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

is fuel mixture adjustable?

Discussion in 'Gen 2 Prius Main Forum' started by northcoaster, Oct 18, 2013.

  1. northcoaster

    northcoaster Junior Member

    Joined:
    Feb 12, 2010
    32
    2
    0
    Location:
    northcoast
    Vehicle:
    2006 Prius
    Model:
    N/A
    Had a mechanic tell me he'd adjusted the fuel mixture (made it a little richer) so the engine wouldn't run as hot and the engine would be better off/last longer don't know why I didn't really ask him about it but now am told by the dealer service reps that the fuel mixture is not adjustable, at least not by mechanics, of course I know it probably is constantly adjusted by the computer but I would like to know if one can go into the car's computer system and reset the fuel mixture so's the engine runs richer? He was plugged into the car with his computer/tool when he was telling me this.....I noticed afterward, on the long trip home, that the mileage seemed about 3-4 mpg less than when we took it in...
     
    #1 northcoaster, Oct 18, 2013
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,200
    6,479
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    I am not aware of any way to adjust fuel mixture via an engine ECU adjustment.

    The Prius engine is not known for running particularly hot, and that would be one of the last things I would personally worry about - even living in the desert Southwest where summer temps are ~110 degrees.
     
    #2 Patrick Wong, Oct 18, 2013
  3. Britprius

    Britprius Senior Member

    Joined:
    Jun 14, 2010
    5,194
    1,917
    0
    Location:
    Herefordshire England
    Vehicle:
    2008 Prius
    I'm sorry to say I think the only thing that was adjusted was the contents of your wallet.

    John (Britprius)
     
    #3 Britprius, Oct 18, 2013
  4. northcoaster

    northcoaster Junior Member

    Joined:
    Feb 12, 2010
    32
    2
    0
    Location:
    northcoast
    Vehicle:
    2006 Prius
    Model:
    N/A
    Absolutely not! The mechanic is an old friend I've known for over 25 years, he was at my wedding, he's from Japan where he was adopted as a young child by a Toyota mechanic and began wrenching as soon as he could hold one. He's been working on Toyota's for over 50 years; however, I do have trouble understanding him and I think that was the case and why I've never really be concerned but it came to mind recently and I thought I'd check with someone else but now I will call him and see "what up"
     
    #4 northcoaster, Oct 19, 2013
  5. Britprius

    Britprius Senior Member

    Joined:
    Jun 14, 2010
    5,194
    1,917
    0
    Location:
    Herefordshire England
    Vehicle:
    2008 Prius
    This is not something you mentioned in your first post, or I would not have made the comment and withdraw with apologies it in this instance.
    It is I'm afraid all to typical of many "not all" dealers and workshops.
    It is still a fact that mixture adjustment on the Prius is not some simple quick fix like turning a screw and at best is left as is for both economy and longevity of components such as the catalytic converter. Cylinder and ring ware along with oil contamination could also be affected by increasing the amount of fuel injected.

    John (Britprius)
     
    #5 Britprius, Oct 19, 2013
    Data Daedalus likes this.
(You must log in or sign up to post here.)