: How to Minimize Engine Running in Cold Weather



ClarksonCote
01-24-2013, 08:53 AM
If you take trips that don't use all your battery up, but still end up having to run the engine due to low temperature, this thread is for you.

The best way to minimize the amount of times that the engine runs is to use COMFORT heating mode. While a bit counterintuitive, this mode provides more heat to the coolant fluid, and keeps its temperature above the point where the engine would come back on, for a longer amount of time.

Additionally, if you're warm enough in the cabin, turn the fan setting down, but not all the way (which would cause COMFORT mode to turn off). Turning down the fan will preserve more warmth of that coolant fluid, again doing better to prevent the engine from turning on due to low temperatures.

A couple simple examples:
1) My engine used to come on 2, even 3 times in 20F degree weather on an 8 mile trip, using ECO heating mode.
> Switching to Comfort mode reduced this to only the initial engine run due to low temperature.

2) In 10F degree weather, comfort mode would still cause the engine to come on twice
> Decreasing the fan speed in Comfort mode once I was warm, the engine only ran the initial time this morning for this same commute, despite it being minus 4F outside.

So if you want to maximize battery use in cold weather and minimize ERDTLT* then use COMFORT mode with a low fan setting.

Enjoy!

*Engine Running Due to Low Temperature

ghostgs1
01-24-2013, 09:20 AM
Thank you for this tip, I am anxious to give this a try. There is nothing more irritating to me, as to have the engine come on in this situation.

NWeiner14
01-24-2013, 09:39 AM
Actually, the true remedy to this problem - providing you have a 2013 Volt - is to go to the Vehicle Settings on the center console, and under "engine assisted heating" set it to "very cold temperatures". Of course it's so cold out here that the engine will still come on, but at least through most of the rest of this winter it would not if you make this change.

ClarksonCote
01-24-2013, 09:50 AM
Actually, the true remedy to this problem - providing you have a 2013 Volt - is to go to the Vehicle Settings on the center console, and under "engine assisted heating" set it to "very cold temperatures". Of course it's so cold out here that the engine will still come on, but at least through most of the rest of this winter it would not if you make this change.

Yes, that allows the engine to only turn on at a lower outside temperature, but my post was aimed at people that are experiencing this... regardless of setting/model year, and want to prevent subsequent engine runs to maximize battery. Even with the "Very Cold Temperatures" setting, the information provided above minimizes this engine running when it does occur.

Neromanceres
01-24-2013, 09:57 AM
On 2013 models (and very late 2012) there is an option to turn off engine assisted heating while plugged in so to add if you precondition your car you will pre-warm the coolant without the engine starting. So when you get moving you will minimize and possibly delay the first instance of the engine running due to temperature.

saghost
01-24-2013, 10:55 AM
On 2013 models (and very late 2012) there is an option to turn off engine assisted heating while plugged in so to add if you precondition your car you will pre-warm the coolant without the engine starting. So when you get moving you will minimize and possibly delay the first instance of the engine running due to temperature.

Do you have any evidence of this? (minimize or delay - I know the setting exists.)

When we ran a test last winter, we learned that the preheat doesn't affect the engine coolant temp - the cross link valve stays closed and the heater only warms the coolant in the cabin side. Thus, the car still starts the cycle at the same time, and still runs until the engine side is hot and the system cross links. After that, the heater is warming engine coolant and will delay additional ERDTT cycles, which was the point of the original post. Until it cross links, I don't think it affects ERDTT.

flipy
01-24-2013, 10:55 AM
The trick above works on my late model 2012... I pre-condition the car twice... It is -30celcius ( -22F ) outside. I set the climate on COMFORT 22.5C and fan low. As soon that I unplug the car ( the car is being conditioned or the car is turned on ) the engine will start with ERDTLT. But with the settings above , It will only do it once for my 25KM commute ...

My next experience will be to see if I burn less gas if I wait for the ERDTLT to finish while still in the driveway or if I will burn more gas if I drive away while still in the ERDTLT cycle.. :-)

geisemann
01-24-2013, 11:02 AM
From my NEW experience with the volt at cold temps it seems the only way to avoid running the gas engine with my 2012 is two ways.

--Comfort mode with a low fan speed

OR

--Fan off everything off drive it well! It will heat up the battery but no place for the heat to go. This method you need a hat gloves and thick coat!

If you use the FAN ONLY setting or ECO setting it will use the battery heat to try to heat cabin this is bad because the battery will get too cold and boom engine comes on to heat coolant to battery.

That being said I notice if you PREHEAT the volt from your house before you leave it uses more gas because it runs the engine once and then again when you pull out.

So if interested in saving fuel when really cold below 25 better not to preheat. I know sounds weird but seems the case. However if above 25 then you need to preheat as the engine wont come on and it will heat the battery using the grid.

It seems that GM used a 2 KW heater and its good for temps above 25 or so and then the engineers figured that it was better at that point to take advantage of waste heat from the engine.

However I don't pay for electricity at work or many places I drive so a larger heater would be fine with me and less range.

The volt needs

A clock inside like a thermostat its so complex programming this would be very easy. So it can be programed to heat up before you get to your car a few hours ahead of time like your thermostat at home. Also they should have designed a slow heat up cycle for the battery activated by this alarm clock . See in a gas car this was not really worth it but in a electric car where you can build up heat slowly like a hot water heater this is useful.

Auto charge door open. When its cold the volt need to recognize your at home from the GPS so it opens the charge door automatically you just plug in. hitting the switch to open door every day is OK but just a nice to have you simply just take the signal off the gps .

I am a electrical engineer and these could be firmware updates if GM were nice hint hint!

Neromanceres
01-24-2013, 11:11 AM
Do you have any evidence of this? (minimize or delay - I know the setting exists.)

When we ran a test last winter, we learned that the preheat doesn't affect the engine coolant temp - the cross link valve stays closed and the heater only warms the coolant in the cabin side. Thus, the car still starts the cycle at the same time, and still runs until the engine side is hot and the system cross links. After that, the heater is warming engine coolant and will delay additional ERDTT cycles, which was the point of the original post. Until it cross links, I don't think it affects ERDTT.

Two days ago I did a remote start twice. When I unplugged the car the engine did start. But as soon as I got in and started the car and started backing out the engine shut off (~30 seconds elapsed) and stayed off for a couple minutes before starting again.

Matt979
01-24-2013, 11:19 AM
As this is my second winter with the Volt, the comfort settings makes a hugh difference. That said if turning the fan to low is not an option just turn the heat up to 72 or so to give the system a little margin which also will reduce engine starts.

Personally I have got past the no gas usage stage and think its good that the gas engine get some action as its most of the time just sitting there, with some preheating and then comfort at 72 the car is comfortable even at 0 degress and still get awesome MPG.

scottf200
01-24-2013, 12:07 PM
Excellent thread. It will save a lot of gas and frustration.

For details and more background that did empirical testing on this excellent tip see this thread.

COMFORT-setting-limiting-quot-Engine-Running-due-to-low-temperature-quot-ERDTLT
http://gm-volt.com/forum/showthread.php?11181-COMFORT-setting-limiting-quot-Engine-Running-due-to-low-temperature-quot-ERDTLT

~114F (~45C) seemed to be the magic ICE water temp I saw in testing to help clarify what various people before me saw/suggested.

ClarksonCote
01-24-2013, 12:55 PM
Excellent thread. It will save a lot of gas and frustration.

For details and more background on this excellent tip see this thread.

COMFORT-setting-limiting-quot-Engine-Running-due-to-low-temperature-quot-ERDTLT
http://gm-volt.com/forum/showthread.php?11181-COMFORT-setting-limiting-quot-Engine-Running-due-to-low-temperature-quot-ERDTLT

~115F seemed to be the magic ICE water temp I saw in testing to help clarify what various people before me saw/suggested.

Thanks Scott for the always-helpful link references to past threads!

Here's a suggestion for GM... It's too bad the Volt doesn't look at the ICE water temp before determining to start the engine for the first time.

For example, with my 2011, if my car is nice and warmed up from the engine, and I turn off the car, go into a store for 30 seconds, and come back, the engine will start up again when the car is turned back on. Granted, it won't run for as long, but it'd be nice to have the condition be:

"If outside temperature is less than (SET_POINT) AND coolant temperature is less than (COOLANT_LOW_TEMP) then run engine until (COOLANT_HIGH_TEMP)"

versus

"If outside temperature is less than (SET_POINT) then run engine until (COOLANT_HIGH_TEMP)"

This kills a trip's MPG if you're stopping at a lot of places. Granted, you could leave the car on while going into different stores with Comfort climate mode on, but you're using a lot more battery here and some also don't want to leave their car running, even if it is locked up.

ShannonVolt
01-24-2013, 01:37 PM
If you take trips that don't use all your battery up, but still end up having to run the engine due to low temperature, this thread is for you.

I stand behind what ClarksonCote said above. IT WORKS!! Gained more MPG's and allowed me to run more on battery. Did it today!!

I recommend we sticky this bad boy.

Joeyvolt
01-24-2013, 01:41 PM
I would have never known this.

When the engine runs, I automatically put it in Comfort. I figured why use Eco, might as well enjoy the heat if you must burn fuel.

ClarksonCote
01-25-2013, 11:08 AM
I would have never known this.

When the engine runs, I automatically put it in Comfort. I figured why use Eco, might as well enjoy the heat if you must burn fuel.

Well, in other scenarios, I use Fan Only so that only the waste heat from the engine is used, without the resistive heater or occasional A/C to remove humidity.

pdt
01-27-2013, 05:05 PM
Thanks for the tip. Comfort with low fan works great. Even with <15F temperatures, it only gave me the one initial engine start, then nothing for the remainder of the battery depletion. Sweet.

Volusiano
02-01-2013, 07:51 AM
--Fan off everything off drive it well! It will heat up the battery but no place for the heat to go. This method you need a hat gloves and thick coat!

If you use the FAN ONLY setting or ECO setting it will use the battery heat to try to heat cabin this is bad because the battery will get too cold and boom engine comes on to heat coolant to battery.This is not correct because the thermal loop to heat/cool the battery does NOT have the ICE in this loop, and it is completely separated from the thermal loop to heat the cabin which includes the ICE in this loop.

The only thing that can heat the thermal loop for the battery is the variable high voltage heating element inside of the battery housing. As long as there is juice in the battery, this heating element will continue to work to heat up the battery if it gets too cold. If there's no more juice in the battery, and the battery is too cold, then of course the ICE has to kick in to generate electricity to power this battery electric heater. But there's no way the hot liquid generated by the ICE heat can ever be used to cool the battery because it's on a completely separate thermal loop for the cabin heating.

The high voltage electric heater used to heat the coolant in the ICE/cabin thermal loop is a different/separate heater than the heater in the battery housing used to heat up the battery.

The whole discussion here is based on the assumption that there's plenty of juice in the battery to power the electric heater in the ICE/cabin thermal loop. If that's the case, then there should be plenty of juice left in the battery to power the battery heater as well. So in this scenario, the ICE would never kick in just to power the battery heater to warm up the battery.

Steve-o
02-19-2013, 11:39 AM
I have read all the suggestions here with great interest, but my 2013 Volt, built in December 2012 I think, locks out the electric heater once the engine has heated the coolant beyond a certain temperature. The first time the engine starts, I switch to comfort mode and turn the temperature up to HI (above 86 degrees or so; lower temperatures behave the same) and the electric heat turns on, then the electric heat turns off while the engine is still running. From then on, the engine is providing all the heat and the electric heat never turns on again.

I have wracked my brain trying to figure this out, but it seems that the coolant temperature at which the electric heat turns off (because it is warm enough) is below the minimum coolant temperature where the engine turns back on. This is with the engine assisted heating configured to turn on at either 15 degrees or 35 degrees. The behavior is the same either way.

So, although I would love to use a little more electricity and a little less gas, there just doesn't seem to be any way to do anything to affect the behavior of engine assisted heat. This is with a car that I think was built two months ago. Do the rest of you who have succeeded in minimizing ERDTLT have earlier models? (Probably a silly question, since you were here before me.) Has anyone else tried this with a newer car?

It's frustrating, but I still can't complain about 115 mpg lifetime average during the worst weather of the year for Li-ion batteries.

SolarVolt
02-19-2013, 01:14 PM
I would have never known this.

When the engine runs, I automatically put it in Comfort. I figured why use Eco, might as well enjoy the heat if you must burn fuel.

I believe when the engine is running, the elecrical heater is disabled. Selecting ECO or COMFORT while the engine is running will not change the temperature comming out of the vents. Only the temp setting will adjust the heat output at that point. Once the engine shuts off (because the coolant has reached it setpoint temp), the ECO or COMFORT setting comes back into play again.

@Steve-o: Not certain on the 2013 models. Could it be that your fan setting is so high (drawing too much heat off the coolant loop) for the electric heater to maintain the coolant temp? As a test, you can set your fan to its lowest setting, still in COMFORT mode. After the engine runs the first time, your electric heater should be able to maintain your coolant temp above the engine run setpoint.

saghost
02-19-2013, 01:32 PM
The electric heat will be off while the engine is running. On the older Volts, the heat comes back on progressively as the coolant temperature falls after the engine shuts off. Are you sure you don't get any electric heat after the engine has been off for a while, before it comes on again?

Steve-o
02-19-2013, 01:54 PM
To add to my previous post, I have tried comfort mode with various temperatures and fan speeds 1, 2, and 3 (0 won't help, obviously). There is certainly heat coming from the vents, provided by the engine, but the climate display shows the electric heat OFF after the engine has run for a while. Both the engine and the electric heat are on for a minute or so, but then the electric heat turns off, never to turn on again, because the engine is maintaining the coolant temperature, I assume, above the electric heat set point. I don't have to wait long for the engine to run again, either. It is about a minute between runs, meaning the engine is running most of the time in cold weather (14 degrees this morning, for instance).

I have talked to a Volt adviser, a Volt adviser specialist, and a service technician at the dealer, and no one can explain how it all works. Apparently, it is especially challenging for them, because it keeps changing. The service technician has given me the latest software update related to heat, which did make a difference, since the electric heat never turned on before, but he can't do anything more for me.

I still love the car, though. I just wish I understood it.

frankydude
02-19-2013, 02:01 PM
The engine assisted heating is probably the engineering part of the Volt that gets the most criticized, and for good reasons.
On 2011 and 2012s, the ICE engine will start when you precondition AND you are plugged! - If you are in a
garage, here comes the fumes! Some geniuses will suggest to open the garage door - when it's -20C and you want to
heat up the Volt - that defeats the whole purpose of preconditionning. The ICE should simply never start when plugged.

The heating system won't let you choose if you want to drain more your battery and have less range but the ICE stays OFF,
or not. The algorithm is: If outside temps is below -4C then start the engine.
You go to the grocery store - 0,5 mille - if below -4C the ICE kicks ON. Very nice to show how "green" you are!
Enter the grocery, buy what you need, pay, go out in the Volt, start and here again the darn ICE starts...
How good is it for an ICE engine to start and stop shortly after at -20C ambient temperatures?
Condensation builds up in the engine, and has not much chance to get evacuated.

And why start right away when pushed on? go figure.
There could be a simple screen with: Do you want the ICE to start? Then the driver can say Yes or No, as was done for the
Engine Maintenance Mode. If the driver knows he wants to do a long trip, he will answer Yes. If it's a short trip - No.

Of course, if you stay in California or in Florida, you don't even know that there is engine assisted heating, as you don't get bugged by it.
But if you get your Volt and drive it around Montreal for a week, you will understand what the conception problem is.
ICE assisted heating has to be revised and corrected, for those design bugs.

Francois
B2653

mdanieltech
02-16-2014, 04:31 PM
--Comfort mode with a low fan

I'm buying a new volt next week is this still true for saving as much battery as possible??

I live in Michigan and this winter is awful just trying to see what's the best idea to save as much battery as possible.

Thanks!

css28
02-16-2014, 04:43 PM
I'm buying a new volt next week is this still true for saving as much battery as possible??

I live in Michigan and this winter is awful just trying to see what's the best idea to save as much battery as possible.

Thanks!

That only works on pre-2013s. Below 15 F you won't make your 36 mile range doing this anyhow.

Over the past week I've gotten by burning less than .75 gallons of gas with ERDTT set to "very cold" That's over 38*5 = 190 miles (for over 250 mpg).

This ERDTT avoidance stuff is mostly important for those who are running short trips in the very cold.

In your case the ERDTT will be what keeps you comfortable and safe with very little gas.

mdanieltech
02-16-2014, 05:49 PM
That only works on pre-2013s. Below 15 F you won't make your 36 mile range doing this anyhow.

Over the past week I've gotten by burning less than .75 gallons of gas with ERDTT set to "very cold" That's over 38*5 = 190 miles (for over 250 mpg).

This ERDTT avoidance stuff is mostly important for those who are running short trips in the very cold.

In your case the ERDTT will be what keeps you comfortable and safe with very little gas.

so should I do the same thing as you set mine to very low temperature?

css28
02-16-2014, 07:11 PM
Our situations are very similar so I'd say yes.