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Why my Wh/mi so bad?

And if you ever find yourself in a situation where there's a truck barreling at you and the only way out is with maximum acceleration, you're screwed. If you don't want the extra power 99.9% of the time you're driving, then fine -- just don't use it by never pressing the accelerator pedal past a certain point! I can accelerate as quickly or as slowly as I want in any mode just by modulating the amount of pressure I'm putting on the accelerator. Sometimes I can get < 200 Wh/mi if I am driving for maximum efficiency.
Yeah, I figured you'd try to use that as an excuse. In 35+ years of driving, I've never been in a situation where I could have avoided an accident with more acceleration. Have you? on the other hand, I do admit that I've made turns into traffic with my MY that I wouldn't with another car precisely because I know I have the acceleration. That's an entirely different situation, though. If I'm pulling out into traffic then I'm far better off being aware then trying to compensate for poor driving with a faster car.

Did you pay the extra $2000 for the acceleration boost? If not, why not? What if you find yourself in a situation in which a truck is barreling at you and the only way out is with maximum acceleration? $2000 is a small price to pay to save your life, wouldn't you agree?

Living in MN, chill mode is also nice in the winter time when the roads are slippery as it makes it easier to start without spinning the tires.
 
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And if you ever find yourself in a situation where there's a truck barreling at you and the only way out is with maximum acceleration, you're screwed. If you don't want the extra power 99.9% of the time you're driving, then fine -- just don't use it by never pressing the accelerator pedal past a certain point! I can accelerate as quickly or as slowly as I want in any mode just by modulating the amount of pressure I'm putting on the accelerator. Sometimes I can get < 200 Wh/mi if I am driving for maximum efficiency.
Agreed. My wife and I share the Y and we just keep it in standard acceleration. Neither of us are speed demons and have a lifetime average of 252 Wh/m after 18K miles, but it’s nice to immediately tap into the power when needed/desired. On occasion I’ve also averaged just under 200 Wh/m on a daily roundtrip commute:

FAE7418B-C837-4EE4-8C39-A26123AB754C.jpeg
 

thesmokingman

Active Member
Jun 21, 2021
3,954
12,028
Socal
There is zero reason to ever put these cars in chill mode. All it does is software limit the total power to the motors; you can do exactly the same thing by not pressing down on the accelerator pedal so much. Except when in chill mode, if you ever actually need the extra power to get out of a certain situation, you won't be able to do it, because it won't be possible to go into the configuration and change things back quickly enough. So it's all downsides and no upsides to putting the vehicle in that mode.
Read the thread man and the post you replied to.
 
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Yeah, I figured you'd try to use that as an excuse. In 35+ years of driving, I've never been in a situation where I could have avoided an accident with more acceleration. Have you?
I haven't, but one of my mom's friends was in a situation where she barely was able to power out of a situation she found herself in. And she ended up replacing her rather boring sedan with a high performance one after that incident. It might be rare, but it happens.
Did you pay the extra $2000 for the acceleration boost? If not, why not? What if you find yourself in a situation in which a truck is barreling at you and the only way out is with maximum acceleration? $2000 is a small price to pay to save your life, wouldn't you agree?
I'm surprised that you didn't ask me why I didn't pay the extra $10k (at the time I purchased) for the P model.
Living in MN, chill mode is also nice in the winter time when the roads are slippery as it makes it easier to start without spinning the tires.
True, but like anything, you get used to it, and learn to drive in standard mode if that's what you're using all the time.
 
This is interesting info and makes me wonder, since I just received my new Model Y Long Range, when should I consider my new car ‘broken in’ and expected to be as efficient as it is likely to become?
when you get used to the acceleration and stop having fun by flooring it! 😉

The tires and suspension will change a bit over the first thousand miles or so but there shouldn’t be much breaking into do. The bigger issue for you is going to be winter weather. Cold kills efficiency. It does so with ICE cars, too, but the effects are worse for an EV. My lifetime average is around 270 Wh/mi. In the summer I’m typically down around 250 but never below 300 during the winter. I drove up to our cabin in Northern Wisconsin yesterday - half the trip was going 70 on I35 and the other was going 60 on state highways. Average for the trip was about 340. In the summer I generally get 250 or so (better if I stay off of the interstate.)

Also, have you checked your tires since delivery? You can't always depend on the factory or service center to fully inflate them and I wouldn't be surprised if they are low.
 
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I'll add another suggestion that is completely unproven but I suspect may help a bit - get a screen for the panoramic sunroof.

Glass is a horrible insulator. Tesla has done all it can by using various laminates to block infrared radiation, etc, but in the end it's a single pane of glass. If you touch the glass in the summertime it's often too hot to touch. No matter what kind of laminates they have, that glass is radiating heat into the cabin that you need to get rid of. If you touch it in the winter time it's ice cold and is cooling off the air that you're spending watt-hours to heat up. Adding a sunscreen creates an air gap that will insulate and help prevent the heat loss/gain which will help efficiency.

That said, I have no hard data about exactly how much this will affect efficiency. Obviously it depends on the weather, how sunny it is, etc, and I can't exclude the possibility that the difference will be small compared to the other windows, but the surface area of the roof is quite large so I suspect it's non-trivial.
 

Pianewman

2021 MYLR VIN 88,XXX, Rd/Wh, 12/20 delivery
Supporting Member
Oct 28, 2020
2,640
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when you get used to the acceleration and stop having fun by flooring it! 😉

The tires and suspension will change a bit over the first thousand miles or so but there shouldn’t be much breaking into do. The bigger issue for you is going to be winter weather. Cold kills efficiency. It does so with ICE cars, too, but the effects are worse for an EV. My lifetime average is around 270 Wh/mi. In the summer I’m typically down around 250 but never below 300 during the winter. I drove up to our cabin in Northern Wisconsin yesterday - half the trip was going 70 on I35 and the other was going 60 on state highways. Average for the trip was about 340. In the summer I generally get 250 or so (better if I stay off of the interstate.)

Also, have you checked your tires since delivery? You can't always depend on the factory or service center to fully inflate them and I wouldn't be surprised if they are low.
I'm going to clarify the above highlighted statement:

Highway: For sure, once an ICE gets to fully operating temperature and stabilizes, it's efficiency won't be as dramatically affected by lower ambient temperature.

City: For a short commute (less than 10 miles), ICE efficiency is seriously reduced, as it struggles to get up to operating temps. With an ICE, occupants have the ILLUSION of a fully warm car because HVAC systems are much quicker to ramp interior temps up than 30 years ago. Oil temp still lags way behind.

My wife and I have a 3.5 mile commute. Her 2019 Avalon Hybrid (or our 2017 Prius) mileage drops from lower 40s to the mid-20s. My MY? changes from 300Wh/mi to 330Wh/mi.

As usual, YMMV!
 
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spokey

Active Member
Aug 8, 2020
1,327
804
Flagtown
I would lose about the same percentage. My lifetime is 261 wpm so I'm thinking summer is probably around 250. I pay more attention in the winter and although I don't meticulously track it, I believe I run about 300 wpm. The 2015 Outback (30.7 lifetime) was 32 summer and about 26 winter. So both run/ran about 20% loss.
 
when you get used to the acceleration and stop having fun by flooring it! 😉

The tires and suspension will change a bit over the first thousand miles or so but there shouldn’t be much breaking into do. The bigger issue for you is going to be winter weather. Cold kills efficiency. It does so with ICE cars, too, but the effects are worse for an EV. My lifetime average is around 270 Wh/mi. In the summer I’m typically down around 250 but never below 300 during the winter. I drove up to our cabin in Northern Wisconsin yesterday - half the trip was going 70 on I35 and the other was going 60 on state highways. Average for the trip was about 340. In the summer I generally get 250 or so (better if I stay off of the interstate.)

Also, have you checked your tires since delivery? You can't always depend on the factory or service center to fully inflate them and I wouldn't be surprised if they are low.
Thanks, Sleepydoc, I will check the tires tomorrow. Good idea!
 
I'll add another suggestion that is completely unproven but I suspect may help a bit - get a screen for the panoramic sunroof.

Glass is a horrible insulator. Tesla has done all it can by using various laminates to block infrared radiation, etc, but in the end it's a single pane of glass. If you touch the glass in the summertime it's often too hot to touch. No matter what kind of laminates they have, that glass is radiating heat into the cabin that you need to get rid of. If you touch it in the winter time it's ice cold and is cooling off the air that you're spending watt-hours to heat up. Adding a sunscreen creates an air gap that will insulate and help prevent the heat loss/gain which will help efficiency.

That said, I have no hard data about exactly how much this will affect efficiency. Obviously it depends on the weather, how sunny it is, etc, and I can't exclude the possibility that the difference will be small compared to the other windows, but the surface area of the roof is quite large so I suspect it's non-trivial.
Another great idea, I’ll look into this as well
 
I'll add another suggestion that is completely unproven but I suspect may help a bit - get a screen for the panoramic sunroof.

Glass is a horrible insulator. Tesla has done all it can by using various laminates to block infrared radiation, etc, but in the end it's a single pane of glass. If you touch the glass in the summertime it's often too hot to touch. No matter what kind of laminates they have, that glass is radiating heat into the cabin that you need to get rid of. If you touch it in the winter time it's ice cold and is cooling off the air that you're spending watt-hours to heat up. Adding a sunscreen creates an air gap that will insulate and help prevent the heat loss/gain which will help efficiency.

That said, I have no hard data about exactly how much this will affect efficiency. Obviously it depends on the weather, how sunny it is, etc, and I can't exclude the possibility that the difference will be small compared to the other windows, but the surface area of the roof is quite large so I suspect it's non-trivial.
One further question. The roof shades I’ve seen so far in online browsing appear to be mesh, intended to reduce summer heat in the Model Y. Do you have any experience with something that may be more insulating for winter cold?
 
One further question. The roof shades I’ve seen so far in online browsing appear to be mesh, intended to reduce summer heat in the Model Y. Do you have any experience with something that may be more insulating for winter cold?
They would still do so by the same mechanism - creating an air gap.

I drove up to our cabin over the weekend. It wasn’t terribly cold, about -10º C but the sunroof was definitely ice cold and I’m sure I lost a fair amount of heat through it.
 
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Pianewman

2021 MYLR VIN 88,XXX, Rd/Wh, 12/20 delivery
Supporting Member
Oct 28, 2020
2,640
2,368
Fort Worth

Excellent heat deflection, works well as an insulator. Ugly, for sure, but I don't spend much time contemplating my car's ceiling.
 

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