sold on the "charge to 80% maintenance level" which would do me for a day without any anxiety and leave room for an unexpected trip to only need a charge to get home.
AlanSubie4Life
Efficiency Obsessed Member
100kWh/0.885 = 113kWh
When using an 11.5kW, 48A/240V setup.
Assuming no preconditioning etc.
Use 0.75-0.8 or so if using 120V/12A
AlanSubie4Life
Efficiency Obsessed Member
0.885 comes from EPA testing.
You were asking specifically about adding 100kWh to the battery.
If you are speaking about how much energy is required to get 100kWh of useful work, then it's probably a bit lower (due to feature drain, sleep drain, preconditioning losses, etc.).
Meaning it could take 120kWh or 130kWh to get 100kWh of useful work. Depends on what features you use and how much driving you do, and how much time the car spends sitting.
In the past in cold climates people have estimated to multiply the meter in the car (which only counts energy use when not in park) by about 1.4 (reciprocal is 0.71). It could be as low as 1.25 or 1.3 (reciprocal is 0.77) for people who try not to use features and live in warmer climates.
Only for the purpose of making the reporting consistent and the maths easy. Since nobody has a 100kW battery I figured no explanation required.
AlanSubie4Life
Efficiency Obsessed Member
Oh I know that, what I was saying is that you were specifically asking about how much energy from the wall is required to add a given amount of energy to the battery.
That is the ~0.885 multiplier - it's possible that is actually for the 7.7kW charge level (not clear what Tesla charges with when they do the EPA test in their Fremont lab - maybe they use the Mobile Connector at 32A), but in any case 11.5kW is going to take it to something like 0.9 or 0.91 best case.
But anyway if you account for other losses rather than just the charging losses, those can of course add up.
But to the original questions, roughly divide the battery energy by 0.9 to get wall energy, or multiply the wall energy by 0.9.
This is well established because it's a critical part of the EPA test - these losses have to be measured to provide the MPGe numbers. And the pack capacity has to be measured to establish the range numbers.
The EPA test doesn't measure feature drain or standby drain in any meaningful way though - all it has to do is measure the loss overnight with the car asleep, but in many use cases there is a lot more drain than that on average. Hence the different multiplier.
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Wattsisname
MY Red/White/Gems
But they were the result of a parameter based standardised method of testing.
At the risk of a smack for stating the obvious, "real life" driving style, road/highway and climatic conditions to name a few metrics are so very variable.
After road trips, it's the Wh/mile that interests me as it was with ICE mpg. I try to ignore those other imponderables like idles/phantom drain, Sentry mode, dog mode.... did I miss anything,,,
I should maybe care more about the "tank" capacity than I do but I know I won't. We always stop every two hours or so ( getting on means less concern about pressing on) and a little bit of trip planning, which I enjoy, means there is always a SCharger at hand for a splash without the dash.
When not travelling, I follow the charging advice during periods of low mileage town driving for battery health sake and thereafter. " it is what it is".
Disclaimer. The above are the geriatric musings of one who will be chuffed to be driving Lizzie Y at the end of the battery guarantee period whatever the actual range.
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L2 and even occasional L3/DC chargers show me 85% charging efficiency.
This is based off what the car computer shows as kwh added vs what the charger meter bills for
AlanSubie4Life
Efficiency Obsessed Member
No. This is just what they start with at the moment.
You can discard whatever is telling you 4% capacity loss - it is nonsense.
Energy screen will show you about 79.5kWh so you are good to go.
I hooked up Tesla Spy the other day and it appears that Tesla started the BMS off with a 79.6 Nominal Full Pack. I understand the Energy buffer of 3.58 but this Nominal Full Pack is low for a car just off the line. This would also make since because of all the TeslaFi data showing all the 2024 Model Y's sitting either 283-285 20" or 300-303 19". Maybe Tesla has down a 2.5 ish kWh soft cap stop people from complaining about random degrade.
As of this morning with a 80% charge Tesla Spy is showing the below numbers:
Nominal Full Pack 79.6 kWh
Nominal remain 64.3 kWh (80%)
Energy buffer 3.58 kWh
Usable 60.7 kWh
Full pack when new 82.1 kWh.
As of this morning with a 80% charge Tesla Spy is showing the below numbers:
Nominal Full Pack 79.6 kWh
Nominal remain 64.3 kWh (80%)
Energy buffer 3.58 kWh
Usable 60.7 kWh
Full pack when new 82.1 kWh.
AlanSubie4Life
Efficiency Obsessed Member
When new they often move higher it seems.
That being said for some reason in EPA testing they got less out of it than prior years (79kWh vs 81-82kWh).
Current degradation threshold for 304 miles is about 79.5kWh.
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