$2.3 billion Icy Road Regenerative Braking Lawsuit

[mongo]

Funny how everyone tries to compare regen to driving a manual. In a manual I push the clutch in and "regen" stops how do you stop regen during an emergency in a tesla?

Assuming regen is not active in Neutral:

For an X:
Neutral
Push the lever up or down to the first position and release to shift into Neutral. Neutral allows Model X to roll freely.

For an S:
Neutral
Push the lever up or down to the first position and release to shift into Neutral. Neutral allows Model S to roll freely.

 

[LCR1]

Assuming regen is not active in Neutral:

For an X:
Neutral
Push the lever up or down to the first position and release to shift into Neutral. Neutral allows Model X to roll freely.

For an S:
Neutral
Push the lever up or down to the first position and release to shift into Neutral. Neutral allows Model S to roll freely.

Only took 120 comments for someone to come up with a viable solution. However when I'm sliding and counter steering, neutral isn't the easiest thing to get to in a timely fashion.

 

[JHWJR]

Give the car a little juice until the acceleration is ZERO.

Your physics is impeccable. Your expectations of mere humans in "emergency" situations and the likelihood of instinctive, panicked reactions may be suspect.

 

[Lasttoy]

Driver error, driving to fast for conditions. Car can't fix stupid.

 

[bxr140]

Do we know what the outcome was? Or still in litigation?

 

[David99]

I just tested regen braking on slippery roads. It really works poor on slippery roads at least on my old RWD. As you release the pedal, regen ramps up, the wheels starts to slip, regen ramps down, the wheels get grip again and this repeats on and on. It feels rough, uncontrolled and poor. It will make the car unstable.
To slow the car down carefully on slippery roads you need to apply the brakes on all 4 wheels gently. You cannot do that in a Tesla. If you let the accelerator go to touch the brake carefully, regen will kick in and apply a negative torque. In very slippery conditions this is too much and it would be very very counter intuitive to keep the foot gently on the accelerator in those situations.

 

[mongo]

I just tested regen braking on slippery roads. It really works poor on slippery roads at least on my old RWD. As you release the pedal, regen ramps up, the wheels starts to slip, regen ramps down, the wheels get grip again and this repeats on and on. It feels rough, uncontrolled and poor. It will make the car unstable.
To slow the car down carefully on slippery roads you need to apply the brakes on all 4 wheels gently. You cannot do that in a Tesla. If you let the accelerator go to touch the brake carefully, regen will kick in and apply a negative torque. In very slippery conditions this is too much and it would be very very counter intuitive to keep the foot gently on the accelerator in those situations.

Thank you for the real world testing. Next trip, would mind checking if shifting to neutral works better? Not that one can use it all the time, but for a stop on ice, it may be useful.

 

[hacer]

Funny how everyone tries to compare regen to driving a manual. In a manual I push the clutch in and "regen" stops how do you stop regen during an emergency in a tesla?

Very simple: push the shift lever to neutral (half-bump up or down does this). It is exactly like pushing in the clutch to regain stability in icy conditions. You still have the (usually unwise) option of applying some brake pedal pressure.

 

[David99]

Shifting to neutral in a tricky situaton is something I have actually practiced. I was going almost sideways on an icy freeway at 50 mph and after that experience I realized how important it would be.

 

[David99]

Thank you for the real world testing. Next trip, would mind checking if shifting to neutral works better? Not that one can use it all the time, but for a stop on ice, it may be useful.

It's actually not that easy when you start sliding. The natural reaction is to counter steer so your hands are very busy doing strong and wide movements and it takes quite some skills and practice to take one hand off and do a gentle half way push down/up on the shifter stalk to hit Neutral. It sounds easy in theory, but when your car goes sideways on the road and you are sliding into oncoming traffic you will find yourself having a hard time doing it.

 

[mknox]

I just tested regen braking on slippery roads. It really works poor on slippery roads at least on my old RWD. As you release the pedal, regen ramps up, the wheels starts to slip, regen ramps down, the wheels get grip again and this repeats on and on. It feels rough, uncontrolled and poor. It will make the car unstable.
To slow the car down carefully on slippery roads you need to apply the brakes on all 4 wheels gently. You cannot do that in a Tesla. If you let the accelerator go to touch the brake carefully, regen will kick in and apply a negative torque. In very slippery conditions this is too much and it would be very very counter intuitive to keep the foot gently on the accelerator in those situations.

Shifting to neutral in a tricky situaton is something I have actually practiced. I was going almost sideways on an icy freeway at 50 mph and after that experience I realized how important it would be.

Agree completely with the assessment of regen on a RWD Model S. My experience exactly.

I tried a practice run putting the car in Neutral, but had some difficulty getting it back in Drive while still rolling. I had to apply some pressure to the Brake to get it to shift. I would get the beep-beep-beep and message about applying the brake to shift. That was some time, and several software updates ago, so must try again to see if this is still the case.

 

[SeaDoc]

Black ice, snow tires, learn to drive, not a fault of Tesla, but of owner... Glad he's alive, thank Tesla you're not dead... Another bogus lawsuit to garner income for lawyers... Merry Christmas!!!

 

[David99]

Agree completely with the assessment of regen on a RWD Model S. My experience exactly.

I tried a practice run putting the car in Neutral, but had some difficulty getting it back in Drive while still rolling. I had to apply some pressure to the Brake to get it to shift. I would get the beep-beep-beep and message about applying the brake to shift. That was some time, and several software updates ago, so must try again to see if this is still the case.

It seems to shift back to D without any issues for me. I usually press the accelerator a little so regen doesn't kick in

 

[Uncle Paul]

You can also just partially reduce throttle. There is an area where there is no forward thrust and no regen.
The gauge on the dash will visually show where this is, so you can be very accurate.

I have had many ICE cars where lifting throttle immediately induced engine braking, especially when in the lower gears.

It is up to every driver to become aware of the driving characteristics of the vehicle that they are controlling and drive appropriately. Driving on slippery roads is a skill set that must be honed. Driving foolishly and then blaming the vehicle is not appropriate.

 

[mongo]

It's actually not that easy when you start sliding. The natural reaction is to counter steer so your hands are very busy doing strong and wide movements and it takes quite some skills and practice to take one hand off and do a gentle half way push down/up on the shifter stalk to hit Neutral. It sounds easy in theory, but when your car goes sideways on the road and you are sliding into oncoming traffic you will find yourself having a hard time doing it.

Totally agree, I was thinking of pre-emptive neutral approaching a stop sign or such. Only relevant in a small portion of the stopping instances.

 

[dgpcolorado]

Shifting to neutral in a tricky situaton is something I have actually practiced. I was going almost sideways on an icy freeway at 50 mph and after that experience I realized how important it would be.

One more counter-intuitive thing I've played with is braking with ABS. Those of us who learned to drive snow and ice in the "olden days" were taught to pump the brakes to keep them from locking up. With ABS one is supposed to jam on the brakes and let the system brake the car but the pulsing tends to cause drivers to release brake pressure. It takes practice to learn to trust ABS, in my experience.

By coincidence I also had a chance to play with regen and slick conditions yesterday, since my road was unplowed and the snow packed down by previous cars. Since there were no other cars around I got to play around with going too fast for the conditions, which is fun. Usually roads are plowed and sanded here and slick conditions are uncommon. If ice is a problem, say at an intersection where other cars have glazed the snowpack, it is best to approach the area slowly — that's a winter driving experience thing. If I skid on ice I am going too fast for the conditions. That sort of cautious driving also includes feathering the accelerator. I agree that shifting to neutral in a Tesla is harder to remember to do than stepping on the clutch to get neutral in icy condtions, something I have done many times in ICE cars (I have near zero experience with automatic transmission cars, so I can't speak to that).

 

[mongo]

One more counter-intuitive thing I've played with is braking with ABS. Those of us who learned to drive snow and ice in the "olden days" were taught to pump the brakes to keep them from locking up. With ABS one is supposed to jam on the brakes and let the system brake the car but the pulsing tends to cause drivers to release brake pressure. It takes practice to learn to trust ABS, in my experience.

By coincidence I also had a chance to play with regen and slick conditions yesterday, since my road was unplowed and the snow packed down by previous cars. Since there were no other cars around I got to play around with going too fast for the conditions, which is fun. Usually roads are plowed and sanded here and slick conditions are uncommon. If ice is a problem, say at an intersection where other cars have glazed the snowpack, it is best to approach the area slowly — that's a winter driving experience thing. If I skid on ice I am going too fast for the conditions. That sort of cautious driving also includes feathering the accelerator. I agree that shifting to neutral in a Tesla is harder to remember to do than stepping on the clutch to get neutral in icy condtions, something I have done many times in ICE cars (I have near zero experience with automatic transmission cars, so I can't speak to that).

Did you determine if hard braking that engages ABS also disables regen (and is more stable). That would be an interesting data point.

Perhaps instead of the dead pedal spot for the left foot, Tesla could add a 'clutch' switch. Simple enough module that sends a neutral override CAN message.

It will be interesting to see if the 3 with PM motors will perform better. Torque and speed control are much easier with PM.

 

[David99]

Did you determine if hard braking that engages ABS also disables regen (and is more stable). That would be an interesting data point.

I tried it a little bit and regen is still active when ABS is active.

 

[David99]

Here is what regen does on a slippery road. As you release the pedal, regen ramps up, the wheels starts to slip, regen ramps down, the wheels get grip again and this repeats on and on. It feels rough, uncontrolled and poor. It will make the car unstable. This is a RWD car.

 

[neroden]

Assuming regen is not active in Neutral:

For an X:
Neutral
Push the lever up or down to the first position and release to shift into Neutral. Neutral allows Model X to roll freely.

For an S:
Neutral
Push the lever up or down to the first position and release to shift into Neutral. Neutral allows Model S to roll freely.

Bingo. I learned how to get into neutral years ago in a standard shift car -- I was specifically industructed to do so if skidding, because of engine braking -- and I have done so in Model S on ice.

I guess most people don't know how to drive. Model S is like a standard. If you start skidding on ice, steer INTO the skid, go into neutral, and then slowly touch the brakes as you regain control. I did this in my *first week* driving the Model S because back in 2013 it arrived without snow tires in February.