Icy roads

[JohnnyMac_]

Hi All,

I first got into my Model Y about 8 months ago. As we all know there’s a learning curve involved in the transition, but I drive a lot for work… every day. I’m now pretty dialed-in on what the car can and cannot do, and my confidence level is high because correct split-second reactions are second nature at this point. Driving gets more exciting and overall, much easier the more the advantages of the car are mastered. That said, there is one situation I find more difficult to deal with compared to my old gas guzzler… ice, especially on a steep downgrade.

I live in the mountains, and 20 + winters later understand what to do and what not to do to stay out of the ditch on the side of an icy road, although this is my first winter in an e-vehicle. The key factor is maintaining traction, and unless you’re running studded tires (which is not an option if you run dry highways and snowy mountain roads) it doesn’t take much to lose it on ice. A small pulse of power or a touch of the brakes at the wrong moment can put you into an uncontrollable spin. In a conventional car you have the option of simply releasing the gas pedal (and not touching the brake) when you’re on the edge of busting loose. But in an electric vehicle, when you let off the accelerator the motor(s) inherently brake, and that’s problematic.

I’d love to hear your thoughts on this and maybe pick up a pointer or two.

Thank you,

Johnny

 

[Goobers]

It’s pretty much what you said in the beginning, to dial in how much you lift the accelerator pedal.

Even in an ICE, there is still a little bit of power from the engine going to the wheels, it’s just the idle speed of the engine puts so low that depending on the speed, it can act as “power” (low speed) or it can also act as an “engine brake” (higher speed). Of course, this has a greater effect in manual (direct link) than automatics (torque converter).

Anyway, my point is that, in EV… you now have to lift to the point where you’re similarly putting minimal power or allowing minimal regen braking.

Another option is to simply put it in neutral to roll along and then feather the brakes to slow down.

 

[outdoors]

Welcome @JohnnyMac_

Ice is sure one of those things that is problematic in all cars regardless of type of power. Would say that many times from driving in an Tesla since 2017 in both RWD and AWD is similar in your described potential situation. Staying out of the ditch coming upon ice. The regen is very often not at full. Especially if one has stopped during the day for any period of time. If not the feather of the accelerator with snow tires is the best you can do. Maybe a positive I have seen over time is the ability to get out of a situation quicker that is about to turn south with power. One learns with time.

I try to stay home in ice, or stay put. I know some can't. A deer collision took 6 months for parts and to finally be done. I don't want to endure that again with situations I can control.

I drove 72k in miles last year all in a Tesla. Many in the winter across Canada and back multiple times. Shoot I love the winter. Really how can anyone drive on ice more than just a stretch at anything more than 10 miles an hour without studs. Maybe even less. See below. 1/2" glaze. Couldn't make it up the hill(I could). 18 cars piled up behind us.

Driving in neutral is inherently dangerous. Maybe if you want to burnish the brakes. One could enter service mode to do that however. Those that suggest such in the snow or even ice are misguided and offering an idea that I doubt they have tried or would do in given situation. Once you give up power you are at the mercy of getting it back and then the control to get wheels re-engaged. I try stuff for fun in a large controlled environment. Think I wouldn't try it on a road where others lives are at risk.

Would suggest studded, but I know in your situation you can't.

 

[Goobers]

It is true that you give up the ability to immediately use power of the timing calls for it on a ICE, but for many people in a panic, that thought would never come. They’re standing on the brake pedal and triggering a skid.

For those people, it would be better to calmly come to a stop first. Or at least to reduce speed until you’re at one you can confidently manage.

And unlike an ICE, switching between N and D is as simple as a flick of the stalk and more importantly does NOT suddenly jerk the motor or wheels, because (at least with Tesla) they are always linked. Switching to neutral only allows the wheels to spin without being affected by the pedal when you want it to roll freely (when you don’t want to worry about too much power or regen breaking traction).

So you can instantly switch back to D (or R if you were backing up) on the fly.

As for ”turning with power.” I would agree, but that’s conditional. You need experience and traction. Lacking either of those makes it pointless and potentially might make the situation worse.

 

[andaconda]

Give "off road" mode a try. It makes a major difference on ice and in snow.

 

[JohnnyMac_]

It’s pretty much what you said in the beginning, to dial in how much you lift the accelerator pedal.

Even in an ICE, there is still a little bit of power from the engine going to the wheels, it’s just the idle speed of the engine puts so low that depending on the speed, it can act as “power” (low speed) or it can also act as an “engine brake” (higher speed). Of course, this has a greater effect in manual (direct link) than automatics (torque converter).

Anyway, my point is that, in EV… you now have to lift to the point where you’re similarly putting minimal power or allowing minimal regen braking.

Another option is to simply put it in neutral to roll along and then feather the brakes to slow down.

Thanks for your reply Goobers.- That's what I do, feather the accelerator and it works fine. It's just counterintuitive to use the gas pedal when you're trying to slow down. (but not too fast) haha

 

[JohnnyMac_]

Welcome @JohnnyMac_

Ice is sure one of those things that is problematic in all cars regardless of type of power. Would say that many times from driving in an Tesla since 2017 in both RWD and AWD is similar in your described potential situation. Staying out of the ditch coming upon ice. The regen is very often not at full. Especially if one has stopped during the day for any period of time. If not the feather of the accelerator with snow tires is the best you can do. Maybe a positive I have seen over time is the ability to get out of a situation quicker that is about to turn south with power. One learns with time.

I try to stay home in ice, or stay put. I know some can't. A deer collision took 6 months for parts and to finally be done. I don't want to endure that again with situations I can control.

I drove 72k in miles last year all in a Tesla. Many in the winter across Canada and back multiple times. Shoot I love the winter. Really how can anyone drive on ice more than just a stretch at anything more than 10 miles an hour without studs. Maybe even less. See below. 1/2" glaze. Couldn't make it up the hill(I could). 18 cars piled up behind us.
View attachment 921320
Driving in neutral is inherently dangerous. Maybe if you want to burnish the brakes. One could enter service mode to do that however. Those that suggest such in the snow or even ice are misguided and offering an idea that I doubt they have tried or would do in given situation. Once you give up power you are at the mercy of getting it back and then the control to get wheels re-engaged. I try stuff for fun in a large controlled environment. Think I wouldn't try it on a road where others lives are at risk.

Would suggest studded, but I know in your situation you can't.

Hey Outdoors - thank you for the insight. Yes, that road right there is the stuff of nightmares. Glad you got through it unscathed. ))

 

[JohnnyMac_]

Give "off road" mode a try. It makes a major difference on ice and in snow.

I did use that one time but there was something I wasn't sure about - I can't recall exactly. I'll give that another go... thank you. ))

 

[JohnnyMac_]

It is true that you give up the ability to immediately use power of the timing calls for it on a ICE, but for many people in a panic, that thought would never come. They’re standing on the brake pedal and triggering a skid.

For those people, it would be better to calmly come to a stop first. Or at least to reduce speed until you’re at one you can confidently manage.

And unlike an ICE, switching between N and D is as simple as a flick of the stalk and more importantly does NOT suddenly jerk the motor or wheels, because (at least with Tesla) they are always linked. Switching to neutral only allows the wheels to spin without being affected by the pedal when you want it to roll freely (when you don’t want to worry about too much power or regen breaking traction).

So you can instantly switch back to D (or R if you were backing up) on the fly.

As for ”turning with power.” I would agree, but that’s conditional. You need experience and traction. Lacking either of those makes it pointless and potentially might make the situation worse.

You make a very interesting point with N. I will file that in the back of my mind - might even play with that a bit on an empty downgrade. Thank you my friend. ))

 

[outdoors]

It is true that you give up the ability to immediately use power of the timing calls for it on a ICE, but for many people in a panic, that thought would never come. They’re standing on the brake pedal and triggering a skid.

For those people, it would be better to calmly come to a stop first. Or at least to reduce speed until you’re at one you can confidently manage.

And unlike an ICE, switching between N and D is as simple as a flick of the stalk and more importantly does NOT suddenly jerk the motor or wheels, because (at least with Tesla) they are always linked. Switching to neutral only allows the wheels to spin without being affected by the pedal when you want it to roll freely (when you don’t want to worry about too much power or regen breaking traction).

So you can instantly switch back to D (or R if you were backing up) on the fly.

As for ”turning with power.” I would agree, but that’s conditional. You need experience and traction. Lacking either of those makes it pointless and potentially might make the situation worse.

Yet it is not as simple as you say. The tire has to re engage surface. Sure no linkages, but upon putting back into drive you run the same problem you left drive with to begin with. Learn how to feather first very well before trying this. One doesn't even need ice to practice. Foolish ideas in thought are often ones that don't end up well in practice.

Edit add: First winter @Goobers in your MYP with 21". How is it going? Are you delivering for the restaurant with those 21's? Snow tires? Or are you running performance tires in the winter.

Let's make sure we have a little more experience than just on paper before tossing out half baked suggestions.

 

[Nikola Strange]

Any use of snow tires? I actually used off road mode once during a snow storm. according To the forum off road mode during ice is not recommended?

 

[hmadsen]

I dont know if you can actually do this as i have not yet taken delivery of my MY LR, but if possible, would it not be prefereable to disengage the regenerative braking when travelling on slippery surfaces like this.

I mean, then letting go of the accelerator would be the same as coasting in neutral / or with clutch depressed, on a manual transmission car, would it not.

 

[avramd]

The key factor is maintaining traction, and unless you’re running studded tires (which is not an option if you run dry highways and snowy mountain roads) it doesn’t take much to lose it on ice.

Johnny,

You might get some value out of the thread I started on track mode snow settings. I realize you don't have track mode, but the conversation may still be informative.

TL/DR:

• There are several brands of studless ice tire
• It is not true that you can't run studded tires on dry highway
• You could set your regenerative braking to "Low" instead of "Normal" when there is a concern there might be ice
• Ultimately, the best solution is to "retrain your brain" to do what I call "reverse threshold braking."

Long version:

Studless Ice Tires​

This is a thing. They us a microscopic solution to the problem; at microscopic level, ice isn't perfectly smooth. Blizzak's were the first, the Michelin X-Ice tires are excellent. I'm running Nokian Hakkapeliitta R5's, with what they call "Arctic Crystals" - tiny sharp bits mixed into the rubber that continually get exposed as the tire wears down. I have vaguely circumstantial evidence that the X-Ice might be better than the Hakka's, but haven't tried them back to back.

Studs on Dry​

If you are worried about road noise, Nokian Hakkapeliitta 8/9/10's have excellent quite-stud technology. It's not as quiet as non-studded tires, but still quieter than the average ICE car. People worry that the studs will wear out really fast on dry - that is not true unless you drive hard. The same tech that keeps them quiet allows them to recede into the tire when they hit dry pavement.

I've been running studded tires Dec-Mar for 10 years, and I'm on dry pavement 98% of the time. I got 5 winters out of the first set, and 3 years out of the 2nd before selling that car. They are not "good as new" at the 5th year, but they are still better than no studs.

Reverse Threshold Braking​

Yes, as others have said, you can lock up your wheels on a regular gas car by letting off the gas, if the surface is slippery enough. So there is already sort of a need for this. And yes, shifting to neutral is another option, although once you've lost control, you are better off if you can skip this and focus just on car control.

You may already be familiar with Threshold Braking even if you haven't heard the term. This is when you carefully apply the brakes in a slippery situation, expecting to feel the ABS activate, and then let up a little on the brakes until ABS stops. You keep iterating on this cycle, constantly looking for that "perfect amount" of braking that slows the car as much as possible without activating the ABS. It is better to keep doing it rather than hold at one particular spot where the ABS disengaged, b/c the surface is always changing. What might have been the max stopping power 20 feet ago might not be the max now - especially if all you do is keep lifting every time ABS engages.

As you've observed, a Tesla will activate ABS just from regenerative braking. The first few times this happened for me, it led to me basically giving up - no foot on either pedal, feeling like there is nothing I can do, and thus doing nothing but wait until it was over. Feeling the car go crazy with ABS and barely stop at all, without touching a pedal was quite aggravating at first. Fortunately I was at a winter driving school, so there was nothing to hit, it was part of the exercise.

What I eventually figured out is that threshold braking still works with regenerative ABS - you just have to turn the concept upside down. Think of your accelerator foot as if it was sandwiched between the accelerator and an "upside down brake pedal" on top of your foot. The more you lift your foot, the harder you are pressing that brake pedal. If you are skidding, it's b/c you are trying to slow down faster than the surface will allow for - you are asking for more friction than it has. So you have to "ask for less." The way you slow down less is to press the accelerator a little more.

It is counter-intuitive, so it's freaky at first: You want to stop as fast as possible, so the last thing you want to do is accelerate more. But it is an illusion. Pressing the accelerator a little bit when you are skidding won't make you accelerate more - it will make you decelerate less.

This takes practice. At first just letting go of years of experience is hard. Once you are past that, it takes time to figure out the right amount, and get used to making very small adjustments of the accelerator pedal. This is best done at an actual winter driving school if you can find one, in empty parking lots, or if all else fails, on wide straight roads with no other traffic on them. Definitely do it at extremely low speeds.

 

[outdoors]

Johnny,

You might get some value out of the thread I started on track mode snow settings. I realize you don't have track mode, but the conversation may still be informative.

TL/DR:

• There are several brands of studless ice tire
• It is not true that you can't run studded tires on dry highway
• You could set your regenerative braking to "Low" instead of "Normal" when there is a concern there might be ice
• Ultimately, the best solution is to "retrain your brain" to do what I call "reverse threshold braking."

Long version:

Studless Ice Tires​

This is a thing. They us a microscopic solution to the problem; at microscopic level, ice isn't perfectly smooth. Blizzak's were the first, the Michelin X-Ice tires are excellent. I'm running Nokian Hakkapeliitta R5's, with what they call "Arctic Crystals" - tiny sharp bits mixed into the rubber that continually get exposed as the tire wears down. I have vaguely circumstantial evidence that the X-Ice might be better than the Hakka's, but haven't tried them back to back.

Studs on Dry​

If you are worried about road noise, Nokian Hakkapeliitta 8/9/10's have excellent quite-stud technology. It's not as quiet as non-studded tires, but still quieter than the average ICE car. People worry that the studs will wear out really fast on dry - that is not true unless you drive hard. The same tech that keeps them quiet allows them to recede into the tire when they hit dry pavement.

I've been running studded tires Dec-Mar for 10 years, and I'm on dry pavement 98% of the time. I got 5 winters out of the first set, and 3 years out of the 2nd before selling that car. They are not "good as new" at the 5th year, but they are still better than no studs.

Reverse Threshold Braking​

Yes, as others have said, you can lock up your wheels on a regular gas car by letting off the gas, if the surface is slippery enough. So there is already sort of a need for this. And yes, shifting to neutral is another option, although once you've lost control, you are better off if you can skip this and focus just on car control.

You may already be familiar with Threshold Braking even if you haven't heard the term. This is when you carefully apply the brakes in a slippery situation, expecting to feel the ABS activate, and then let up a little on the brakes until ABS stops. You keep iterating on this cycle, constantly looking for that "perfect amount" of braking that slows the car as much as possible without activating the ABS. It is better to keep doing it rather than hold at one particular spot where the ABS disengaged, b/c the surface is always changing. What might have been the max stopping power 20 feet ago might not be the max now - especially if all you do is keep lifting every time ABS engages.

As you've observed, a Tesla will activate ABS just from regenerative braking. The first few times this happened for me, it led to me basically giving up - no foot on either pedal, feeling like there is nothing I can do, and thus doing nothing but wait until it was over. Feeling the car go crazy with ABS and barely stop at all, without touching a pedal was quite aggravating at first. Fortunately I was at a winter driving school, so there was nothing to hit, it was part of the exercise.

What I eventually figured out is that threshold braking still works with regenerative ABS - you just have to turn the concept upside down. Think of your accelerator foot as if it was sandwiched between the accelerator and an "upside down brake pedal" on top of your foot. The more you lift your foot, the harder you are pressing that brake pedal. If you are skidding, it's b/c you are trying to slow down faster than the surface will allow for - you are asking for more friction than it has. So you have to "ask for less." The way you slow down less is to press the accelerator a little more.

It is counter-intuitive, so it's freaky at first: You want to stop as fast as possible, so the last thing you want to do is accelerate more. But it is an illusion. Pressing the accelerator a little bit when you are skidding won't make you accelerate more - it will make you decelerate less.

This takes practice. At first just letting go of years of experience is hard. Once you are past that, it takes time to figure out the right amount, and get used to making very small adjustments of the accelerator pedal. This is best done at an actual winter driving school if you can find one, in empty parking lots, or if all else fails, on wide straight roads with no other traffic on them. Definitely do it at extremely low speeds.

Probably the best explanation I have heard in a while in writing. By someone that knows what they are doing. Practice.

 

[avramd]

Probably the best explanation I have heard in a while in writing. By someone that knows what they are doing. Practice.

I appreciate that, thank you. I know I use a heck of a lot of words, probably more than most people are signing up to absorb. It is tricky to balance losing the point vs. losing the audience.