Best way to brake at red light?

Discussion in 'Fuel Economy' started by Appletank, Dec 15, 2016.

?

Method #

  1. Number 1

    16.7%
  2. Number 2

    83.3%
  3. You have failed

    0 vote(s)
    0.0%
  1. Appletank

    Appletank Member

    I know mashing the brakes right before the intersection is bad, and I often don't have the space to be able to roll for blocks on end without pissing off everything behind me, but I was wondering whether it is better to gently brake all the way, or brake hard a bit early, then roll the rest of the way?

    Ex.
    1)
    40 >>>>>>>>>>>>>>>30>>>>>>>>>>>>>20>>>>>>>>>10>>>>>0 Red
    2)
    40>>>>>30>>>>>>>>>>>20>>>>>>>>>>>>>>>10>>>>>>>>>>>>0 Red
    My reasoning was that with Method 2, you are rolling for a longer period of time, therefore hopefully lessening the total time spent idling, and maybe more time in no/littlebit-fuel rolling mode.

    Or am I doing it all wrong?
     
  2. PaleMelanesian

    PaleMelanesian Beat the System Staff Member

    I do something more like 2, but for the reason that I'm rolling slower for longer time, increasing the chance I'll still be rolling when it turns green again.
     
    Mendel Leisk likes this.
  3. Appletank

    Appletank Member

    well yeah, spending 0 time in idle would be the best, i figured.
     
  4. Carcus

    Carcus Well-Known Member

    When I'm on my "well known route", .. depending on traffic conditions...I am sometimes able to:
    1. adjust my speed,
    2. adjust when I enter into traffic,
    well before the stop in order to build some space between me and the other traffic in order to optimize coasting.
    / I realize that's not what you're asking, .. but it is another way to deal with the problem.
     
  5. phoebeisis

    phoebeisis Well-Known Member

    I never turn the engine off while rolling-I motor on P&G
    I never do long gentle braking


    I know my lights-and am always looking ahead-adjusting my motor on P&G with the lights in mind
    If I KNOW I'm not going to make the light-I LIFT off-immediately Folks following can switch lanes-blow by me if they want
    And occasionally I will boost to 40(in a 35) when my sixth sense tells me I can make the light with a little more GO pedal

    My P&G cycle in a 35 mph zone - city traffic- is
    lift at 35 which carries me up to 37 glide down to 28 mph repeat repeat
    My entire cycle is about 1/4 to 1/3 mile 34 seconds or so and averages about 31 mph
    I am aware of other drivers I keep them in mind -31 mph average in a 35 zone-seems fair to me
    I try to avoid long gentle braking(wasting energy)

    I hold more kinetic energy and the hope the light will change(but study your route)
    Avoid the brakes-brakes are poison
    Occasionally I will miss and have to briskly brake -


    Oh I will occasionally brake hard-ish early -but retain some speed-when I expect the light to change
    and I want to save as much energy/speed as possible for when the light changes

    Keep an eye on your routes-you will get a feel for your lights
    Luck
    charlie
     
  6. Elixer

    Elixer Well-Known Member

    #2 is better for the reasons Pale stated - to increase your chance that you don't have to brake to 0mph, and can instead carry momentum through the intersection. However if you have an automatic transmission that won't allow the engine to be shut off except when stopped, #1 is better if you know you're going to have to stop as it will allow you to shutoff the engine sooner. If you drive a hybrid with regen braking that charges the battery, something closer to #1 is often better as a steady press on the brake pedal is necessary to keep the regen engaged, and the battery charges more efficiently with a steady current flow.
     
    PaleMelanesian and BillLin like this.
  7. Appletank

    Appletank Member

    My car is kinda old, no engine shut off. I'm pretty sure it has deceleration fuel cut off, but not exactly at which RPM region.
     

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