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New regen profile for P85D?

Discussion in 'Model S: Driving Dynamics' started by stevezzzz, Jan 6, 2015.

  1. stevezzzz

    stevezzzz R;SigS;P85D;SigX

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    I've noticed that the regen braking force builds up much more slowly when I lift off the go pedal on the D than on my Sig S. Has anyone else noticed this? I don't know for sure which software versions are running on both cars, but I haven't had an update on the Sig in a month or two.

    So, questions:

    - Is this a firmware version difference, or a 2WD vs. AWD thing?

    - Does the regen profile of the D differ in other substantive ways from the 2WD version?
     
  2. randompersonx

    randompersonx Member

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    P85D is my first Telsa, but at highway speeds, if I take my foot off the go pedal, I seem to get up to maximum regen immediately (unclear how much this is, but it's past the 60KW line -- perhaps 90KW?) What did you experience in your Signature, and what are you seeing in the P85D?
     
  3. stevezzzz

    stevezzzz R;SigS;P85D;SigX

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    What I'm seeing is that the onset of regen braking is much slower in the D than the Sig: two or three seconds to get to full regen, as opposed to half a second or so for the Sig. I haven't needed full regen at highways speeds yet, so I can't speak to the max amplitude difference, if it exists.

    Early on (back in the fall of '12), full regen was nearly instantaneous; one of the early firmware updates softened the onset a bit, but it hasn't changed at all since then, at least not according to my proprioceptive receptors (read: 'uncalibrated tush').
     
  4. Jaff

    Jaff Active Member

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    I haven't noticed this yet, but I have only driven our D for a few kms, and not at highway speed.

    There was a large difference between the Roadster regen & our Sig's regen...after logging a few more kms on the D, I am sure the D's regen will become the "new normal" and you will get used to it quickly.
     
  5. billarnett

    billarnett Member

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    In what ways is the P85D regen different from the Roadster? My only complaint about my Roadster is that the regen is too weak. With AWD the opportunity is there for it to be much stronger....
     
  6. ra-san

    ra-san Member

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    Roadster Regen feels stronger and more immediate than the S. Of course, it's lighter so the same amount of regen slows it more.
     
  7. wk057

    wk057 Senior Tinkerer

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    I was about to start a new thread on this when I spotted this one.

    I drove my fiance's P85 about 600 miles in the past week. Then I got back in my P85D after letting it sit for 5 days (yeah, it was hard being apart...) and the difference in regen is VERY noticeable. The P85 regen kicks in quickly and strong as soon as you let up. The P85D, while it almost always reaches higher power levels, feathers it out much more slowly than the P85. I ended up needing to use the friction brakes because of this more often than I would have in the P85, a large efficiency loss.

    It also seems that even though the P85D regen meter goes higher than the P85's, the slowing/decel/stopping distance seems to be either longer than the P85. I assume this is due to added weight, but could be the feathering delay also which seems to actually be in the 1 full second range...

    I prefer the P85 method. When I let my foot completely off of the pedal, I expect full regen... not full regen in 1.5s. :-\

    Fixing this to behave like the (P)85/60 would improve efficiency because I would use the friction brakes much less.
     
  8. NielsChr

    NielsChr Member

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    partly agree.

    at pressent they have a setting for "regen low" or "regen high"
    they just need to make a slider with options like "insane", "fast", "normal" or "slow" regen mode.
     
  9. David99

    David99 Active Member

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    I agree, there should be a slider for regent amount and "speed" (how fast it kicks in).
     
  10. EarlyAdopter

    EarlyAdopter Active Member

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    Wonder if it has anything to do with the increased weight of the P85D. Have you tried it with two (or maybe three?) people in the P85 vs. only one in the P85D?
     
  11. wk057

    wk057 Senior Tinkerer

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    Yeah, even with five people in the P85 it still reacts quicker than the P85D does with just me.

    Keep in mind the P85D isn't *that* much heavier than the P85. IIRC it's about the same as a passenger or two difference from the (P/S)85.
     
  12. Vitaman

    Vitaman Member

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    The Regen is sometimes so anemic that several times I have accessed the Control screen to see if "low" was inadvertently selected.
    Only drove the P a few times but remember a faster response. Our i3 has even stronger regeneration than the P....that level of immediacy is my favorite. It is the easiest to modulate.
     
  13. wk057

    wk057 Senior Tinkerer

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    I guess I need to do a quick 60-0 regen video in the same spot in both cars... slow-mo playback should easily show the difference.
     

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