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Driving in "B" Mode Regularly

Discussion in 'Prime Main Forum (2017-2022)' started by stevepea, May 25, 2017.

  1. Trollbait

    Trollbait It's a D&D thing

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    We can discuss other cars here?!:D

    GM first had the Paddle shifters in the ELR, and then put them in the gen2 Volt. These cars have also have 'gear' selections like the Prius for controlling regen level. Other plug ins have the paddle shifters, and/or use a traditional shifter for this control.

    The differences with the PiP are going to come down to the fact that it has a smaller battery. That is mostly why the car kicks in the ICE than comparable PHEVs, and it puts a lower cap on regen capture that could lead the hybrid mode B behavior sooner.

    Perhaps not obviously stated, but not contradicting. What I described as the most efficient way to drive is, and being in B does not prevent driving as such, but the conditions on the road and in traffic can make that difficult. When the conditions prevent the most efficient driving, then being in B could lead to making the best of the less efficient conditions.

    In addition to the increased amount of time in regen B can give in traffic, because of it coming on faster, it can also lead to engaging the friction brakes less often than with D. Again, the traffic conditions and what the other drivers are doing that determine how more effective driving in B is over D.

    And convenience can make efficient driving easier, just like a hybrid system makes it easier to hypermile than in a traditional ICE car.:)
     
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  2. giora

    giora Senior Member

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    This is in the rare edge cases which I excluded IMO.
    You did not answer my question though: A scenario in which you lift off in D and only after 2-3 seconds (as traffic allows) using brake, when speed is much lower, is less efficient than being in B in your opinion? And I will add: If it is only 1 second? half a second?

    Convenience can make driving easier. I agree.
     
    #82 giora, Jun 3, 2017
    Last edited: Jun 3, 2017
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  3. Trollbait

    Trollbait It's a D&D thing

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    It's an edge case.
     
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  4. giora

    giora Senior Member

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    Ha Ha.. I assume you were joking. These are the most common scenarios of driving a plug-in in city and heavy traffic (just for those few who might take you seriously).
     
    #84 giora, Jun 3, 2017
    Last edited: Jun 3, 2017
  5. Trollbait

    Trollbait It's a D&D thing

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    I said earlier that is was easier to hypermile a hybrid than an ICE.
    The is because techniques like engine off is automatic, and others are easier, like gliding by accelerator control instead shifting the neutral.
    Many are likely to find that one pedal driving makes it easier for the same reasons.
     
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  6. giora

    giora Senior Member

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    Being in B makes it harder to glide, not easier.
     
  7. stevepea

    stevepea Senior Member

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    I hope those reading this thread -- who actually have the Prime, and are curious and interested to try it for themselves to see -- will do so. I don't claim to be omnipotent. All I can do is report what I see with my own eyes, driving the actual car, and ask others interested in trying (who have the car), to do so, and report their own findings -- either way. Which I have, from the beginning.

    I'm not here to "win" an argument. From my very first post on this I have simply reported my own first-hand observations -- that have consistently shown to me:

    While in EV Mode, City/Rush-Hour Traffic conditions, driving in B is better, and extends the battery longer than driving in D+more braking.

    I have gone out of my way to say these have been my own observations -- and have asked others so inclined (and who actually have the vehicle) to try it and post their results -- either way (as one or two have, by the way). But I have observed enough now first-hand (and still test it by going back and forth occasionally) that personally, I make driving in B my default for those conditions. Others are free to do as they please.

    I was going to start replying again (to a post with blanket statements and, by the way, contradictions) but I'm just not going to go down that rabbit hole.

    Everyone's opinion on the matter is pretty clear by now... so as I suggested before, instead of more posts back and forth from those unable to try it in the actual car, why don't we hit pause, and wait to hear the results (either way) from others who have the Prime, and have tried it in the actual car?

    (If anybody misunderstood, my one post yesterday was meant solely as an update -- as since the original posts, I have driven the car more in B, and wanted to report if there was any change in my observations or not).

    But if anyone is curious, I invite you to give it a try sometime: try driving in "B" when you're in EV-Mode City/Rush-Hour conditions, and judge for yourself (and if you don't mind, post what you observe here).
     
    #87 stevepea, Jun 3, 2017
    Last edited: Jun 3, 2017
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  8. bwilson4web

    bwilson4web BMW i3 and Model 3

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    From my BMW i3-REx experience with single pedal driving, "B" is closer and nicer IF driving w/o dynamic cruise control. I've adopted it when in multi-cycle, stop light traffic and not on cruise control.

    Bob Wilson
     
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  9. Krzysiek_KTA

    Krzysiek_KTA Active Member

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    I can confirm exactly the same with my Prime. I try to use DRCC whenever the traffic is steady/predictable, but when in heavy rush hour stop and go traffic the "B" in E/V mode works better (at least for me).

    @stevepea : actually after 1.5k miles trying different modes in my Prime I ended up in switching between "D + DRCC and "B" mode while in E/V driving depending on traffic conditions. I barely use brake except to completely stop the vehicle :)

    Kris
     
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  10. giora

    giora Senior Member

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    Better - yes, for you. Nicer - as @bwilson4web put it - yes, for him. These are all subjective terms, to each his own driving style. I challenge the term 'more efficient' or 'extend the battery (charge) longer than D' especially when followed by a blanket statement of 'City/rush-hour traffic conditions'. This is not a subjective term and at least needs controlled experiment data set to prove or disprove (preferably something that can be repeated by others).
    Me personally, I don't buy it as presented (the increase in efficiency). It is against the laws of physics I know. It has all the chances to be less efficient in most situations.
     
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  11. CharlesH

    CharlesH CA HOV Decal #5 on former PiP

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    Apart from the efficiency question, is there a safety issue driving in B mode in city conditions? Specifically, if you are in D mode, let off the throttle, and apply the brakes, the brake lights will come on. But I don't think that the brake lights come on when you let off the throttle in B mode, even though you are slowing down just as much as if the brakes were applied to some extent. Or am I off base here somewhere?
     
  12. heiwa

    heiwa Active Member

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    Physics versus intuition/feeling is exciting to me! I too have felt B mode may be more efficient. Wouldn't it be something if evidence shows there is no difference?!

    For safety as CharlesH and few others mentioned, I do not use B mode when there are cars in close proximity behind my car.

    Posted via the PriusChat mobile app.
     
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  13. heiwa

    heiwa Active Member

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    Sorry to post such non-contributing post. I meant to thank you all for having such interesting and useful information.

    Posted via the PriusChat mobile app.
     
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  14. Trollbait

    Trollbait It's a D&D thing

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    And this is the first comment to such in this thread. Are you able to compare the PiP to a Prime yet?

    The deceleration rate in B is along the lines of downshifting a step on a typical transmission. If that is enough for someone behind to hit you, then they were too close or weren't paying attention.

    Plug ins capable of harder deceleration without the brake pedal have the brake lights come on. The lights on or off depends on the deceleration rate, and may be specified in the vehicle code.
     
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  15. fuzzy1

    fuzzy1 Senior Member

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    It depends on how strong B mode is compared to downshifts in regular non-hybrids. All of them can do it too, though not all drivers use this method. I'm not hearing any flack about it being a serious safety issue in non-hybrids.

    In the regular Prius, B mode braking in city conditions is less strong than ordinary downshifts. B in a Prime is stronger, but I haven't yet driven one to get a feel for it.
     
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  16. Lee Jay

    Lee Jay Senior Member

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    I agree with it - it's harder to glide in B-mode. Still possible, just harder.
     
  17. alexcue

    alexcue Active Member

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    It's substantial how much you slow down in B mode. I'm still playing with it in city traffic. It isn't quite one pedal driving, but you will get to a crawl with it. I'd definitely use the brake to alert some people behind me that I'm slowing down quicker though if I see them getting REAL close.
     
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  18. CharlesH

    CharlesH CA HOV Decal #5 on former PiP

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    I took a look at my wife's Honda Pilot. It does not have B mode. Instead, you can limit it to "2" or "1". I guess that is like a two-step B mode. In city driving with a non-hybrid, why would one ever do that rather than press the brake pedal?
     
  19. alexcue

    alexcue Active Member

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    To keep from riding the brakes down a long hill. Low gears have always been around Automatics. If you grew up driving a stick (or for that matter riding a motorcycle), you always downshifted to slow down, and be at the right gear to pick up speed again.
     
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  20. CharlesH

    CharlesH CA HOV Decal #5 on former PiP

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    I understand the use for long downhills, which I why I qualified my question for "city driving".