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fuel octane

Discussion in 'Technical Q&A' started by George, Mar 27, 2004.

  1. George

    George Rookie

    Nov 2, 2003
    11
    I may have inadvertantly put 87 octane into my 348. Does it have antiknock sensors? Can I use an octane booster? Help.
     
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  3. kenyon

    kenyon F1 Rookie

    Oct 7, 2002
    2,836
    East Yorkshire
    Full Name:
    Justin Kenyon
    Octane 87 is to low.
    You must use no lower then 97 octane.
    You can add a ocatne buster, but I would advise to empty fuel system as much as possible and a higer octane above 97 to dilute octane 87.
    The car will run rough and not good for long periods on 87 octane.

    Actually I have never heard f octane 87, are you sure you mean 97 ocatne ??
     
  4. EVO8

    EVO8 Karting

    Mar 6, 2004
    89
    Cerritos, LA
    Full Name:
    Philip
    He's probably from CA. Most gas stations only have 87,89, and 91 octanes. Only a few stations scattered around CA have 93 or 100 octanes.

    -Philip
     
  5. Brian C. Stradale

    Brian C. Stradale F1 Rookie
    Lifetime Rossa

    Mar 17, 2002
    3,603
    Dallas, TX, USA
    Kenyon, octane is computed/reported differently in the US.
    To give you an idea of how to compare: 87 is typical "regular grade"; 89-90 is "mid (plus) grade"; and 91-93 is "super grade". At high altitudes, those numbers drop 1 or 2.
     
  6. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
    7,077
    87 is too low (falls into the 'duh' catagory).
    You can use octane booster (not recommended) these will only lift octane by a point or two per can (0.1 to 0.2 octane increment)

    or

    go to the local paint supplier and get a gallon of tolulene (118 octane) and a gallon of xylene (117 octane). 95% of what goes in octane booster is these two chemicals.

    or

    Stay away from more than 50% throttle in the RPM band between 2500 and 4000 RPMs where the engine is most sensitive to octane.
     
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  8. Smiles

    Smiles Moderator
    Moderator Owner

    Nov 20, 2003
    14,138
    Pittsburgh, PA
    Full Name:
    Matt F
    George,

    Listen to your car more than the previous responses.

    How is it running? Although your car doesn't have the standardized OBDII computer, it does have anti-knock sensors that will retard the ignition within milliseconds. You'll have less power, but no harmful detonation.

    If the octane is too low, you'll feel some loss of power, especially at the higher RPM range as Mitch described.

    I'd add an octane booster. It may do nothing more than give you peace of mind. Then run your car at lower RPMs for a while and add the highest octane you can find.

    I would NOT add tolulene or xylene to your tank. If you do freak out and need something more, go to a small airfield and buy a few gallons of avgas. You'll be breaking federal law by putting aviation gas in your car, but it IS around 108 octane. But that's only if you're really freaking out.

    Like I said, listen to your car. It should be fine. Just be sure to refill with the recommended octane next time.

    --Matt
     
  9. Dr_ferrari

    Dr_ferrari Formula 3
    Professional Ferrari Technician Consultant

    Nov 2, 2003
    1,064
    Pocono Sportscar
    Full Name:
    Jim McGee
    A little or even a tank of 87 octane will not harm your engine if driven normally, just don`t make it a practice. 92 - 94 octane is more than adequate for proper engine operation in most cases.
    The higher the octane, the better but I believe 97 would be excessive.

    If tank is full.I would run it down to a 3/4 tank and fill with high octane (93 or +). After that you should be just fine.

    NOTE: 348 does not have knock sensor.

    best regards, Jim
     
  10. Wasco

    Wasco Formula Junior

    Dec 9, 2003
    486
    Salem
    Full Name:
    Randy
    Agree run it with maybe a little booster ( no need to drain system) but pay close attention to the pre-ignition noise of knocking. High Octane means it will compress more before exploding. If you run to low of an octane your combustion mixture will ignite when the piston is on the way up instead of in the power stroke or on the way down. Really not good on your motor, stupendous amounts of stress.


    If you dont hear any signs of preignition your are probly ok!
     

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