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

2005 weird gas gauge readings during cold weather

Discussion in 'Gen 2 Prius Main Forum' started by pmanipole, Dec 11, 2017.

  1. pmanipole

    pmanipole Junior Member

    Joined:
    Sep 11, 2017
    15
    5
    0
    Location:
    virginia
    Vehicle:
    2005 Prius
    Model:
    Two
    the weather is getting cold here and i noticed the gauge is saying there is less gas in the tank then there really is. i had 3 bars today and just went the the store(about 6 miles round trip) and the gauge went down to 1 bar. i stopped at the gas station and filled the tank up with just 6.5 gallons. it now reads full. on the way to work this morning i get about 20 miles down the road and it already has dropped one bar. is this a normal thing with this car in the cold. during the summer it was reading correct as i go by miles/gallon and not by the gauge for fill ups. i average around 44 mpg so i know the car is working correctly.
     
    #1 pmanipole, Dec 11, 2017
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    108,918
    49,500
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    normal = snafu. you have a bladder in the gen 2 which can do crazy things as the weather changes.
     
    #2 bisco, Dec 11, 2017
    TheLastMojojomo and Raytheeagle like this.
  3. TheLastMojojomo

    TheLastMojojomo Active Member

    Joined:
    Sep 14, 2016
    231
    162
    0
    Location:
    US
    Vehicle:
    2009 Prius
    Model:
    Touring
    It's because of the bladder tank. When it gets cold it doesn't expand as much when filling with gas. I can get 3 - 4 more gallons of gas in my 2G Prius during the summer at its warmest than the winter at its coldest. That's Wisconsin weather for ya. Haha.

    Posted via the PriusChat mobile app.
     
    #3 TheLastMojojomo, Dec 11, 2017
  4. pmanipole

    pmanipole Junior Member

    Joined:
    Sep 11, 2017
    15
    5
    0
    Location:
    virginia
    Vehicle:
    2005 Prius
    Model:
    Two
    so when i fill it up is it really taking a full tank or am i running with less gas in the tank then i think? i would hate to be riding down the road with 3 bars and then run out of gas.
     
    #4 pmanipole, Dec 11, 2017
  5. TheLastMojojomo

    TheLastMojojomo Active Member

    Joined:
    Sep 14, 2016
    231
    162
    0
    Location:
    US
    Vehicle:
    2009 Prius
    Model:
    Touring
    You are running with less gas but just go by the gauge. You won't be able to drive as far but the gauge will still be relatively accurate. Sometimes when it's really cold my prius gas gauge will read one bar below full after a fill up. Just follow the gauge.

    Posted via the PriusChat mobile app.
     
    #5 TheLastMojojomo, Dec 11, 2017
  6. fuzzy1

    fuzzy1 Senior Member

    Joined:
    Feb 26, 2009
    17,325
    10,170
    90
    Location:
    Western Washington
    Vehicle:
    Other Hybrid
    Model:
    N/A
    Most likely the later.

    Based on past discussions about Gen2 fuel tank bladders, I think it is much more likely that you are not getting a full refill. The bladder becomes less flexible and more finicky when cold.
     
    #6 fuzzy1, Dec 11, 2017
(You must log in or sign up to post here.)