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Discussion Starter · #1 ·
Yesterday during a longer road trip I noticed that my power gauge readout changed when I switched drive modes.
I was going constant speed at 67MPH (Cruise control set) on a straight and level highway in MOUNTAIN MODE. The Power gauge showed 13KWh.
The battery was at 50% charge level.
I switched to NORMAL mode, the ICE turned off and the POWER GAUGE readout (on the Driver Information Center) switched to 22KWh being used. Getting curious, I switched back to MM, ICE came on and the readout switched back to 12-14KWh. Again, back to NORMAL and the readout jumped to a value between 21 and 24KWh.
All at same speed, straight and level road.
Thinking about it, my uneducated guess is, that in MM the ICE provided some direct torque to the wheels which is not accounted for on the display. Am I correct?

Also I noticed that detent/friction issue in the steering wheel for the first time. Very lightly but noticeable. I received the letter from GM a few months ago, that they would fix it if it occurs to my 13 VOLT. Should I have it done? Or is it a waste of time?
 

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Yesterday during a longer road trip I noticed that my power gauge readout changed when I switched drive modes.
I was going constant speed at 67MPH (Cruise control set) on a straight and level highway in MOUNTAIN MODE. The Power gauge showed 13KWh.
The battery was at 50% charge level.
I switched to NORMAL mode, the ICE turned off and the POWER GAUGE readout (on the Driver Information Center) switched to 22KWh being used. Getting curious, I switched back to MM, ICE came on and the readout switched back to 12-14KWh. Again, back to NORMAL and the readout jumped to a value between 21 and 24KWh.
All at same speed, straight and level road.
Thinking about it, my uneducated guess is, that in MM the ICE provided some direct torque to the wheels which is not accounted for on the display. Am I correct?

Also I noticed that detent/friction issue in the steering wheel for the first time. Very lightly but noticeable. I received the letter from GM a few months ago, that they would fix it if it occurs to my 13 VOLT. Should I have it done? Or is it a waste of time?
I have a MY2012 so can't speak about power gauge changes.

My understanding of the detent/friction in the steering is that it can be gotten rid of by making some lock to lock turning of the steering wheel - obviously at very low speed. A deserted parking lot would be an ideal place to do that, although in my situation, getting into and out of my garage requires going lock to lock.
 

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Not exactly sure what you were looking at, but when in Mountain Mode the car reserves a few kWh of energy. Are you weren't looking at miles? When switching between Normal and MM you should see your range increase or decrease by 12-13 miles. Or do you mean kW? That might also be accurate since the generator will not be remotely as efficient as the battery.

Note you never have 24 kWh available. The battery only holds less than 18 kWh and a good bit of that is reserved.
 

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You are correct. Under certain circumstances the ICE does link to the ring gear and provides some power directly to the wheels.
 

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Under certain circumstances the ICE does link to the ring gear and provide some power directly to the wheels.
But any power going directly from the engine to the wheels should still show up in the displayed "kW" (not "kWh" :p) figure in the power flow display.

So I'm stumped as to why the OP would be seeing what he's seeing.

HighRollsVoltDriver,
Out of curiosity, why are you using Mountain Mode in the first place?
 

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But any power going directly from the engine to the wheels should still show up in the displayed "kW" (not "kWh" :p) figure in the power flow display.

So I'm stumped as to why the OP would be seeing what he's seeing.

HighRollsVoltDriver,
Out of curiosity, why are you using Mountain Mode in the first place?
It is a direct mechanical link. Part of the power goes directly to the wheels with no electrical power being generated, hence no KW being generated for the power bypassing the electrical system.
 

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It is a direct mechanical link. Part of the power goes directly to the wheels with no electrical power being generated, hence no KW being generated for the power bypassing the electrical system.
Is this right?

I had always thought that the displayed kW figure included all power consumption -- both electrical and mechanical.
 

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As the engine never directly turns the transmission (it's through MGA), I presumed they were able to measure the actual power output based on the stats of MGA and MGB.
Of course, I'm no electrical engineer.
 

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Discussion Starter · #9 ·
Sorry, of course, I meant KW, not KWh. I know the difference, just a brainfart.

The manual says: "The power gauge informs the driver of the total power coming from the engine or battery to operate the vehicle...".
From this I understand, that it should not make a difference, where the power comes from. It should display the TOTAL power. That includes mechanical torque, right?http://gm-volt.com/forum/images/smilies/confused.png

When I saw 13KW at 67MPH, it appeared very low to me and I initially thought that the wind must have given me a good push. Indeed it was windy. Could tell from the tumble weeds I was racing with. I figured, that I could make the 20 miles to the next town (and through it) on battery and go back to MM afterwards again. My EV miles prediction showed 15 miles but was not really reliable because I had started my trip in 14 inches of fresh snow and freezing temps with full heat on. Down in the desert it was dry and in the 40´s with a good tailwind. When I switched to NORMAL, I was quite surprised that it showed so much more on the gauge, although 22KW was a more reasonable value for the speed that I was going. I switched back and forth repeatedly to confirm it. I know I know, not really good for the clutches and the ICE... But I was curious.

BTW after that tittle test program I made the 18 remaining miles on battery to and through that next town. Switched back to MM when I was at highway speed again after that town with 2 indicated EV miles to go.

Another thing I noticed: I cannot switch directly from MM to HOLD even with ICE OFF. Have to go to NORMAL first. The manual says that you have to be in an electric drive mode. Isn´t MM with ICE off an electric mode?

To JSMAY:
I like to use MM when I cruise along. Hate to have an empty battery. It´s like an empty beer mug. I have to have it refilled.
No, seriously, the use of MM during long trips allows me to go pure electric when I approach cities or even little towns. I like it better to go slow on electric. Also, yesterday further down the road I still had a 9 miles long 2500ft uphill stretch ahead of me. I don´t like to climb mountains with an empty battery. The ICE does not rev up that high and that long when the battery is partially charged.
Usually I try to make a pinpoint landing to have the battery deplete just when I reach my destination with a known good charge opportunity. It´s like playing a game.


To jbakerjonathan:
Will try the lock to lock turn on the steering wheel next time I feel the detent. Thanks for the advice.

To all who will tour Northern New Mexico in the future, I stayed at 2 places, where the hotel/lodge manager let me charge my VOLT on any outdoor outlet:
Garrett´s Desert Inn near downtown Santa Fe (2 nights), Old Santa Fe Trail
Riverside Lodge & Cabins in Red River, Main Street (1 night)

During an overnight stay in one of the Earthship homes near TAOS, NM I just charged 1KWh or so, because those houses are off grid and and their solar battery is just slightly bigger than the VOLT´s HV battery. But still - it works.

On all opportunities I just used the default 8A setting. I better be safe on outlets I don´t know.

Sorry for drifting off topic...

Love my VOLT more than ever!
 

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I have noticed too that you can't go from MM to hold. Gotta get back to Normal first. I prefer to use hold to retain battery charge rather than MM to build it back up. MM is pretty noisy when it's building charge and powering the car. I've noticed the Volt dips into the battery reserve in hold similar to in MM when climbing, then builds it back up when power demand decreases.
 

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I have noticed too that you can't go from MM to hold. Gotta get back to Normal first. I prefer to use hold to retain battery charge rather than MM to build it back up. MM is pretty noisy when it's building charge and powering the car. I've noticed the Volt dips into the battery reserve in hold similar to in MM when climbing, then builds it back up when power demand decreases.
...and it probably is more expensive to charge the battery with the genset. I believe that charging in MM to the 40-50% level takes more gasoline than running out the battery charge and driving in CS, where the battery is kept at a lower level of charge.

My understanding of why the lock to lock manipulation works, in lieu of a SW update, is that the system gets "recalibrated" by sensing the physical limits of the range. How often one has to do that manipulation, one set of lock to lock, or "x" times before recalibration is achieved I don't know.
 
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