Do brake lights illuminate during auto-regen?

[4thPcar]

I've been wondering about this for some time, like every time I get on the freeway these past 2 years. I use the auto-regen religiously and it does 90% of the work for me during bumper-to-bumper traffic. So I wonder, does the guy behind me realize I am slowing down?

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[Donar]

Mine are not. Easy to check when it’s dark.

 

[W1NGE]

I've been wondering about this for some time, like every time I get on the freeway these past 2 years. I use the auto-regen religiously and it does 90% of the work for me during bumper-to-bumper traffic. So I wonder, does the guy behind me realize I am slowing down?

No they don't.

Deceleration is not high enough to be a legal requirement.

 

[WuffvonTrips]

I don't think previous discussions have resulted in a definitive answer. @W1NGE is correct for at least the vast majority of cases, but it's conceivable that in certain scenarios auto-regen could exceed the legally mandated threshold that requires the brake lights to come on...
https://www.taycanforum.com/forum/threads/brake-lights-during-recuperation.15786/post-247580

 

[bn8959]

I can confirm that it does.

but only when regen is in auto mode and it’s decelerating at a significant rate (ie you are approaching a car in front that is going very slowly).

‘Normal’ regen mode will not cause the lights to come on. There is a threshold where they will come on if regen is causing it to slow down quickly.

similar behaviour in ACC mode.

 

[bn8959]

I can confirm that it does.

but only when regen is in auto mode and it’s decelerating at a significant rate (ie you are approaching a car in front th

‘Normal’ regen mode will not cause the lights to come on. There is a threshold where they will come on if regen is causing it to slow down quickly.

similar behaviour in ACC mode.

Although I don’t know if there are regional differences, there may be different behaviour in other countries with different laws.

 

[Tooney]

I don't think previous discussions have resulted in a definitive answer.

+1. That's an understatement!
'Do Taycan brake lights come on during auto-regen?' is right up there with 'how many angels can dance on the head of a pin?'.

 

[W1NGE]

I can confirm that it does.

but only when regen is in auto mode and it’s decelerating at a significant rate (ie you are approaching a car in front that is going very slowly).

‘Normal’ regen mode will not cause the lights to come on. There is a threshold where they will come on if regen is causing it to slow down quickly.

similar behaviour in ACC mode.

Akin to an emergency stop - then of course the brake lights would come on and potentially flash rapidly!

 

[Hirschaj]

I can confirm that it does.

but only when regen is in auto mode and it’s decelerating at a significant rate (ie you are approaching a car in front that is going very slowly).

This! Absolutely yes, your brake lights will come on when using auto-regen as long as the rate of deceleration crosses a certain threshold. I have confirmed using my own car.

 

[LongLive959]

It works well. But I’ve stopped using Auto mode because I could see it being very annoying for the driver behind me if the lights are coming on in certain situations. I am still trying to relearn normal driving after a decade of “one pedal driving”…..so maybe getting used to letting off early and cruising will help me not get so close.

it’s frustrating being behind new Tesla drivers who don’t get that their brake lights are constantly coming on (it’s led to many a fight between my wife and I!)

 

[Hirschaj]

But I’ve stopped using Auto mode because I could see it being very annoying for the driver behind me if the lights are coming on in certain situations.

I wondered about this myself when I first got the car. I ended up using auto-regen during a PCA driving event where we were all lined up driving together. During a stop I asked the car behind me about my brake lights and if they were coming on frequently. They said no, that they came on normally (during heavy deceleration) and did not light up frequently besides that. They noticed no difference from normal driving. So now I use it every time in that type of event and I don't worry that it's annoying to anyone, because it's not.

 

[outie]

It works well. But I’ve stopped using Auto mode because I could see it being very annoying for the driver behind me if the lights are coming on in certain situations. I am still trying to relearn normal driving after a decade of “one pedal driving”…..so maybe getting used to letting off early and cruising will help me not get so close.

it’s frustrating being behind new Tesla drivers who don’t get that their brake lights are constantly coming on (it’s led to many a fight between my wife and I!)

Our neighborhood is full of Teslas (all 4 are teslas at a 4-way stop sign intersection is not uncommon). I go downhill all the time and by your logic these Teslas would brake all the way downhill which is not the case. The brake lights only come on when necessary.

 

[C17r15]

To the OP - there is very little regen sub-10mph / 12kmh, and no regen below 3mph / 5kmh.

At that speed it’s likely rolling resistance from the tires / drivetrain that is bringing the car to a halt, and in that case doubt the brake lights would be illuminated.

I've been wondering about this for some time, like every time I get on the freeway these past 2 years. I use the auto-regen religiously and it does 90% of the work for me during bumper-to-bumper traffic. So I wonder, does the guy behind me realize I am slowing down?

 

[LongLive959]

Our neighborhood is full of Teslas (all 4 are teslas at a 4-way stop sign intersection is not uncommon). I go downhill all the time and by your logic these Teslas would brake all the way downhill which is not the case. The brake lights only come on when necessary.

They come on based on how hard they regen. But they do come on. It depends on how well the driver is controlling the go pedal. It’s not uncommon for newbies and bad drivers to be constantly letting off and lighting up (more common on highway with drivers used to completely letting off the gas to cruise). But at least the Teslas indicate on the dash when the brake lights are active.

The question here is, does the Taycan light up on auto regen and when. It would be nice to have some sort of indication if the brake lights come on during auto regen….but it is how it is. Whatever

 

[4thPcar]

so….it depends! I feel a lot more knowledgeable now, though no more certain!

I attended a funeral across country last year and the rental agency gave me a new Mercedes EV (not the economy car I ordered). After the ceremony we drove "caravan style" to a restaurant. It was a long drive down an straight road, lots of lights. I drove as I always do, coasting in traffic and only using the brake to slow down for traffic or lights. When we arrived at the restaurant my cousin ran up to me and said "ARE YOU OK? you were braking constantly the whole way."

I guess I'm not the only one confused by new tech!

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