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B Drive Question

Discussion in 'Prius c Main Forum' started by preeusluver, Jan 12, 2018.

  1. preeusluver

    preeusluver New Member

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    I bought a 2015 C. I live in the Sierra Nevada mountains where going down steep grades is a routine driving experience.

    So as I start down a low grade in B Drive its a silent gear. As I continue downgrade as it steepens suddenly it sounds like I have turned on a blender as car speeds up and gear begins to work harder to keep car from speeding up. I mean this gear really starts to windout in a very loud high pitched whine. Now when I owned a pickup and down shifted at too high a speed one would get a similar sound.

    So my question is can one shift into this gear at any speed below 60 mph without doing damage. Is this whining gear a normal sound as it works to keep slowing the vehicle on steep grades? Is it doing and damage to use it when it goes into the blender sound? The manual does not elaborate on a speed range or max speed for shifting into B, or that it would make such a loud blender sound on steep grades. Appreciate any help understanding this gears use and noise potential.
     
    #1 preeusluver, Jan 12, 2018
  2. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    B is safe at any speed, the computers do not let you exceed redline. (5200 RPM)
    B does not change the gearing, it just adds engine braking. It was counter-intuitive at first that the harder you braked, the louder the engine got.
    My Gen 2 had a very similar engine as the c, I described it as a baritone sewing machine.
     
    #2 JimboPalmer, Jan 12, 2018
  3. Sam Spade

    Sam Spade Senior Member

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    Yes and yes. Perfectly normal.
    USE your brakes a little.
    B mode is intended to reduce the need for the conventional brakes, not to eliminate their use altogether.
     
    #3 Sam Spade, Jan 13, 2018
  4. Mendel Leisk

    Mendel Leisk Senior Member

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    I would reserve B for mountain descents. Would never use it for short hills, anything around town, or just for deceleration. Just leave it in D, use brake as needed; it'll charge the battery better, less wear-and-tear.
     
    #4 Mendel Leisk, Jan 13, 2018
  5. ChapmanF

    ChapmanF Senior Member

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    Do the Sierra Nevadas count? I think they're pointier than anything we've got in Indiana....

    -Chap
     
    #5 ChapmanF, Jan 13, 2018
  6. Mendel Leisk

    Mendel Leisk Senior Member

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    Yeah, sustained, relentless downgrades, wherever they may be, lol. But every time you encounter a downhill around town, fugedaboutit.
     
    #6 Mendel Leisk, Jan 13, 2018
  7. padroo

    padroo Senior Member

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    I use "B" sometimes in stop and go traffic to keep from tapping my brakes. It makes it more like driving a stick.
     
    #7 padroo, Jan 13, 2018
  8. preeusluver

    preeusluver New Member

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    Slightly pointier by several thousand feet of uphill grade but whose counting!
     
    #8 preeusluver, Jan 17, 2018
  9. preeusluver

    preeusluver New Member

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    Thanks for calming my anxious mind since I keep thinking the engine will just blow up as the whine reaches fever pitch. I cannot believe the manual does not discuss other than to say B is the braking gear...very lame!

    Heres a trivia...what gen is a 2015 priuc C? Still a preemie in the world of prius.
     
    #9 preeusluver, Jan 17, 2018
  10. Sam Spade

    Sam Spade Senior Member

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    None of the above. It is it's own "gen".
     
    #10 Sam Spade, Jan 18, 2018
  11. ztanos

    ztanos All-around Geek!

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    Isn't it a "modified" Gen 2 Prius engine, though?
     
    #11 ztanos, Jan 19, 2018
  12. ChapmanF

    ChapmanF Senior Member

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    Yes, it's a 1NZ-FXE. Why not call it a modified Gen 1 engine? Eh?

    By the same token, the c was born the same time as the mid-Gen 3 refresh, and is most similar to a Gen 3 in the various included tech.

    -Chap
     
    #12 ChapmanF, Jan 19, 2018
    ztanos likes this.
  13. ztanos

    ztanos All-around Geek!

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    That's fair. It really is a hybrid of Gen 2 and Gen 3. :D See what I did there? A hybrid. Ha ha ha ha. I'll see myself out.
     
    #13 ztanos, Jan 20, 2018
  14. preeusluver

    preeusluver New Member

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    So to summarize its too special to have a GEN # and so we give it a 1NZ-FXE! I am just a simple son of a camel driver...so I will also call it based on this fascinating discussion a modified gen 1- 3 hybrid gen 2-3! Meanwhile I'll just cruise down the Sierra grades in B drive sounding like i am making a frappucino at Starbucks. Thanks all:LOL:
     
    #14 preeusluver, Jan 22, 2018
    ztanos likes this.
  15. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    As soon as there is a gen 2 Prius c, yours will be a gen1 c.
     
    #15 JimboPalmer, Jan 22, 2018
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