2018 Climate Control Efficiency

[andy.connor.e]

Have a question for any of you pre-heat pump Model 3 owners. Do any of you know if setting the climate control to Auto is more efficient than just picking a temp and running on fan speed 2 like you would in an ICE vehicle?

Normally i pick 68°F and fan speed 2 for heat, and i adjust it between 66-70 depending how cold it is outside. Now that auto seat heaters is tied to auto climate, im wondering if anyone had experimented with that

OR

have some references to people doing these experiments and have some results.

 

[skygraff]

Totally anecdotal but I've found manual to be both more efficient and quieter. A lot of times, I cycle between off and manual (all 3 fans - foot/face(side windows/windshield @ 3 and usually 70 in winter with AC off) unless there's a lot of fogging.

That said, with the difficulty accessing any other controls without turning on HVAC (voice commands are really intermittent), I've been testing auto a bit and have noticed it's settling on a lower fan setting than in the past so I'm probably going to take a long drive with it on auto and see how it goes.

 

[jjrandorin]

Do any of you know if setting the climate control to Auto is more efficient than just picking a temp and running on fan speed 2 like you would in an ICE vehicle?

I have no idea about efficiency, but I have set all my cars to "auto" for the past 15 years. Before tesla, they were all BMWs, but they were also all on "auto" so I dont know about this "pick a temp and set fan speed to 2 like you would on an ICE vehicle" as if thats a standard thing.

I keep my tesla on auto just like the BMWs and the cabin temp is just as comfortable as the BMWs, to me.

 

[Theone8181]

I've always stuck with auto, but I'd prefer if it used a lower fan speed. I used to have a BMW and could set that to auto and quiet if that makes sense.

 

[Shelburne]

I can't comment about the efficiency of auto vs. manual, but in cold weather, once the cabin is warm enough, I always switch to recirculated air. On damp days, that can lead to window fogging, but then I just blast defrost for a minute or so and then revert to recirculated air. I find the cabin stays warmer and the car uses less of it's charge to keep it that warm.

 

[valaeyron]

Been using auto since v11. I feel like it costs more energy than manual control. Yes I am quite comfortable (68 degree cabin, seat heaters auto) but I think the savings with manual comes from being able to decide to be “slightly cold” for awhile.

I’d be more inclined to leave it on auto if I had a LR. The trade off is more acute with an SR+.

 

[andy.connor.e]

my windows fog up almost instantly when i switch to recirculate. i have to imagine it takes less energy to heat the cabin air rather than the outside air. Im pretty much content with picking a temp and setting a fan speed.

For some of you riding BMWs, i am here to inform you that if you drive an economy car (corolla, camry, civic etc...), or most older model vehicles that are not the maximum trim, they do not have auto climate.

 

[valaeyron]

For some of you riding BMWs, i am here to inform you that if you drive an economy car (corolla, camry, civic etc...), or most older model vehicles that are not the maximum trim, they do not have auto climate.

Yep. This SR+ is the most expensive car we have ever purchased. We have, by choice, always selected vehicles ~$25k or less…and at that price point you can get some nicer (but still basic) features, but auto-anything is not common.

 

[GtiMart]

My previous "base" WRX had auto and my wife's relatively basic Subaru Crosstrek does too. I believe it's coming to more common cars too, not just luxury models. Leave it on auto, one less thing to worry about, especially since all controls are on a single screen. Automatic systems is the only way a UI like in a Tesla can work... when they iron out the bugs

 

[valaeyron]

My previous "base" WRX had auto and my wife's relatively basic Subaru Crosstrek does too. I believe it's coming to more common cars too, not just luxury models. Leave it on auto, one less thing to worry about, especially since all controls are on a single screen. Automatic systems is the only way a UI like in a Tesla can work... when they iron out the bugs

Yes, things trickle down, but for most people who aren't driving luxury cars OR keeping their cars for 5-10 years...auto conveniences aren't the norm.

 

[CarlThompson]

Hi Andy. When I had the 2018 manual climate control definitely seemed more efficient to me and as someone else pointed out you can set it so it doesn't get annoyingly loud the way auto does.

 

[MrG_NY]

I found just the opposite with Auto. I find it's much quieter and my fans never run on high except for a couple of minutes when it's really hot outside. The temperature stays where I have it set. So with what I observe, auto should be more efficient.

 

[skygraff]

Took that long drive.

Except for right at the beginning of each segment, the fan was actually set where I would’ve put it in manual so it really wasn’t as bad as the early days of auto. Efficiency was pretty much a wash but, of course, used more energy than turning it completely off and holding your breath (to avoid fogging the windows).

I definitely wish I could view the seat heater status without activating the HVAC (could use the phone app but shouldn’t while driving). Annoyingly, if you have everything in auto but turn it off for a few minutes, seat heat goes to high when you turn everything back on. Generally, in those cases, I was perfectly warm but the windows were fogged - my butt didn’t need the heat; suppose I could’ve engaged windshield defog but that kicks the fans way too high and still end up opening HVAC to reconfigure after.

Suffice to say, it looks like auto and manual are finding parity and you shouldn’t worry about it from an efficiency standpoint unless you’re hyper-miling. As they say, YMMV.

 

[Theone8181]

Took that long drive.

Except for right at the beginning of each segment, the fan was actually set where I would’ve put it in manual so it really wasn’t as bad as the early days of auto. Efficiency was pretty much a wash but, of course, used more energy than turning it completely off and holding your breath (to avoid fogging the windows).

I definitely wish I could view the seat heater status without activating the HVAC (could use the phone app but shouldn’t while driving). Annoyingly, if you have everything in auto but turn it off for a few minutes, seat heat goes to high when you turn everything back on. Generally, in those cases, I was perfectly warm but the windows were fogged - my butt didn’t need the heat; suppose I could’ve engaged windshield defog but that kicks the fans way too high and still end up opening HVAC to reconfigure after.

Suffice to say, it looks like auto and manual are finding parity and you shouldn’t worry about it from an efficiency standpoint unless you’re hyper-miling. As they say, YMMV.

I do find it tends to burn my legs when that happens, wish I could limit the seat heating to 1.

 

[AKinDC]

I've always loved auto on my 2019, until the V.11 update...now it's all over the place.
Sometimes too hot, sometimes too cold, sometimes blowing chilly air when it should be warm.
Really frustrating. I had it set to 68 since I bought the car, and never moved it until the recent update.

 

[valaeyron]

I found just the opposite with Auto. I find it's much quieter and my fans never run on high except for a couple of minutes when it's really hot outside. The temperature stays where I have it set. So with what I observe, auto should be more efficient.

Different preferences. Auto is certainly convenient but manual allows for conscious trade offs if desired (i.e., seat heat vs resistive heater, if you have a pre-heat pump M3)…

 

[andy.connor.e]

Hi Andy. When I had the 2018 manual climate control definitely seemed more efficient to me and as someone else pointed out you can set it so it doesn't get annoyingly loud the way auto does.

yeah, really just wanted to satisfy my never ending curiosity.

My previous "base" WRX had auto and my wife's relatively basic Subaru Crosstrek does too. I believe it's coming to more common cars too, not just luxury models. Leave it on auto, one less thing to worry about, especially since all controls are on a single screen. Automatic systems is the only way a UI like in a Tesla can work... when they iron out the bugs

The way that a UI like a Tesla can work for me, is i've decided to just put the temp at 70, fan at 2, seat heater on 1, and never turn it off. Turns on when i get in, turns off when i get out. Pretty standard and would work that way on any car but i really dont need the cabin at any particular degree temperature. i just want a bit of AC or heat running to prevent the cabin from getting colder/hotter than i can tolerate.