Cold Weather Range Prediction Accuracy

[gad1976]

I’m new to Tesla with a 2023 MYLR. I’ve read a lot about cold weather and am familiar with the reduced range. Not concerned with that. Plenty of charging stations.

I am curious if the Tesla onboard computer is accurate when predicting cold weather range or if I need to mentally calculate a buffer in cold weather. I know the computer can’t predict every variable but I’m wondering if it tells me I can travel 275 miles on a 15 degree day if that prediction is relatively trustworthy or if I need to take the cold weather into account myself and build in a buffer?

I drive about 3,000 miles a month in Wisconsin.

Thanks for your thoughts.

 

[E90alex]

If you put your destination in the navigation it will account for weather and terrain and will be pretty accurate.

If you’re talking about the range number on the top of the screen, that number does NOT change with conditions or driving style and is not achievable in normal driving so it cannot be relied on as a judge of how car you can actually drive, no matter what season or conditions.

 

[gad1976]

Interesting. So the navigation computer does make allowance for weather but not the main displayed number? Thanks. This helps.

 

[E90alex]

Correct. The mileage number on the top of the screen is more or less useless and should not be relied on as a judge of how far you can drive. It’s recommended to leave it on % display instead.

Just be sure to use the navigation for long trips and go by what it says as to when and where you need to charge.

 

[jcanoe]

In colder temperatures the Tesla Model Y will lower the displayed % state of charge, especially overnight, by as much as 3% to compensate for the colder temperature. The displayed estimated range should also be lower by the same amount (3%.) If you drive the same route at the same time of day the variables would be weather (including wind, precipitation and temperature) and traffic.

You can use the Wh/mile readout under the Trip odometers: current trip, since last charge, Trip A and Trip B as a gauge of your winter driving efficiency. After several thousand miles your lifetime Wh/mi will be consistent. Your Wh/mi for the current trip or since last charge will be higher in winter. In WI probably 20% to 30% higher. LPT: Rename Trip B to Lifetime and don't reset this one.

The estimated range display by the battery indicator is not as accurate as the Energy Screen metrics. The range display does not factor your speed, only the posted speed limits. The Energy Screen, while driving along a route using the Navigation system will factor weather conditions (including temperature, wind and precipitation), traffic in metropolitan areas in addition to elevation changes for the route and your driving speed. In general you can trust the information displayed on the Energy Screen including the estimated remaining battery charge when you arrive at your destination or next charging stop.

LPT: If you are concerned about reaching a destination with the current battery charge start out driving at or below the posted speed limit for the first half of the trip leg. Let the glide slope displayed on the Energy Screen be your guide as to your energy consumption and range or need to stop for a quick charge. If the consumption and range look good at the halfway point then gradually increase your speed if you want.

Above 60 MPH you can improve your efficiency and range by almost 10% for every 5 miles per hour you lower your speed. 10 MPH slower nets almost 20% increase in efficiency and range. Slowing down is like having a built-in battery reserve.

The seat heaters and steering wheel use a small fraction of the energy used by the heat pump. If you are at the point on a trip where you have range anxiety even after lowering your speed cycle the climate control off and on (so the windshield, windows don't fog) and use the seat heater(s) and steering wheel heater to stay warm.

 

[gad1976]

Thanks so much. This is excellent info. Thanks for helping a newbie.

 

[jcanoe]

Thanks so much. This is excellent info. Thanks for helping a newbie.

If you have many charging locations available on your route (Supercharger or DC Fast Charger stations) there is no need to charge to 100% before starting out on a trip. Charge to no more than 90% before setting out; plan to stop every 2 to 3 hours to charge. Plan to arrive at the Supercharger with less than 30% state of charge and stop charging when the state of charge is at or below 80%. This ensures the fastest, most efficient Supercharger charging session. Properly preconditioned for Supercharging * a Supercharger charging session that takes the battery from below ~30% to 80% will take less than 30 minutes; closer to 20 minutes.

* Always enter the charging location as the next stop or destination in the Navigation system. The Tesla Model Y will automatically precondition for optimal Supercharging when you are some distance from the Supercharger (now DC Fast Charge stations too** ).

** To use a DC Fast Charge station such as Electrify America you need to set up an account. You would also need to purchase a Tesla CCS Combo 1 Charging Adatper (available from the Tesla.com online store, or one of the third-party CCS1 Tesla charging adapters sold on Amazon and other online sites. (Prices of these third-party CCS1 adapters have been falling, these are now available for under $100 if you shop around online. It was only a year ago that Tesla Model Y, Model 3 owners were paying hundreds of dollars more to purchase grey market CCS1 adapter from Tesla in S. Korea.)

 

[jcanoe]

A Better Route Planner (ABRP) is available for your phone and on the web. ABRP can help plan charging stops while traveling. You can set your ABRP profile including vehicle make & model, preferred highway driving speed, maximum driving speed, departure state of charge, charging stop state of charge and destination state of charge. You can set your charging preference so there are fewer but longer charging stops or more frequent but shorter charging stops while on a trip.

 

[gad1976]

In colder temperatures the Tesla Model Y will lower the displayed % state of charge, especially overnight, by as much as 3% to compensate for the colder temperature. The displayed estimated range should also be lower by the same amount (3%.) If you drive the same route at the same time of day the variables would be weather (including wind, precipitation and temperature) and traffic.

You can use the Wh/mile readout under the Trip odometers: current trip, since last charge, Trip A and Trip B as a gauge of your winter driving efficiency. After several thousand miles your lifetime Wh/mi will be consistent. Your Wh/mi for the current trip or since last charge will be higher in winter. In WI probably 20% to 30% higher. LPT: Rename Trip B to Lifetime and don't reset this one.

The estimated range display by the battery indicator is not as accurate as the Energy Screen metrics. The range display does not factor your speed, only the posted speed limits. The Energy Screen, while driving along a route using the Navigation system will factor weather conditions (including temperature, wind and precipitation), traffic in metropolitan areas in addition to elevation changes for the route and your driving speed. In general you can trust the information displayed on the Energy Screen including the estimated remaining battery charge when you arrive at your destination or next charging stop.

LPT: If you are concerned about reaching a destination with the current battery charge start out driving at or below the posted speed limit for the first half of the trip leg. Let the glide slope displayed on the Energy Screen be your guide as to your energy consumption and range or need to stop for a quick charge. If the consumption and range look good at the halfway point then gradually increase your speed if you want.

Above 60 MPH you can improve your efficiency and range by almost 10% for every 5 miles per hour you lower your speed. 10 MPH slower nets almost 20% increase in efficiency and range. Slowing down is like having a built-in battery reserve.

The seat heaters and steering wheel use a small fraction of the energy used by the heat pump. If you are at the point on a trip where you have range anxiety even after lowering your speed cycle the climate control off and on (so the windshield, windows don't fog) and use the seat heater(s) and steering wheel heater to stay warm.

A Better Route Planner (ABRP) is available for your phone and on the web. ABRP can help plan charging stops while traveling. You can set your ABRP profile including vehicle make & model, preferred highway driving speed, maximum driving speed, departure state of charge, charging stop state of charge and destination state of charge. You can set your charging preference so there are fewer but longer charging stops or more frequent but shorter charging stops while on a trip.

Just found this. It looks like a great app.

 

[BitJam]

I drive about 3,000 miles a month in Wisconsin.

you might want to consider the products from a Canadian company called EVinsulate. They can help you cut your wintertime range loss in half. As a bonus their double pane roof helps keep the cabin cooler in summer.

 

[SageBrush]

Interesting. So the navigation computer does make allowance for weather but not the main displayed number? Thanks. This helps.

That is correct, but the estimated range at the beginning does not account for road friction (bad roads, wet roads, snowy roads etc), or cabin heating. The important point here is the *in the beginning.* As you drive the car takes these environmental parameters into account as it accrues performance data.

So ignore the first couple minutes of driving. From about 15 minutes into the trip the estimator is very good

 

[gad1976]

That is correct, but the estimated range at the beginning does not account for road friction (bad roads, wet roads, snowy roads etc), or cabin heating. The important point here is the *in the beginning.* As you drive the car takes these environmental parameters into account as it accrues performance data.

So ignore the first couple minutes of driving. From about 15 minutes into the trip the estimator is very good

Just to clarify, are you saying the navigation computer takes about 15 minutes of driving before it’s predicted arrival numbers are accurate? Or are you saying that the displayed mileage in the top corner of the screen is accurate after about 15 miles of driving? Thanks!

 

[BitJam]

Just to clarify, are you saying the navigation computer takes about 15 minutes of driving before it’s predicted arrival numbers are accurate? Or are you saying that the displayed mileage in the top corner of the screen is accurate after about 15 miles of driving? Thanks!

The displayed mileage on the top corner of the screen is not accurate. I suggest you change it to percent and not worry about it again. The car learns about your driving habits from the actual amount of energy you use while driving. This lets it make more accurate predictions of your range. I don't know how quickly it can figure this out. Again, it's not something you need to worry about.

As you drive, you will learn more about the car and it will learn more about your driving habits. Don't try to cut the range close to zero in your first weeks of ownership.

Congrats on your new car!

 

[gad1976]

The displayed mileage on the top corner of the screen is not accurate. I suggest you change it to percent and not worry about it again. The car learns about your driving habits from the actual amount of energy you use while driving. This lets it make more accurate predictions of your range. I don't know how quickly it can figure this out. Again, it's not something you need to worry about.

As you drive, you will learn more about the car and it will learn more about your driving habits. Don't try to cut the range close to zero in your first weeks of ownership.

Congrats on your new car!

Thanks!

 

[BitJam]

Thanks!

Enjoy the car! If you're anything like me, you'll have a blast.

There is a learning curve, especially figuring out how to best use autopilot. But also with regen braking and the nuances of all the controls, such as how to engage the parking brake. There are funny/sad YouTube videos made by people who didn't know about the parking brake.

I love self driving but I approach AP (and FSD) as driver assist, not driver replacement. I tried to figure out how the car and I could combine for the best experience. People who play the game of "let's see just how well this car can drive itself" usually have a less positive experience. Yes, it does stupid things sometimes but it has made my driving SO much easier. It also saved the life of a young deer that ran in front of my car so I'm a big fan. I saw the deer too late to stop in time.

BTW I got a set of insulated sun shades for all the glass except the roof for well under $100 from eBay. I see this as cheap insurance in case I'm stuck somewhere and I need to rely on the car to keep me warm or cool. They're also handy for camping in the car if you're not an early riser.

 

[jcanoe]

The estimated range displayed next to the battery icon at the top of the Tesla screen can be switched to display % state of charge (SOC). Some prefer to display the estimated range while others prefer the % SOC. The estimated range displayed is on the main screen is based off of a Wh/mile value of less than 240 Wh/mile derived from data Tesla submitted to the EPA. This does not correspond to real world highway driving at 70 MPH+, only relates to driving a simulated course not exceeding 45 MPH while using no climate control. The percent SOC is independent of the EPA consumption data and your driving habits, provides information on the state of the battery.

The Tesla Model Y battery management system can adjust (decrease) the displayed % SOC to account for lower battery temperatures by up to -3%. The Navigation system factors in elevation changes, temperature, weather (wind and precipitation forecasts) when calculating arrival SOC once you select a destination.

The Energy Screen displays projected energy consumption versus your actual consumption along a planned route based on your speed and the other factors. The estimated range displayed on the Energy Screen is updated as your drive. The further you travel along the planned route the more accurate the estimate.

When traveling, unless you are very familiar with a particular route always stop to charge when the Tesla Model Y Navigation system indicates a charging stop at a Supercharger or other charging station.

In winter, short trips are inefficient because additional energy is used to warm the battery and the passenger cabin. Trips of under ~30 minutes duration benefit from preconditioning the Tesla Model Y before starting to drive. If the Tesla Model Y is plugged in while preconditioning then energy from the battery that is used to warm the battery and passenger cabin during preconditioning is replenished using grid power. You can initiate preconditioning manually using the Tesla app or set a weekday or all week schedule (for the same time) to precondition. You may find that in winter you only need to precondition for ~10 minutes before driving.

The Tesla Model Y will warm the battery as required but does not warm the battery as much as before to speed up preconditioning and to save energy. One of the reasons to precondition the Tesla Model Y's battery was, in the past, so that there would be some level of regenerative braking. You can now set the Tesla Model Y to blend the friction brakes automatically when regenerative braking is reduced or unavailable (as when the battery is cold). The Tesla Model Y will decelerate normally when blended friction braking is being applied so there is no need to spend time and energy to extensively warm the battery before driving as was previously performed. The Tesla Model Y will display a blue snowflake symbol when the battery is cold.

A Tesla Model Y with a cold battery (when a blue snowflake is being displayed) can be driven with no damage to the battery. Available power may be reduced if the battery is cold but this is usually not noticeable in normal driving. When the Tesla Model Y is actively warming the battery the Tesla Model Y will display 3 vertical curvy lines next to the battery icon to indicate resistive heating is being performed, perhaps for ~15 minutes.

If the Tesla Model Y determines that the battery is too cold to charge (battery temperature approaching or below 32F/0C) then the battery will be warmed before charging is initiated. Charging the battery generates some heat within the battery so additional battery warming may not be needed while the battery is charging. The battery can be warmed as needed even while charging or while Supercharging. This can extend the time needed to complete charging to the set battery charging limit.

Other than while preparing to charge, charging or while preconditioning the Tesla Model Y, to save energy, will not warm the battery when the Tesla Model Y is parked even when plugged in.

 

[SageBrush]

are you saying the navigation computer takes about 15 minutes of driving before it’s predicted arrival numbers are accurate?

Yes

 

[geraltofrivia]

Hi

My first post here. I just got the Model Y Per 23, one month ago. I was wondering a couple of things. Since now the temps are dropping in the New England area, how much of a battery loss percentage wise is expected? Especially when the temps are around 0 F.

Also what is a good way to minimize this, would preconditioning the car in the morning makes any difference?

Should the car be connected to the charger overnight in Cold weather?

If in any case these questions are already answered, please point me towards that.

 

[jjrandorin]

If in any case these questions are already answered, please point me towards that.

(moderator note)

Welcome to TMC,

I moved your new thread into one of the existing discussions on cold weather and battery. You can also search this TMC subforum (model Y) for "cold weather" and find several other discussion threads on this topic, if this one does not provide the discussion you are looking for.

 

[gad1976]

In answer to my questions a few months ago, I have found the computers prediction in Cold Weather to be quite good.