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

Super Highway Mode

Discussion in 'Gen 2 Prius Main Forum' started by Jolly, Mar 3, 2014.

  1. Jolly

    Jolly Junior Member

    Joined:
    Aug 23, 2013
    81
    12
    0
    Location:
    Appleton, Minnesota
    Vehicle:
    2008 Prius
    Model:
    Five
    I've been using this technique for a while now and I have a question. I'm sorry if it's been addressed already 'cause I know I've seen it here before. Anyway, I'm driving to work today -got my rpms at 1280 or so and timing at 14. Then I hear the engine go up in rpms, similar to a regular transmission when you punch it and it backshifts to a lower gear. I know it's done this before but today is the first time I actually heard it. I was getting great mpg and then it dropped way down. I never changed my position on the accelerator. Can anyone explain to me what is going on at that point?
     
  2. HaroldW

    HaroldW Active Member

    Joined:
    Mar 17, 2012
    716
    95
    0
    Location:
    Grand Forks BC Canada
    Vehicle:
    2014 Prius
    Model:
    Three
    There must be more than 14 degrees maybe 14-17? Once you fall out of SHAM you loose the advantage. That is what you are noticing.With a honda hybrid the range for SHAM is 30- 37 degrees. I have not had a prius long enough to no the range for the prius.:) H
     
  3. Jolly

    Jolly Junior Member

    Joined:
    Aug 23, 2013
    81
    12
    0
    Location:
    Appleton, Minnesota
    Vehicle:
    2008 Prius
    Model:
    Five
    If you're talking temperature it was 3 above 0 when I drove to work.
     
  4. fuzzy1

    fuzzy1 Senior Member

    Joined:
    Feb 26, 2009
    17,100
    10,035
    90
    Location:
    Western Washington
    Vehicle:
    Other Hybrid
    Model:
    N/A
    It is more touchy and less useful on our GenIII Prii than it is on GenIIs and Honda Hybrids.

    No, he is talking about angle degrees on the ignition timing.
     
  5. Jolly

    Jolly Junior Member

    Joined:
    Aug 23, 2013
    81
    12
    0
    Location:
    Appleton, Minnesota
    Vehicle:
    2008 Prius
    Model:
    Five
    Yeah, I kind of figured that out later. Sometimes I have senior moments.

    I guess my question is why did it do that? I never changed position on the accelerator pedal. It just jumped from 14 degrees to 21 or so all on its own.
     
  6. edthefox5

    edthefox5 Senior Member

    Joined:
    Jul 25, 2007
    10,096
    4,795
    0
    Location:
    Clearwater, Florida
    Vehicle:
    2007 Prius
    Model:
    Two
    Because its freezing out and engine runs to heat the cat. Grill block the car.

    What is the ICE coolant temp when its doing this?
     
  7. Jolly

    Jolly Junior Member

    Joined:
    Aug 23, 2013
    81
    12
    0
    Location:
    Appleton, Minnesota
    Vehicle:
    2008 Prius
    Model:
    Five
    I can't honestly say. But I was about five minutes into my trip but it was terribly cold. I use an EBH but even then it takes awhile. I'm gonna guestimate about 140 degrees F.