New fuel findings
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  1. #1
    Fellow Frogger! bazgti's Avatar
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    Default New fuel findings

    i tried the fuel at the united servo last week
    its 95 ron with another 3 ron added in the form of ethanol
    so its called 98
    it made my car ping up hill under load.
    this does not happen with the optimax or the bp 98.
    im suss on this fuel now.
    think ill stick ti the shell and bp fuel.

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    the shell optimax leaves a sooty residue on the chrome exhaust tips that i regularly clean off.
    the united fuel did not do this but thats not a good enough reason to use it.
    my freind also says his car does the same thing with shell optimax.
    i dont think the car is running rich so im assuming its a residue.
    any thoughts??????????
    -BAZZ

  2. #2
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    In my view, any fuel whereby your car pings is reason enough not to use it. If the only problem you have with Optimax is a sooty residue around your exhaust tip, then that's a problem I could live with over pinging any day.

  3. #3
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    Quote Originally Posted by bazgti
    i tried the fuel at the united servo last week
    its 95 ron with another 3 ron added in the form of ethanol
    so its called 98
    it made my car ping up hill under load.
    this does not happen with the optimax or the bp 98.
    im suss on this fuel now.
    think ill stick ti the shell and bp fuel.

    the shell optimax leaves a sooty residue on the chrome exhaust tips that i regularly clean off.
    the united fuel did not do this but thats not a good enough reason to use it.
    my freind also says his car does the same thing with shell optimax.
    i dont think the car is running rich so im assuming its a residue.
    any thoughts??????????
    -BAZZ
    Bazz

    1. Soot is a product of the incomplete combustion of hydrocarbons.
    2. Incomplete combustion is caused by a lack of oxygen, read rich mixture
    3. Ethanol is an oxygenated molecule, which means ethanol containing fuels require less oxygen from the air.

    First, a clarification, then we will discuss your observations: Oxygenated fuels contain oxygen atoms incorporated in their molecular structure, not free oxygen dissolved in them as I read in some "pearls".

    The soot you see in your exhaust tip shows that the engine runs slightly rich under load, and this is what you want. By adding ethanol you increase the percent of oxygen in the combustion equation, now your mixture is leaner, no soot on the exhaust tip but no power either. In cars where fuel is controlled by the O2 sensor, the sensor is fooled by the ethanol so if you are going to run oxygenated fuels you have to dyno tune the cars for those fuels. In cars without O2 sensor control you just increase the fuel supply until you start running slightly rich again. So don't get rid of that rag, the exhaust tip will need cleaning no matter what.

    There is no question, BTW, that you CAN increase power with oxygenated fuels, but your engine has to be tuned for them. The way one normally does it is by getting the highest octane you can get, then adding around 5% ethanol, acetone or dioxane. Dioxane is a big no-no as it is a nasty chemical, but none-the-less people get a hold of it and use it in drag racing. I recently added 5% anhydrous (water free) ethanol to BP 100 RON and there is no question the car worked better, but that was a carburated car without an oxygen sensor and I adjusted the fuel supply.

    Thanos

  4. #4
    Fellow Frogger! Dr_Pug's Avatar
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    Quote Originally Posted by Thanos
    Bazz

    1. Soot is a product of the incomplete combustion of hydrocarbons.
    2. Incomplete combustion is caused by a lack of oxygen, read rich mixture
    3. Ethanol is an oxygenated molecule, which means ethanol containing fuels require less oxygen from the air.

    First, a clarification, then we will discuss your observations: Oxygenated fuels contain oxygen atoms incorporated in their molecular structure, not free oxygen dissolved in them as I read in some "pearls".

    The soot you see in your exhaust tip shows that the engine runs slightly rich under load, and this is what you want. By adding ethanol you increase the percent of oxygen in the combustion equation, now your mixture is leaner, no soot on the exhaust tip but no power either. In cars where fuel is controlled by the O2 sensor, the sensor is fooled by the ethanol so if you are going to run oxygenated fuels you have to dyno tune the cars for those fuels. In cars without O2 sensor control you just increase the fuel supply until you start running slightly rich again. So don't get rid of that rag, the exhaust tip will need cleaning no matter what.

    There is no question, BTW, that you CAN increase power with oxygenated fuels, but your engine has to be tuned for them. The way one normally does it is by getting the highest octane you can get, then adding around 5% ethanol, acetone or dioxane. Dioxane is a big no-no as it is a nasty chemical, but none-the-less people get a hold of it and use it in drag racing. I recently added 5% anhydrous (water free) ethanol to BP 100 RON and there is no question the car worked better, but that was a carburated car without an oxygen sensor and I adjusted the fuel supply.

    Thanos
    Euxaristo giea to mathima, ta e3igises poli kala....
    04' GTi 180

  5. #5
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    Quote Originally Posted by Dr_Pug
    Euxaristo giea to mathima, ta e3igises poli kala....
    Parakalo

    And just in case there is anyone in this forum who does not speak Greek (or read Greeklish) , he said "thanks for the lesson, you explained things well" to which I replied "you are welcome"

    Thanos

  6. #6
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    top info Thanos, ty. Euxaristo. Gracias. Merci.
    Puggy.

  7. #7
    Fellow Frogger! bazgti's Avatar
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    Quote Originally Posted by Thanos
    Bazz

    1. Soot is a product of the incomplete combustion of hydrocarbons.
    2. Incomplete combustion is caused by a lack of oxygen, read rich mixture
    3. Ethanol is an oxygenated molecule, which means ethanol containing fuels require less oxygen from the air.

    First, a clarification, then we will discuss your observations: Oxygenated fuels contain oxygen atoms incorporated in their molecular structure, not free oxygen dissolved in them as I read in some "pearls".

    The soot you see in your exhaust tip shows that the engine runs slightly rich under load, and this is what you want. By adding ethanol you increase the percent of oxygen in the combustion equation, now your mixture is leaner, no soot on the exhaust tip but no power either. In cars where fuel is controlled by the O2 sensor, the sensor is fooled by the ethanol so if you are going to run oxygenated fuels you have to dyno tune the cars for those fuels. In cars without O2 sensor control you just increase the fuel supply until you start running slightly rich again. So don't get rid of that rag, the exhaust tip will need cleaning no matter what.

    There is no question, BTW, that you CAN increase power with oxygenated fuels, but your engine has to be tuned for them. The way one normally does it is by getting the highest octane you can get, then adding around 5% ethanol, acetone or dioxane. Dioxane is a big no-no as it is a nasty chemical, but none-the-less people get a hold of it and use it in drag racing. I recently added 5% anhydrous (water free) ethanol to BP 100 RON and there is no question the car worked better, but that was a carburated car without an oxygen sensor and I adjusted the fuel supply.

    Thanos
    Once again Thanos comes through with a thorough informed but not over the top hard to understand ,technical post.
    bravo Thanos.
    your right id rather keep a rag in the boot than run lean and not very mean.
    im pretty happy with the way my car goes,ive driven a few 205's now and have had people drive mine for a second opinion and all agree that it still goes well and still has good torque and handling for the 190,000 on the clock.
    although i have spent a bit on suspension and major servicing this year but it certanlly shows .
    although i need control arm bushed replaced as oil had got in them it still drives abd goes well.
    im still waiting for victoria to follow new south wales and get the 100 ron optimax.
    ill be doing some head/cam work mid next year so ill be able to take advantage of the higher octane rating.
    wwhhooo hoooo look out-
    yharsoo [spelling???}Thanos-BAZZ

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