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I've been "toughing out" the 40 F temps by using the bun & steering wheel warms so far. But no that our temps are below 40 F I have started to use the ICE to heat the cabin. Seems like I have two options:

1. Use the Climate control button, set the heat where I want it, then wait for the ICE to generate enough heat to warm the cabin. With this approach, it appears that the engine simply idles (somewhere around 1,000 RPMs -- I haven't figured out how to find the RPMs without going into sport mode) until the set cabin temp is reached.

2. Set the heat where I want it, then drive in Sport Mode. In Sport the engine RPMs vary from 1,200 to 4,000 depending on pressure on the gas pedal. Because the engine running at higher RPMs. / burning more gas, the cabin warms up to the set temp faster. It also generates some power back to the traction battery. Once the cabin is adequately warmed, I revert to EV or HEV driving mode.

Assuming my observations above are accurate, my questions are:

1. Which of the two above option is likely to be more energy efficient?
2. Is there another option I've missed. No, I don't want to pre-heat the car remotely.

Thanks & happy Thanksgiving to all.
 

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I can't answer your question directly, but for most cars, setting a temperature of say, 72 degrees, runs both the heater and the air conditioner to achieve and maintain the proper temperature. Even at low temperatures, at least if the defroster is on, the air conditioner operates. While I like setting a temperature, I've always known this is a very inefficient way for a system to operate (Oh, you want /warm/ air? Let's mix the heated air with air-conditioned air!). Obviously and especially with a HEV or PHEV, this operation is extremely inefficient, and hopefully Kia has done something to prevent such inefficiency. Hopefully someone else can comment on that, although it may take a Kia engineer. ;-)

However, you might try: When warming up the car, set the cabin temperature as high as it will go. This should insure 1) You get ALL the heat available from the heater, and it's not mixed with cooler air, while you await a comfortable temperature, and 2) The AC should not come on at all. (As a 6 day long owner, I wasn't sure, but see that there is a light above the AC button, so hopefully, even when it's turned on by AUTO, it will light, alerting you to AC use, and you'd turn it off.)
 

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Assuming my observations above are accurate, my questions are:

1. Which of the two above option is likely to be more energy efficient?
2. Is there another option I've missed. No, I don't want to pre-heat the car remotely.

Thanks & happy Thanksgiving to all.
Good question and one I've pondered myself. In a normal car, idling is a very inefficient way to warm up the engine (and the driver by extension). In fact, my VW TDI will take basically forever to warm up at idle, so there's really no point to it. The PHEV is a little different as the HSG is used to load the engine, making it warm up much faster while extracting useful work from it, assuming the battery isn't already fully charged. If you just jump in and drive then the energy drawn from the ICE will reduce the rate of drain on the battery so that's good.

So, to answer the question I think it's probably (very) slightly more efficient to just leave it in EV mode and let the ICE run with just the HSG as a load.

Actually, are we sure the ICE is just running at idle in this mode? It would make sense for the Kia engineers to run the ICE at whatever RPM was most efficient and resulted in the fastest warmup time. With no tach (unless in Sport mode, which defeats the purpose in this case) it's hard to tell. I guess if you had a OBDII reader you could monitor the RPMs when the ICE is running for heat in EV mode.

In practice, I doubt you'd be able to measure the difference in MPG under real world conditions as the normal day-to-day variations would probably make it impossible to detect.

Still, it's fun to think about how to extract the last watt of efficiency out of the system. 🤓
 

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... 2) The AC should not come on at all. (As a 6 day long owner, I wasn't sure, but see that there is a light above the AC button, so hopefully, even when it's turned on by AUTO, it will light, alerting you to AC use, and you'd turn it off.)
Ah-ha! User beware! I assumed that when using AUTO, if the AC comes on, the AC light would come on, and in fact that is true, if you turn the temperature down very low. But today in my Niro Touring, with an outside temperate of about 70 degrees, and inside set at 72 degrees, after the car sat a bit and was started, the dash vents blew very cool, air-conditioned air, and NO AC light was on! Seems wrong, but it was definitely cool air, as outside air was muggy (South Carolina winter, after all). So, I think my suggestion of turning the set temperature up high to be sure the inside heats up quickly and no AC is used is definitely worth consideration.
 

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Signet7, what I've always heard about the AC coming on with the defroster is that there are two reasons for that: 1) it works better, because it helps to dry the air, and up until the point where you are dealing with ice, having dry air is more important than having warm air, to clear the windshield. The second reason I've heard many times is that if you shut your AC off in the fall and don't run it again until next summer, you risk drying out the seals in your AC system, getting a leak, and then needing expensive repairs. But if you run the AC at least once or twice every month all year long, then there's less risk of that. The guy who recently inspected the AC unit in my house told me the same thing: I should run it a few times over the winter.

You mentioned that you thought it was running even when the light was out. I suspect you are right about that, at least, I think this can happen under certain conditions (such as running the defroster). But I also suspect that if you then turned it on (by pressing the AC button and turning on the light) and then turned it off by pressing the AC button again, that this would shut it off for real. If you try this and reach a conclusion, I'd be interested to hear.

Dovidan I think if your're driving a PHEV then you have a third option, which is turn on the heat, and then toggle the car into Hybrid mode. Turning on the heat will cause the ICE to run at minimum RPM until it reaches a minimum temp. Putting it in Hybrid mode will cause the RPM to increase while you are driving, but not as high as Sport Mode would do, but once you stop (or have acquired significant surplus battery charge), the ICE will shut down if the heat-logic's minimum engine temp criteria is satisfied.

With that said, if I was still living in Maine instead of Southern California, I'm pretty sure I would be using Sport Mode for the first couple of miles during the coldest part of the winter, for two reasons: one reason being I want the car to heat up as fast as possible, the other is that where I lived in Maine, stops were pretty brief, and having the ICE shut down while cold, only to have to start up again 5 seconds later, is probably less efficient than keeping it running for that five seconds, and my limited experience with Sport Mode suggests that it's less likely to shut down at a stop (compared to Hybrid Mode), at least when the ICE is cold.

I don't use Sport Mode very often, but I recall being focused on it before I purchased the car, and on my test drives my impression was that it didn't have a very big impact on fuel economy. If you have a regular commute, you could try it both ways and reach your own conclusions on this question.
 

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While it will differ a bit depending on the type of driving you're doing, my personal experience shows far better fuel economy leaving the HVAC on auto and driving in normal EV mode. The ICE only runs at a fast idle to warm the coolant for heating the cabin. So the faster I'm driving, with fewer or no stops, I'll show over 100 MPG. If I use either HEV or Sport mode, I seldom see more than about 60 MPG, and much lower if the ICE is running during slow or stop/go traffic. I only engage HEV or Sport if I desire to save some EV range for a later part of the trip. Also, with the ICE running, it is supplying a slight charge to the battery, so I'm still seeing 30 miles or more of EV range, even with the temps dropping into the 30s (F) around here. Overall, they seem to have programmed the system pretty well to minimize the fuel burned for cabin heating.
 

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Signet7, what I've always heard about the AC coming on with the defroster is that there are two reasons for that: 1) it works better, because it helps to dry the air, and up until the point where you are dealing with ice, having dry air is more important than having warm air, to clear the windshield.
AC definitely helps dehumidify the air, and works quite quickly. The defroster can and will produce heat to actually defrost the outside of the windshield, but long before that, if moisture has condensed on it, the dry dehumidifed air produced by the AC will reduce, then eliminate, the misting. Many times in cool but humid weather, ALL the windows can mist over, and starting the AC eliminates it quickly (defrosters don't need to be on to do this).
You mentioned that you thought it was running even when the light was out. I suspect you are right about that, at least, I think this can happen under certain conditions (such as running the defroster). But I also suspect that if you then turned it on (by pressing the AC button and turning on the light) and then turned it off by pressing the AC button again, that this would shut it off for real. If you try this and reach a conclusion, I'd be interested to hear.
Okay, so I had to go out to the garage with the door open and test this. It's near 70 degrees in the car and out. Here's what I did:
  • Started the car normally, with HVAC on AUTO and set at 72 degrees. Air coming out of the vents was definitely cooled, but AC light was off.
  • I then pressed the AC button, which turned on the light, and turned OFF the AUTO button light, but did not leave it that way long (did not want to greatly cool the HVAC system). Cool air continued.
  • I then turned OFF the AC (light goes out), and of course the AUTO button light stays off; we're using it manually now. Cool air slowly warms up to room temperature. As you say, turning AC ON, then OFF, will /keep/ it off, if nothing else is pressed.
  • I then pressed AUTO, at which point the AC light still stays out, but cooled air begins to exit the vents. It stayed that way, with the AC obviously on, but not indicated.
  • I lowered the temperature setting slowly: the fan speed went up, moving more and more cool air, but the air stayed cool, and the AC light remained off.
  • Once I reached Max Cool (as low as it can be set), the AC light came on, as did the Recirculate light. Obviously, lots of cool air.
  • Changed the temperature back to 72 degrees: fan slowed down, but cool air kept coming from the vents. Recirculate light stayed on, until turned off, or Auto was hit again.
It's obvious to me from the above that the AC compressor is working, probably much of the time, when in AUTO mode, but without any indication that it is. Basically, you cannot depend on the AC light to indicate if the AC is on in AUTO model Once the AC button is pressed, you are no longer in AUTO mode, so if you then turn OFF the AC, it /will/ be off, which is what you are looking for.

Hope this helps. Happy Heating! (And Happy Thanksgiving!)
 

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It's obvious to me from the above that the AC compressor is working, probably much of the time, when in AUTO mode, but without any indication that it is.
Today's automobiles generally use a variable compressor. They no longer have a clutch that cycles the compressor on and off when cooling is called for. That could be why the A/C light doesn't come on, or it's simply the way the engineers programmed the system. It's far more efficient compared to the older cycling compressors.

I leave my system on auto almost full time. The only time I would switch it off was on temperate days that I didn't really need heat or cooling. Just to add that extra mile or so of range in EV mode. That said, during the summer I could easily exceed the EPA rating of 26 miles (which is made with HVAC off) just driving normally and with the A/C on. The best I did was 34 miles, and I'm sure if I was trying to drive for max economy it would have been higher.
 
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