We need "Off-Road Assist" for snow driving

[The Other Dan]

You can't adjust the power split in a straight line. The split only occurs when you turn the wheel.
Try it sometime, even in the dry. Make the car full FWD. Mash the throttle. Car still does 0-60 in about 3 seconds, which is not possible for FWD.
Now, drive it that way but feed in some steering angle and it will overwhelm the front tires.
This is why they call it "handling balance" not "power split".

Yep, I know how it works, but it sill allows you to adjust some of the negative handling traits during the winter like always -on regen brakes. Letting off the accellerator and essentially only having brakes on the rear is a recipe for disaster. If they at least gave us back the different regen settings, that would help.

The tesla isn't my snow car, I've got my jeep diesel for that. But I still miss my '05 STi or '99 RSTi for the snow. (Among other times) RWD bias for the fun and fully locked center diff when it's not so fun. On a set of Blizzaks, the thing was a tank.

 

[gearchruncher]

I can adjust the power split, traction control, and even the amount of regen braking.

You mean the mode that works exactly as you describe in this thread. Albeit with a little more user control. Yes, that mode.

Yep, I know how it works, but it sill allows you to adjust some of the negative handling traits during the winter like always -on regen brakes

It sure wasn't clear to someone that isn't deeply familiar with track mode that it doesn't do what people are asking for, you made it sound like it was.
So now people know that track mode isn't this either, in terms of how the torque split system works.

 

[TimothyHW3]

Do we have Y drivers here who tested off-road mode in the snow? How is the acc pedal working, the manual said off-road mode changes the way it handles too.

 

[The Other Dan]

It sure wasn't clear to someone that isn't deeply familiar with track mode that it doesn't do what people are asking for, you made it sound like it was.
So now people know that track mode isn't this either, in terms of how the torque split system works.

After re-reading the thread, it sounds like the system operates like an old Haldex system. It needs to see some wheel spin before it sends power to the front. That it or am I missing something? Almost all AWD systems work like that, unless you can manually lock the center diff. Some are just more noticeable than others.
I'm guessing that Tesla has some warning on the off road mode indicating off road use only. In which h case you'll never see it on the 3.

 

[STS-134]

After re-reading the thread, it sounds like the system operates like an old Haldex system. It needs to see some wheel spin before it sends power to the front. That it or am I missing something? Almost all AWD systems work like that, unless you can manually lock the center diff. Some are just more noticeable than others.

Not true. Different systems have different power distributions and only the crappiest AWD systems are full time asymmetric all wheel drive with 100% of power to the rear unless and until the rear wheels slip. Subaru's AWD has always been 50/50 front/rear AFAIK.

I'm guessing that Tesla has some warning on the off road mode indicating off road use only. In which h case you'll never see it on the 3.

Off road mode isn't intended for use in the snow. It's intended for use...off road.

 

[The Other Dan]

Not true. Different systems have different power distributions and only the crappiest AWD systems are full time asymmetric all wheel drive with 100% of power to the rear unless and until the rear wheels slip. Subaru's AWD has always been 50/50 front/rear AFAIK.

Off road mode isn't intended for use in the snow. It's intended for use...off road.

Your right, most cars & SUVs aren't RWD biased, most are FWD biased.

Subarus are typically FWD biased, with a viscous center diff. The STIs, at least in the mid 2000s (GDs), were RWD biased with the variable locking center diff. It memory serves it was geared 35/65 rwd biased.
Most of the VAG (including Lamborghini) and Ford/Volvo products use(ed) the Haldex system which needed wheel slip to start transferring power. Most of them were FWD biased. At the time, Ford said it needed only 1/7th of a tire rotation to detect slip.

 

[The Other Dan]

OK, after reading several threads on this, it looks like this probably wasn't the best thread to have bumped. Alot has changed since the thread was started, and there is now a snow mode of sorts as Tim has eluded to, you just don't push a button. It was implemented last winter '21/'22.
From the videos I saw, it activates the front motor as soon as it sees slip, and keeps the front powered up for quite a while. Miles/minutes with no slip detected. It also reduces/turns off regen braking.
It turns off the front motor for efficiency sake as opposed to anything else when it doesn't sense any slip.

Prior to that, a common suggestion/idea was....drumroll... to run it in Trackmode. 50/50, regen very low or off, stab control turned up.

Off-road mode, Model Y, was suggested, but it looks like that acts more as increased LSD function. A couple people noted it activated slip start too.

 

[STS-134]

OK, after reading several threads on this, it looks like this probably wasn't the best thread to have bumped. Alot has changed since the thread was started, and there is now a snow mode of sorts as Tim has eluded to, you just don't push a button. It was implemented last winter '21/'22.
From the videos I saw, it activates the front motor as soon as it sees slip, and keeps the front powered up for quite a while. Miles/minutes with no slip detected. It also reduces/turns off regen braking.
It turns off the front motor for efficiency sake as opposed to anything else when it doesn't sense any slip.

Kind of a stupid algorithm. It should just switch to 50/50 power distribution whenever the temperature is close to or below freezing and the wipers are activated, and keep this setting as long as the temperature remains close to or below freezing. And a manual override (force "snow mode" on) wouldn't hurt either.

 

[gearchruncher]

Kind of a stupid algorithm. It should just switch to 50/50 power distribution whenever the temperature is close to or below freezing and the wipers are activated, and keep this setting as long as the temperature remains close to or below freezing.

The Model 3 uses a Permanent Magnet motor in the rear, and induction in the front. The PM motor is more efficient. The more time the car spends in the 50/50 mode, the shorter the range, which is already limited in cold conditions.

Simple rules like outside temp and wipers don't work. Cars park in garages and aren't cold right away. Temps are often very cold without any snow/ice. Wipers aren't needed in a lot of snow unless it's actively snowing. Temps can be 60 degrees while you're driving on snow. These types of simple rules often lead to very unpredictable behavior.

 

[STS-134]

The Model 3 uses a Permanent Magnet motor in the rear, and induction in the front. The PM motor is more efficient. The more time the car spends in the 50/50 mode, the shorter the range, which is already limited in cold conditions.

The IPM Syn RM in the rear is more efficient than the induction motor but only by a few %. I believe it's something a few percent (low single digits) more efficient.

Simple rules like outside temp and wipers don't work. Cars park in garages and aren't cold right away. Temps are often very cold without any snow/ice. Wipers aren't needed in a lot of snow unless it's actively snowing. Temps can be 60 degrees while you're driving on snow. These types of simple rules often lead to very unpredictable behavior.

Sure, so they could just provide a manual override. Do you think I care about the impact on range if the car is in danger of slipping? Seriously. There are more times when I have plenty of range than times I don't.

 

[TimTam]

All of the above are particularly applicable in the upper Midwest. As a bonus, everything from rime to glare ice to slop can be found within a block. I will say that modern snow tires help (a LOT) on ice at unfortunate angles. I have stopped successfully while AWD SUVs on all seasons slid right through a 4-way stop. Those Nokians earned their price. As noted above, I couldn’t have cared less about range at that moment in time.

 

[gearchruncher]

The IPM Syn RM in the rear is more efficient than the induction motor but only by a few %. I believe it's something a few percent (low single digits) more efficient.

Tesla cares enough about this to not run 50/50 all the time. So they really don't want to end up in this mode when it's not needed on top of cold.

Sure, so they could just provide a manual override. Do you think I care about the impact on range if the car is in danger of slipping? Seriously. There are more times when I have plenty of range than times I don't.

Sure, that is the clear answer, since the driver knows what they want and can make the tradeoff. Just one more option in a menu...

But why work on any of this? FSD will do all of this for you in 3 months, 6 months tops.

 

[TimothyHW3]

Tesla cares enough about this to not run 50/50 all the time. So they really don't want to end up in this mode when it's not needed on top of cold.

Exactly and most likely due to EPA testing all possible drive modes on the car which will penaltilize their EPA range.

But no problem, if we get this over the sexy buttons, I wouldn't mind it.
I know for a fact that the car is undrivable in the above conditions without this mode and I am not waiting to start slipping into oncoming traffic first for Tesla to figure out it needs snow mode. And I am coming from a BMW with RWD...

 

[BigNick]

Exactly and most likely due to EPA testing all possible drive modes on the car which will penaltilize their EPA range.

But no problem, if we get this over the sexy buttons, I wouldn't mind it.
I know for a fact that the car is undrivable in the above conditions without this mode and I am not waiting to start slipping into oncoming traffic first for Tesla to figure out it needs snow mode. And I am coming from a BMW with RWD...

EPA testers are clueless button-pushers and box-checkers.

You would only use winter mode in actual winter conditions, and the conditions (cold, snow on the road) would cost you far more range than activating winter mode in warm dry weather.

Does the EPA test the car in actual winter conditions? I don't think they do.

 

[TimothyHW3]

Does the EPA test the car in actual winter conditions? I don't think they do.

EPA has a 5 cycle test that, I believe, includes some sort of winter testing, of sorts. At least in the 2 cycle test they factor in winter and put a 30% penalty for not doing the 5 cycle test so there must be some "winter" scenario in that full cycle test.

As far as buttons, I belive, might be again wrong, they have to test the car in all possible scenarios and modes (chill, sport) and if they see "winter mode" I am inclined to think they will test it in that mode and as soon as the 50/50 kicks in, a range test will be rediculously low.

I have absolutely no other explanation, why Tesla would go the distance to hide the snow mode and do it "automatically" without giving the user the option to enable it (albeit with an alert - this will reduce your range etc.)

This is to me the only other explanation Tesla removed the low regen setting on Model 3 and Y, because EPA might test the slow cycle in that low regen mode and get less range. I have no other explanation for the removal of that mode either. Might bring 5% more range in that test.

 

[ay221]

EPA has a 5 cycle test that, I believe, includes some sort of winter testing, of sorts. At least in the 2 cycle test they factor in winter and put a 30% penalty for not doing the 5 cycle test so there must be some "winter" scenario in that full cycle test.

As far as buttons, I belive, might be again wrong, they have to test the car in all possible scenarios and modes (chill, sport) and if they see "winter mode" I am inclined to think they will test it in that mode and as soon as the 50/50 kicks in, a range test will be rediculously low.

I have absolutely no other explanation, why Tesla would go the distance to hide the snow mode and do it "automatically" without giving the user the option to enable it (albeit with an alert - this will reduce your range etc.)

This is to me the only other explanation Tesla removed the low regen setting on Model 3 and Y, because EPA might test the slow cycle in that low regen mode and get less range. I have no other explanation for the removal of that mode either. Might bring 5% more range in that test.

With the S3XY buttons, one can reduce regen to 50, 25 or none and works on chill mode. They are working a way to change FWD/RDW bias settings. If only Tesla will add their interface.