# How's your heater?



## Prodigal Son

Either my heater doesn't work properly or my expectations are out of whack. If you crank it up to "HI", do you actually get hot air blowing? Mine's just a bit warmer than ambient, it feels like.


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## Prodigal Son

Update: Manually turning on the rear vents is an easter egg that enables Oven Simulator, apparently. Not sure why the rear vents need to be activated to make the FRONT vents throw hot air as well, though.


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## Vladimír Michálek

I would submit a bug report to Tesla.


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## MelindaV

Prodigal Son said:


> Update: Manually turning on the rear vents is an easter egg that enables Oven Simulator, apparently. Not sure why the rear vents need to be activated to make the FRONT vents throw hot air as well, though.


Good to know there is the oven simulator mode though! I can live with the rear vents open


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## LucyferSam

I haven't paid too much attention to the air coming out of the vent (the reason I love the vent system is that I don't have to feel air coming out of the vent) but mine warms my car up quickly enough and it's barely gotten above freezing since Sunday. I'd definitely check in with a service center on what's going on.


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## TirianW

Heat pumps are notorious for only blowing warm air not hot air like a combustion or electric furnace. The air slightly warmer than the desired temperature but not "hot". It sounds like if you just run the climate control, it is only using the heat pump to heat the car, where as if you enable "oven mode" it forces the resistance heater on which blows "hot" air. So resistance heater - hot air, less efficient; heat pump - warm enough air, more efficient.


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## Prodigal Son

TirianW said:


> Heat pumps are notorious for only blowing warm air not hot air like a combustion or electric furnace. The air slightly warmer than the desired temperature but not "hot". It sounds like if you just run the climate control, it is only using the heat pump to heat the car, where as if you enable "oven mode" it forces the resistance heater on which blows "hot" air. So resistance heater - hot air, less efficient; heat pump - warm enough air, more efficient.


Oh hell did I miss that there's a heat pump AND a resistance heater? I had no idea.


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## TirianW

Prodigal Son said:


> Oh hell did I miss that there's a heat pump AND a resistance heater? I had no idea.


The biggest difference between an air conditioner and a heat pump is the reversing valve (now, technically there are other differences, the expansion valves are different, sometimes there is a change to the receiver/drier, the control system is more complex), so it makes sense to just put a heat pump into the car. Some manufacturers "dumb down" the the heat pump to an air conditioner to make the "budget" versions of their cars (glaring at Nissan here), but technically the heat pump is not much more expensive than the air conditioner.


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## jsmay311

Prodigal Son said:


> Oh hell did I miss that there's a heat pump AND a resistance heater? I had no idea.


No. You didn't. It would be news to everyone. (i.e., it's very likely not true.)


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## rxlawdude

Our 12/28 delivered M3 was taken on a road trip the next morning to Sedona and Flagstaff, where ambient temps were in the low 40s-60s.

The heat in the M3 not only was great, it was actually better than in my MS.


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## Prodigal Son

rxlawdude said:


> Our 12/28 delivered M3 was taken on a road trip the next morning to Sedona and Flagstaff, where ambient temps were in the low 40s-60s.
> 
> The heat in the M3 not only was great, it was actually better than in my MS.


Do you mind doing a test for me? If you use the app to set the heat to "HI" and run the climate control while not in your car, what temperature is the interior at after 5 minutes?


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## rxlawdude

Prodigal Son said:


> Do you mind doing a test for me? If you use the app to set the heat to "HI" and run the climate control while not in your car, what temperature is the interior at after 5 minutes?


I'd have to do the test in SoCal balmy (relative) temps, so I will report on the interior temperature increase to make it a bit more scientific.

EDIT: Starting interior ambient 72F. Heat to HI at 1558. Ending interior ambient @ 1603: 82F. 10F rise in 5 min.


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## Maevra

Prodigal Son said:


> Update: Manually turning on the rear vents is an easter egg that enables Oven Simulator, apparently. Not sure why the rear vents need to be activated to make the FRONT vents throw hot air as well, though.


In my experience, if you're trying to blast the heat on HI after the car has been off for hours (ex. first thing in the morning), it'll take a while for the heat to come on at a standstill. Best thing to get it going quickly is to drive it.

I usually hop into the car when it shows interior temps at 50F. Since I forget to pre-heat often, I crank up the temps to 80F, but the first 5 minutes I'm driving at 10-30 mph the car doesn't heat up much. However, once on the freeway cruising at 60mph the heat REALLY gets going.


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## Maevra

Prodigal Son said:


> Update: Manually turning on the rear vents is an easter egg that enables Oven Simulator, apparently. Not sure why the rear vents need to be activated to make the FRONT vents throw hot air as well, though.


Hmm curious. Turning on the rear vents should actually DECREASE the heat you feel at the front since it's now splitting the air between front and back. Maybe ask the Tesla SC about that...


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## LucyferSam

Prodigal Son said:


> Do you mind doing a test for me? If you use the app to set the heat to "HI" and run the climate control while not in your car, what temperature is the interior at after 5 minutes?


Just ran this test in me car, in 5 min it went from 59 to 79. It had been about 2 hours since parking it and plugging it in to change, outdoor ambient temperature is 36.


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## Prodigal Son

rxlawdude said:


> I'd have to do the test in SoCal balmy (relative) temps, so I will report on the interior temperature increase to make it a bit more scientific.
> 
> EDIT: Starting interior ambient 72F. Heat to HI at 1558. Ending interior ambient @ 1603: 82F. 10F rise in 5 min.


Interesting, same as I get up here in norcal. I suspect it won't go over 82 when remotely heating. Time to find new ways to test!


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## LucyferSam

Prodigal Son said:


> Interesting, same as I get up here in norcal. I suspect it won't go over 82 when remotely heating. Time to find new ways to test!


Think I must have misread my clock last night, retested this morning with a timer set: 44F outdoor ambient, 42F in the car, after 5 minutes on high it was at 81. Definitely slowed down at 80 as that last degree took ~25 sec.


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## MelindaV

LucyferSam said:


> retested this morning with a timer set* - 44F outdoor ambient,* 42F in the car, after 5 minutes on high it was at 81.


ok - to clarify, are you saying it's 44F below zero or 44F?


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## NRG4All

jsmay311 said:


> No. You didn't. It would be news to everyone. (i.e., it's very likely not true.)


I agree with you. My understanding is that they use the windings in the driver motor to generate heat used to warm the cabin. They somehow have come up with a way to keep the armature still while sending current through the windings to create the heat. Of course, once you are under way, this heat is created naturally. Normally that heat, using a heat pump, would be lost. If it works in the long run, it seems like a very elegant solution.


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## LucyferSam

MelindaV said:


> ok - to clarify, are you saying it's 44F below zero or 44F?


Hah, 44F, not -44F, edited the post to make it clearer. Don't think real temp has ever gotten quite that cold here (though windchill has a few times in my life).


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## LucyferSam

NRG4All said:


> I agree with you. My understanding is that they use the windings in the driver motor to generate heat used to warm the cabin. They somehow have come up with a way to keep the armature still while sending current through the windings to create the heat. Of course, once you are under way, this heat is created naturally. Normally that heat, using a heat pump, would be lost. If it works in the long run, it seems like a very elegant solution.


There is an electric cabin heater. The excess heat from the motor is only used to warm the battery based on what we've seen so far.


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## Sandy

TirianW said:


> The biggest difference between an air conditioner and a heat pump is the reversing valve (now, technically there are other differences, the expansion valves are different, sometimes there is a change to the receiver/drier, the control system is more complex), so it makes sense to just put a heat pump into the car. Some manufacturers "dumb down" the the heat pump to an air conditioner to make the "budget" versions of their cars (glaring at Nissan here), but technically the heat pump is not much more expensive than the air conditioner.


No heat pump for the cabin in the Model 3. This is the heater used for cabin heat source:

https://www.borgwarner.com/news-med...cabin-heater-extends-driving-range-for-new-ev










Schematic:


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## rxlawdude

NRG4All said:


> I agree with you. My understanding is that they use the windings in the driver motor to generate heat used to warm the cabin. They somehow have come up with a way to keep the armature still while sending current through the windings to create the heat. Of course, once you are under way, this heat is created naturally. Normally that heat, using a heat pump, would be lost. If it works in the long run, it seems like a very elegant solution.


The cabin heat is resistive heating elements. The BATTERY temperature management steals heat from energizing the motor armature in such a way as to not producing torque.

So much misinformation. So little time.


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## Maevra

Prodigal Son said:


> Update: Manually turning on the rear vents is an easter egg that enables Oven Simulator, apparently. Not sure why the rear vents need to be activated to make the FRONT vents throw hot air as well, though.


So this has been bugging me since yesterday and I did some tests. This is what I found:

1. Turn on HVAC on HI but DON'T tap on any of the other settings- car starts HVAC in "Auto" mode. The dash vents aren't emitting any air (or so little that I didn't notice it). The foot vents are where most of the heat was coming from. Fan speed was auto-set to 3.

2. Adjusting any of the other settings- puts the HVAC into "Manual" mode and the hot air started circulating from the dash (after I tapped that option) as well as the foot vents. Foot vents reduced heat but chest-level air was noticeably stronger and hotter even though fan speed remained at 3. My rear vents were also on at that time. Overall, Manual mode warmed the car up faster than when I would leave it on Auto (and again, fan speed wasn't changed).

So I think it's not a bug per se, it's likely just the difference with Auto vs. Manual mode. Auto mode seems to heat the car up more gently, but switch it to Manual and it'll get hotter faster.

I'd be interested if any fellow owners can test this and see if they have similar results.


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## Guest

TirianW said:


> Heat pumps are notorious for only blowing warm air not hot air like a combustion or electric furnace.


That depends, but usually it is more efficient to have less hot condenser. Home heat pumps are set to around +40C air. Car can be set slightly higher, like 45C. Heat pumps can heat up to 70C but are not super efficient in that zone (hot water heating pumps do that).
Cars with HP are usually set up to heat air to around 40C with HP and if cabin is very cold (starting to drive) then PTC heater adds some more to get 60-70C. After heatup PTC is killed and air is warm. Smarter ICE vehicles usually limit air output temp to around 70C when heatup happens, and reduce to whatever needed later on. 70C is uncomfortably hot actually. Dumb ICE vehicles can go up to 100C if blower speed is low and engine is fully warmed up. 100C is not comfortable nor safe for windscreen. Actually 70C is also risky if it is -20C outside.


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## Hav77

Right on que if you haven't seen this yet by Zac & Jesse:


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## Simon Says

One thing I am just wondering recently with some cold weather. Are there any vents opening to direct hot air towards your feet? Or is the only option the main vent opening? In the same line is there another opening near the windshield for defogging/defrosting?


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## Maevra

Simon Says said:


> One thing I am just wondering recently with some cold weather. Are there any vents opening to direct hot air towards your feet? Or is the only option the main vent opening? In the same line is there another opening near the windshield for defogging/defrosting?


There are dedicated foot vents and yes they do blow hot air. Yes there are also separate vents for the windshield defogging. Pressing the rear defogger also activates the side mirror heaters.


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## MelindaV

Simon Says said:


> One thing I am just wondering recently with some cold weather. Are there any vents opening to direct hot air towards your feet? Or is the only option the main vent opening? In the same line is there another opening near the windshield for defogging/defrosting?


Have you been in a car built in the last 80 years without either of these?


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## mbrucem

Simon Says said:


> One thing I am just wondering recently with some cold weather. Are there any vents opening to direct hot air towards your feet? Or is the only option the main vent opening? In the same line is there another opening near the windshield for defogging/defrosting?


There are definitely foot vents. You can manually set it or use Auto.


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## mbrucem

Maevra said:


> So this has been bugging me since yesterday and I did some tests. This is what I found:
> 
> 1. Turn on HVAC on HI but DON'T tap on any of the other settings- car starts HVAC in "Auto" mode. The dash vents aren't emitting any air (or so little that I didn't notice it). The foot vents are where most of the heat was coming from. Fan speed was auto-set to 3.
> 
> 2. Adjusting any of the other settings- puts the HVAC into "Manual" mode and the hot air started circulating from the dash (after I tapped that option) as well as the foot vents. Foot vents reduced heat but chest-level air was noticeably stronger and hotter even though fan speed remained at 3. My rear vents were also on at that time. Overall, Manual mode warmed the car up faster than when I would leave it on Auto (and again, fan speed wasn't changed).
> 
> So I think it's not a bug per se, it's likely just the difference with Auto vs. Manual mode. Auto mode seems to heat the car up more gently, but switch it to Manual and it'll get hotter faster.
> 
> I'd be interested if any fellow owners can test this and see if they have similar results.


Glad to test whatever you want, BUT, not sure what you want or if needed when you use the App.

1). I live in MN and it is cold, really cold, for part of the year. -2 F right now. (That is an F for Fahrenheit, but we do use other F bombs describing the cold as well).
2). I use the app to preheat the car. It only takes 4-5 min to get the cabin from -10F to +70F. I do this as I start to put on my shoes, or as I am leaving wherever I am (restaurant, movie, store) and the car is warm and ready to go.
3). I have never gotten into my Tesla when it was cold... not sure why anyone would? So much so I have stopped wearing a coat in this crazy weather because it is warm inside and in the car (coat with me just in case). 
4). This also warms up the battery so there is better acceleration and range (which are limited with very cold battery).
5). There is a vampire effect of about 15-20 miles a day when it is this cold sitting outside, and the range does drop too.
6). Still waiting on the App to be able to turn on the defrost and heated seats - silly that this is not done yet.


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## Simon Says

MelindaV said:


> Have you been in a car built in the last 80 years without either of these?


Well I was in a M3 4 months ago. I can tell you it was my first time in my life that I was in a car without visible vents. I played with the new vent control and never thought of peeking under. Since all reviews mention that the only vent is that giant slit in the dash I got concerned last week as I activated the foot vent in my BMW that I would not have happy feet in my M3. In terms of what was in a car and understood as standard in the last 80 years I take nothing for granted with this car. We probably could get a long list of things that are assumed as basic in cars i.e. speedometer in a driver centric cluster, and see that it is not in there.


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## Simon Says

Maevra said:


> There are dedicated foot vents and yes they do blow hot air. Yes there are also separate vents for the windshield defogging. Pressing the rear defogger also activates the side mirror heaters.


Thanks for the info.


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## MelindaV

Simon Says said:


> We probably could get a long list of things that are assumed as basic in cars i.e. speedometer and see it is not in there.


there is a speedometer


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## Maevra

mbrucem said:


> Glad to test whatever you want, BUT, not sure what you want or if needed when you use the App.
> 
> 1). I live in MN and it is cold, really cold, for part of the year. -2 F right now. (That is an F for Fahrenheit, but we do use other F bombs describing the cold as well).
> 2). I use the app to preheat the car. It only takes 4-5 min to get the cabin from -10F to +70F. I do this as I start to put on my shoes, or as I am leaving wherever I am (restaurant, movie, store) and the car is warm and ready to go.
> 3). I have never gotten into my Tesla when it was cold... not sure why anyone would? So much so I have stopped wearing a coat in this crazy weather because it is warm inside and in the car (coat with me just in case).
> 4). This also warms up the battery so there is better acceleration and range (which are limited with very cold battery).
> 5). There is a vampire effect of about 15-20 miles a day when it is this cold sitting outside, and the range does drop too.
> 6). Still waiting on the App to be able to turn on the defrost and heated seats - silly that this is not done yet.


I did my tests only while in the car, not via app.

Wealth of info here, thanks @mbrucem! Crazy how fast the cabin pre-heat works in cold weather! Agree on #6, wish they'd add the ability to activate defrost and heated seat from the app.


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## Prodigal Son

Update: Dropped off the car for tint + ceramic coating today and got a chance to compare with someone else's Model 3, which heated up MUCH faster and got much hotter than mine. Walked over to the Walnut Creek showroom and compared against their floor car, and same result. Clearly need to get mine serviced, so having it checked out on Saturday.


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## teslarob

Sounds like there's an issue with one of the actuators or flaps in the HVAC unit. If you get heat from the rear vents but not the front, it seems like the heater itself is working fine, but the issue is with air distribution. Let us know what they find!


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## Dan Detweiler

...and I think the kicker to this entire conversation is that there is no way ANY ICE car could possibly achieve these types of results in just 5 minutes. This is especially true if it is sitting stationary since its ability to heat the cabin is a result of the engine warming up first. No matter what your numbers on the 3 come out to be, it is still going to be WAY faster than any ICE car.

Dan


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## Tom Hudson

Our old Solectria Force has a resistance heater that's decent down to around freezing, but of course it sucks amps. When it gets colder than that or we're going further than a short trip, we switch to the kerosene-fired unit which is tied into the heater core and provides more heat with less power consumption from the battery. Looking forward to seeing how the 3 handles the heating here in Wisconsin, and I've been wondering how the heat system is configured.


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## jsmay311

Hav77 said:


> Right on que if you haven't seen this yet by Zac & Jesse:


This test is kinda worthless for comparing to an ICE vehicle since they just let that Civic idle the whole time. Usually when an ICEV driver wants the car to warm up, they're already driving it, causing the engine (and air coming from the vents) to heat up faster than if the engine was just idling.


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## Guest

Dan Detweiler said:


> ...and I think the kicker to this entire conversation is that there is no way *ANY *ICE car could possibly achieve these types of results in just 5 minutes. This is especially true if it is sitting stationary since its ability to heat the cabin is a result of the engine warming up first.


Well.. regular cheap ICE.. no. But there are exceptions. Techy solutions... I can bring examples from BMW world.
My old bimmer has auxiliary heater as standard (because it is diesel, it can't warm up at all below -15*C, it is that efficient). It takes one minute to fire up (or fire up with remote from as far as 1km). On the second minute some heat is already felt. As it is 5.5kW heater, everything gets hot in 5 minutes. On cheaper 3-series it was solved by electric heater in coolant loop, 1kW power. This is not 3-4kW like EV's handle, but it is noticeable. Next upgrade happened like in 2005 when PTC heaters appeared in optional 4-zone climate HVAC systems. These are instantaneous (like Tesla) but still, not as powerful, 1300W (not sure one or two are used).
And the highest-end update was to some gasoline engines that switched to electric water pumps. When engine starts main coolant pump is kept stalled. Coolant heats up within like.. i don't even know. Like 30 seconds? And then small cabin heater loop pump can extract a lot of heat. This must work very fast. Though I don't have specific data for that.

EDIT: there are two 1300W heaters on 5 and 7 series, one on 3-series. So... pretty much the same heating speed as EV starting from 5-series.


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## JWardell

arnis said:


> Well.. regular cheap ICE.. no. But there are exceptions. Techy solutions... I can bring examples from BMW world.
> My old bimmer has auxiliary heater as standard (because it is diesel, it can't warm up at all below -15*C, it is that efficient). It takes one minute to fire up (or fire up with remote from as far as 1km). On the second minute some heat is already felt. As it is 5.5kW heater, everything gets hot in 5 minutes. On cheaper 3-series it was solved by electric heater in coolant loop, 1kW power. This is not 3-4kW like EV's handle, but it is noticeable. Next upgrade happened like in 2005 when PTC heaters appeared in optional 4-zone climate HVAC systems. These are instantaneous (like Tesla) but still, not as powerful, 1300W (not sure one or two are used).
> And the highest-end update was to some gasoline engines that switched to electric water pumps. When engine starts main coolant pump is kept stalled. Coolant heats up within like.. i don't even know. Like 30 seconds? And then small cabin heater loop pump can extract a lot of heat. This must work very fast. Though I don't have specific data for that.
> 
> EDIT: there are two 1300W heaters on 5 and 7 series, one on 3-series. So... pretty much the same heating speed as EV starting from 5-series.


I doubt those 1500W heaters can run very long before killing the 12v battery. Are you sure they are not heater plugs typical in most diesel engines that heat only the core of the engine for just a few seconds so it can start?


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## Guest

JWardell said:


> I doubt those 1500W heaters can run very long before killing the 12v battery.


They run on alternator. Not on battery. They do not start if engine is not idling/running.

Those are 100A elements. Running on 13,6-15,5V (special voltage regulation system).

All diesel engines have glow-plugs. What I talk about is PTC heaters. Like in EV's. Most ICE's don't have those.


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## Prodigal Son

Dan Detweiler said:


> ...and I think the kicker to this entire conversation is that there is no way ANY ICE car could possibly achieve these types of results in just 5 minutes. This is especially true if it is sitting stationary since its ability to heat the cabin is a result of the engine warming up first. No matter what your numbers on the 3 come out to be, it is still going to be WAY faster than any ICE car.
> 
> Dan


True but in the end it's not the speed that bothers me, it's the actual temps it'll hit regularly, which are low.


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## Griff

jsmay311 said:


> This test is kinda worthless for comparing to an ICE vehicle since they just let that Civic idle the whole time. Usually when an ICEV driver wants the car to warm up, they're already driving it, causing the engine (and air coming from the vents) to heat up faster than if the engine was just idling.


I disagree. Sitting in the car while it warms up is a bit silly, but I assume it was just for entertainment value. If you run outside to start your ICE, or are lucky enough to have a remote start, the time that it takes to warm up is completely relevant.


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## Twiglett

Griff said:


> I disagree. Sitting in the car while it warms up is a bit silly, but I assume it was just for entertainment value. If you run outside to start your ICE, or are lucky enough to have a remote start, the time that it takes to warm up is completely relevant.


Its also inadvisable to remote start your ICE to warm up when its in the garage


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## Estring_US

Maevra said:


> So this has been bugging me since yesterday and I did some tests. This is what I found:
> 
> 1. Turn on HVAC on HI but DON'T tap on any of the other settings- car starts HVAC in "Auto" mode. The dash vents aren't emitting any air (or so little that I didn't notice it). The foot vents are where most of the heat was coming from. Fan speed was auto-set to 3.
> 
> 2. Adjusting any of the other settings- puts the HVAC into "Manual" mode and the hot air started circulating from the dash (after I tapped that option) as well as the foot vents. Foot vents reduced heat but chest-level air was noticeably stronger and hotter even though fan speed remained at 3. My rear vents were also on at that time. Overall, Manual mode warmed the car up faster than when I would leave it on Auto (and again, fan speed wasn't changed).
> 
> So I think it's not a bug per se, it's likely just the difference with Auto vs. Manual mode. Auto mode seems to heat the car up more gently, but switch it to Manual and it'll get hotter faster.
> 
> I'd be interested if any fellow owners can test this and see if they have similar results.


I agree on using manual mode. Still drive an ICE car but purchasing a M3 Long Range in 4 to 5 months. On my ICE car I only use manual mode when the cabin is up to temp. I use manual mode to get hot air. SO it makes sense to use manual mode on an M3 as well. Once cabin is warm switch to Auto mode to maintain a comfortable heat. BTW - I live in Wisconsin where we get very cold temps in winter.


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