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COMFORT setting limiting "Engine Running due to low temperature" ERDTLT

37K views 56 replies 25 participants last post by  Usurero7 
#1 · (Edited)
The "Engine Running due to low temperature" has been discussed a fair amount. Some users have mentioned that when using COMFORT climate setting that it reduces the number of times that "Engine Running due to low temperature" happens and the ICE turns on. Others recently stated it did not have any affect. I normally use ECO so I tried COMFORT this morning.

In the past while in ECO and using the scangauge I've seen the ICE turn_back_on/ERDTLT on when the "WT" Water (engine) Temp drops down to 114F (45C). I've seen it vary in the ICE shut off when the WT goes up to 154F (67C) - 164F (73C).

Thought I would provide some empirical numbers with a statistical sampling of 2 <grin> using COMFORT/74/auto. [edit]The test was for 12 miles. Mainly 40 MPH driving hitting mostly of green lights. Also my test on the way home showed the same thing.[/edit]

Using a ScanGuage this a.m. while it was 13F (-10C) ambient temp out:
  • ICE came on after a couple minutes of leaving 55F garage and ran for 3 minutes (0.07gal) until "WT" water (engine) temp hit about 164F.
  • I noticed in my other vehicles that the Scangauge IA (intake air temp) would be very close to the ambient/outside air temp on my displays (Ford Exped, Honda Civic) BUT in the Volt I saw the the IA remain in the mid 40Fs ... remember the ambient outside temp was 13F (-10C). Perhaps I'm misreading this or is the Volt shutting some intake flap to help keep the ICE temp from dropping too fast.
  • "WT" dropped on my 12 mile trip to work to 123F (50C) and stayed there! Actually within a few miles of work I saw it go back up to 125F (51C) and 127F (52C) ... and the ICE was still OFF. In other words, I never saw it drop to 114F (45C) again where the ICE would turn back on. ... remember the ambient outside temp was 13F (-10C).
So does this mean that the 'exchange' stays open in COMFORT mode and the electric heat (COMFORT) is keeping the "WT" / ICE "warm". That is above the 114F (45C) lower threshold?!? I've seen that suggested by others.

P.S. Testing is a little annoying because I think my ScanGuage shuts off based on 0 RPM after 30sec so I keep having to press the 'home' button letting monitor the WT water (engine) temp down to the 114F (45C). I'm surprised noone with a DASHDAQ or other have graphed this ERDTLT processing ... but perhaps all those supertechs are in the warm regions. [update]:this thread setting SETUP->FUEL->TYPE->HYBRID to avoid his.[/update]

[update] Going home test and fan speed setting impact:
I was able to get similar examples on the way home from work as the way to work (above example). Plus experimented with fan speed impact to lowering the engine temp (WT water temp). Lower fan speed slows down the cooling of engine temp ... as makes common sense.

A little experimenting 2/3s the way home showed if I used AUTO (4 level fan speed resulting) then the "WT" water (engine) temp went to around 125F but if I used 2 level fan speed manually then WT temp would go to 134F. I even saw it climb from 125F to 134F when I switched to 2 level fan speed from AUTO/4 when I did the switch with 2 miles left coming home.

KEY POINT: both fan speeds still let the engine temp stay above the ~114F threshold that would have done turned ICE on (ERDTLT).
[/update]

[update] Using precond/remote_start to warm ICE for shorter ERDTLT initial runs:
Also see my post#12 of this same thread that shows how the ICE temp gets warmed up by doing precond/remote_start ... this should reduce the time/gas for the first ERDTLT running. [/update]
 
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#3 ·
The past two days have been cold so I've gotten the "Engine Running due to low temperature" message repeatedly. I typically run with FANS ONLY/AUTO RECIRC and am comfortable enough.

Has anyone else noticed that the ICE seems to ready gobble gas when turning on and off in this mode??? I've used more gas in the past 2 days than I have in the past 4 months.
 
#4 ·
I think others have mentioned this as well. The reason seems to because it runs at a higher RPM to heat up the ICE/WT quickly so it can shut off. This is likely using less gas than running at a lower RPM for a longer period of time to heat up the ICE/WT. Try COMFORT. I thik your FAN ONLY setting is just pulling the heat out of the ICE/WT faster since the electric heaters are not running. I've never used FAN ONLY in these winter temps but I have used ECO and that is very different than my COMFORT testing this morning.
 
#5 ·
I want to ask how *far* your commute is, because that could be affecting whether the coolant has enough time to cool down. My commute of 30 miles each way will typically result, on very cold days, of the engine coming on 3 times no matter what I do. I usually try to keep the heater off until i see the engine come on, and then I switch to comfort, figuring I'm not going to burn that much battery power while I'm using heat from the coolant.
 
#6 ·
I'll update the original post with this as well.

The test was for 12 miles. Mainly 40 MPH driving hitting mostly of green lights.
- When I used ECO my ICE came on 3 times several days ago.
- Today using COMFORT it came on 1 time with the "WT" engine temp staying above the 114F threshold per my post.
 
#9 ·
Using a ScanGuage this a.m. while it was 13F ambient temp out:
  • ICE came on after a couple minutes of leaving 55F garage and ran for 3 minutes (0.07gal) until "WT" water (engine) temp hit about 164F.
  • I noticed in my other vehicles that the Scangauge IA (intake air temp) would be very close to the ambient/outside air temp on my displays (Ford Exped, Honda Civic) BUT in the Volt I saw the the IA remain in the mid 40Fs ... remember the ambient outside temp was 13F. Perhaps I'm misreading this or is the Volt shutting some intake flap to help keep the ICE temp from dropping too fast.
  • "WT" dropped on my 12 mile trip to work to 123F and stayed there! Actually within a few miles of work I saw it go back up to 125F and 127F ... and the ICE was still OFF. In other words, I never saw it drop to 114F again where the ICE would turn back on. ... remember the ambient outside temp was 13F
My testing going home show similar results even tho it was 11F.

A little experimenting 2/3s the way home showed if I used AUTO (4 level fan speed resulting) then the "WT" water (engine) temp went to around 125F but if I used 2 level fan speed manually then WT temp would go to 134F. I even saw it climb from 125F to 134F when I switched to 2 level fan speed from AUTO/4 when I did the switch with 2 miles left coming home.
 
#10 ·
Comfort mode definitely helps prevent the ICE from kicking in. At least with my unscientific tests :). It sounds like your tests are showing with a lower fan speed that the coolant is able to better retain its temperature. Which makes sense since less heat is being transferred to the cabin.

Today, using Eco both ways on 30 mile round trip, the ice kicked in a half dozen times each way Using Eco allows me to get home with a few miles of charge on cold days like today, but at the cost of the ICE turning on due to temp. Using comfort doesn't allow me to get home with charge, but i need to test if the ICE uses less gas in comfort than when the ICE turns on due to temps since the last few miles I have no charge left.
 
#11 ·
Thanks Scott for posting your semi-scientific results. On my 6 degree drive home (7 miles) I had one long ICE run at the beginning and a short run at the end (compared with two long runs this morning).

Next question... if you precondition (in a warm garage) with Comfort selected and fan on 1 or 2, does it decrease the length of the initial ICE run?
 
#12 · (Edited)
Next question... if you precondition (in a warm garage) with Comfort selected and fan on 1 or 2, does it decrease the length of the initial ICE run?
Interesting question. It seems as if you are asking if the ICE is warmed up some by the electric heaters running while in COMFORT. For example:

a) if your garage is normally 55F and you leave when it is 25F out then as soon as the car's "center stack" see you are outside and it hits 25F you will see the ICE run. The ICE then needs to go from 55F to ~160F before it quits (ie. ~3 minutes).

b) same situaiton as "a)" except by preheating doe sit change your ICE "WT" temp to say 95F from 55F as your garage normal temp. And if you leave when it is 25F out then as soon as the car's "center stack" see you are outside and it hits 25F you will see the ICE run. The ICE then needs to go from 95F to ~160F before it quits (ie. ~X.Y minutes).

I don't know. Curious. May not be much of a difference in time or gas I'm guessing. Well not to me but some of you folks are "gas anxiety" freaks <grin>.

I may experiment.

[update]
Experiment: 11:30pm 55F garage -- Full battery charge; CLIMATE; fan speed 2.
0 minutes - 55F WT 66IA -- WT = Water (engine) Temp

Precondition/remote_start - 1
5 minutes - 58F WT 66IA
10 minutes - 78F WT 67IA

Precondition/remote_start - 2
15 minutes - 82F WT 69IA
20 minutes - 95F WT 71IA

Conclusion: It would seem the initial ERDTLT would run a less time and use less gas because instead of going from 55F WT to ~160F it would start at 95F WT and go to ~160F ... but that is with two remote starts.
[/update]
 
#13 ·
Makes sense to me - in comfort, the electric heater is warming the coolant more and the engine needs to run less. I just keep it at 72 auto / comfort most of the time, unless I can possibly stretch out the electric range enough to get home, With a $40 / month fixed electric rate for charging from DTE, I don't have an incentive to get home with more than 1 mile range.
 
#14 ·
I tested Comfort mode today with the ambient @ 19°F. Yesterday it was 17°F so I think the two drive cycles are comparable.

I was shocked at how much difference there was between Fan Only and Comfort mode when the Engine is force to run for low ambient.

In Fan Only the engine ran ~ 30% of the time and cycled on and off about 6 times (maybe more as I did not log the number). In Comfort mode the engine turned on once at the start of the trip, ran for ~ 3 minutes and never turned on again. MPG was ~ 60 MPG on Fan Only and 193 MPG on Comfort mode. Trip length was 14.1 miles.

This does use a lot more battery so as long as you have enough to make the trip it does significantly reduce the engine run time. I did set the temperature to 65 °F and set the fan to low.
 
#16 ·
Mixed bag

I generally run in Fan-only and have recirculate on and fan speed set to off or lowest setting, do not have heated seats, pre-condition, twice if able. This morning I opened the garage door, got in the Volt, turned it on, then got out to clean my wife's windshield. It was VERY frozen, so took me a few minutes. I went in to tell her that it still had some ice on and to warm it up well before leaving. When I went back out to the garage the Volt's ICE was running "due to temperature". I stopped at a gas station (to buy gas for the snowblower) and the ICE came on at least a second time. I did not get on the freeway due to congestion (on the freeway) and noticed that the ICE never seemed to come back on even though I had no environmental heat on. The outside temp was 7 degrees F. The range did come down to 25 miles (it has been around 33 up to now). I could swear that even with the controls set to fan-only that I felt some heat. I did have to run the defroster for a short while early on.
 
#17 ·
I generally run in Fan-only and have recirculate on and fan speed set to off or lowest setting, do not have heated seats, pre-condition, twice if able.
<snip>
The outside temp was 7 degrees F. The range did come down to 25 miles (it has been around 33 up to now). I could swear that even with the controls set to fan-only that I felt some heat.
I have not tested this with a temp measuring device but others have made comments that when in FAN mode it will still use waste heat from the ICE and provide heat.

The point of thread was that if you do use COMFORT that it will use the electric heaters. This will also "TRY" to keep the ICE temperature above the lower threshold of 114F and causing "Engine Running due to low temperature" ERDTLT a 2nd+ time. I suspect it is by design and the 'heat exchanger' is in play. Lot of subtle engineering things in our clever Volt's.
 
#19 ·
Interesting thread. Good work Scottf200 in collecting data and trying to figure out the best way to further optimize the VOLT. The car does have a lot of smarts to it and fun to figure out it's various levels of intelligence. Driving the VOLT continues to really make the conventional ICE cars seem so crude.
 
#20 ·
I tried this yesterday (sub 24*) on short trips with a 3/4 charged battery, and it does seem to cut down on engine run time. Can't really guess what the battery impact was, but more experimenting is in order.

Seems like the ECO and Comfort buttons might be a bit opposite than what people might infer them to be, from an engine run stand point.

Can we guess this is probably cheaper than gas at this point??... unless one is on one of those crazy tiered baseload rates that some folks have posted.
 
#23 ·
I think above -4c Eco saves energy by not using the heating elements as much as well as using lower fan settings. But once you get below -4c it no longer is "eco" because the battery thermal management needs the heat. So it will run the gas motor, burning more fuel to get that heat seeing as it can't get it from the electric heating elements in the Eco mode setting.

I tried it a couple days ago when we had a high temp of -8c and it's true, the ICE comes on about 1/4th of the time in Comfort as it did at the same temp range in Eco. I didn't loose that much range either. Maybe a couple of KM's, but my burned about 2 litres less fuel which I think is a fair trade. I'd rather not burn the fuel.
 
#31 ·
I'm curious about what sort of impact cabin temperature settings have on this. Like, if you have the fan on low, would a temperature setting of 60 be significantly different than 70? My gut tells me not if the car has been sitting outside in the cold and, due to the low fan speed, the heater will be fighting a losing battle for the cabin but will keep the water temperature up there. But if you have a heated garage, it would make a difference. Since the cabin would potentially start out above 60F and the heater wouldn't have to work as hard.

Or potentially it's irrelevant if comfort has two separate goals. To warm the cabin AND to keep the water temperature up. With higher fan settings just makes the second task more difficult. Rather than a single goal of keeping the cabin temperature up and the water temperature regulation is just a result of the first activity. Meaning low fan settings and a low cabin temperature setting would make the water temperature task much easier to accomplish.

It'd be fun to see some actual numbers if someone with access to them wanted to do a quick test.
 
#32 ·
It'd be fun to see some actual numbers if someone with access to them wanted to do a quick test.
From the rest of the post, it wasn't sounding like a quick test to me (about four variables.) If you can define the specific data points you'd like taken, it's possible we can get them for you. There are several folks with DashDAQ or other CanBus monitoring around (if it involves ERDTLT, I mostly haven't been cold enough this year for it.)
 
#33 ·
I think a good test would be, while it's sub-26F outside, to run in comfort with 40-50F set for cabin temp and fan on low. And then measure what that does to the water temps. To see if maintaining water temps is an active duty of comfort. Or meerly a side benefit of warming the cabin in comfort mode.

A few of the posts made it sound like the water temperature was being actively maintained. So if that's a duty of comfort mode, keeping cabin temperatures low might be an effecient way to help keep the ICE from triggering.

I hope I explained it a little better in this post.
 
#34 ·
I'll be shocked if the Volt allows a cabin temp setting that low - most cars go to "low" somewhere between 55 and 65 as the lowest setting.

Ok, I understand your test concept better - set the climate as cold as you can in comfort and see if the heater runs and holds the water high when the engine is off. This could also possibly be tested (and maybe more effectively, since you can't set the comfort mode as cold as that ambient,) by taking a car in a low state of charge, running in mountain mode until the engine is warm, and then switching back to normal and monitoring the engine temps, I think.

Based on my recent experience below, you'd have to be watching the climate screen indicator or overall power flow as well as the engine temp - if the car doesn't want heat, I suspect it'll turn off the coolant pump, which will leave the engine hot without the electric heater running.

(I learned yesterday that the car stops drawing heat out of the engine at 104F - I cycled MM for a bit, then got where I wanted electric drive while in Fan Only in 40F weather. I was surprised how fast the coolant temp dropped at first, but when it reached 104F, it stopped and stayed there for the rest of my battery life (5 minutes?) though the engine didn't start and the screen didn't show any heaters running or unexplained power draws - I think the car shut off the electric coolant pump and stopped running coolant through the heater core.)
 
#35 · (Edited)
I was off on a 15 minute ride tonight to play racquetball at a local club and tried this.

20F outside. COMFORT 60F (lower and it states "LO") with fan on speed 1. Heat icon did not show it was on on the CLIMATE screen. After the initial ERDTLT I watched the temp drop to 116F and the ICE kicked back on for ERDTLT within 10 minutes. I think if the 'heat icon is not ON' then it will just cool down and the ICE will start.

On the way home later it was 16F outside. COMFORT and 72F with fan on speed 3 and the WT (Water/coolant ice Temp) stayed above 132F ... and ICE stayed off.

BTW, Volt tech at the Chicago auto show knew exactly what I was talking about when I told him all this. They know it works like this.
 
#36 ·
Great findings. It would have helped if I had read this before tonight. My ICE ran 1/4 of the time on a 27 mile trip. The 1st leg of the trip was almost all EV, and the return trip was much colder. I ended up with 40% battery left due to the engine running so much. I was of course in eco mode.

I know you probably already know about this, but definitely hope you have the scanguage in hybrid mode. It will prevent it from shutting off after being at zero RPM. If that doesn't do it, or you need any other help with scanguage let me know. I know exactly the people to tell if there's a problem.
 
#39 ·
Interesting. So I am guessing the heater came on in reaction to cabin temperature rather than water temperature but simply couldn't keep the water temperature stable in eco, right?

Based on all of this information, I am guessing that the water temperature is raised/maintained by the electric heater but water temperature itself has nothing to do with the power draw of the electric heater. So eco/comfort and climate temperature are the only factors that determine power draw from the electric heater while in CD. And keeping the water temperature up is just a secondary effect of the primary goal of raising the cabin temperature.

Meaning that as the temperatures go down, you'll probably have to compensate with higher climate settings to get the heater cranking harder. And there is no magic optimal setting if your only goal is to limit ICE operation.
 
#40 · (Edited)
Interesting. So I am guessing the heater came on in reaction to cabin temperature rather than water temperature but simply couldn't keep the water temperature stable in eco, right?
Maybe. That wasn't the way I interpreted the data, but it's possible. There wasn't an obvious change in the heat output or fan settings ruing this period. What I thought we were seeing was that with a given heating requirement, the car would let the engine coolant provide the warmth until it fell to ~150F, and then would supplement with electric heat (and that the power allowed by Eco was less than the heat being pushed into the cabin.)
 
#41 ·
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This morning it was quite cold here in Quebec : 1°F

I did a 14 miles city round trip that took me about 50 minutes.

I used comfort settings, 74°F temp and the fan at 2. The ICE ran only when I got out of the garage (ERDTLT) ... but THATS IT FOR THE ENTIRE TRIP !!

I noticed that when I use a setting of 72°F and it's so cold outside ... the ICE run's periodically !!!

So the trick seems to use a minimum of 74°F (23°C) temp settings ...

On the finish line, I ended up with 215 MPG, 0.07 Gallons used ... 12.5 EV miles / 1.2 ICE miles and ... 6.1 Kwh burned. Please see attached pictures ...

Yes, that means that a full charge only gets me 20 miles ... but for short trips I prefer the ICE to run the less possible. And by the way, at this setting, the cabin is VERY comfortable (even too hot for my taste) ...

Another trick ... when going to the corner store ... I leave the car «running» ... so that I don't get another ERDTLT during the return home which spares another 0.7 gallons of gas ...

Anyway, a month from now, daytime temperature will be over 25°F ... can't wait to see what I will be getting in may !!

Sly
 
#42 ·
View attachment 4629 View attachment 4630

This morning it was quite cold here in Quebec : 1°F

I did a 14 miles city round trip that took me about 50 minutes.

I used comfort settings, 74°F temp and the fan at 2. The ICE ran only when I got out of the garage (ERDTLT) ... but THATS IT FOR THE ENTIRE TRIP !!

I noticed that when I use a setting of 72°F and it's so cold outside ... the ICE run's periodically !!!

So the trick seems to use a minimum of 74°F (23°C) temp settings ...

On the finish line, I ended up with 215 MPG, 0.07 Gallons used ... 12.5 EV miles / 1.2 ICE miles and ... 6.1 Kwh burned. Please see attached pictures ...

Yes, that means that a full charge only gets me 20 miles ... but for short trips I prefer the ICE to run the less possible. And by the way, at this setting, the cabin is VERY comfortable (even too hot for my taste) ...

Another trick ... when going to the corner store ... I leave the car «running» ... so that I don't get another ERDTLT during the return home which spares another 0.7 gallons of gas ...

Anyway, a month from now, daytime temperature will be over 25°F ... can't wait to see what I will be getting in may !!

Sly
Thanks for the info.. I've tried comfort but never at 74F.. (I'd be sweating and have to take my coat off at that temp, but I guess I can do that if it reduces gas usage). I've tried comfort at 62 or Low and it helped a little compared to fan.. but not too much.

That was eiither very slow driving (16mph) or as you suggest you did, you left it parked and running. How long was the stop (its not that you got 20miles.. you got 20 miles + half an hour of warm sitting in the car (e.g. useful for picking someone up anyhow).
 
#44 ·
Out of curiosity, does anyone's Volt actually state "Engine Running Due to Low Temperature"? Mine just states "Engine Running Due To Temperature" (no word "Low"). I have seen ERDTLT bandied about for the past 4 months and occurred to me when the message popped up.
 
#45 ·
I'm confused. I haven't been back to the dealer, so the only software updates I've had are whatever GM pushed OTA (I've been told they did update the Bluetooth stack that way...)

Last year, the two times I got it, I could have sworn it said engine running due to low temperature (but I don't have a picture.) This year, it definitely says just due to temperature.

Either GM pulled something clever or I'm losing my mind... :) (maybe both?)
 
#48 ·
Tried a bit of experimenting today. I had to run my wife to the train and do some quick errands. It was very cold (-18C) so I preheated the car. I did not use remote start but just started the car while it was plugged in. I was showing full charge before I did this, but the charger (240V) started up right away. I have started doing this when it is cold to preheat the car without the annoyance of hitting the remote twice, and the benefit is that I have found that if I get the timing right I get about 2.1% higher state of charge (88% instead of 85.9%). This equates to about 0.3 kw more power in the battery. This is important to me since my commute is 70 km each way. The formula I use is 30 minutes run time for freezing, and 10 minutes for every degree colder. Normally I do this with the climate set to ECO. Today I set the climate to COMFORT. What I found was that after 1 hour the heater had drawn so much power I was down to only 78% SOC. It seems at comfort the heater draws more than the 240V charger can supply. So I think I will preheat on ECO and then switch to COMFORT for the drive to minimize ERDTT.

Lots of people have commenting on the advantage of running COMFORT during low temps and I agree with them, but I wanted to see just how many times the ICE would cycle with climate set to FAN ONLY and temp at 23C. Holy smokes! The ICE ran so much that after my errands I actually returned to my garage with a higher SOC (78.8%) than the 78% I had when I left. The car makes a great generator!
 
#49 ·
one funny thing happened yesterday -- I had my 2013 in "Hold" mode, but the ICE wasn't running at the moment (it was using up the small buffered charge the ICE had built up in the battery). And then the ERDLT message came on, and the ICE did start up.

So ERDLT's can happen even when you're in "Hold" mode.
 
#50 ·
Loved the last 3 post!

Looks like they read my_comment/question/forum_threads in the "Winter Driving Tips Web Chat" because they included it in an answer. I've never seen a GM person mention it ... ever.

12:49 Comment From Steve L.
On my 2013 Volt, our recent single-digit-temperature mornings have forced the ICE to run periodically (ERDTLT) during my 25 mile commute. Seems like 3 or 4 on/off cycles are typical, with each lasting only a couple of minutes. Would it be easier on the ICE (thinking of wear & tear since the engine doesn't thoroughly "warm up") to just select "Hold" mode for 10 minutes or so near the start of my commute to avoid the short ERDTLT "burns" ? Thanks!

12:49 Darin Gesse: Hi Steve - There should be no concern as the engine has been designed for running on these short bursts. However, if you want, you can run the HVAC in the Comfort setting to minimize the number of times the engine runs. You will use more EV range for heat, but will reduce gas consumption, assuming you can make it to your destination on a full charge. - Darin
 
#51 ·
engine running due to temperature

I really love many things about my 2012 volt but this is one of the biggest things I hate. I commute 5 miles through town and when it is below 25f the engine runs almost my entire commute and I average 30 mpg. I live in Kansas and it is normal to see temps around 15 through the winter months. I leased this one but want to buy a 2015 model in late 2014 and hope they resolve this. It should be an option to run the engine if the owner wants better battery performance and comfort. Normal driving and short trips should not require burning fuel.
 
#52 ·
I really love many things about my 2012 volt but this is one of the biggest things I hate. I commute 5 miles through town and when it is below 25f the engine runs almost my entire commute and I average 30 mpg. I live in Kansas and it is normal to see temps around 15 through the winter months. I leased this one but want to buy a 2015 model in late 2014 and hope they resolve this. It should be an option to run the engine if the owner wants better battery performance and comfort. Normal driving and short trips should not require burning fuel.
For the 2013 models there is a "very cold" config setting of ~15F. I understand your short trip point. For people that just want to freeze ... I think they should buy a BEV and not pay extra for the ICE. The car is made to reduce not eliminate gas usage for the masses/normal folks. I crank the heat with my wife in the car and set it modestly for myself but use it. COMFORT and low fan speed helps keep ERDTLT away. Use 3 rightmost vents to keep warm + heated seats.
 
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