1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Entering Stage 4 - you actually don't need to be fully stopped.

Discussion in 'Gen 2 Prius Fuel Economy' started by Bob64, Feb 21, 2009.

Page 1 of 2
  1. Bob64

    Bob64 Sapphire of the Blue Sky

    Joined:
    Apr 9, 2007
    1,540
    92
    0
    Location:
    Virginia
    Vehicle:
    2007 Prius
    Model:
    N/A
    I've been, like the rest of you, trying to get into stage 4 whenever possible over the past year and a half of ownership.

    Here's a tidbit that I don't think anyone else noted (see bolded bit). You can enter stage 4 when the following conditions are met:

    Speed is 0-6 mph for ~7 seconds (or so). That's right, you don't need to be at a complete stop! But you also must not be hitting the gas at this period of time.
    Coolant temp >= 70c
    ICE is ON.
    Battery isn't low.
     
    #1 Bob64, Feb 21, 2009
  2. JimboK

    JimboK One owner, low mileage

    Joined:
    May 1, 2006
    2,817
    187
    49
    Location:
    Chesterfield, VA
    Vehicle:
    2005 Prius
    Someone else (Hobbit, I think) mentioned it briefly somewhere along the line, but IIRC didn't quantify it like you have. And I've been unwilling to experiment and, in the process, risk losing 0.00275 MPG for the trip. ;) Thanks for the info!
     
    #2 JimboK, Feb 21, 2009
  3. efusco

    efusco Moderator Emeritus
    Staff Member

    Joined:
    Nov 26, 2003
    19,891
    1,191
    9
    Location:
    Nixa, MO
    Vehicle:
    2004 Prius
    Model:
    N/A
    I do realize that...Sometimes when I've been stopped, waiting for stage IV and the light changes and traffic starts to move in front of me, but I haven't made the move to Stage IV yet, I'll take my foot off the brake and let the car slowly start moving just so the traffic behind me doesn't get completely pissed off... I'd estimated 5mph was the magic number, but hadn't confirmed whether it was 6 or 5 or 7.
     
    #3 efusco, Feb 21, 2009
  4. Oddest_raindrop

    Oddest_raindrop New Member

    Joined:
    Jan 15, 2008
    75
    12
    0
    Location:
    wisconsin
    Vehicle:
    2008 Prius
    Model:
    N/A
    Just curious how can you tell your in stage 4?
     
    #4 Oddest_raindrop, Feb 21, 2009
  5. efusco

    efusco Moderator Emeritus
    Staff Member

    Joined:
    Nov 26, 2003
    19,891
    1,191
    9
    Location:
    Nixa, MO
    Vehicle:
    2004 Prius
    Model:
    N/A
    The only sure way is by the behavior the car exhibits.

    In S4 the ICE shuts off when you take your foot off the gas at ANY speed below 41mph.
    In S3 it will shut off when you lift your foot off the gas only b/w 35mph and 41mph.

    In reality I know I'm in S4 b/c I make a conscious effort to put it into that stage. I warm the ICE up to at least 157F (monitored via CAN-View, though a scan-gauge will work fine), come to a complete stop (or slow to less than 6mph as suggested by the OP) while the ICE is running, then wait the ~7 seconds for the ICE to shut off.
     
    #5 efusco, Feb 21, 2009
  6. hobbit

    hobbit Senior Member

    Joined:
    Mar 23, 2005
    4,089
    468
    0
    Location:
    Bahstahn
    Vehicle:
    2004 Prius
    Model:
    N/A
    I'm pretty sure I heard it from someone else, but it is true and
    I also use the fact to creep along just fast enough to convince
    someone behind me that I *am* moving until the "dance" completes
    and I can take off normally. Really handy in morning stop-n-
    crawl where deliberate distancing actually makes it harder to
    come to a complete stop most of the time.
    .
    _H*
     
    #6 hobbit, Feb 21, 2009
  7. Doc Willie

    Doc Willie Shuttlecraft Commander

    Joined:
    Jun 27, 2007
    1,714
    141
    0
    Location:
    Out there, somewhere
    Vehicle:
    2007 Prius
    Wait a minute. If I leave my driveway still in the warm up cycle, and drive for 50 miles, never going below 10 MPH, does that mean I never got into S4?

    There must be some other conditions, because I regularly get into S4 shortly after engine temp passes 152 F. Evidenced by RPM 0 IGN 5 on ScanGuage as I P&G.
     
    #7 Doc Willie, Feb 23, 2009
  8. JimboK

    JimboK One owner, low mileage

    Joined:
    May 1, 2006
    2,817
    187
    49
    Location:
    Chesterfield, VA
    Vehicle:
    2005 Prius
    You don't have to be in S4 for the ICE to shut down, as long as your speed is between 34-40 MPH. For it to be in S4 and, therefore, also shut down at lower speeds, requires the so-called "idle check" first: coming to a complete stop -- er, make that nearly complete, as Bob has documented -- for ~7 seconds.
     
    #8 JimboK, Feb 23, 2009
  9. a priori

    a priori Canonus Curiosus

    Joined:
    Aug 14, 2007
    3,083
    407
    23
    Location:
    Chicagoland (West)
    Vehicle:
    2010 Prius
    Model:
    V
    But . . . to Doc Willie's point . . .

    Does it really matter whether you've hit Stage 4 when you get up to highway speed and travel at 50+ for a long stretch of time? Is there any real benefit in getting there at that point?
     
    #9 a priori, Feb 23, 2009
  10. EZW1

    EZW1 Active Member

    Joined:
    Aug 20, 2008
    722
    80
    7
    Location:
    Phoenix, AZ
    Vehicle:
    2016 Prius v wagon
    Model:
    Four Touring
    It will go into stage 4 while constantly driving but might take a tad longer to do so. I've been on long drives without stopping and noticed it in stage 4 when I back off the pedal and get it into elec propulsion. In the morning headed to work, if traffic doesn't permit a stop a few miles down the road, I've noticed I can get stage 4 about 5-8 miles down the road as opposed to 2 miles if I make a stop. Go figure.
     
    #10 EZW1, Feb 23, 2009
  11. a priori

    a priori Canonus Curiosus

    Joined:
    Aug 14, 2007
    3,083
    407
    23
    Location:
    Chicagoland (West)
    Vehicle:
    2010 Prius
    Model:
    V
    Thanks for the added info. Still, would it matter whether you hit Stage 4 so long as you are travelling at highway speeds the whole time? I've hit the so-called "Warp Stealth" or "Super Stealth" at speeds greater than 41mph, but it seems to be quite a freakish thing and not something I would be aiming for at 55+. Is there any other benefit to being in Stage 4 at high speed?
     
    #11 a priori, Feb 23, 2009
  12. usbseawolf2000

    usbseawolf2000 HSD PhD

    Joined:
    Sep 22, 2004
    14,487
    2,994
    0
    Location:
    Fort Lee, NJ
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    I can confirm it since I have done it before too. I found the ICE start easier after the shutdown. It seems as the battery discharge threshold is lower than the "stop S4".
     
    #12 usbseawolf2000, Feb 23, 2009
  13. efusco

    efusco Moderator Emeritus
    Staff Member

    Joined:
    Nov 26, 2003
    19,891
    1,191
    9
    Location:
    Nixa, MO
    Vehicle:
    2004 Prius
    Model:
    N/A
    I won't say you're wrong, as it may be possible that there are conditions where you can go into S4 from a cold start without an idle check...but I've never done it in the 85k miles and almost 5 1/2 years with my Prius. And I've driven as much as 4 hours straight from the cold start to a distant location in a plenty warm car and not yet be in S4. The ICE will still shut off in S3 when you slow to a stop from say 55mph b/c it will pass through the 41mph-34mph gap. But If you get going again, without doing the idle check, and get up to only 20mph and take your foot off the gas, in S3, the ICE will continue to run.
     
    #13 efusco, Feb 24, 2009
  14. Bob64

    Bob64 Sapphire of the Blue Sky

    Joined:
    Apr 9, 2007
    1,540
    92
    0
    Location:
    Virginia
    Vehicle:
    2007 Prius
    Model:
    N/A

    Are you gliding at or between 35-41mph? Thats the ONLY time i've ever been able to turn off the ICE outside of stage 4 while moving above 7mph.
     
    #14 Bob64, Feb 24, 2009
  15. patsparks

    patsparks An Aussie perspective

    Joined:
    Jul 12, 2007
    10,664
    567
    0
    Location:
    Adelaide South Australia
    Vehicle:
    2004 Prius
    Model:
    N/A
    My scan gauge shows my engine shuts down when my foot is off the accelerator just 100 metres after leaving my home. My speed would be under 30km/h. Do Aussie Prius behave differently? I'll pay more attention to the coolant temperature tomorrow.
     
    #15 patsparks, Feb 24, 2009
  16. Doc Willie

    Doc Willie Shuttlecraft Commander

    Joined:
    Jun 27, 2007
    1,714
    141
    0
    Location:
    Out there, somewhere
    Vehicle:
    2007 Prius
    Yes. I guess that's what is happening, and what I wanted to know.
     
    #16 Doc Willie, Feb 24, 2009
  17. JimboK

    JimboK One owner, low mileage

    Joined:
    May 1, 2006
    2,817
    187
    49
    Location:
    Chesterfield, VA
    Vehicle:
    2005 Prius
    My experience is the same.
     
    #17 JimboK, Feb 24, 2009
  18. danl

    danl New Member

    Joined:
    Jan 26, 2009
    231
    6
    0
    Location:
    Boston, MA
    Vehicle:
    2009 Prius
    Hmm, newbie here. What's this stage 3 - stage 4 stuff. Sounds really interesting. Any stickie I've missed?
     
    #18 danl, Feb 27, 2009
  19. JimboK

    JimboK One owner, low mileage

    Joined:
    May 1, 2006
    2,817
    187
    49
    Location:
    Chesterfield, VA
    Vehicle:
    2005 Prius
    #19 JimboK, Feb 27, 2009
  20. efusco

    efusco Moderator Emeritus
    Staff Member

    Joined:
    Nov 26, 2003
    19,891
    1,191
    9
    Location:
    Nixa, MO
    Vehicle:
    2004 Prius
    Model:
    N/A
    #20 efusco, Feb 27, 2009
(You must log in or sign up to post here.)
Page 1 of 2