Model 3 in Snow/Ice

[ev_go123]

Lets not forget the OP is in South Carolina. Unless they are driving to the mountains, (s)he probably sees snow once a year and the entire state shuts down for it.

I'm sure in OP's position I'd stick with good performance all seasons and avoid the hassle of storage/switchover of winter/summer tires.

Right I'm sure OP wouldn't want to bother with swapping to winter tires for maybe one snow storm per year, very understandable. In that case, I would recommend just stay off the roads when it snows that one time. If you really need to, you can get by with NEW all season tires, but anything else, just stay home.

Also emphasis on the new tires--if the tread is worn out, they're dangerous in snow, doesn't matter if the car has AWD, ABS, or the best traction control systems on the planet, it still has to abide by basic physics (friction).

Also remember, you can be very experienced, have winter tires, and the best AWD car, but that doesn't mean everyone else on the road does. All it takes is someone to slide out of their lane/intersection and hit you, and all that prep is for naught.

 

[tm1v2]

The dual motor cars are not as rear-biased as they were last winter. I looked at ScanMyTesla while driving on snow and ice. Once the car detects slipping at the back, it starts using the front motor more than before. It gets used in regen and in acceleration, even in gentle actions (as opposed to just in hard acceleration like before). Eventually if the car doesn't detect slipping for a little while it will revert to a rear bias for efficiency.

As for the back sliding under regen... the only way for the software to find the traction limit is to go over the limit. Therefore, the tires will lock for a fraction of a second. Regen will lower quickly and the stability system will take over and ensure you don't spin out but you need to get used to it. The car will constantly try to raise the regen so it will hit that limit again. It's the only way to constantly be around the traction limit.

The car is still very "careful", preferring to brake all the time when trying to corner. It has a very understeering behavior which I don't personally like, but might feel safer for others.
"Slip Start" behavior also seems to have changed. This year it allows a bit more rotation of the car. Instead of just lowering the traction control activity, it seems to relax stability control a bit. I prefer to drive on snow and ice using that mode. Now, this might not be good for people that already feel nervous of the back slipping under normal conditions because of regen.

Starting off heavily rear-biased and waiting to react to slip that already happened...is rear-biased. If the car remembers that slippage for a bit then automatically tried a heavily rear bias again, that sounds unpredictable to me as the driver, and doesn't really solve the issue (even if it helps some).

Let me be frank: If maximum traction in snow and ice is your goal, reactive AWD just isn't as good as fulltime AWD.

You don't need to find the traction limits of each wheel to understand that most likely the front wheels have some traction, and using only/mostly the rear motor initially for acceleration or regen is almost always going to make slipping and spinning easier than starting off around 50/50. Again, normally what the Model 3 does is fine and good (I like how it drives!), but it should be easier to force a more balanced torque distribution. Probably all we need is the Model Y's "Off-Road Assist" mode.

I've driven ICE cars with essentially reactive systems not unlike the Model 3's normal behavior. They have a clutch-based center coupler but no actual center differential. They have the same tradeoffs as we do: They retain much of the driving feel of their base RWD or FWD roots, they're more efficient than fulltime AWD, they do have lots more traction than 2WD...but their behavior in slippery conditions just isn't as good as fulltime AWD.

Our cars could do much better than those part-time AWD ICE cars, because our cars could proactively drive both motors without the downsides of those crappy (IMO ) center clutch coupler AWD systems. M3P and MY already can! (Track Mode and Off-Road Assist, respectively.) And of course our cars will immediately drive both motors when you request more torque than the rear alone can deliver, but that's going to be way too much for the snow.

 

[Jeremy3292]

Lets not forget the OP is in South Carolina. Unless they are driving to the mountains, (s)he probably sees snow once a year and the entire state shuts down for it.

I'm sure in OP's position I'd stick with good performance all seasons and avoid the hassle of storage/switchover of winter/summer tires.

Yes, this is an unusual event for us here in SC and it would never make sense to buy dedicated snow tires. I use all season tires year round. It was more of a discussion around the M3 LR and how it performs in snow, as I do not have experience with this and was wondering what those who use it in snow regularly think. I do not plan to drive in snow/ice at all, just some of the side roads weren't fully defrosted yet yesterday when I started the topic.

 

[GtiMart]

I'm not going to disagree with you @tm1v2 , I was just trying to explain how the car behaves today. I would welcome an option for a mode that works better and is more fun on snow and ice, without going full-blown track mode on the dual motor. (Note: I would take full track mode if they gave it to me on my non-P model though ) I had a similar option on my previous Subaru WRX that would reduce traction and stability controls (more than slip start) without turning them off. That car was fun on the snow. I have been stating this requirement for 2 years on this forum now, but Tesla have not been listening. I even tried to go through a local Tesla club representative as I know they have some kind of communication channel with Tesla, to no avail.

I can apologize about the use of the "biased" word. English is not my first language, maybe I didn't quite use the correct word.

 

[tm1v2]

No need to apologize about your word choices, terms like "front bias" and "rear bias" are really just vague, casual descriptions of more complex and distinctive behaviors that we often don't fully understand (we didn't engineer these cars), and that would take too many words to describe anyways.

WRX are great fun in the snow!

 

[Markardi]

I see a lot of people talking about regen and that's great .. if you have it! If the temps are cold enough you lose regen until the battery can warm up. It's currently -17C (1.4F) and going down to -30C (-22F) tonight. We just came off a storm that dumped an average of 38cm (15") of snow in the area. When I get in my car to go home I know I'm not going to have any regen.

Like other have said, good tires are #1. I use X-Ice over a performance winter tire for the increased snow and ice traction. The tires, AWD, and traction control make this a formidable snow handling car. I also keep the car in Chill mode pretty much the whole time.

 

[ay221]

I see a lot of people talking about regen and that's great .. if you have it! If the temps are cold enough you lose regen until the battery can warm up. It's currently -17C (1.4F) and going down to -30C (-22F) tonight. We just came off a storm that dumped an average of 38cm (15") of snow in the area. When I get in my car to go home I know I'm not going to have any regen.

Like other have said, good tires are #1. I use X-Ice over a performance winter tire for the increased snow and ice traction. The tires, AWD, and traction control make this a formidable snow handling car. I also keep the car in Chill mode pretty much the whole time.

If you don't have regen due to cold or a full battery, does one pedal driving still work or do you have to use the friction brake?

 

[Braumin]

If you don't have regen due to cold or a full battery, does one pedal driving still work or do you have to use the friction brake?

Friction brakes.

 

[afadeev]

We recently had ~6" of snow here in South Carolina which is a very unusual event. This got me thinking about my M3 LR and how it performs in the snow. I am postulating that my M3 LR is probably a lot "safer" than a regular ICE sedan in snow bc it is AWD, and perhaps more importantly, you do not need to use the brakes to slow down as the car "engine brakes" aka regen braking.

You are wrong with your assumption.
Physics are physics, and AWD will only help you to go faster in marginal traction conditions on any given car. It will do nothing to help you maintain traction during turns, or decelerate (actually, AWD imposes a weight and handling penalty). Tires do all the work for both use cases, and winter tires are your only answer to improving traction in the snow.

The above holds 100% true equally for EVs and ICE vehicles.

I experienced this this morning on some still icy roads and when I felt the car start to slip/slide. So I let off the accelerator entirely and my car came to a stop virtually immediately without use of the brakes (regen). I believe this thinking is in line with the general recommendation to NOT use your brakes in the snow/ice when sliding.

There is no such "do not use brakes" recommendation in an emergency or over snow/ice. EVER!
If you need to slow down - use the brakes!
Regen deceleration is a mild from of braking. Unfortunately, regen braking is applied mostly at the rear axle, which can break rear wheels' traction before the fronts, and cause snap oversteer. BTDT over both snow, and water (throttle lift oversteer entering clover-leaf turns).
Brakes always work best, and engage evenly across all four corners of the car.

AWD helps you get moving, and to some degree allows you to go around corners faster because all four wheels are(or can be) participating in propelling the car. On a 3/Y, I understand that the front motor is largely idle unless the rears are slipping or the accelerator is pressed pretty hard. AWD shouldn't be notably better than 2WD in slowing or stopping a car.

Exactly right.
Heavier AWD cars will take longer to stop, and will exceed tire adhesion limits sooner than lighter cars.
AWD is great for going faster than you should. That's one of the main reasons the majority of cars that spin out and get stuck in the ditch during a snow storm are AWD SUVs on all-season tires.

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[ay221]

I'm going to have to scratch the model 3 off my list unless they have an upcoming snow mode update. Wanted a car to replace my fun car 718 GTS and my beater car which might be going on it's last legs. Will take a look at the Y or another brand. waiting until fall, so hopefully model 3 does add it.

 

[afadeev]

I'm going to have to scratch the model 3 off my list unless they have an upcoming snow mode update. [....]Will take a look at the Y or another brand. waiting until fall, so hopefully model 3 does add it.

Out of curiosity, what exactly do you mean by "snow mode"?
I wasn't aware of any magical "snow mode" on Model Y. The higher CG will be a bit more of a handling handicap, but higher clearance might allow one to blow through deeper snow covered roads.

 

[tm1v2]

I'm going to have to scratch the model 3 off my list unless they have an upcoming snow mode update. Wanted a car to replace my fun car 718 GTS and my beater car which might be going on it's last legs. Will take a look at the Y or another brand. waiting until fall, so hopefully model 3 does add it.

@ay221 Just get the M3P. If you're coming from a 718 GTS you can swing an M3P, no?

Track Mode is pretty awesome. If you like to drive hard and have the budget for an M3P, just get one, don't think twice about it.

 

[ay221]

@ay221 Just get the M3P. If you're coming from a 718 GTS you can swing an M3P, no?

Track Mode is pretty awesome. If you like to drive hard and have the budget for an M3P, just get one, don't think twice about it.

Thanks. I was just viewing the track mode use on youtube. Didn't know anything about it but looks nice exactly what is needed for bad winter days. Back on the top of the list.

 

[MG535]

So… winter tires aren’t on your list but an imaginary magical “snow mode” is? And if thats not available then track mode on an Performance 3?

 

[tm1v2]

So… winter tires aren’t on your list but an imaginary magical “snow mode” is? And if thats not available then track mode on an Performance 3?

Who are you asking, and what list do you mean? You can put snow tires on any car of course, it's not a feature you would car shop by. Whereas Tesla's Track Mode is a unique feature of the M3P (and now the MSPlaid).

@Jeremy3292 (the OP) is in South Carolina. Even with recent climate change, snow is very rare there, deep snow rarer still. I too would NOT bother with real snow tires in South Carolina. All-seasons should be fine for the winter there. I wouldn't even bother with snow tires as far north as Virginia or Maryland, unless living in the mountains or other rural parts.

@ay221 Is in Colorado. They didn't say anything about their winter tire selection, but I'm sure anyone living in Colorado is familiar with snow tires.

 

[ay221]

This is the video I found that showed me the track mode snow setting. Setting looks pretty cool. Nice that you can lower the regen and set the handling balance

 

[tm1v2]

@ay221 Just in case it's not clear from the video, Track Mode doesn't come with a Snow preset, but you can absolutely make your own Snow configuration and save it. That's what the owner/driver of the car did.

 

[Braumin]

@ay221 Just in case it's not clear from the video, Track Mode doesn't come with a Snow preset, but you can absolutely make your own Snow configuration and save it. That's what the owner/driver of the car did.

Does Track mode not heat the battery as well? I thought it did when it was enabled. I will be honest I haven't tried it in snow yet with my M3P.

 

[tm1v2]

@Braumin My understanding is Track Mode always attempts to cool the drivetrain as much as possible to delay onset of thermal throttling. The assumption is you're actually tracking it, or doing other very hard driving, and you're going to heat things back up no matter what.

Now I assume - but haven't verified - that at some measurement of cold it will stop attempting to cool things further, to avoid making the car undrivable or such. Or maybe that's just not a problem in practice. There seem to be plenty of M3P owners using Track Mode in the snow so I think in practice it works out fine one way or another.

For sure whenever I've enabled Track Mode the cooling fans kick into high speed, which I assume means it's actually cooling things. But I haven't even driven the car in freezing weather yet, maybe it behaves differently if you enable Track Mode at the start of a drive while the car is very cold (e.g. sitting outside overnight in freezing weather).

 

[bedoig]

@tm1v2 I don't own a Performance, but my understanding is that the selectable torque split in track mode only applies under heavy cornering / slip angles. Even in track mode with 50/50 (or whatever) selected, your straight line torque delivery is still going to be heavily (mostly entirely) rear biased unless slippage occurs (as others have mentioned) or you're flooring the accelerator. It's not going to give you full time AWD with 50/50 torque split. Which makes sense, because otherwise if you toggle 100% to front or rear you'd be limiting total acceleration to the power available from one motor, and we know that doing that doesn't actually affect straight line acceleration.