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7.0 Regen Reduced? Smoother? Less "Aggressive"?

Discussion in 'Model S: Driving Dynamics' started by GOPJEW, Nov 11, 2015.

  1. GOPJEW

    GOPJEW Member

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    7.0 Regen Reduced? Smoother.

    So with roughly 6k miles in a little less than 3 months on my car I have become fairly well attuned to it's performance characteristics. However, after my 7.0 update I have noticed that my regeneration seems much "smoother" and much less "aggressive"
     
  2. GOPJEW

    GOPJEW Member

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    So with roughly 6k miles in a little less than 3 months on my car I have become fairly well attuned to it's performance characteristics. However, after my 7.0 update I have noticed that my regeneration seems much "smoother" and much less "aggressive"

    Has anyone else noticed this? Has Tesla verified this? Protecting the motors wear?

    I just notice that I need to brake significantly more than previously...obviously a costlier prospect.

    Thoughts?
     
  3. zdre

    zdre 40kWh Model S P6415

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    I definitely noticed this and will be contacting Tesla. According to release notes, the regen efficiently was increased. However, I do not think the regen power curve was modified or modified enough to match the previous deceleration. That means regen is capturing same or more energy during a specific time period, but slows down the car less. I am not sure if Tesla would want to increase the max regen power much above 60kWh, but at least they could increase the power at lower speeds.
     
  4. BertL

    BertL Active Member

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    I only had 6.2 in my S90D for a few days before 7.0 came out, but I much prefer 7.0 STANDARD as it allows me to drive without often using the brake, but is much smoother for me and my passengers as I let up on the accelerator than what I experienced in my initial test drive and with 6.2. This regen low vs standard thing (with 6.2) is what I made the most comments about on my test drive and played with the most during that time.

    I drove Lexus RX hybrids for 10 years, so know very well what regen was with those two rides, made use of it to help slow my vehicles (also had to use the brakes a lot more because of that design), but I also appreciated that I was able to create a smooth deceleration to a stop most of the time as my foot came off the accelerator pedal. MS regen is much more aggressive than my hybrids were when in STANDARD, and feels closer to what I knew with my Lexi if set to LOW. I'll leave it to everyone else to speculate on the Tesla regen energy curves between 6.2 and 7.0. I am fine if Tesla were to introduce a 3rd regen option as is being discussed in a parallel thread, but PLEASE TESLA if you are listening, keep an option for people like me that like 7.0 STANDARD, which allows fairly-easy-to-achieve smooth deceleration and apparently decent regen energy benefits at the same time.
     
  5. Soolim

    Soolim Member

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    Tesla, if the regen has been modified for smoother deceleration, please allow the driver to have three choices: Low - Medium - High regens in next F/W update. I would like to control regen for deceleration the same way as I control power for acceleration by applying varying pressure to the pedal with regen set to high.
     
  6. yobigd20

    yobigd20 Well-Known Member

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    that means they need less deceleration for the same regen power. so each time they increase regen efficiency, the car will 'feel' like regen is slower and less effective than before. this has happened on pretty much every single version release.
     
  7. apacheguy

    apacheguy Sig 255, VIN 320

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    Rest assured, there is no way Tesla will ever eliminate standard regen.
     
  8. liuping

    liuping Active Member

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    If I take my foot of the accelerator at the same point on the off ramp I did prior to 7.0, I will not be nearly as close to stopping at the top of the ramp. I've taken that off ramp hundreds of times, so I know what it felt like and it's not the same now. I have to apply far more braking than previously.

    If I have to brake harder, there is more power that could have been recovered, so I think it's reasonable to have a "strong" setting on the regen option.
     
  9. yobigd20

    yobigd20 Well-Known Member

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    but since they increased regen efficiency, aka the amount of power captured from regen got higher using less braking torque/distance, then that means they are maxing out on regen already and you have to use your friction brakes more to stop at the same distance as before.

    this is kind of hard to explain.

    lets say theres a certain torque they apply to get max 60kW regen and that would stop your car in 100ft or so. (making numbers up here)

    they reprogram to increase efficiency.

    now all the sudden they hit max 60kW regen using much less torque. so since less stopping torque is being applied it's going to take 130ft to stop your car from the same speed/spot as before.

    that means what you're used to feeling out of regen is going to be much different from this point forward. if keep letting go of the accelerator at the same spot, you're going to need to apply your friction brakes more to stop at the same point. the alternative is to let go of the accelerator earlier than before. this gets difficult to do as the distance increases to gauge when to let to to stop at the right point.


    each time they increase efficency it just means the car is going to glide further than before and the less 'braking' feeling its going to have.
     
  10. sorka

    sorka Active Member

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    If efficiency went up then why didn't the max regen increase beyond 60KW?
     
  11. Max*

    Max* Autopilot != Autonomous

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    I'm no expect, but I don't buy it.

    If efficiency went up, then they could capture more regen (not necessarily more than 60kw instantaneous, but if you integrate the curve, it would have a higher kwh), thus when coasting to a stop, you'd stop at the same point as pre-v7 but have more kwh stored back in the pack.
     
  12. tstafford

    tstafford Member

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    Brake manufacturers are going broke - Tesla cut them a "break".
     
  13. yobigd20

    yobigd20 Well-Known Member

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    Probably because the regen unit or the motor wasn't designed to handle anything higher.
     
  14. CHG-ON

    CHG-ON Still in love after all these miles

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    I find myself braking more than I used to. I really don't understand the efficiency gain because I'm no physicist. But I preferred the other profile and would also prefer to not wear my brakes. I can say that it is much smoother, which is nice. There have been many complaints in the past about the abruptness of regen. So I suppose this is their answer to it.

    The only real issue I have with the new profile is that if I initiate regen earlier, my brake lights come on way too early for normal driving as the car slows down. I would think that would be very annoying for those behind me. I know that it would drive me nuts to have a car apparently braking well before the intersection. I would interpret that as a "granny" or paranoid driver.
     
  15. liuping

    liuping Active Member

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    I get the concept, but when I have to apply the brakes at the end of the ramp, the regen is nowhere near 60kW, so I don't think that is what happening here. It's already started dropping as the car slowed, so there was more regen energy to be had.
     
  16. Todd Burch

    Todd Burch Electron Pilot

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    I don't think this has to do with a change in efficiency, or maximum regen.

    They've just changed the throttle mapping, both on the consumption (demanding power) and production (regen) side. With 7.0, a given amount of pedal travel produces less power than it did on 6.2, until you get to full pedal travel, at which power is the same as it was on 6.2. In other words, the power increase for a given unit of pedal travel starts out more gradual, then ramps up faster in the later portion of its travel than on 6.2.

    The same is true of regen, except in the opposite direction....initially as you apply less pedal the regen comes in more gradually, then it ramps in stronger than before as the pedal continues to come out.

    Why did Tesla do this? Probably to give the driver more control at low throttle inputs, a smoother ride, and to decrease impact forces on the drivetrain (gear lash, etc).

    End effect to the driver? The input your foot is used to applying for a given regen situation is now no longer enough to provide the same amount of deceleration. In other words, to slow down at the same rate, your foot now needs to pull back more than it did before.

    Because of motor memory, when we tend to apply the same inputs as before, we end up just decelerating at a more gradual rate, requiring more braking.

    Moral of the story? Try applying more aggressive foot movements during regen than you did before. (By that I mean your foot should pull back more, not necessarily move quicker or be more jerky). If you do this, you should find the regen force available to be the same as it was before.

    I don't really like the new mapping. It feels too mushy to me. I much preferred the tighter mapping of 6.2.

    This is what I gather as someone driving the S since December of 2012 and coming up on 60,000 miles.
     
  17. Soolim

    Soolim Member

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    What you described make sense to me except the part I quoted above. I thought "Try applying more aggressive foot movements during regen" mean remove my foot from the pedal. Why does move quicker (remove the foot from the pedal) not generate the maximum amount of regen? Unless the 0-100% regen (whatever that max kW regen might be) has been mapped to the 0-100% power for acceleration (whatever that max kW might be)? In other words, the amount of regen depends on how much you have been accelerating prior? I would appreciate your additional explanation.

    Totally agree
     
  18. zer0cool

    zer0cool Member

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    Yes it's smoother and doesn't appear to have reduced range. Quite amazing. I most DEFINITELY like the new smoother regen more than the one before.
     
  19. kirkbauer

    kirkbauer Member

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    I think smoother and more efficient is great, but I agree that now I need to use my brakes more which will wear them out quicker. If physically possible Tesla should up the max regen amount so I get more regen braking and make that a "Max" setting or something.
     
  20. scaesare

    scaesare Active Member

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    As I posted in one of the V7 firmware threads:

    It does appear to have a remapped cureve that's less abrupt.... although I think the side effect is that it's typically taking me longer distances to slow down by bit.[1]

    On my daily commute there are several places (intersections, stop signs, and speed limit changes) where I have visual cues as to where I disengage cruise control from a set point to come to a stop or slow down for the new zone, and it seems that I'm no longer slowing down quite as much.

    Not entirely scientific, but typically very repeatable over 10's or even 100's of cycles previously...

    [1] I hadn't mentioned this previously because there have always been claims of regen change after a FW update that seems to be largely perception rather than reality... so I've waited until I had some time to drive/test with 7.0 and test my markers.
     

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