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

why gas mileage going down

Discussion in 'Generation 1 Prius Discussion' started by hpdtoyotatrd, Mar 26, 2020.

  1. hpdtoyotatrd

    hpdtoyotatrd New Member

    Joined:
    Jan 10, 2020
    3
    0
    0
    Location:
    San diego
    Vehicle:
    2001 Prius
    Model:
    N/A
    my mpg use to b around 45 and now it is around 34-36.

    what is considered a tune up or fix.
     
  2. sam spade 2

    sam spade 2 Senior Member

    Joined:
    Mar 31, 2018
    7,035
    2,782
    0
    Location:
    USA
    Vehicle:
    2017 Prius c
    Model:
    Four
    Asked and answered on here about a thousand times.......literally.
    Please do some searching in previous threads.

    Summary: You have a very old car, presumably with a LOT of miles.
    There could be a LOT of things causing it, most likely a combination of things.

    It is impossible to be much more specific than that without some more information.
    Reviewing the old message threads should give you an idea of what information is important to the question.
     
  3. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

    Joined:
    Oct 28, 2010
    7,673
    6,492
    0
    Location:
    Redneck Riviera (Gulf South)
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    "Tune up" is like a car backfiring.
    Everybody thinks they sorta know what they are, but when was the last time you heard a car backfire in real life?

    This is because they pretty much DON'T....
    Even in 20-year old cars.
    Same with "tune-ups"

    If your check engine light is not on then there are still somethings that might cause your mileage to tank, but you're going to have to start looking at some things.
    You might be dragging a wheel either because of a braking issue or a very low tire.
    You might have a dirty throttle body or mass air flow sensor.
    You might be using the A/C.
    You might be driving in a new part of the state that has a lot of hills.
    You might have a bad 12v battery.
    You might have changed the way you're obtaining your MPG figures.....


    We're going to need some more details.

    Oh....and do not take the car to a dealer and ask them to "clean your injectors" or ask if your throttle body needs to be cleaned.

    There's a pandemic, and a repair manager salivating all over the place at the thought of charging somebody $200 to put a $5 bottle of snake oil in the gas tank may constitute a bio-hazard.

    Even dealership mechanics and service writers do not deserve that.....

    Good Luck!
     
  4. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,686
    48,936
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    tires pressure
     
  5. audiodave

    audiodave Active Member

    Joined:
    Feb 3, 2017
    783
    268
    0
    Location:
    US
    Vehicle:
    2004 Prius
    Model:
    Five
    Alignment
    Posted via the PriusChat mobile app.