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

P&G, warp stealth, SHM....

Discussion in 'Gen 2 Prius Fuel Economy' started by FirstFlight, Mar 14, 2011.

  1. FirstFlight

    FirstFlight Member

    Joined:
    Oct 9, 2010
    429
    77
    0
    Location:
    New Jersey
    Vehicle:
    2005 Prius
    Model:
    N/A
    I don't understand some things. Here is my issue. I just bought my Prius three weeks ago. I've adjusted the tire pressure, made sure the oil is below the full line and did the stuff you guys have recommended to make sure I get good gas mileage.

    One problem is, I'm only getting 48 MPG. It's still chilly here in New Jersey and I do have some hills that are a problem so if 48 MPG is all I can get then I do accept that. However, I do have some questions.

    When I try and glide over 40 MPH, I either get regen or the car makes me use electric. I just want to coast down a hill without regen and without using the electric. There is no in-between, I've tried it so many times. If I'm under 38 MPH, it works perfect but above that it won't let me. I used to put it into neutral until I read the thread that it can hurt your engine.

    Also, can someone please explain (in plain English) what exactly super highway mode and warp stealth are?
     
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    108,908
    49,488
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    1) 48 is very good this time of year how far is your commute one way?
    2) it is very difficult to glide over 40 mph
    3) can't explain shm or ws, sorry.
     
  3. benjdm

    benjdm Junior Member

    Joined:
    Sep 27, 2008
    13
    0
    0
    Location:
    Upstate NY
    Vehicle:
    2008 Prius
    'Warp Stealth' is a fancy term for using only the electric motor while going fast enough that the internal combustion engine is spinning. (42 mph and above, the ICE is going to spin.)

    http://www.techno-fandom.org/~hobbit/cars/warpstealth.html

    Super Highway Mode is a fancy term for a sweet spot for the engine. I don't believe it can be found easily without a scan-gauge.
     
  4. ystasino

    ystasino Active Member

    Joined:
    Apr 17, 2007
    793
    50
    0
    Location:
    Tucson, Arizona
    Vehicle:
    2007 Prius
    Model:
    Two
    You can do better.

    At 42 mph or above the "yellow arrow" condition is what you should seek. Highway driving is significantly different and generally requires more refinement than P&G.

    The good news is that above 42 mph and while driving on the highway you will never really be concerned with dropping the main battery bars below 6 because the increased speed regenerates and charges the battery quickly. The other good news is that if your trips on the highway are longer than ~8 miles A/C and heating have limited impact on your mpg.

    The bad news is that the battery is anemic for carrying the Prius forward in anything else other than heading downhill. So while using the battery only when going downhill by feathering the pedal (yellow arrows only no orange) is crucial for better mpg it is not sufficient to get you better mpg than what you are already getting. Scangauge helps a lot because it can indicate RPM and with some easy programming kWh which will both tel you if you're accelerating efficiently. Absent scangauge or more advanced instrumentation you could try and accelerate so that your MPH is equal or 1.2x the instantaneous MPG displayed in your energy MFD screen. This is not fast accelerating and you should be patient with it as you are learning about the car. By all means if the uphill requires don't hesitate to go to MPH=2xiMPG but only when it is really necessary.

    Without care and without SG I used to get about 48 MPG in highway driving in MD. With SG and by looking at RPM only I got about 53 mpg during this winter. In a recent trip to Philadelphia and back I got 58.8 mpg without driving particularly slowly. You can read about it here:

    http://priuschat.com/forums/gen-ii-...super-highway-mode-lower-speeds-50-55mph.html
     
  5. KK6PD

    KK6PD _ . _ . / _ _ . _

    Joined:
    Mar 24, 2008
    4,003
    944
    118
    Location:
    Los Angeles Foothills
    Vehicle:
    Other Hybrid
    Model:
    N/A
    48 mpg, for a newbie, in Winter no less, is great!
    I am lookng forward as to what mpg you will be getting on July 4th, middle of summer!
    Let us know. Just keep doing what your doing, your doing it right .... 48mpg ..... hmmmmmm[​IMG]
     
  6. JimN

    JimN Let the games begin!

    Joined:
    Nov 26, 2006
    7,028
    1,116
    0
    Location:
    South Jersey
    Vehicle:
    2010 Prius
    Model:
    V
    FirstFlight, it's going to take a lot longer than 3 weeks for you to adjust to the car but you are on the right track.

    NJ covers a lot of territory. What are your routes? If you are stuck in NYC traffic or flying on NJ3 that may be about all you'll get particularly in the winter. If you can change your route to slower county roads that would help.

    It would help if you can cut back on the cabin heat. Try setting the heat around 72. The car is happier when it is 15-20F warmer than it is. Patience.
     
  7. FirstFlight

    FirstFlight Member

    Joined:
    Oct 9, 2010
    429
    77
    0
    Location:
    New Jersey
    Vehicle:
    2005 Prius
    Model:
    N/A
    I've filled up three times so far.

    First tank was 51 MPG MFD, 55 calculated
    Second tank was 54 MPG MFD, 48 calculated
    Third tank was 55 MPG MFD, 48 calculated

    My route is about 30 miles from 80 (exit 28) to Kearny.

    Next year I'm going to try the grill blocking, that should help me a little bit. I didn't realize it was best to just use electric at high speed (warp stealth). I was trying to get the engine to propel the car instead of using electric only.