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

Worse fuel economy after gas over-fill

Discussion in 'Gen 4 Prius Fuel Economy' started by VancouverPrius, Feb 22, 2024.

  1. VancouverPrius

    VancouverPrius New Member

    Joined:
    Jan 31, 2024
    12
    3
    0
    Location:
    Vancouver
    Vehicle:
    2022 Prius
    Model:
    Technology
    I made the mistake of overfilling my gas tank. A bit of gas poured out of the tank, maybe a tablespoon.

    Since the overfill I have noticed I get pretty bad fuel economy upon start up. Maybe 25-75 L/100KM of course it then drops but takes a while to hit 6 L/100KM.

    I can't remember what the fuel economy was like before hand, but I suspect it was better.
     
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    108,143
    49,149
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    It’s likely just your imagination. Track your fill ups for a few tanks to see what they look like
     
    Louis19 likes this.
  3. Louis19

    Louis19 Active Member

    Joined:
    Feb 4, 2022
    364
    326
    0
    Location:
    Laval Québec Canada
    Vehicle:
    2022 Prius Prime
    Model:
    Upgrade
    well , follow @bisco advice.....BTW upon starting anything could indicate bad fuel economy during engine warm up cycle , outside temp , charge level of the traction battery and so on
     
    #3 Louis19, Feb 24, 2024
    Last edited: Feb 24, 2024
  4. fuzzy1

    fuzzy1 Senior Member

    Joined:
    Feb 26, 2009
    17,204
    10,110
    90
    Location:
    Western Washington
    Vehicle:
    Other Hybrid
    Model:
    N/A
    When I used to watch instant fuel consumption on my ScanGauge, both moving MPG and stationary gallons/minute were horrible just after cold-engine start-up, then gradually improved as the engine warmed. This is simply the nature of internal combustion engines.

    Don't overthink this. The total trip fuel economy or consumption at the end of the trip segment is the only figure that matters.