[iridium130m]

Not for going, but for stopping. My theoretical Snow / Low traction drive mode would greatly reduce or disable regenerative breaking, forcing the volt to immediately use the traditional brakes, giving me immediate 4 wheel braking.

The Volt does great going in the snow as I am finding out today, but the regenerative braking in low traction situations, especially with the hidden patches of ice under the snow is frustrating and extends the stopping distance while the car sorts out the fact that the front wheels suddenly don't have enough grip because they just hit a patch of ice and switches over to the traditional brakes giving me 4 wheel braking like a traditional car.

I had this happen a couple times today and it jolts the drivetrain pretty severely as the front wheels loose then suddenly find traction, even in with careful breaking. If all 4 wheels were braking from the beginning, the stopping forces are more distributed giving me more stopping traction and hidden small patches of ice don't upset the car nearly as much.

As a work around, i started shifting the car into neutral when coming to stops in these conditions, forcing the car to disable regenerative braking and giving me much more predictable stopping.

 

[ViperRT10Matt]

For this and other reasons, I much prefer Tesla's model where the brake pedal has zero affect on regen, and is used to apply friction brakes only.

 

[Paulacton84]

usually, when there is hidden ice under falling snow, I try to drive so that I don't need much braking- I get to test this again tomorrow morning on the way to work..... But the alternative to what you suggest is to rely on the ABS and stabiity control to keep the car decelerating decently when one or more of the wheels are going to lose and reagin traction. This runs against years of teaching myself to let off the brake pedal in low traction situations, but it seems that pressing firmly and continuously does the best job of stopping when the ABS and SC are well designed. How I miss rear wheel drive.....

 

[jsmay311]

That's a pretty interesting idea. I wonder if there could be a way for the car to be smart enough to figure out when to enter this type of mode automatically. Otherwise a manual setting would work.

As a work around, i started shifting the car into neutral when coming to stops in these conditions, forcing the car to disable regenerative braking and giving me much more predictable stopping.

That's a pretty smart workaround. I assume ABS works normally in "N"?

 

[saghost]

One more option, if you're comfortable with heel-and-toe or two foot driving: we learned in testing that if the accelerator is slightly depressed (beyond the regen presumably,) the car will skip regen and go straight to the pads when you push the brake pedal.

 

[iridium130m]

My frustration is with the braking process the volt goes through...this process is fine in the dry and wet, but not ideal in the snow:

* try to regenerate first for braking
- because it is snow and I always use delicate braking, the volt won't attempt to use the friction brakes since light braking can be normally satisfied with regeneration. Sudden firm braking will go straight to friction brakes, but one should never be sudden with brakes or throttle in the snow (unless you are being a hooligan )
* if slick, one or both front wheels lock up then slide
- Note that I believe the open differential can potentially make this worse as only one tire needs to loose complete traction disrupt regenerative braking since the stopping force from both tires must goes through this open diff to make it to the single braking force, the motor / generator, versus have an independent brake force on each wheel with traditional brakes.
* volt figures out a wheel has stopped, so it then stops regenerating, switches to tradition braking, then ABS kicks in, taking time and extending the stopping distance.

The issue that I ran into with being firmer with the brake pedal and trying to trust the ABS is if the traction was suddenly restored before the traditional breaking / ABS kicks in, the drivetrain gets a heck of a jolt in the process as the stopped tire now suddenly gets shunted to spin again, sending that force through the diff, gearset, clutch and motor/generator: can you say shot motor generator bearing anyone?

My theoretical Snow / Low traction mode would reduce risk of damage to the drivetrain and give a more braking capabilities by using all four wheels independently and immediately in gentle stop situations such and snow/ice driving.

 

[iridium130m]

One more option, if you're comfortable with heel-and-toe or two foot driving: we learned in testing that if the accelerator is slightly depressed (beyond the regen presumably,) the car will skip regen and go straight to the pads when you push the brake pedal.

great thought, i will try that next time I am out!

 

[iridium130m]

That's a pretty interesting idea. I wonder if there could be a way for the car to be smart enough to figure out when to enter this type of mode automatically. Otherwise a manual setting would work.



That's a pretty smart workaround. I assume ABS works normally in "N"?

Seemed like it, i'll verify when I am out again this afternoon, but I thought I heard it pulsing like normal without the wait of regen/skip to occur.

 

[Steverino]

I know this is about "could be" and "in the future", but my today solution is to avoid both L or cruise in snow. That plus snow tires work very well.

 

[emartin00]

The issue that I ran into with being firmer with the brake pedal and trying to trust the ABS is if the traction was suddenly restored before the traditional breaking / ABS kicks in, the drivetrain gets a heck of a jolt in the process as the stopped tire now suddenly gets shunted to spin again, sending that force through the diff, gearset, clutch and motor/generator: can you say shot motor generator bearing anyone?

My theoretical Snow / Low traction mode would reduce risk of damage to the drivetrain and give a more braking capabilities by using all four wheels independently and immediately in gentle stop situations such and snow/ice driving.

How is that any different than a car without ABS? You aren't really putting a lot of stress on the drive train in this situation. There is nothing but EMF stopping the tire from spinning. Going from stopped to start isn't going to hurt an electric motor.

 

[iridium130m]

I know this is about "could be" and "in the future", but my today solution is to avoid both L or cruise in snow. That plus snow tires work very well.

Fully Agreed...I believe driving low can be downright dangerous in the snow as the possibility of locking up the front wheels from sudden regeneration if you suddenly lift off throttle means temporary steering loss while the volt sorts its braking situation out. Not good. (this applies to all cars for that matter and engine compression / braking can really disrupt the car too).

Unfortunately (or fortunately most days of the year), even in drive, the volt prefers regenerative braking when the brake pedal is used versus friction brakes. Watching the power meter on my '13 shows this well in the situations i describe. I should see if I can get my wife to grab a video of it this afternoon when we go out.

 

[Rons2013]

I have had no issues with driving in snow, and I'm Always in "L". Worst case - icy roads on hills (and I Live in the foothills of the Berkshires - Nothing is flat around here), going downhill - Steeply downhill - while also around curves, I have yet to experience a problem where the Regen braking was a bother or in any way made the car more difficult to drive than otherwise.

I Have had "issues" with the regen causing ABS triggering over simultaneous slippery conditions and bumps - where the regen drops out Apparently as a first step to the ABS working. It's not been noticeable to me in the snow, ever.

Maybe it's having actual Snow tires on the car..

 

[shiranpuri]

I haven't found the volt to be any worse than other cars in the snow... the fact that it regens as much as it can is largely transparent.

 

[iridium130m]

I assume ABS works normally in "N"?

Confirmed, ABS works as normal in "N" in my Volt...I jumped on the brakes moderately in Neutral and "low traction" popped up and I had the pulsating brakes.

 

[Selling Volts At Sundance]

I haven't found the volt to be any worse than other cars in the snow... the fact that it regens as much as it can is largely transparent.

I have had no issues with driving in snow, and I'm Always in "L". Worst case - icy roads on hills (and I Live in the foothills of the Berkshires - Nothing is flat around here), going downhill - Steeply downhill - while also around curves, I have yet to experience a problem where the Regen braking was a bother or in any way made the car more difficult to drive than otherwise.

I Have had "issues" with the regen causing ABS triggering over simultaneous slippery conditions and bumps - where the regen drops out Apparently as a first step to the ABS working. It's not been noticeable to me in the snow, ever.

Maybe it's having actual Snow tires on the car..

Strongly agree. My Volt rolls through 4"- 6" of snow like a baby Cadillac Escalade. What a BLAST to drive!

Having had a number of 4X4's I am absolutely pleased with this machines traction in the snow as well. A tip for you, though is to disable Traction Control when stopped at a light in heavy snow. This will stop the bogging down that ALL new cars with TC experience.

As far as breaking, I drive in "L" until the snow reaches 7" or deeper as I want the full rolling inertia to keep me going in the deep stuff.

Stopping is no issue for me, no different then any other modern car with Traction Control, StabiliTrack, Antilock Breaks, Panic Break Assist and Hill Stop Assist all computer controlled, so long as I drive mindful of the conditions.

So, enjoy your machines, If the conditions are not up to your driving ability, do not blame the car.

As Steverino has pointed out, snow tires may help, but me, I'm loving this Winter Wonder Land in my Chevy Volt EREV!


1) Link Goes To Twitter Pic- Snow Storm- FREE Fueling at The Solar Carport-

https://pbs.twimg.com/media/BdZWb54CcAAwQoV.jpg:large



2 ) Link Goes To Twitter Pic- 6" Snow Tracks-

https://pbs.twimg.com/media/BfGmAwBCIAEuyPg.jpg:large

Best-


Thomas J. Thias

 

[iridium130m]

Drove again more this afternoon, road conditions more consistent than this morning: mainly just moderate snow and snowpack, so regen then switch over to friction braking when the front wheels lost grip during moderate braking was more consistent without the driveline thrashing that I was getting this morning under light braking...seems like patchy ice is what really throws the car off as individual tires suddenly loose and find grip. I was still getting better braking control in Neutral as all four tires were immediately digging in for traction versus only the fronts, so I still stand by my request for a Snow / Ice drive mode to provide this without shifting.

 

[Norton]

I know exactly the conditions you were driving in today, Bro. I left work early cause I was skeerd...

Regen when braking on powdery snow over patchy ice is weird. It almost got me in trouble in a Gen 1 Insight.
Selecting Neutral worked in that car also.
In really slick conditions (regen) braking on the front wheels only is NOT good.

It would be a Snow/Ice/No Regen mode.

But it won't happen. GM is tight with the functional SW upgrades.
Like Hold mode, power flow display, etc for '11 and '12 Volts,,, "You can get it. Just buy a new car".

 

[40545]

I know this is about "could be" and "in the future", but my today solution is to avoid both L or cruise in snow. That plus snow tires work very well.

What he said, L in snow/ice is can be invigorating.

 

[ptarp]

I ran studded snow tires all winter. Hardly ever slid or spun tires in my Volt, and drove in L all the time. Got them back off today because there's only one day in the near future with a 30% chance of snow, but temp is supposed to be high enough to melt it all back off. I was getting real tired of the stud's noise.
If I end up in snow again, I'll just leave a bit earlier for work and drive a bit slower.
Seems like a lot of wrecks in bad weather are people in a hurry and driving too fast for conditions. If there's a layer of snow sticking to roads and I don't have the studs on, I limit speed to 35-40mph max even if speed limit is 55, unless the temp is over freezing and there's puddles of water. Sometimes, I just go by feel if tires spin when starting off from stop signs, but nothing has made me put the car in "N" or "D" all winter. Even with the snow tires off, I'm sure I'll be in "L" again just because that's where I always pull the shifter.

Side note on rear wheel drive since that's been mentioned in this thread. The only car I ever completely lost control in was 20 years ago in an old Datsun hatchback with RWD. I wasn't accelerating or braking, just holding 30mph on a level highway. Car spun about 450 degrees for no reason I know of other than a patch of black ice, and I'm just glad I didn't take out those mailboxes that I stopped right next to, or the car that was coming from the other direction..

I think if you're not stopping fast enough in the Volt, and brake pedal isn't pulsing, just press harder. However, the trick in snow and ice is not to be going so fast or so close to someone else that you rely completely on ABS and traction control to safely make the stop for you. It's not something to completely rely on, and slower will be safer in the snow/ice.

 

[40545]

For this and other reasons, I much prefer Tesla's model where the brake pedal has zero affect on regen, and is used to apply friction brakes only.

Read wheel drive in the snow. What could possibly go wrong?