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Descending steep mountain roads at 30mph?

Discussion in 'Model S: Driving Dynamics' started by ratsbew, Dec 4, 2014.

  1. ratsbew

    ratsbew Member

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    Can regen alone keep speed under control (about 30mph) on twisting steep (7-10%) descents? I recently did a lot of mountain driving in my manual transmission car, and even 3rd gear wasn't enough for me to not touch the brakes.
     
  2. mmh

    mmh Member

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    Yes, easily. You'll still have to use the accelerator a bit to limit regen.
     
  3. FLDarren

    FLDarren Member

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    Yes it can. I went through a 6 miles stretch of 8% decline in central Tennessee and regen was able to maintain any speed I wanted. (25-80mph)
     
  4. ecarfan

    ecarfan Well-Known Member

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    Absolutely I have done it many times. No brakes required.
     
  5. pgiralt

    pgiralt Active Member

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    Easily. I've come down some steep mountain roads in the Asheville, NC area and the only time I'd have to use the brakes is occasionally on hairpin turns.
     
  6. santana338

    santana338 Member

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    Yes. A bunch of us drove up Mt. Washington in NH then came back down. I only hit my brakes three times on the descent, but others made it down without touching them at all. It was foggy and I kept losing the car in front. That's my excuse for having to tap the brakes three times.

    Average grade over 8 miles is 11.9% and the max grade is 22%.
     
  7. Cottonwood

    Cottonwood Roadster#433, Model S#S37

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    Absolutely. Do it all the time coming down off of Wolf Creek Pass, etc.

    If you have over 80% battery, and do long, sustained, downhill regens, you can hit regen limits that are similar to Supercharger taper charging limits. It's an obscure limit, but I have had it happen with a full charge out of Pagosa heading east over Wolf Creek Pass, and leaving Aspen with a full charge, heading east over Independence Pass. This limit is not an issue for short, pulse regens, and only happens on long, sustained regens.

    Enjoy!
     
  8. RiverBrick

    RiverBrick Active Member

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    In the Winter you may run into having regen limited to due to a cold battery, and you'll have to use the breaks.
     

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