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Model S braking

Discussion in 'Model S: Driving Dynamics' started by umuhk, Oct 10, 2013.

  1. umuhk

    umuhk Member

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    Does the Model S use combined braking (on the brake pedal), or simple friction braking only? I'm coming from an Escape Hybrid 4x4, which uses combined braking ("brake by wire"), and I'm wondering just how much re-learning I'll need to do. I know that one-pedal driving with standard regen will take a bit of getting used to, but I'm curious about brake usage.
     
  2. vfx

    vfx Well-Known Member

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    Pushing the brake in a Tesla only works the calipers on the discs.

    And letting your foot of the accelerator kicks in the regen (motor "braking" by turning the motor into a generator).

    Each system is totally separate.

    Getting used to it takes 2 minute to 20 minutes depending on who you are.
     
  3. Doug_G

    Doug_G Lead Moderator

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    What vfx said. Took me two stop lights to get used to Tesla braking. By 20 minutes I preferred it to ICE braking.
     
  4. umuhk

    umuhk Member

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    Ok. That will take some getting used to for me, since my current practice is to let off the accelerator for "neutral" (coasting), ride the brake lightly to brake with regen, and then increase the pressure to gradually engage the calipers. It seems like the equivalent for the Model S is to lighten up the accelerator for regen, then switch to the brake pedal for calipers -- coasting would require an explicit shift to neutral and back.

    It sounds awkward at the moment, but we'll see how it sorts out. It's taken a few years for my pedal habits to get optimised for efficiency in the Escape.
     
  5. Zextraterrestrial

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    switching back takes longer and just plain sucks!

    you'll get used to either waiting until just the right time to let off the accelerator or feathering it so you coast in 'neutral' in no time. you can put it in neutral too and I messed around with it for a while but now just try and time the stops perfectly so you only need the calipers to stop from ~ 2mph
     
  6. kjl

    kjl Member

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    It took a little bit of time for me to get used to as well, but I like it more than regular driving now.

    Think of it this way: to maintain constant speed in a normal car, you can't really let the accelerator up completely - friction in the drivetrain and rolling resistance and wind resistance all combine to slow you down slightly. To maintain constant speed, you have to keep your gas pedal pressed in slightly.

    In the Tesla, you also have to keep the accelerator pedal pressed in to maintain constant speed - it's just that if you let the pedal up all the way, your deceleration will be (significantly) faster in the Tesla than in a normal car.

    When I was still getting used to it, I would accelerate quickly to, say, speed up to the traffic in a faster lane and zip into that lane and then let off the accelerator, which would turn the brake lights on and decelerate quite significantly, making me look like a total douche, and driving in moderate traffic was usually annoying (speed up, slow down more than I intended, speed back up, slow down more than I intended, ad nauseam).

    Now that I'm used to it, I don't feel like there is any downside to the Tesla approach except occasionally I'll want to lift my foot up completely (stretch my leg, shake out my ankle, shift my weight around, or whatever), and in a normal car, doing that results in a very slight slowdown, which is mostly unnoticeable to other cars and your passengers. In the Tesla, doing that results in the equivalent of a hard/med brake press, which is unexpected for other cars (and annoying to you and your passengers). The workaround is to either click into neutral for a few seconds or to engage the cruise control, both of which are fine workarounds since the scenario is rare.

    The upside obviously is that you need to actually need to switch pedals very rarely..
     
  7. brianman

    brianman Burrito Founder

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    The way I describe it is that the Model S is about 1/3rd of a pedal shifted from the ICE that I was used to. Meaning the "complete release of accelerator" position on my ICE is roughly equivalent to the "1/3rd pressed accelerator" position in my Model S. It's very easy to adjust your driving to match the car behavior in the general sense.

    If you want to do complete release of the pedal and your speed is steady, then use cruise control. If your speed isn't steady, then there isn't a "press no pedals but maintain momentum" option in the Model S (unless you're going down like a 12% grade).
     

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