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Glide over 41 mph. Possible?

Discussion in 'Gen 2 Prius Fuel Economy' started by NeoPrius, Sep 25, 2008.

  1. NeoPrius

    NeoPrius Member

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    A couple of times I've been cruising along thinking I'm in "Warp Stealth Mode" at around 60 mph, and I look down at the MFD, and I'm in glide. I can sustain this as long as I don't do anything and the road conditions don't change (e.g. going up or down a hill).

    Been trying to duplicate this, but any time I try, I go into Warp Stealth.

    Just curious if anyone else has noticed this - or better yet, figured out the trick for getting into and maintaining glide mode at speeds well over 41 mph.
     
  2. morpheusx

    morpheusx Professor Chaos

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    the engine spins regardless over 42 MPH, but you are not using any gasoline if you get into the state with either no arrows or just yellow above that speed. The cruise control replicates the no arrows state frequently while cruising at highway speeds.
     
  3. NeoPrius

    NeoPrius Member

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    Driving along this morning at 50 mph (no cruise control), I looked down and there I was, in glide again.

    Now that I think about it, you're right. Cruise control does replicate this (high speed glide) condition frequently. I wonder if the cruise control has control over more than just the accelerator, or has some sort of feedback that the driver does not have - been wondering about this for a while.

    Any time I try to get into high speed glide, I can't get there. Only when I'm not trying - not even thinking about it, that's when I get there.

    True, just yellow arrows (in warp stealth) does not use gas, but it draws off the pack, which eventually has to be recharged by the ICE. So technically you're using gas.
     
  4. Rokeby

    Rokeby Member

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    Folks with CanView, or ScanGauge with the right X-Gauge programmed in,
    -- efusco? -- have reported that there is draw from the HV battery in
    both No-Arrows glide and when gliding in "Neutral." There is less draw in
    "Neutral." I guess that technically speaking, both these glides use fuel.

    No-Arrows glide extends the distance, gliding in "Neutral" saves SOC.
     
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  5. kayak_hauler

    kayak_hauler New Member

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    It depends on what else you have on. If your running the AC, even in N the battery has to power that. So even though the MFD shows no arrows, because your not sending power for propulsion, you'll see ~4 amps or more on the scanguage to run the AC. When you see no arrows above 40, you ingition timing goes to 5 and no fuel is going to the ICE even though its still spinning to keep MG2(1?) from over-revving.
     
  6. Santiago

    Santiago New Member

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    I agree.... when I try for stealth above 42 I can't achieve it but I have seen it on occasion. Very nearly true with warp stealth (yellow arrows) but I have seen that on occasion too. More likely I get orange arrows with 99.9 MPG. What mode is that? I'd like to call tha something! Now I've gone past 500 miles I will experiment with cruise control but likely disable it when going up a hill so as not to floor board it and drag the MPG down to 25-30.

    Any comments on this scenario or my tactics?:confused:
     
  7. miscrms

    miscrms Plug Envious Member

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    Warp Stealth is the orange arrows from battery to emotor to wheels above 42mph mode. It is generally harder to get into than regular stealth mode. I'm not sure if anyone has come up with a name for the glide mode >42mph. Its considerably harder to get into than Warp Stealth, and way harder than regular glide. Both are easier when the battery SOC is high. After coming down a long hill and having the battery green (7-8 bars) you should find the car goes into these modes much easier. The car may even drop into these modes automatically.

    This is one of the keys to the PHEV conversions. Even though you can't run at high speed in EV mode, the PHEV battery keeps the OEM battery SOC up at full for a long time. That tricks the car into using modes like warp stealth and high speed glide a lot more often, which improves high speed MPGs a lot more than you would expect.

    Rob
     
  8. 9G-man

    9G-man Senior Member

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    Orange arrows DO NOT come from the battery.

    No, Warp stealth is yellow arrows from the battery (electric) above 42MPH.
    Very easy to do, by lifting foot off gas pedal and reapplying lightly, above that speed.
    Gliding above 42 MPH is gliding. Very hard to achieve, and usually turns into warp stealth anyway. It's more of an allowed condition, than a mode achievable by the driver (like warp stealth), but results from the same technique.
    Orange arrow come from the gas engine (ICE) and represent just that.
    Misinformation can be very confusing to Noob's

    My personal rant....
    Gliding, stealth, and warp stealth are the NO-GAS modes of travel of the Prius. They are what set the Prius apart from all other ordinary cars. They are the means to achieving stellar gas mileage. Learning how to consciously induce and exploit these modes should be the goal of every Prius owner, IMHO.
     
  9. diamondlarry

    diamondlarry EPA MPG #'s killer

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    X's 2. I agree and that is my goal every time I push the "POWER" button. See sig for results.
     
  10. NeoPrius

    NeoPrius Member

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    I have not tried gliding in Neutral. I'm a little worried that I'll have a brain glitch and accidentally put it in "R" instead of "D" while moving forward as I switch out of neutral. The car should be programmed not to allow reverse while moving forward, but I'm not going to risk it until I know for sure. Does anyone know?

    I'm averaging about 51 mpg for several tanks on my normal commute, but I'm still looking for that "step function" in mpg that will get me up to 60 mpg. Mostly highway, very heavy traffic in the AM, mixed on the way back in the PM. Long rolling hills also. Definitely have to stay with the traffic here or other drivers get PO'ed. You all that are getting over 60 mpg... do you have conditions like this, or are you driving more slowly on flat back country roads?
     
  11. diamondlarry

    diamondlarry EPA MPG #'s killer

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    The car won't allow going into reverse when you are traveling down the road. If you try to do this, the car will just beep at you as if to say, "Stupid human, you can't do that!" Also, if you try to hit the "P" button while driving, the car will just go into neutral. Anyone over 6' tall will know that these are welcome saftey features as it could be easy for them to accidentally bump the lever/button with their knee.

    I drive mostly on county roads as much as I possibly can to avoid PO'ing other drivers. Even when there is traffic, I live in a farming area and people are used to slow moving vehicles and usually just go around without incident. Of course, you still get the occasional idiot that hangs on your bumper despite the fact that there is no oncoming traffic and they are in a "passing" zone.:confused::mad: I don't consider myself as obstructing traffic when they have a safe/legal chance to pass and don't or won't; they're just SOL.
     
  12. Rokeby

    Rokeby Member

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    NeoPrius,

    It has been reported that if, when moving forward, you shift to either reverse
    or park, either nothing happens or the car shifts to "neutral." There might be
    some annoyed beeping too. I have never experienced this -- knock on wood.

    I have limited experience with gliding in neutral. The condition just feels
    weird to me. I am most concerned with the absence of regen braking. So as
    a constant reminder, and perhaps as a way to minimize the delay in getting
    regen braking back, when gliding in neutral I keep my hand on the shift knob.

    Most of the reported 60+ MPGs is achieved on country/rural secondary roads,
    in rolling terrain, with little traffic, air temps 60 - 80 deg F, at <45MPH. Lucky
    bums! Monitoring ScanGauge/CanView readouts and preheat with a block
    heater is typical. Very selective use of an EV switch seems to be a part of
    the equation as well.
     
  13. Santiago

    Santiago New Member

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    9G-Man, easy for you, difficult for me. I have tried releasing the pedal and gently applying some force but still have great difficulty finding the right combination of release/apply to get the yellow arrows above 42. Below 42, I have great success and I am doing the exact thing above 42 with orange instead of yellow arrows being the final product. I'm not sure how to get out of this rut!:nerd:
     
  14. NeoPrius

    NeoPrius Member

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    Gliding in neutral: will give it a shot to see what it does, but probably won't use it often.

    'Got me an engine block heater. One of these days before the winter comes, I'll put it in. I've got too many other projects in the queue right now.

    Thanks!
     
  15. mikewithaprius

    mikewithaprius New Member

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    Forgive the thread resurrection, it seemed better than starting a new one.

    Yesterday I experienced what appeared to be a sustained engine off glide over 42 mph while I was aiming for warp stealth, and I thought it might be interesting for some to record the conditions.

    I was doing a short drive in 25°F weather (I know, I know...). I drove about 20-30mph with one stop at a stoplight, then took a ramp onto the highway. Just going an exit or two with a relatively low speed limit and four lanes for traffic, which was sparse at this time of night, I got up to 50 mph in the right lane and then slowly bled speed for mileage. This was perhaps 5 minutes or so into the drive, during the warmup phase.

    Here's where it happened: I came over the crest of hill, after which I was intending to go into warp stealth. First I got SHM so tried again, and then all the arrows went off. My speedometer read between 46-47 mph at this time. It wasn't for a split second - it stayed there for as long as I wanted, many seconds, and it was impossible to get only electric draw for warp stealth, only no arrows glide maintaining speed or regen if I backed off.

    Since I couldn't really believe my eyes I kept trying to *get out* of the glide, especially after reading how the car avoids this to protect the engine, but it kept settling back into it. After more reading today it looks like at that speed there would be no damage anyhow.

    I'm still sans Scangauge, so I have no idea what was really happening at that time. Since I was on the highway I honestly couldn't tell if the engine even really shut off, since when it relights in SHM it can be very subtle I find. It seems to be a quirk of the startup mode.

    Curious if anyone, especially with a Scangauge, has seen anything like this.
     
  16. dabize

    dabize New Member

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    It happens to me regularly at 2-3 places in my commute. But I never try for it. All of these sites feature a slight downhill grade after a small crest, which requires some kind of "pulse".

    I find myself going into the no arrows glide at 45-50 MPH, and then can coast down toward 41. Oddly, instead of smoothly melding with a regular glide at 41, it tends to kick out yellow arrows at 43 or so, followed by the usual warp stealth/glide transition (yellow arrows, brief green arrows followed by no arrows as speed falls past 40).

    My impression is that a power-free glide at higher speeds combined with a slight downhill grade somehow favors the phenomenon by fooling the instrumentation into behaving as it would at speeds below 41 MPH.
     
  17. Tekdeus

    Tekdeus Shifted to Green

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    Is it true that gliding in Neutral above 41mph still draws on the battery to spin the ICE? Today I happily glided down a bridge in N at about 50mph thinking I was coasting completely free.
     
  18. macmaster05

    macmaster05 Senor Member

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    This achievement depends almost entirely on the slope of the road as dabize pointed out.
     
  19. mikewithaprius

    mikewithaprius New Member

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    Tekdeus, gliding 42 mph and over in neutral uses gas, the engine is basically idling there. If you use warp stealth the electric draw is very slight, so that's more desirable, and gives better mileage.

    I've also read somewhere on here that neutral at higher speeds could be damaging for the engine. Because of that I personally only use it for a glide below 42 mph when my foot needs a rest (and no traffic, of course :-D).
     
  20. KK6PD

    KK6PD _ . _ . / _ _ . _

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    I get to do this everyday....

    [​IMG]

    Rolling down the "2" everyday, I must note that going home uphill, really takes the fun out of it!