GM Volt Forum banner

1 - 11 of 11 Posts

·
Registered
Joined
·
23 Posts
Discussion Starter #1
Here in Toronto, as in much of the mid and east of North America, 2013-14 has been a relatively cold winter (unlike our non-winter of 2011-12). This has been my second winter with my 2012 Volt (which I love) and it has performed very well, but I have a few observations and questions. My trips and commutes have been quite short which has caused me to burn more gasoline than I would care to. A few weeks ago when I started the car it said it needed to run the gas engine for about 10 minutes since the engine had not been in use much, which surprised me since the engine had been coming on regularly to make heat. So is this behaviour activated to thoroughly heat up the engine in order to "clean" it out? Another trick I learned here on this site is to put the climate control in "comfort" mode which usually prevents the gas engine from coming on again (after the initial start) in very cold weather. This has been a very valuable thing to know, thanks! I have also wondered about the relatively high fuel consumption to heat the car up and I was wondering if a more fuel efficient method might be possible? I know this is nit-picking, but I still wonder. Another thing I wonder about is Volt regenerative breaking in cold weather because it is said the Tesla S does not do so until the battery gets sufficiently warm. Also, what about hybrid cars such as the Prius, is regenerative breaking thwarted by very cold temperatures? In the Leaf?
 

·
Registered
Joined
·
2,351 Posts
Here in Toronto, as in much of the mid and east of North America, 2013-14 has been a relatively cold winter (unlike our non-winter of 2011-12). This has been my second winter with my 2012 Volt (which I love) and it has performed very well, but I have a few observations and questions. My trips and commutes have been quite short which has caused me to burn more gasoline than I would care to. A few weeks ago when I started the car it said it needed to run the gas engine for about 10 minutes since the engine had not been in use much, which surprised me since the engine had been coming on regularly to make heat. So is this behaviour activated to thoroughly heat up the engine in order to "clean" it out? Another trick I learned here on this site is to put the climate control in "comfort" mode which usually prevents the gas engine from coming on again (after the initial start) in very cold weather. This has been a very valuable thing to know, thanks! I have also wondered about the relatively high fuel consumption to heat the car up and I was wondering if a more fuel efficient method might be possible? I know this is nit-picking, but I still wonder. Another thing I wonder about is Volt regenerative breaking in cold weather because it is said the Tesla S does not do so until the battery gets sufficiently warm. Also, what about hybrid cars such as the Prius, is regenerative breaking thwarted by very cold temperatures? In the Leaf?


Blame ERDTT which cares absolutely NOT if your interior is already warm since it will cause you to burn fuel when the temp drops just below a random threshold determined by a cheap @$3 sensor. At least spring/summer should be arriving soon!:cool:
 

·
Registered
Joined
·
152 Posts
Another thing I wonder about is Volt regenerative breaking in cold weather because it is said the Tesla S does not do so until the battery gets sufficiently warm.
The Tesla's battery is warmed by the electric motors, whereas your Volt has an electric resistive heater to warm the battery. Thus the Tesla needs to be driven for a few miles before its full power will be available when it is very cold outside.

Also, what about hybrid cars such as the Prius, is regenerative breaking thwarted by very cold temperatures? In the Leaf?
The Prius immediately starts the engine to generate heat, and the new models have resistive heaters in line with the regular heater core to keep the air warm at low speeds where the engine does not run all the time. As for the Leaf, I have no first hand knowledge, but as I understand it winters suck in that vehicle.
 

·
Registered
Joined
·
2,867 Posts
It seems strange but when the Volt has Engine Running Due To Temperature (ERDTT) does not count towards Engine Maintenance Mode (EMM) so that is why you had the EMM even though there was plenty of engine use. Has the only engine use been ERDTT and not due to exceeding the EV range? If so, that explains the EMM you reported.
 

·
Registered
Joined
·
152 Posts
It seems strange but when the Volt has Engine Running Due To Temperature (ERDTT) does not count towards Engine Maintenance Mode (EMM) so that is why you had the EMM even though there was plenty of engine use. Has the only engine use been ERDTT and not due to exceeding the EV range? If so, that explains the EMM you reported.
I've never seen EMM run as I use the engine quite a bit, but ERDTT never allows the engine to warm past 150. For the engine to run efficently and clean itself it must get up to an operating temperature of 180-190 for a moderate amount of time.
 

·
Registered
Joined
·
1,979 Posts
...The Prius immediately starts the engine to generate heat, and the new models have resistive heaters in line with the regular heater core to keep the air warm at low speeds where the engine does not run all the time.
Actually not quite true. Since 2010 there's been an exhaust-to-coolant heat exchanger to shorten the warmup cycle.

The engine will be kicked on if the coolant temperature drops too much relative to the heater setting.
 

·
Registered
Joined
·
562 Posts
Maybe ERDTT didn't run long enough at a high enough temperature to meet the minimum necessary to reset the counter for the maintenance runs?
If you shut it off before the maintenance run is done, it starts at a lower % than before, depending on how long it's been since it was shut off (maybe depends on how much the engine's cooled off?)
 

·
Registered
Joined
·
23 Posts
Discussion Starter #8
It seems strange but when the Volt has Engine Running Due To Temperature (ERDTT) does not count towards Engine Maintenance Mode (EMM) so that is why you had the EMM even though there was plenty of engine use. Has the only engine use been ERDTT and not due to exceeding the EV range? If so, that explains the EMM you reported.
Yes the engine was only on due to cold weather, not because I exceeded EV range.
 

·
Registered
Joined
·
152 Posts
Actually not quite true. Since 2010 there's been an exhaust-to-coolant heat exchanger to shorten the warmup cycle.

The engine will be kicked on if the coolant temperature drops too much relative to the heater setting.
Trippy! I just looked up that system, rather neat compared to the old one.
 

·
Registered
Joined
·
1,409 Posts
Someone tell me I'm the only one but mine also does not consider [partial at least] warm up cycles. Every couple of weeks mine comes on the last 1/4 mile or less from home and therefore runs until I shut the car off in the garage.

And I still get EMM messages too.

I guess that is one of the features that would make you want to buy a new car rather than expect a software update.
 

·
Registered
Joined
·
350 Posts
Here in Toronto, as in much of the mid and east of North America, 2013-14 has been a relatively cold winter (unlike our non-winter of 2011-12). This has been my second winter with my 2012 Volt (which I love) and it has performed very well, but I have a few observations and questions. My trips and commutes have been quite short which has caused me to burn more gasoline than I would care to. A few weeks ago when I started the car it said it needed to run the gas engine for about 10 minutes since the engine had not been in use much, which surprised me since the engine had been coming on regularly to make heat. So is this behaviour activated to thoroughly heat up the engine in order to "clean" it out? Another trick I learned here on this site is to put the climate control in "comfort" mode which usually prevents the gas engine from coming on again (after the initial start) in very cold weather. This has been a very valuable thing to know, thanks! I have also wondered about the relatively high fuel consumption to heat the car up and I was wondering if a more fuel efficient method might be possible? I know this is nit-picking, but I still wonder. Another thing I wonder about is Volt regenerative breaking in cold weather because it is said the Tesla S does not do so until the battery gets sufficiently warm. Also, what about hybrid cars such as the Prius, is regenerative breaking thwarted by very cold temperatures? In the Leaf?
Yup, happened to me too. ERDTT is the only time the ICE runs because I rarely exceed the battery capacity. A couple of days ago we got the first EMM in the 17 months we own the car, despite many ERDTT events this winter. Also in Toronto. This winter we got ERDTT almost every day. Really sucks gas. Dropped my mpg (imperial gallons of course) all the way to 260. Bummer :)
 
1 - 11 of 11 Posts
Top