Snow Mode fail - costly result

[tylerdurden03]

I swap my all season tires out and put on winter tires when snow comes in the Eastern Sierras. The all season tires don’t cut it either the weight of an electric truck in snow. This is different than ICE trucks where all seasons were totally fine for me even in very heavy snow. I do agree we should be able to fill turn off brake regeneration as I can do in my Tesla but in my opinion the tires are the first line of defense.

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[Birdowin]

I use a different technique when on snow or ice. When I start to slide I gently apply acceleration. and turn the front wheels in the direction that I want to go. This also worked on my old 4wd dodge Ram diesel. It takes some getting used to but in my 50 years of snow driving I have perfected the technique. Find a big empty parking lot and practice.

 

[Bullwinkle]

I wanted to share a very unfortunate event from a snowstorm drive last week. Bottom line: I ended up against a tree after sliding through a downhill curve, through a shallow ditch and about 20’ of heavy brush.

I was in Snow Mode and driving at a cautious speed since conditions were poor and plows/salt trucks had not been out yet. However, despite my many years of driving in Midwestern winter wether with no issues, I found myself unable to correct my slide by tried and true techniques: take foot off pedals and resist steering until traction is regained.

To be fair, there were numerous cars off the same road that evening to the point the sheriff closed the road twice due to accidents. So maybe there was nothing that could have prevented my accident at that time in those conditions. That was my original thought until I reviewed the incident video in my R1S.

What I noticed in the video, however, was that my brakes were applied a bit before I slid and went off the road - even though my foot was not on a pedal. I assume this was the regen engaging and locking up my wheels since I was at low speed and it thought I was coming to a stop. The Snow Mode documentation says it “reduces” regen, but that was not enough in this case. There should be no regen braking at all or only some sort of anti-lock regen if any (if that is possible).

Going forward (once my extensive damage is repaired), I will manually turn off regen whenever there are slippery winter conditions. I hope Rivian refines these settings to address this risk in the future so others don’t have the same result as me.

Now I start the long, frustrating process of coordinating collision repairs and insurance approvals - and not being able to drive my R1S!

I am really sorry this happened to you. I agree with your premise that even low regenerative braking can induce a slide.
I posted this thread in early December discussing this exact issue:
Snow Mode--still too much regenerative braking

 

[LeeY]

The consistency in this thread should send a clear signal to Rivian. They have some thinking to do.

 

[LDC]

I find that my R1S is relatively terrible in the snow, compared to my previous Audi and BMWs with winter tires. I was attributing that to the tires- I have the 20" All-Terrain tires that came with the R1S, and have put off getting actual winter tires since we’re in yet another minimal snow winter here in Minnesota (unfortunately!!).
Do others think the slipperiness in the snow is mostly due to regen brakes or the tires? Now that I think about it, the car seems to slip more when I’m slowing down versus driving at a steady speed or speeding up, which would argue that it’s more of a regen brake issue than a tire issue. I’m sure winter tires would help regardless.

 

[Bullwinkle]

Cincy doesn't get enough snow to form a muscle memory on driving in this stuff.

I think my road has been snow covered all but 1 week since Jan 1st.

Even Minnesota doesn't get enough to practice often. Also, although feathering the accelerator enough to disengage regenerative braking can work, it is really a tricky thing to do in a sudden emergency...and most of us drive other cars that require very different behavior, so it is near impossible to react quickly and instinctually.

 

[SkiLizardHead2]

Yes, factory ATs. Will definitely get something snow rated by next winter. (I’m assuming snow will be long gone by the time repairs are finished…)

Agree 100% with Sub that tires are most important. The AT tires are not really designed to optimize performance on snow and especially ice. I have lots of experience with M X ice studless snow/ice tires on my Tesla MX and ICE vehicles like 4-Runner, Outback, etc and they are excellent but you may have some weight ratings issues for Rivian depending on wheel size. Another excellent snow/ice tire is the Nokian 275/60R-20 Nokian Hakkapeliitta R5 SUV which I put on my 2025 R1S. I have limited experience with it but so far snow and ice traction appears very similar to M X-Ice and rolling resistance is low as well - (range reduction only approx 5-10%).

 

[defcon888]

Best advice I can give about driving in snow is......"DON'T" unless you absolutely must.....but then again I am from a part of California that doesn't get snow, but I am close enough to drive in it (close to Tahoe). To me, it just isn't worth the hassle because there usually is a ton of traffic and I don't want to be caught stuck in sub-zero temps.

 

[crewzer]

Really sorry to hear that! Hope you get back on the road with you R1S soon.

100% agree the snow mode isn't doing enough.

In my limited ownership and all in winter and in Tahoe snows (heavy snow & steep roads), I had to quickly learn to - turn on snow mode, reduce regen to lowest setting that is allowed, and reduce traction to low (minimal). I am on 22in all-season tires. I don't go often enough in snow to invest in a 2nd set of winter wheel+tire package.

New Rivian, driver here, why would traction control off be better in snow /ice?
Thanks!

 

[TollKeeper]

I was in a similar situation over the weekend.

The main interstate I was on, was fine. The exit ramp.... Not so much.

I watched the car in front of me completely slide down the ramp almost sideways, thru the intersection (on a red light), and continue down the on-ramp on the other side. He got lucky, and straightened it out on the on-ramp, and just went on.

I saw this, so I started braking earlier, regen started, and shortly after the ABS was going full tilt. I managed to stop, with the nose of my -S- about 4 feet into the intersection, just as my light turned green. It could have gone differently!

Snow mode is about useless, as I dont notice a difference in-between the All-Purpose mode, and snow, no matter the regen setting.

I am hoping to burn out these craptastic 22" Pirelli's this year, and switch over to Michelin or Continental.

 

[Jonger1150]

I did curb rash my driver's side rear rim being an idiot a few weeks ago driving through an empty parking lot. That will be the spare after the next tire replacement. LOL

 

[superfly_snook]

I think it’s natural to second guess ourselves when these things happen but it sounds like the situation may have been more than even a 4x4 with snow/AT tires could overcome.

 

[dcramm]

Rivian... Please listen

Menu:
Snowmode - Check
Optional - Turn Off Regen - Check

Stop forcing us to chose safety over regen!

I just drive our ICE vehicle instead of Rivian to a ski trip because of exactly this issue and was glad I did, given the snow.

 

[HaveBlue]

We need Regen off on all modes. Even off road mode. Descending steep rutted hills, the car will lurch forward in free fall when one wheel loses traction. You can't use the brakes because the vehicle would just stop entirely. Having to put it in neutral for no Regen is pretty stupid. It's the only way to apply braking to all wheels.

Last weekend I went 4 wheeling in the rocks and snow. The Rivian stayed at home and we took the Lexus.

 

[bbonkk]

Glad you are safe. The fact the sheriff closed the road due to excessive collisions suggests driving under the conditions present was imprudent no matter the vehicle or experience of the driver. Forward your thoughts regarding Snow Mode to Rivian and ask them to respond. It would be interesting to read their comments, especially if the lead Snow Mode instructor at Rivian responds. Good luck with repairs and drive well.

I wonder if trailer mode turns off the regen????

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