Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Staying comfortable in Extreme Cold

This site may earn commission on affiliate links.
Even at a balmy 25F I have cold legs too with interior set at 78. In the summer 75 feels comfortable.

I have also noticed that when charging I need to back the temp down to 75 or 76. I have searched for a draft (leak) while driving but so far nothing is evident. Biggest complaint of the car for me.

Thanks for the sunshade tip. Thought I would never take it out of its bag as it does not seem to be required in the summer.
 
Feet and windshield during my night drives, the day drive was feet only 1/2 the time and feet and windshield the other half. Oddly enough we found our legs were actually colder when we selected feet and dash wrongly assuming this would make our bodies the most comfortable.

The reason I ask is because this year (2nd winter with the car) I have been driving mainly in "feet mode", and find it much more comfortable. It still directs enough air to the windshield (30% of airflow, according to the manual) to keep it clear without trouble, although sometimes a little bit of dash vent is needed to clear up the driver's window. I also keep 3 of the 4 dash vents closed so when I do change the setting, all (or at least more of) the dash air is going where I need it (driver's window vent). I usually have the temp at 20C (not sure what that is in F, 70-ish?), and often find the car too warm with my jacket on although usually head too warm, feet less so. Fan on manual, non-recirc, A/C off, usually fan speed between 3 and 5 depending on outdoor temperature and vehicle speed. I have a completely unfounded theory that leaving a slower fan speed means the car is constantly providing some heat in trying to get the interior temp to the set point, vs high fan speed where it will cycle between warm and cool air once it hits the setpoint. It may just be that because I believe it to be so, I percieve it to be so and I am warming myself by the placebo effect, but passengers don't complain and they have no idea about my secret theory, so maybe there's some truth there.

Granted, S is probably different from X, and I have the solid roof instead of pano so the lesser amount of glass up top is probably helping me out too.
 
Understood that there is no waste heat. However, it's a thermostat. I want the temperature to be x degrees. Do what you need to do to make that happen
For an EV to keep the cabin toasty warm at -20F requires a lot of battery power. Yes, Teslas have a relatively big battery, but it is not an infinite source of energy. It has limitations.
I think it is likely Tesla never did extreme cold testing on this body
Tesla has sold thousands of Model S in Norway, where it gets as cold or colder than Montana. The Norwegians appear to find the car's heating performance acceptable, though when I watch Bjorn's videos shot during the winter he is wearing a lot of clothes and he has added insulation to the underside of his sunroof.
 
And now I know you are telling it to us straight, because you and I share musical preferences.
IMG_0128.jpg
 
I was thinking about this earlier today and had to wonder... Would the BioHazard mode have any effect on keeping the car warmer? If it pressurizes the cabin etc shouldn't that protect from cool outside air leaking in and in turn would allow the cabin heat to stay inside better?
 
  • Helpful
Reactions: vandacca
The reason I ask is because this year (2nd winter with the car) I have been driving mainly in "feet mode", and find it much more comfortable. It still directs enough air to the windshield (30% of airflow, according to the manual) to keep it clear without trouble, although sometimes a little bit of dash vent is needed to clear up the driver's window. I also keep 3 of the 4 dash vents closed so when I do change the setting, all (or at least more of) the dash air is going where I need it (driver's window vent). I usually have the temp at 20C (not sure what that is in F, 70-ish?), and often find the car too warm with my jacket on although usually head too warm, feet less so. Fan on manual, non-recirc, A/C off, usually fan speed between 3 and 5 depending on outdoor temperature and vehicle speed. I have a completely unfounded theory that leaving a slower fan speed means the car is constantly providing some heat in trying to get the interior temp to the set point, vs high fan speed where it will cycle between warm and cool air once it hits the setpoint. It may just be that because I believe it to be so, I percieve it to be so and I am warming myself by the placebo effect, but passengers don't complain and they have no idea about my secret theory, so maybe there's some truth there.

Granted, S is probably different from X, and I have the solid roof instead of pano so the lesser amount of glass up top is probably helping me out too.
I do exactly the same thing! Second winter, solid roof as well. I have added a small cardboard deflector (only about 1/2 inch deep) for the driver foot heat to direct some hot air more to the inside foot. Have not taken a FLIR shot of the difference but I've been comfortable for the last few cold snaps. Without deflecting the hot foot air most ends up on the outside foot.
DriverHotAirFlow.jpg
 
  • Like
  • Informative
Reactions: Ulmo and TLej
I was thinking about this earlier today and had to wonder... Would the BioHazard mode have any effect on keeping the car warmer? If it pressurizes the cabin etc shouldn't that protect from cool outside air leaking in and in turn would allow the cabin heat to stay inside better?

If Bioweapon Defense mode is a recirculating mode (seems like it should be at least partially recirc, but I don't really know) then your windows will fog up when it's very cold outside. I should try it in the morning: it's supposed to reach -10° F. here overnight.
 
If Bioweapon Defense mode is a recirculating mode (seems like it should be at least partially recirc, but I don't really know) then your windows will fog up when it's very cold outside. I should try it in the morning: it's supposed to reach -10° F. here overnight.

My understanding from reading too much along with too many X videos is it doesn't actually recalculate the air. Supposedly it draws air in through the filters with enough air pressure to make positive pressure in the car so that the only air that can come in is via the filter (and I'm guessing through the heater) and not through any gaps or seals but I'll be curious to hear if it has any effect :)
 
My under-informed guess is that in order to create the interior overpressure that makes Bioweapon Defense mode work (the excess pressure in the cabin means that all the little cracks and leaky seals vent interior air to the outside, so that the only outside air reaching the cabin has to pass through the HEPA filter), they must close the cabin exhaust valve, same as when selecting Recirculation mode.
 
Thank you for the detailed response. It is very informative. Along those lines, trying to tease out causes and effects: were any of these other ICE vehicles you have driven in this -20degF weather (God that must be cold) 100% Aluminum? I believe aluminum is the second best metallic conductor of heat, surpassed only by copper. So, its fundamentally problematic . Audi A8, newest Ford F150? What else is all aluminum? Isn't there a Jag too?

The aluminum vs steel won't make a significant difference. Steel sheet metal on a modern car is around 20 gauge, maybe even thinner. Thats 0.0375" thick. Its not going to provide any significant insulation regardless of what material its made from.
 
Tire Pressure:

This needs to be checked carefully before any winter voyage. I set them 4 lbs over recommended pressure especially in winter using 'full-tread' Blizzak/X-Ice tires.


Heated suits, shoes & gloves:

Get the entire outfit at your Motor Cycle supplier. Then you only have to run the defroster at its minimum to keep windshield clear. View these 12 volt outfits as survival gear in addition to the blankets & rain gear you already have stowed in the Tesla.
--
 
Last edited:
Tlej, good tip on closing vents and just directing one to driver's window, it definitely fogs over pretty quickly since the windshield vents pointed at it aren't adequate.

Ecarfan, you further iterate my point, Bjorn is dressed like he's going skiing and has added insulation to his roof.

Wycolo, as I have stated, I don't feel I should have to dress like I'm going snowmobiling to drive my $120,000 car.

To those wondering about bioweapon mode, I will try it next time I go for a drive, our ridiculously cold weather is over, but it's still cold enough to see if it will cause "insta-fog".
 
  • Like
Reactions: TLej
Got my MS 90D two weeks ago and got the winter surprise as well:
SuperCharge is slow, insufficient heating inside, 20 miles regular drive consumes 40+ miles rated range...
I don't mind the slow charging, 600+whpm, etc. I do think Tesla should make the heater a bit more powerful!
 
Feet and windshield during my night drives, the day drive was feet only 1/2 the time and feet and windshield the other half. Oddly enough we found our legs were actually colder when we selected feet and dash wrongly assuming this would make our bodies the most comfortable.
I'm thinking of getting some BlueTooth controlled heated insoles for long road trips. lol
 
Got my MS 90D two weeks ago and got the winter surprise as well:
SuperCharge is slow, insufficient heating inside, 20 miles regular drive consumes 40+ miles rated range...
I don't mind the slow charging, 600+whpm, etc. I do think Tesla should make the heater a bit more powerful!

I agree as well, at this price level of automobile, we have the right to expect better performance. In my personal opinion, the Sub Zero package (that means BELOW ZERO, Tesla ;) ) should include additional insulation in all of the doors, the fender wells, the floor, the roof and the "firewall" That extra insulation probably wouldn't add more than 100 lbs, if that. I'd happily take a couple miles of range hit in the summer for the extra comfort and added range in the winter due to the extra weight. I also feel the size of the heater should be increased in that package. I don't understand why they don't use an A/C compressor that you can run in reverse as a heat pump, MUCH more efficient then a resistive heater. I have one on the roof of my RV, so I know small packaging is possible. I realize they lose efficiency below 15 degrees or so and stop working altogether below zero, but that would be the reason for the resistive heater backup. Considering typical winter days are in the teens or higher, I feel the heap pump would be an excellent addition. I, for one, would happily pay 2-3,000 extra for a true Sub Zero Package if it included these items.