Safer or better driving experience with energy recovery?

[Avantgarde]

2023 cars are not immune to losing braking coming to a slow stop and suddenly having to depress the brake pedal an extra inch or so to resume braking. It is the transition from regenerative braking to hydraulic. The regen stops (at approx 3 or 4 mph) and the software doesn't blend in the hydraulic system without a fair amount of additional brake pedal travel. Scary when it happens. I complained of this problem to my dealer and the fix, like yours, was to update the software. Car went back to having normal feeling brakes. What is weird is that the braking action was not like this when the car was new and the problem was intermittent. Not sure what would have changed that a software update would fix, but so far it has. Porsche needs to do much better. Blending the two systems seems to be needlessly complicated and not well implemented.

It is possible earlier 23s still have the old software. I believe the new code became available June 2023 so 1H production cars likely had the old software. One thing i can tell though, the issue is not limited to blending of regen and pads. Even when during pure regen braking (which we specifically tested with the service foreman, who had a great ear in diagnosing when the pads were engaged), the pedal becomes way to soft at relatively lower speeds. (Apparently an intentional design to give more pedal fidelity at lower speed, but with poor execution/calibration).

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[gtm]

It is possible earlier 23s still has the old software. I believe the new code became available June 2023 so 1H production cars likely had the old software. One thing i can tell though, the issue is not limited to blending of regen and pads. Even when there during pure regen braking, the pedal becomes way to soft at lower speeds. (Apparently an intentional design to give more pedal fidelity at lower speed, but with poor execution/calibration).

Mine was December 2022 production so pre-updated software. And very true "with poor execution/calibration". Any manufacturer has to do better than this. Considering Porsche's reputation for performance it is doubly disappointing.

 

[WasserGKuehlt]

OP, I, too, find recuperation mode to be safer in certain situations: I turn it on by reflex in traffic, and I also use it on mountain driving. In traffic it’s easier to modulate speed and smooth out the stop-and-go ahead of me, and on descents I find the mild braking effect is exactly what’s needed, as touching the brakes at higher speeds yields too much deceleration. It’s particularly useful on ice/in low traction situations (not sure if that applies Down Unda), as it is effectively “engine braking”.

 

[f1eng]

This part of your quote confused me. If turning it off gets better range, what's the point of having regenerative braking? I always thought the purpose of it was to return some energy (however minimal) back to the battery and hence, improving range (in whatever capacity).

I think what you're saying (and maybe I'm misunderstanding) is that the benefit of "coasting" outweighs the benefit of returning energy back to the battery? If so, has anyone ever been able to quantify the difference?

If you need to slow down regenerative braking puts energy back into the battery and is more efficient. If you are travelling at constant speed coasting is more efficient than having a bit of throttle still on.

Porsche say it is more efficient and they are in a position to have done controlled tests so will know. I leave mine on coast all the time.

Certainly when optimum fuel use became worthwhile to optimise overall race performance in Formula 1, and probably always was in long distance sports car racing, lift and coast was the best compromise to use less energy losing the least performance.

 

[WuffvonTrips]

Anyone who owns a 2022 or older Taycan should test drive 2023 or newer model and pay attention to the brake feeling. I did not realize how long and problematic my brake pedal travel was until i drove 2023 & 24 Taycan loaners when my car was in for service. Older models run on an inferior Porsche Stability Management software version that results in a way too long & inconsistent brake pedal with a massive deadzone. I got mine fixed after i complained. The Major difference in braking behavior was acknowledged by the service foreman, who originally thought my brakes are fine but did not hide his surprise after back to back drives between my car and newer models.

My MY22 (built May'22, owned from new, PSCB fitted) thankfully has none of the brake issues that are reported on this forum, and the brakes, regen and pedal feel no different to the MY23s and 24s I've driven in a wide variety of conditions. The only thing I've ever noticed about the brakes is how impressive they are when really demanded.
I'm not disputing others' negative experiences, but I wonder if other factors are at play, for instance, is it more of an issue with RWD due to regen only on the rear axle?

 

[Avantgarde]

My MY22 (built May'22, owned from new, PSCB fitted) thankfully has none of the brake issues that are reported on this forum, and the brakes, regen and pedal feel no different to the MY23s and 24s I've driven in a wide variety of conditions. The only thing I've ever noticed about the brakes is how impressive they are when really demanded.
I'm not disputing others' negative experiences, but I wonder if other factors are at play, for instance, is it more of an issue with RWD due to regen only on the rear axle?

It is possible not all cars are impacted. But I know other Turbo drivers complained about the same thing so it does not look like a RWD isolated issue. I have PSCBs so, feels like no relation there either...

 

[DerekS]

Recently I switched on energy recovery. This is known universally as regenerative braking

No, it's not.

Regenerative braking is not user-adjustable on the Taycan.

What you enabled is the lift-off-accelerator recuperation.

 

[f1eng]

It is possible not all cars are impacted. But I know other Turbo drivers complained about the same thing so it does not look like a RWD isolated issue. I have PSCBs so, feels like no relation there either...

It seems on balance a brake bleeding problem. There is a particular procedure for brake bleeding which based on previous discussions on this solves the problem a few people have had. Seems odd that a few cars haven’t had their brakes properly bled, but maybe it is a fiddly procedure.

 

[or1]

OP, I, too, find recuperation mode to be safer in certain situations: I turn it on by reflex in traffic, and I also use it on mountain driving. In traffic it’s easier to modulate speed and smooth out the stop-and-go ahead of me, and on descents I find the mild braking effect is exactly what’s needed, as touching the brakes at higher speeds yields too much deceleration. It’s particularly useful on ice/in low traction situations (not sure if that applies Down Unda), as it is effectively “engine braking”.

We have particularly icy conditions in Norway right now, and my view is a bit different than this. Also on ice and slippery snow I prefer coasting (=no regen-on-liftoff) as I am then 100% sure that all wheels are rolling with no attempted braking. Then I use the brake pedal (to get some regen) or acceleration when and where I think there is low risk to it.
The lift-off regen can well be so weak and controlled that the car won't start skidding, but better safe than sorry.

 

[gtm]

It seems on balance a brake bleeding problem. There is a particular procedure for brake bleeding which based on previous discussions on this solves the problem a few people have had. Seems odd that a few cars haven’t had their brakes properly bled, but maybe it is a fiddly procedure.

There may be more than one issue with the brakes but ... My car had the "Brake Symptom – Brake Pedal Travel Perceived as “Too Long” Just Before the Vehicle Comes to a Standstill: Observe Specified Procedure (SY 90/21)". The initial fix (TSB dated 7/22/22) was to replace the brake booster, master cylinder and (obviously) bleed the brakes. TSB 90/21 was revised (1/20/23) to just bleeding the brakes. How a car can leave the factory with good brakes and ingest air without the system being opened up escapes me but based on posts here it has worked in some cases. Right now the remedy/TSB is to update the brake (PSM) software only. My car was in last week for the battery test and I asked to have the brakes looked at. The transition from regenerative braking to the hydraulic system had become consistently noticeable, but intermittently the car would lose braking and require depressing the brake pedal an extra inch or two to resume braking. It was not this way when it was new but developed over the miles. The software update completely cured the issue. There is no longer anything noticeable blending the brakes and the "pedal drop" hasn't happened once since the update. I have no clue what to make of the changing service bulletin proceedures, nor what would cause the symptoms to develop over time, nor why only some cars seem to be affected, but it seems clear there is a problem and Porsche didn't/doesn't really know how to address it. Kind of disturbing and has left me driving around just waiting for the problem to return.

 

[Avantgarde]

If you need to slow down regenerative braking puts energy back into the battery and is more efficient. If you are travelling at constant speed coasting is more efficient than having a bit of throttle still on.

Porsche say it is more efficient and they are in a position to have done controlled tests so will know. I leave mine on coast all the time.

Certainly when optimum fuel use became worthwhile to optimise overall race performance in Formula 1, and probably always was in long distance sports car racing, lift and coast was the best compromise to use less energy losing the least performance.

There may be more than one issue with the brakes but ... My car had the "Brake Symptom – Brake Pedal Travel Perceived as “Too Long” Just Before the Vehicle Comes to a Standstill: Observe Specified Procedure (SY 90/21)". The initial fix (TSB dated 7/22/22) was to replace the brake booster, master cylinder and (obviously) bleed the brakes. TSB 90/21 was revised (1/20/23) to just bleeding the brakes. How a car can leave the factory with good brakes and ingest air without the system being opened up escapes me but based on posts here it has worked in some cases. Right now the remedy/TSB is to update the brake (PSM) software only. My car was in last week for the battery test and I asked to have the brakes looked at. The transition from regenerative braking to the hydraulic system had become consistently noticeable, but intermittently the car would lose braking and require depressing the brake pedal an extra inch or two to resume braking. It was not this way when it was new but developed over the miles. The software update completely cured the issue. There is no longer anything noticeable blending the brakes and the "pedal drop" hasn't happened once since the update. I have no clue what to make of the changing service bulletin proceedures, nor what would cause the symptoms to develop over time, nor why only some cars seem to be affected, but it seems clear there is a problem and Porsche didn't/doesn't really know how to address it. Kind of disturbing and has left me driving around just waiting for the problem to return.

Same thing with mine. The service foreman first updated the PSM and he said that alone solved the issue 90%. Then he bled the brakes just in case and argued that also did help a bit. They put everything in detail in writing step by step (and how the PSM update simply made pedal more responsive and firm in particular) like a doctor reporting what was administered on a patient.

 

[gtm]

Same thing with mine. The service foreman first updated the PSM and he said that alone solved the issue 90%. Then he bled the brakes just in case and argued that also did help a bit. They put everything in detail in writing step by step (and how the PSM update simply made pedal more responsive and firm in particular) like a doctor reporting what was administered on a patient.

Do you feel the problem has been completely solved or still "not quite right"? For now my brakes have gone back to being like they were when the car was new. i.e. pretty much perfect. I'm just hoping this is a permanent fix.

 

[Avantgarde]

Do you feel the problem has been completely solved or still "not quite right"? For now my brakes have gone back to being like they were when the car was new. i.e. pretty much perfect. I'm just hoping this is a permanent fix.

I feel like my issue is 100% solved. My car actually never felt like this even when brand new.

Now for the ones who are interested in nerdy details here is another symptom of issue that annoyed me (and completely fixed now). When I had the power meter up, I could see the slightest touch to the accelerator would result in a blue bar reacting on the gauge, but the similar slight touch to the brake would not result in the same immediate response on green regen indicator (you'd need a relatively deeper press) - annoying character during spirited driving. Actually, if i tried I could do very fast back to back slight pumps on the brake pedal, not exceeding 1/4 of an inch of a press, without triggering the green bar at all while making a lot of mechanical pedal noise. I had the foreman do the same test and he agreed. Now the odd part was, if I simply put my foot down the same 1/4 of an inch and waited a split second, the green bar would react, which made me believe that the car was mechanically recognizing the touch to the pedal but not reacting right away. On the loaner (and now my car after the update), there is no way I could touch the pedal without triggering the green bar. And obviously you can only do this test when your car is not using the brake pads (eg car uses pads first couple minutes of a trip to clean them, during which green bar does not respond at all).

 

[Jhenson29]

No, it's not.

Regenerative braking is not user-adjustable on the Taycan.

What you enabled is the lift-off-accelerator recuperation.

It is all still regen braking though. The overrun recup has a much lower torque limit (that varies by conditions) than braking recup but it’s all still the same braking mechanism, which is regen. “Overrun recup” and “braking recup” are more interface and limit distinctions.

 

[Mike in CA]

And what probably would have saved you as well (and is less invasive/annoying) is setting it to Automatic Recuperation. That's also distance based., so not invasive at all as long as there is no car in front of you. I don't think it will make a full stop, but it will decelerate the car a bit, waking you up from your distraction and triggering your brake reflex.

I agree. I use Auto mode most of the time. My problem with Recuperation mode is that not only does it feel unnatural to have the car slow significantly every time I lift off the accelerator, but it is actually less efficient than coasting due to energy losses in the regeneration process. Auto mode, as you point out, doesn't engage regeneration unless there's a car within the adjustable distance range and otherwise allows for unrestricted coasting. Kind of the best of both worlds, IMHO.,

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