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

When do you fill up your gas tank?

Discussion in 'Gen 3 Prius Fuel Economy' started by mediahound, Sep 17, 2013.

  1. mediahound

    mediahound Active Member

    Joined:
    Aug 7, 2013
    903
    155
    2
    Location:
    SF Bay Area, California
    Vehicle:
    2013 Prius
    Model:
    Four
    Gas is heavy so you get better mileage as your gas tank gets more empty, which should bring up your MPG average.

    So when do you fill up typically? Is it best to wait until its almost empty?
     
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    110,133
    50,050
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    it's not heavy enough to make a noticeable difference. when the last pip blinks if i'm in familiar territory and at two pips if not.
     
    JMD likes this.
  3. JimboPalmer

    JimboPalmer Tsar of all the Rushers

    Joined:
    Apr 14, 2009
    12,470
    6,871
    2
    Location:
    Greenwood MS USA
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    Do you know what is really heavy? A gas can with at least 3 gallons of gas so you can start your car again. I start looking when the MTE is under 50.
     
    hybridbear likes this.
  4. Mike Rosenzweig

    Joined:
    May 21, 2013
    120
    60
    0
    Location:
    Redmond, WA
    Vehicle:
    2013 Prius
    Model:
    Four
    Since I live in an area that is subject to possible natural disasters and weather woes, I always fill up with 3 pips remaining. To me, its from old habit of filling up at quarter tank on my previous cars.

    SAMSUNG-SGH-I317 ? 2
     
    JMD likes this.
  5. mediahound

    mediahound Active Member

    Joined:
    Aug 7, 2013
    903
    155
    2
    Location:
    SF Bay Area, California
    Vehicle:
    2013 Prius
    Model:
    Four
    Ya, I guess I'll just fill up when it's convenient.
     
  6. ursle

    ursle Gas miser

    Joined:
    Jun 28, 2006
    1,049
    192
    0
    Location:
    NH
    Vehicle:
    2011 Prius
    Model:
    Four
    When I need gas, and I put in oil and air when needed.
     
  7. Wayward

    Wayward Member

    Joined:
    Oct 17, 2012
    145
    26
    0
    Location:
    Idaho
    Vehicle:
    2012 Prius
    Model:
    Four
    I typically wait until I am at 0 DTE if not 20 miles past.
    Of course having only a 10 mile commute makes it pretty easy to know when I will get to the next gas station.
    Funny thing is my wife's car I fill up at 1/4 tank every time but the Prius I want the 450-500+ miles per tank.
    I hate that I have to fill-up my wife's tank after like 260 miles and it costs me $50 and I can go twice as far for $35.
     
    Ray-o-Vac likes this.
  8. dhanson865

    dhanson865 Expert and Devil's advocate

    Joined:
    May 24, 2011
    851
    188
    0
    Location:
    TN, USA
    Vehicle:
    2005 Prius
    No DTE on my Gen II so:

    If the weather is nice I fill up when I've gone 500 miles on a tank (usually hit that with 1 pip left), if the weather isn't nice (winter, raining, long trip planned, anything unusual) I fill up with 2 pips left or something like 400 miles used on the old tank.
     
  9. Ray-o-Vac

    Ray-o-Vac Junior Member

    Joined:
    Jun 13, 2013
    23
    16
    0
    Vehicle:
    2010 Prius
    Model:
    I
    I'll start looking when the last pip is blinking and I am past 500 miles on the tank in familiar territory.
    2 pips regardless of the mileage when I am in unfamiliar territory.
    Being as I am still relatively new to the Prius (4 months) I may have to rethink this when the cooler weather sets in.
     
  10. El Dobro

    El Dobro A Member

    Joined:
    Jul 12, 2011
    7,027
    3,241
    1
    Location:
    NJ
    Vehicle:
    Other Electric Vehicle
    Model:
    N/A
    I start looking for gas around 2 pips.
     
  11. fuzzy1

    fuzzy1 Senior Member

    Joined:
    Feb 26, 2009
    17,557
    10,324
    90
    Location:
    Western Washington
    Vehicle:
    Other Hybrid
    Model:
    N/A
    The mpg loss from fuel weight isn't very much. I'd prefer to lose that weight in unnecessary cargo, especially that spare tire stored at just about belt level. There is more money to be saved by strategically planning refills based on price and route convenience.

    When to fill up? Near home with ordinary short trips, when fuel prices are stable, I typically refill at 2 or 3 bars. Longer trips away from home, I shop by best price along the route, filling anytime from 6 bars to well past DTE = 0. Unfamiliar routes require more margin, be certain the next couple supposedly open fuels don't require dipping into the known comfortable margin. Adverse weather (snow, avalanche prone mountain routes) requires a couple extra bars of margin.

    To paraphrase a guideline Jimbo has posted to other threads (particularly in GenII, more prone than GenIII to prematurely running dry):
    * With the mother-in-law in the car, refill at three bars. She will never stop reminding everybody that you stranded her;
    * With the spouse in the car, refill at two bars. She will never forget that you stranded her;
    * When driving alone, refill at one bar. No one else needs to know that you ran out of gas.

    Because I like to travel in areas such as pictured below, planning ahead to the next fuel is essential, especially in older cars with much shorter fuel range. By the time a low fuel warning lights up, it might be too late.
    [​IMG] [​IMG]
     
    hybridbear likes this.
  12. SuperGLS

    SuperGLS Member

    Joined:
    Jul 11, 2012
    200
    52
    2
    Location:
    Washington DC
    Vehicle:
    2013 Prius
    Model:
    Four
    I can't envision a situation where I would fill up before it was flashing at me. First tank I went 20+ miles past DTE=0 and still had two gallons left.
     
  13. fuzzy1

    fuzzy1 Senior Member

    Joined:
    Feb 26, 2009
    17,557
    10,324
    90
    Location:
    Western Washington
    Vehicle:
    Other Hybrid
    Model:
    N/A
    How about Hiway 30 from Snowville Utah towards Wells Nevada? That has one of the "Next Service 100+ miles" signs that I didn't snap a picture of. Drive at rural speeds, or add some rain or snow and a headwind, and you may not make it.

    My old V8 Ford, starting with a needle on 1/2 tank, probably wouldn't make it even on a dry windless road while obeying the then-national 55 mph speed limit.
     
  14. SuperGLS

    SuperGLS Member

    Joined:
    Jul 11, 2012
    200
    52
    2
    Location:
    Washington DC
    Vehicle:
    2013 Prius
    Model:
    Four
    Right. But I'll never be driving there. I meant for me personally, I don't think I'm likely to be in that situation.
     
  15. bwilson4web

    bwilson4web BMW i3 and Model 3

    Joined:
    Nov 25, 2005
    27,663
    15,663
    0
    Location:
    Huntsville AL
    Vehicle:
    2018 Tesla Model 3
    Model:
    Prime Plus
    God is laughing and Mother Nature has made a new entry in her list:
    In April 2011, a string of tornadoes ripped up the TVA transmission lines in North Alabama. The nearest power needed to operate gas stations and grocery stores was about 80 miles South of our home. As power returned to the region, it eventually reached Decatur, about 35 miles away.

    Bob Wilson
     
    fuzzy1 likes this.
  16. SuperGLS

    SuperGLS Member

    Joined:
    Jul 11, 2012
    200
    52
    2
    Location:
    Washington DC
    Vehicle:
    2013 Prius
    Model:
    Four
    Hah. I'll take my chances. If a tornado comes to claim me I'll have a bit more to worry about than not having a full tank of gas!
     
  17. ewxlt66

    ewxlt66 Active Member

    Joined:
    May 1, 2008
    535
    186
    0
    Location:
    Dana Point, CA
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Plus
    Usually at one pip or at the blink. Ain't nobody got time for that.
     
  18. El Dobro

    El Dobro A Member

    Joined:
    Jul 12, 2011
    7,027
    3,241
    1
    Location:
    NJ
    Vehicle:
    Other Electric Vehicle
    Model:
    N/A
    When there's any notification of a storm approaching, I fill the tank and charge the battery all the way up. That came in real handy when Sandy hit and I used the car as a generator.
     
    bwilson4web likes this.
  19. GardenWeasel

    GardenWeasel Member

    Joined:
    Jul 25, 2009
    76
    51
    1
    Location:
    Columbia, SC
    Vehicle:
    2010 Prius
    Model:
    III
    I usually need 9 to 9.5 gallon on a fill...and last pip is flashing.