Slipping in highway during winter - Regenerative driving problem

[silenteski]

Regen is no problem on ice if you understand that taking your foot off the accelerator is functionally equivalent to pressing the brake, in varying degrees based on how much you lift off the accelerator. Nothing “locks” when you use regen braking. If your tires break free, it’s because you’re applying too much braking, in one form or another.

 

[Headache]

Regen is no problem on ice if you understand that taking your foot off the accelerator is functionally equivalent to pressing the brake, in varying degrees based on how much you lift off the accelerator. Nothing “locks” when you use regen braking. If your tires break free, it’s because you’re applying too much braking, in one form or another

1.. When you let go of the accelerator, there is a delay with increasing braking. That delay is a no good in an emergency.
2. If you want to maximize braking, you want your abs to be fully functional. Individual braking on every wheel. If you have to manually test how much to brake and decide if you are able to even apply the brakepedal, we are vasting valuable time and distance.

 

[tevman]

Regen is no problem on ice if you understand that taking your foot off the accelerator is functionally equivalent to pressing the brake, in varying degrees based on how much you lift off the accelerator. Nothing “locks” when you use regen braking. If your tires break free, it’s because you’re applying too much braking, in one form or another.

Right! Driving an ICE car in Winter has the same caution. But in an ICE, you ease off the accelerator and don't touch the brake until the car lines back up and runs straight. In an EV, you just ease back a bit on the accelerator so that you are introducing a small amount of regen braking. But if you take your foot off the accelerator completely then you are effectively jamming on the brakes for a moment until the Tesla's dynamic anti-skid controls come into play. I don't know how smooth that happens because I don't drop off the accelerator all the way. One pedal driving is very good once you get used to it.

 

[CyanideDN]

We need a snow mode that dramatically reduces regen, and that will satisfy 90% of Tesla users, but what I really want is the full software unlock of the Performance (as in M3Ps track mode) so I can adjust power delivery front and rear to make a “front wheel drive” snow car!

So now there's Track Mode enabled for MYP with the latest holiday update, is there an optimal setting we should use for winter driving under snow or icy condition? I'm familiar with driving in the snow while living in the East Coast, but I had an ICE vehicle so wondering if any software changes should be applied for the Tesla.

 

[52 16 57 39]

I have not set my track mode settings yet - but I “trust” the standard Tesla settings to get me A to B… however when I’m heading into a gnarley situation, I’ll probably set bias to 70 front/30 rear and no regen braking (roll) with stability set to the positive side (to keep me forward) if needed.

I did some quick donuts w drift mode - it’s pretty fun. Then I set it to front wheel drive - and it drove like my ol VW Golf TDI. I’m super excited to find a large parking lot to try 4WD drifts while in track mode.

 

[tm1v2]

So now there's Track Mode enabled for MYP with the latest holiday update, is there an optimal setting we should use for winter driving under snow or icy condition? I'm familiar with driving in the snow while living in the East Coast, but I had an ICE vehicle so wondering if any software changes should be applied for the Tesla.

@CyanideDN Personally I'd want Stability Assist all the way down (-10) for any serious snow/ice driving. No interference seems best if you are practiced in car control.

Handling Bias anywhere from 70/30 like @52 16 57 39 suggested to 50/50 is probably good for a mix of stability and control. I'd likely start off 50/50 as it might give the best control. Or set more rearward if you want to go sideways around turns kicking up snow.

I guess it depends - is a snow covered mountain road a place to drive cautiously and sedately, or is it a winter rally stage? Pick your Track Mode settings accordingly.

I agree with no regen, or at least set it pretty low, because regen in these cars is always rear biased (I believe), very different from typical brake bias. On pavement it's fine but on the really slippery stuff I could see it making the tail feel loose or even come loose, when I don't want it to.

 

[dzajic]

No the abs did not kick in at all. The regen locked the wheels and the abs had nothing to work with. I do live outside of the states and drive on Nokian Hakkapelitta winter tires. probably one of the best unstudded winter tire there is. Unfortunately on soaking wet ice, it is almost like driving on summertires. Uphill the abs and traction did its job perfectly.
in a way i do understand why tesla has removed the possibility to reduce regen, but they should have incorporated a feature that prevented this total lockup.

I think I had the same thing happen to me and it was very alarming. No ABS no ESP, the car started to rotate. I've never had this happen with any other car that has ESP, including two EVs that were rear wheel drive. Tesla needs to figure this out, it's a serious problem.

 

[stians]

Regen bias is 100:0. All of the regen is on the rear axle only. This is one of the things that causes so many problems with strong regen in slippery conditions.

Keith

Exactly! I have a 2017ms living in Norway and like all Norwegians I have a lot of experience on ice/snow. In one particular twisty and bumpy mountain road we use sometimes we have experienced rear axle half-second skids 3 times when on regen (just after releasing pedal) this winter, and never on throttle. It may of course be our very good but slightly aging snow tires, but we have had no problems on other winter surfaces this winter. It feels loose and dangerous

 

[DrGriz]

Exactly! I have a 2017ms living in Norway and like all Norwegians I have a lot of experience on ice/snow. In one particular twisty and bumpy mountain road we use sometimes we have experienced rear axle half-second skids 3 times when on regen (just after releasing pedal) this winter, and never on throttle. It may of course be our very good but slightly aging snow tires, but we have had no problems on other winter surfaces this winter. It feels loose and dangerous

Are you using chill mode or Off road assist? I drove down a 1500 ft twisty mountain road in slippery conditions both today and yesterday (32 degrees F, 0 C) and had no trouble. I did slow down.