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Is Regen Braking different on a D vs. non D Model?

Discussion in 'Model S: Driving Dynamics' started by InsaneDriver, Mar 16, 2016.

  1. InsaneDriver

    InsaneDriver Member

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    Our Tesla is at the SC for the Ludicrous upgrade so we have an older P85 as a loaner.

    I've noticed that the regen seems to be much less 'powerful' compared to our P85D. When I let off the accelerator in our car you really feel the regen kick in but I don't get the same feeling on the loaner. Both cars are set to the same setting.

    Does this have anything to do with the dual motors or is there any degradation over time with regen?

    As a side note, the loaner has the old seats and not the next gen, wow what a difference. The next gen seats are 'insanely better' IMO. And it doesn't have a center console, what a pain in the neck not having it. Really makes me adjust my driving position if I have a drink in the arm rest cup holders. And anything in the center slip and slide area gets beat up. Very happy with our decision to get the Tesla Center Console installed when the car was originally delivered.

    Finally, I was surprised to see the charge setting set to maximum on the loaner car. I backed it off while I have it (you are welcome Tesla). But I guess if you own the company replacing batteries isn't a concern down the road.

    It's always fun to drive different cars, that's for sure.
     
  2. llavalle

    llavalle Member

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    My butt dyno hasn't seen a noticeable regen feeling difference on the P85 loaner I had last week.

    As for the seat, be aware that it's a bit more complicated than "First Gen" and "Next Gen". I have the latest, aka 1.5 version of old, "non Next-Gen" seat. The loaner I had had version 1.0 or 1.1 and they were terrible compared to mine. I would consider mine (69xxx VIN 85D) insanely better than the ones on the loaner (35K VIN P85)
     
  3. rainman50

    rainman50 Member

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    At the same regen Kw value on both cars ,does your car feel more drag than the loaner? How far from max charge was the loaner? If car is near full charge the regen is reduced a lot.
     
  4. InsaneDriver

    InsaneDriver Member

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    Thanks, I am betting this is the reason. The loaner was Fully Charged, I have never charged past 85%. When I dropped it off yesterday I was running on sparks!
     
  5. chriSharek

    chriSharek Member

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    With motors (hence generators) on the front and rear axles, isn't the regen on D models more powerful than the RWD cars? That is also why the rated ranges are higher, right?
     
  6. llavalle

    llavalle Member

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    It's the reason it *could* be more powerful... but it isn't.
     
  7. chriSharek

    chriSharek Member

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    If that's the case, Llavalle, why does the 70D have a greater rated range than the 70 and the 85D greater than the 85?

    It certainly isn't the battery size! :)
     
  8. StaceyS

    StaceyS Member

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    I just wrapped up about 500 miles in a loaner 70D (we have a P85), and I would agree that the regen felt stronger, although I'll clarify: the regen felt like it kicked in strong SOONER. Back in my P85, I felt like there was more give in the regen range before the real regen forces kicked in enough to light the taillights.

    As for the greater rated range of the Ds over the non-Ds, I think it mainly comes down to the fact that in cruising conditions, the smaller front motor is doing all the work while the rear motor is deenergized. The smaller front motor is more efficient at this than the larger rear motor.
     
  9. spock1701a

    spock1701a Member

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    The front and rear motors are geared differently. That way the D models can basically turn off the rear motor that is gear for quicker response while just using the front motor that is gear to lowering RPMs while at freeway speeds conserving energy. At least that's what I remember being explained in the D reveal.
     
  10. chriSharek

    chriSharek Member

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    While the sleep torque certainly adds to range, I've got to believe the regenerative braking uses all 4 wheels now too - instead of just 2. If there are motors there to turn the wheels, they might as well have used them as generators to regen the battery. It wouldn't make sense if they didn't.
     
  11. Max*

    Max* Autopilot != Autonomous

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    Someone (maybe wk057? maybe Ingineer?) had a diagram, and IIRC the diagram showed that only the rear motors are capable of regen.

    My memory could be wrong, and I can't find it now.
     
  12. chriSharek

    chriSharek Member

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    I'm not doubting you, Max, if that's your recollection, but I just don't know why they would do that and NOT take the benefit from all 4 wheels.
     
  13. Max*

    Max* Autopilot != Autonomous

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    That I can not answer, lol (assuming my recollection is correct)
     
  14. Carl

    Carl Member

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    Regen feels exactly the same on my new 85D as on my previous 85. The 'regen-meter' also seems to show the same figures at deceleration.
     
  15. BriansBucketList

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    I test drove a 70RWD, then a 70D, and felt more regen in the 70D. The owner at the dealership told me he expected Tesla to drop RWD cars, and the dual system had regen in both motors. This makes sense to me, but two opinions don't equal a fact. Maybe someone in Massachusetts can pay to see if the service manual provides a clue ? I didn't notice the charge, but did make sure regen setting were the same. I have a two week old 70D and the level of regen, along with frequent use of TACC pretty much allows for one foot driving, with minimal braking. Love the car. It's a rocket ship that handles like a smaller car, I can control with my watch, and I can feed it with solar. I may regret it, but I leased for fear that repair costs and insurance rates could hurt resale value. At least I've got 3 years to watch the EVolution to unfold.
     
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  16. Big Amps

    Big Amps Member

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    I think your answer is in your statement that the charge setting was set to maximum. When the battery is maxed, regen cannot happen. No place to put that juice. I just traded in my 2013 85 with 32K miles on it. Drove home a 90D from the factory (100 miles). They had charged the battery to 100% and there was no regen braking for the first several miles. Now the regen braking on the D feels just like my single motor car.
     
  17. skip8jj

    skip8jj Member

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    @Big Amps, Exactly. Last week we took delivery of a 70D. The battery was a 90% at delivery and every night it gets a charge up to 90% max except for yesterday morning when we bumped it up to 100% in preparation for 100+ mile tour. We live on a hill and, with regen on, I was accustomed to the drag of regen on the descent. However, yesterday morning, I was surprised when there was no drag on the descent. Several miles later, regen braking was back, strong as ever.

    Just learning the idiosyncracies of this car.
     
  18. Barry

    Barry Member

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    I currently have an preAP 85 loaner. Regen feels about the same as my 85D.

    One thing I like bout this oldie is I can see at the back window much better, as the middle seat head rest doesn't block it.
     
  19. trond.strom

    trond.strom Member

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    I think the D models regen on all four wheels.
    The 85 has a tendency to let the rear come out when regen braking in slippery conditions, the 85D keeps everything lined up
     

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