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Traffic jam - bumper to bumper: 2 strategies for best MPG - which one?

Discussion in 'Gen 3 Prius Fuel Economy' started by pakitt, Aug 22, 2010.

  1. pakitt

    pakitt Senior Member

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    I was wondering the other day in a typical bumper to bumper traffic jam in town: what is the best strategy (other drivers permitting...) for best FE?
    Option 1) crawl following preceding car, in order to use the battery as much as possible; likely entering in a re-charge with the ICE to 3-4 bars, repeat
    Option 2) let traffic go a bit ahead, accelerate "briskly" (e.g. 3/5 to 4/5 of HSI bar) and let the car roll, thus delaying (possibly) the ICE re-charge cycle when battery reaches 2 bars.

    Which one is better? ideas? did anyone tried this by resetting the fuel consumption on a flat road with a long enough traffic jam?
    Essentially - do a EV only approach (1) or mini-pulse & glide (2)?
     
  2. bisco

    bisco cookie crumbler

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    i like the second option, but when i try it, people keep pulling in front of me.
     
  3. jstraw20

    jstraw20 Member

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    I tend to go with option 1, 90% of the time the traffic will clear before the the ICE needs to spin up. But as always YMMV.
     
  4. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

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    Whatever method that prevents You from having to use the brake. Which probably means Option 2 is probably Not as effective.
     
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  5. Blizzard10

    Blizzard10 New Member

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    I find a distance and speed that lets me travel w/o catching the car in front of me. Once I have that I can (mostly) maintain the same speed and eliminate the "stop & go" thing. Sure, people see the gap between me and the car in front of me and jump in. I dont care, anybody is allowed to get in front of me anytime, traffic or not.
    The optimal speed can be between 5 and 15mph depending on the traffic.

    I just look way ahead, most of the time by the time I'm approaching the need to brake the cars start moving again at a higher speed than me. I just continue on at whatever speed was working.

    I never worry about closing the gap. I found on several occasions that not only is the car behind me now moving at a rate that keeps him from doing the "stop & go" but as far back as I can see in my lane everybody is just rolling along while the other lanes are going and stopping, doing 15 mph for 50 feet then stopping, then going... Im rolling along at 5mph

    That being said, some people behind me feel some reason the gap must be closed. They get visibly annoyed when they see 5 to 20 car lengths between me and the car in front of me.

    Im not holding anybody up, theres no where to go, nothing to do but stop when I catch up to the car in front of me. Im just rolling along a rate that doesnt force me to "stop & go".
     
  6. jstraw20

    jstraw20 Member

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    I don't mind people flying into the gap in front of me. If they're that concerned about saving .00003 seconds... oh well.

    And I guess I should have clarified my original post: I try to creep along without causing the ICE to kick over, but I don't hang on the tail of the car in front of me...
     
  7. Codyroo

    Codyroo Senior Member

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    I've had tried both and my opinion is that the mini-pulse & glide is superior than the EV only approach. You'll have too much "conversion" waste with the first method (efficiency loss converting gasoline/petrol to electricity and more loss converting the electricity to movement).

    When in traffic now, I always try to pulse and glide. Slow and go traffic is EXCELLENT for this. Stop and go is much much harder.
     
  8. bwilson4web

    bwilson4web BMW i3 and Model 3

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    I would use my GPS to find an alternate route as soon as possible and take a route 'less travelled.' But IMHO, neither approach really works because the vehicle overhead, the energy to run the systems, at speeds under 15 mph (~25 km/h) is likely to defeat any driving style.

    Bob Wilson
     
  9. bisco

    bisco cookie crumbler

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    i don't mind either. it's just that it puts you back in option one and you're creeping along even more slowly. after a while, your battery's going down and you're on the ice.:cool:
     
  10. Tideland Prius

    Tideland Prius Moderator of the North
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    I use a blend of the two. If it's bumper-to-bumper, then you're not going anywhere so I will use the battery to accelerate. However, I will shift to N to allow the car to glide to a stop behind the vehicle in front. Sometimes, in these low speeds, I'd rather not let the car crawl and continuously use the battery. Just P&G with the battery instead. Not sure if it is the most efficient but in these situations (at least in my area), turning on the engine to accelerate doesn't benefit me since it's a very very short burst.

    YMMV
     
  11. elevatus

    elevatus New Member

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    Yeah, I find that I have drive NASCAR style these days to prevent people from slamming into my lane when I experimenting with getting better gas mileage...and I don't even live in California!