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Hi everyone: I getting close to pulling the trigger on a Niro, just got to check out a few more things and then get my wife on board.

I'm curious about the auto stop and start feature: If running in ICE mode and you you are stopped at a light, does the heat and AC continue to run or shut off when the ICE engine shuts off? Thanks.
 

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Apparently any time the IC engine is off AC and heat are not producing but the fan works and whatever heat or cool is in the systems will be transferred. There also may be a provision to keep the IC engine running.

As mentioned, it's quite transparent. In pure EV even when the IC is only producing heat it also charges the battery
 

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A/C is totally electric so it keeps running when the ICE is off. When A/C is on the only time the ICE will come on is if the HV battery is low.
 

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A/C is totally electric so it keeps running when the ICE is off. When A/C is on the only time the ICE will come on is if the HV battery is low.
Yes. Some people think that somehow the A/C needs the engine running. Nope.

I'd also add you shouldn't expect this car to start/stop the motor the way you think a hybrid does. The Niro has programming in some ways similar to the Nissan eNote where it will run at a constant engine RPM regardless of speed (or stop) not only for heating but also in city driving to maintain maximum efficiency with constant rpm and let the electric motor do more of the work.
 

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Yes. Some people think that somehow the A/C needs the engine running. Nope.

I'd also add you shouldn't expect this car to start/stop the motor the way you think a hybrid does. The Niro has programming in some ways similar to the Nissan eNote where it will run at a constant engine RPM regardless of speed (or stop) not only for heating but also in city driving to maintain maximum efficiency with constant rpm and let the electric motor do more of the work.

You are correct about the first part, that the IC engine sometimes runs at a fixed RPM while driving. However, it is only charging the battery and/or keeping itself warm. It is NEVER providing acceleration (power to the wheels) when it's doing that.

The engine can only either be 100% connected to the wheels, or 0% connected. Any percentage in between (for any longer than is necessary for gear shifting) would toast the clutch. The car would require a CVT to do what you're describing.
 

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"Yes. Some people think that somehow the A/C needs the engine running. Nope. "

So you are saying that there is another electric motor to run the AC compressor.
 

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"Yes. Some people think that somehow the A/C needs the engine running. Nope. "

So you are saying that there is another electric motor to run the AC compressor.

Correct. The A/C will blow cold without the ICE ever running. When remote-started and AC turned on, the ICE would only turn on if the battery starts to run low, otherwise it will not turn on. The ICE is otherwise unused for the AC system.



The same is not true for the heater - there is no electric heating element; the heater requires engine heat, and the ICE will always turn on when the heater is on, unless the engine coolant is already hot.
 

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The same is not true for the heater - there is no electric heating element; the heater requires engine heat, and the ICE will always turn on when the heater is on, unless the engine coolant is already hot.
While it is true that the ICE will always run if cabin heat is requested, I think we've established that there is a electric resistance heater included. It can't provide significant heat on it's own but it does assist when the ICE is still cold. This is actually a nice feature since the little bitty ICE can take some time to produce useful heat especially if it's just idling.

I was originally skeptical about the existence of this feature based largely on how anemic it is compared the similar setup in my previous VW Golf TDI, but it is there.
 

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While it is true that the ICE will always run if cabin heat is requested, I think we've established that there is a electric resistance heater included. It can't provide significant heat on it's own but it does assist when the ICE is still cold. This is actually a nice feature since the little bitty ICE can take some time to produce useful heat especially if it's just idling.



Even that is not true. The cars heating system pulls heat from the engine coolent system and additional heat from the exhust system. But if the radiator fluid that cools the engine is hot, then the ICE doesn't need to run if not required even if the heater is turned on. I have driven in cold weather to pick up my daughter and pulled into the parking lot to wait for her, putting the car in park and the engine shuts off but the climate control still has the heater working blowing nice warm air onto me. It can do that for a good 4-5 minutes until the engine coolent gets too cold and forces the ICE to turn back on to warm it back up. If the engine was warm, then usually it takes about 90-120 seconds of ICE runtime to get about 4-5 minutes of warm air before the engine needs to cycle back on again. This is at around the 25F temp outside, and as you can understand, the colder it is outside, the more the engine needs to stay on, and the shorter the warmth will last.
 

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Interesting stuff. Using residual heat is there any circulation or just the heat in the heater or exhaust?
 

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Interesting stuff. Using residual heat is there any circulation or just the heat in the heater or exhaust?
That is an interesting idea. I suppose there could be water circulation if the pump is electric and that could make the heat supplied to the cabin last a bit longer. Not sure it would be a net gain of efficiency on most trips though, you would then have to run the engine a bit longer to bring it back up to temp.
 

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That is an interesting idea. I suppose there could be water circulation if the pump is electric and that could make the heat supplied to the cabin last a bit longer. Not sure it would be a net gain of efficiency on most trips though, you would then have to run the engine a bit longer to bring it back up to temp.
I would think you would gain quite a bit of efficiency if you were smart about it. Once the engine is up to temp there is a lot of heat in the block and other engine components. With the engine off and no coolant flow that heat is lost. If you continue to circulate the coolant you can extract quite a bit of that energy from the thermal mass of the engine and use it to heat the cabin. Your average thermostat opens at around 200 degrees F (93C) whereas the normal max heater output temp would be around 130F (54C). That's quite a difference in temperature. If you assume the ICE is only needed for heat you can probably run the engine at a fairly low duty cycle and still keep the water temp above 130F. It's better still if you can load the engine a bit by using it to charge the battery at the same time. That will warm the engine a lot faster than just idling and extract more useful work from the ICE. There are too many variables to try to estimate the potential gains over running the ICE all the time when heat is required or even just using the residual heat in the heater core but I would be willing to bet they would be significant.

If you think about it, it's very similar to the pulse and glide technique used by hyper-milers.

Hybrids are fun. :nerd:
 

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You are correct about the first part, that the IC engine sometimes runs at a fixed RPM while driving. However, it is only charging the battery and/or keeping itself warm. It is NEVER providing acceleration (power to the wheels) when it's doing that.

The engine can only either be 100% connected to the wheels, or 0% connected. Any percentage in between (for any longer than is necessary for gear shifting) would toast the clutch. The car would require a CVT to do what you're describing.
I never said anything of the sort. How about instead of 'more of the work' use 'the work more of the time'...which of course is more of the work but is more distinct on the work being distinct.
 

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I would think you would gain quite a bit of efficiency if you were smart about it. Once the engine is up to temp there is a lot of heat in the block and other engine components. With the engine off and no coolant flow that heat is lost. If you continue to circulate the coolant you can extract quite a bit of that energy from the thermal mass of the engine and use it to heat the cabin. Your average thermostat opens at around 200 degrees F (93C) whereas the normal max heater output temp would be around 130F (54C). That's quite a difference in temperature. If you assume the ICE is only needed for heat you can probably run the engine at a fairly low duty cycle and still keep the water temp above 130F. It's better still if you can load the engine a bit by using it to charge the battery at the same time. That will warm the engine a lot faster than just idling and extract more useful work from the ICE.
Nice thought, but again, doubt it will save much. Extracting more heat from block means shorter engine off times, and more work to get the block back up to temp.

Seat heaters and wheel heaters and a heavy coat are the most efficient. Especially for BEVs.
 
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