Sneak Peek of the New Prius #5 - B mode confirmed

Discussion in 'Prius, Hybrid, EV and Alt-Fuel News' started by Danny, Nov 3, 2008.

  1. efusco

    efusco Moderator Emeritus
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    I'm pretty sure that's the hazard light button...looks redish with a triangle in the middle to me.
     
  2. EtN

    EtN Irish-Italian Hybrid

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    Yep, it looks like an hazard switch to me too. The "P" button will most probably be square with an LED on it, like the current one.

    EtN
     
  3. randreed

    randreed Same as it ever was . . .

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    I'd rather have buttons for D, R, B, N, and P, instead of a "shift knob, but then again I used to drive an old Dodge with a pushbutton transmission too.

    ;)
     
  4. nyty-nyt

    nyty-nyt Member

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    Is it a big deal that the B mode is on this stick?
    I live in an area with no hills to use it, and if it doesn't allow extra regeneration when, say, a light surprises you and changes earlier than thought, and you can use B to slow down more dramatically, and charge the battery more dramatically, I see no real benefit in "saving some brake pads".
    In shore, I could do without this annoying feature.
     
  5. efusco

    efusco Moderator Emeritus
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    No it's not a big deal, but I think it's something that we wondered if they would remove or not. I think most of us agree that it's more or less an unnecessary feature, but I believe there is something making sort of required...but can't recall the details as to why.
     
  6. Jedi2155

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    I love the use of a B mode as it allows greater regeneration than without.
     
  7. spwolf

    spwolf Senior Member

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    it wont, but i wished it did... it would look cool.
     
  8. San_Carlos_Jeff

    San_Carlos_Jeff Active Member

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    My understanding of B is exactly the opposite.
     
  9. Rybold

    Rybold globally warmed member

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    Did you ever take physics in high school or college? Remember "ROY G. BIV," and that red is the lowest energy wavelength and that blue/violet is the highest energy wavelength, just below "ultra violet" ? Am I bringing back memories? Red and orange are good colors for lights in car interiors. Blue is not. :)

    Here's an experiment for you: at night, turn the lights off in your house. Go into a room with a red digital clock and notice how little it illuminates it's surroundings. Now, walk into a room with a blue digital clock and notice how it lights up the whole room.
    For this reason, BMW from day one and still today, only uses orange lights. Google "BMW dash lights" and you will see that everything is orange. http://i71.photobucket.com/albums/i155/HedsIc/SAVE.jpg When I get in a Toyota and turn the white dash lights all the way up, I have to squint ... and then I can't see the road as well. Here's an example of a man who DIED because of the blinding glare: http://newsbiscuit.com/board/28/92/2//UNADJUSTABLE-INSTRUMENT-LIGHTS-CLAIM-ANO.html

    I definitely see the benefit of "B." In my Corolla, when say 40 car lengths from a red stop light, I will have my car either in Neutral or with the engine coupled to the transmission (engine braking), and I choose one or the other based on my prediction of when the light will change. If I think I'm going the right velocity, then I'll leave it in neutral. If I'm going a little too fast, then I'll use slight engine braking. Having a regen option instead of the engine braking would be great. Having a "neutral" option is clearly more efficient, with consideration to the second law of thermodynamics. To store and reuse your kinetic energy is less efficient than to plan ahead and not have to slow down in the first place.

    .
     
  10. Ichabod

    Ichabod Artist In Residence

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  11. Tideland Prius

    Tideland Prius Moderator of the North
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    Well the question was would it be removed? They need a backup in case your brakes fail going down a mountain side.
     
  12. Rybold

    Rybold globally warmed member

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    Thank you. So, essentially the "B" mode does everything the "D" mode does, plus it adds engine braking (and slightly increases the amount of regen). So then, to be correct, Toyota should change the "B" on the shifter to "+EB" for "plus engine braking." :)
    (excluding the "quirks and factoids" section)

    I find it funny that the author assumes the same reader that must be told that hydraulic brakes don't generate electricity will consider adiabatic heating to be obvious when reading: "By forcing the wheelsto spin the engine and pump air, a good deal of that energy can be turnedto heating the air going through the engine instead of heating the brakeparts. Since fresh air is always coming into the engine, having it leave[SIZE=+1] as much warmer air provides a convenient place to dump excess energy.[/SIZE]" . LOL!
    Additionally, it assumes that same reader knows that W=VA=(J/C)(C/s)=J/s=W. LOL!
     
  13. Sho-Bud

    Sho-Bud Member

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    I like to use the B for something else: traffic jam with stop and go traffic.
    The extra engine breaking makes it much easier. Just try and see if you like it.
     
  14. priusuk2008

    priusuk2008 New Member

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    Well there you go Tony, a much more mature, well read, well mannered bunch of contributors than the normal troll-like "ya really think it'll go up his @$$ ?"
    :D
     
  15. San_Carlos_Jeff

    San_Carlos_Jeff Active Member

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    How can it increase the amount of regen when it's dumping energy in the form of heat? My (limited) understanding is that B decreased the amount of regen. If you need to slow down, using the brakes (w/o engaging the friction brakes) in D gets you the most bang for the buck.
     
  16. qbee42

    qbee42 My other car is a boat

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    This is correct. It is possible that the regen profile could be altered, but ultimately energy is being wasted (deliberately) through engine braking.

    Tom
     
  17. Rybold

    Rybold globally warmed member

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    Heck, I just summarized that article that they referred me to. Are you suggesting that article is full of bologna? I asked a question because I didn't know, and then I was referred to the article that says ""B" mode also increases regeneration current to 30 - 40 amps with no feet on[SIZE=+1] the pedals, so the part about "more regeneration" is somewhat true." http://techno-fandom.org/~hobbit/cars/b-mode.html
    Is that article wrong? Should I ignore that article? If so, then I'm back to step one. Can you please explain to me what "B" mode does then, if that article is incorrect?
    [/SIZE]
     
  18. San_Carlos_Jeff

    San_Carlos_Jeff Active Member

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    That article by Hobbit is great, I think you just missed some of it's points. Further in the paragraph you reference above it says:

    " "B" mode also increases regeneration current to 30 - 40 amps with no feet on the pedals, so the part about "more regeneration" is somewhat true. That is one of
    several mechanisms used to increase the "drag" feeling. That level also varies with the car's speed. However, the car's movement is often supplying much more energy than that, so what isn't captured in the battery is wasted by flailing the engine around. This is *not* more efficient usage -- it is almost always better to gently brake in "D" for" maximum energy recapture, if you have room ahead to do it."

    I added the bold font for emphasis. Hope this helps.
     
  19. efusco

    efusco Moderator Emeritus
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    If you're coasting with your foot off the pedal you're getting about 12-15 amps of regen. If you keep your foot off the pedal and drop into B it WILL increase your regen to 30-40 amps.

    BUT.....with your foot on the brake you can titrate the amount of regen up to around 100 amps AND you're not simultaneously throwing away energy like you are with B-mode (due to the forced ICE spin).

    Does that make more sense?
     
  20. Rybold

    Rybold globally warmed member

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    I think you need to go back and read post#35. Lol. :)
    First, in post #35, you typed "How can it increase the amount of regen...?" Then, in post #38, you quote the article, saying " 'B' mode increases regen..."
    You and I are absolutely in agreement that "B" mode's engine braking is less efficient than "D" mode (no engine braking). We are in agreement on that. I'm just asking whether the statement that " 'B' mode also increases regeneration current to 30 - 40 amps" is true or false. Never once did I ask about overall efficiency. I think I stated much earlier on that I've understood for many years that engine braking (adiabatic compression of air; a compressor) is extremely inefficient.
     
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