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  1. #1
    MetallicaJunkie's Avatar
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    Super Unleaded Gas = Loss of Performance?

    I read this in another thread but i didnt want to hijack it , so i created a new one.... I have always heard that super unleaded gas really doesnt add any performance to our rc engines...i use it for the benefit of the doubt that it's supposed to burn cleaner and has additives that are supposed to be beneficial versus standard pump gas.....

    My question, does using 91 octane vs 87 really lower performance in our engines?
    \"Propellers are notorious for inflicting serious bodily harm while vigorously defending their space\" George Aldrich

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    RE: Super Unleaded Gas = Loss of Performance?



    Higher octane rated fuel burns more slowly than lower octane rated fuel, which is how it helps prevent detonation or pre-ignition. It can also be considered more ignition resistant too.   With our small gas engines, they do not need the high octance fuels and if anything it reduces performance as it doesn't burn as well inside the small engines. 

    In the past in Europe car engines tended to be smaller and the high performance engines had a large number of cylinders in order to keep the pistons smaller, thus they developed 10, 12, and 16 cylinder engines for their sports cars. This was done because a smaller cylinder and piston didn't have detonation or pre-ignition problems like a larger cylinder and piston would have. Also in Europe at the time high grade high octance gasoline was harder to obtain too.  Buit here in the USA the big muscle car engines developed having large cylinder and pistons and they had to have higher octane fuels to prevent detonation and preignition.  A similar effect is with airplane engines, especially the huge large displacement engines.

    Now then for our small RC gasoline engines, they do not have enough displacement to take advantage of high octane fuels. We need lower octane fuels in order to get more of the fuel to burn inside the engine properly. Thus with our little gas engines you would likely have more of a loss of performance using high octane fuel.

    But some fuels like, aviation high octane fuel, does not have ethanol in it, and some people prefer that fuel as it may mean less problems with the carburetor rubber parts degrading over time. Our USA pump gasolines tend to contain ethanol and other substances that can cause the rubber parts to deteriorate faster. A similar reason is there for using the more expensive pre-mix gasolines sold at many stores here too as it doesn't contain ethanol either and also has a more simple mix of chemicals in it too.

    Now in some cases advancing the ignition timing on a small RC engine may help with buring the high octane fuel. But this has to be pretty much, determined on a case by case trial. It may not work with the small engines all that much.Then there is the compression ratio for the engine too, a high compression engine may need the higher octane fuel to prevent detonation or preignition.

    But I expect that our small RC engines would either have a small performance loss, or no performance improvement and maybe a slight increase in fuel consumption burning high octane fuel.

    Some facts and myths about high octane fuel from a car website:
    Octane Facts
    • Knock occurs when cylinder pressures are high. It is normal for an engine to ping a little at full throttle
    because cylinder pressures are very high at full throttle. Engine knock, however, should not be ignored
    since it can result in serious damage to the engine.



    • High octane gasoline burns slower than low octane gasoline. The slow burn prevents engine knock when
    cylinder pressures are high.



    • If your engine runs well and does not knock or ping on low octane gasoline, there is no advantage in
    switching to higher octane gasoline.



    • If your engine knocks or pings, it does not necessarily mean something is wrong with the gasoline. It could
    be a problem with the engine’s electronic control systems, ignition timing or exhaust gas recirculation. On a
    high mileage engine, a carbon build-up in the cylinders can increase cylinder pressures and cause knock.



    • Almost all of today’s new cars have fuel-injected engines that need to use gasoline with a detergent additive.
    They do not necessarily need high octane gasoline with a detergent additive. Generally, new automobiles
    need high octane gasoline only if the manufacturer recommends it.



    • Always follow the auto manufacturer’s octane recommendations in your owner’s manual.




    Octane Myths



    • High octane gasoline improves mileage.
    In general, if your car is designed to run on 87 octane gasoline, high octane gasoline will not improve
    mileage. If switching to high octane gasoline does improve mileage, you might find that your engine, or its
    control systems, need repair.



    • High octane gasoline gives quicker starting.
    No, it doesn’t.



    • High octane gasoline increases power.
    If your car is designed to run on 87 octane gasoline, you shouldn’t notice any more power on high octane
    gasoline. Again, if it does make a noticeable difference, your engine, or the engine’s electronic control
    systems, may need repair.



    • High octane gasoline has been refined more – it is just a better product.
    Additional refining steps are used to increase the octane; however, these additional steps do not necessarily
    make the gasoline a “better” product for all engines. They just yield a different blend of hydrocarbons that
    burn more slowly. The additional steps also increase the price.

    Club Saito #722, Sig Kadet Brotherhood #80, GlowHead Brotherhood #14,
    AMA # 928076

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    RE: Super Unleaded Gas = Loss of Performance?


    ORIGINAL: MetallicaJunkie

    I read this in another thread but i didnt want to hijack it , so i created a new one.... I have always heard that super unleaded gas really doesnt add any performance to our rc engines...i use it for the benefit of the doubt that it's supposed to burn cleaner and has additives that are supposed to be beneficial versus standard pump gas.....

    My question, does using 91 octane vs 87 really lower performance in our engines?
    In most of our engines, I doubt you would notice much difference between 87 and 91 octane. Maybe a slight needle change difference but I doubt even that would change much. In our state regular unleaded is 87 octane, Super Unleaded is usually 89, Premium is 91 and up to 93 depending on station. I've tried all of these fuels at one time or another and can't see much if any difference .... kinda like different oils. Yup .... I mentioned the "oil" word. Sorry!

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    RE: Super Unleaded Gas = Loss of Performance?

    Don't go by believe. Go by what the engine manufacturer tells you to use. More octane does not hurt, too little slowly destroys your engine without you being aware of it until it is too late.

    PS
    Small engines not being prone to knocking is a myth! If combustion pressure rise and temperature rise exceed certain values ANY engine will knock because combustion is spontaneously and not flame front governed.
    Pe, (www.mvvs.nl), MVVS, MOKImotor, RCexl, MTW, Xoar, Mejzlik.
    Blessing in ignorance? There is sanctuary in analysis.

  5. #5
    MetallicaJunkie's Avatar
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    RE: Super Unleaded Gas = Loss of Performance?

    so i guess its safe to say that im not doing any harm in using premium gas in my gassers....thanks for the replies
    \"Propellers are notorious for inflicting serious bodily harm while vigorously defending their space\" George Aldrich

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    RE: Super Unleaded Gas = Loss of Performance?

    See My comments in red



    ORIGINAL: earlwb



    Higher octane rated fuel burns more slowly than lower octane rated fuel, which is how it helps prevent detonation or pre-ignition. It can also be considered more ignition resistant too. This was true in the 1970's when fuel was blended with tetra ethyl lead and high aromatics compounds (large ring structures). TEL is a flame retardant and aromatics being double bonded ring structures disassociate slowly hence slower burning. Its no longer true with unleaded fuels since the octane is recovered with highly branched paraffins.With our small gas engines, they do not need the high octance fuels and if anything it reduces performance as it doesn't burn as well inside the small engines. Complete non sense. Octane requirement is not governed by cubic capacity but by compression ratio. Our 2 strokes don't need high octane because they are relatively low compression. My kart engines, also 2 stroke 100cc engine where higher compression and required higher octane.

    In the past in Europe car engines tended to be smaller and the high performance engines had a large number of cylinders in order to keep the pistons smaller, thus they developed 10, 12, and 16 cylinder engines for their sports cars. This was done because a smaller cylinder and piston didn't have detonation or pre-ignition problems like a larger cylinder and piston would have. Also in Europe at the time high grade high octance gasoline was harder to obtain too. Buit here in the USA the big muscle car engines developed having large cylinder and pistons and they had to have higher octane fuels to prevent detonation and preignition. A similar effect is with airplane engines, especially the huge large displacement engines. More complete and utter nonsense. European car designers designed smaller cars because of shorter distances between towns, and the overall desire to have good handling cars that could be enjoyed on narrow country lanes. Smaller engines were a result of a desire for light weight.

    Now thenfor our small RC gasoline engines, they do not have enough displacement to take advantage of high octane fuels. We need lower octane fuels in order to get more of the fuel to burn inside the engine properly. Thus with our little gas engines you would likely have more of a loss of performance using high octane fuel. More rubbish. Once the spark provides the activation energy to get the mix going it burns due to temperature, pressure and mixture ratio. Higher octane provides a safety against detonation or uncontrolled ignition, nothing more. Compression ratio is the governing factor, it has nothing to do with displacement.

    But some fuels like, aviation high octane fuel, does not have ethanol in it, and some people prefer that fuel as it may mean less problems with the carburetor rubber parts degrading over time. Our USA pump gasolines tend to contain ethanol and other substances that can cause the rubber parts to deteriorate faster. A similar reason is there for using the more expensive pre-mix gasolines sold at many stores here too as it doesn't contain ethanol either and also has a more simple mix of chemicals in it too. Will it stop....Gasoline with ethanol is actually a simpler mix of chemicals. Ethanol free gasoline requires a more complex mix of hydrocarbon to get the octane back. Any engine sold in a ethanol market has compatible seals. The Ethanol is a non issue from a seal compatibility perspective. Fuel storage is a factor if you live in a humid environment. AVGAS is about 90% Alkylate which is a highly branched hydrocarbon that provides excellent octane, very fast flame speed and because its a much simpler mix of hydrocarbons, excellent storage stability. The TEL is added to raise the octane further but mostly to protect older avgas burning engines. Ethanol can be used as a aviation fuel as Brasil has been proving for the past 25years. Issues with your fuel stability at home is largely your fault. Store it the way your fuel marketer suggests, not according ot the principals of internet experts....

    Now in some cases advancing the ignition timing on a small RC engine may help with buring the high octane fuel. But this has to be pretty much, determined on a case by case trial. It may not work with the small engines all that much.Then there is the compression ratio for the engine too, a high compression engine may need the higher octane fuel to prevent detonation or preignition. Advancing the timing won't influence the octane requirement on a low compression ratio 2 stroke...

    But I expect that our small RC engines would either have a small performance loss, or no performance improvement (most likely)and maybe a slight increase in fuel consumption burning high octane fuel. Absolute drivel

    Some facts and myths about high octane fuel from a car website:
    Octane Facts
    • Knock occurs when cylinder pressures are high. It is normal for an engine to ping a little at full throttle
    because cylinder pressures are very high at full throttle. Engine knock, however, should not be ignored
    since it can result in serious damage to the engine.



    • High octane gasoline burns slower than low octane gasoline. The slow burn prevents engine knock when
    cylinder pressures are high. Only true if it is blended with a metallic octane booster



    • If your engine runs well and does not knock or ping on low octane gasoline, there is no advantage in
    switching to higher octane gasoline.



    • If your engine knocks or pings, it does not necessarily mean something is wrong with the gasoline. It could
    be a problem with the engine’s electronic control systems, ignition timing or exhaust gas recirculation. On a
    high mileage engine, a carbon build-up in the cylinders can increase cylinder pressures and cause knock.



    • Almost all of today’s new cars have fuel-injected engines that need to use gasoline with a detergent additive.
    They do not necessarily need high octane gasoline with a detergent additive. Generally, new automobiles
    need high octane gasoline only if the manufacturer recommends it.



    • Always follow the auto manufacturer’s octane recommendations in your owner’s manual.




    Octane Myths



    • High octane gasoline improves mileage.
    In general, if your car is designed to run on 87 octane gasoline, high octane gasoline will not improve
    mileage. If switching to high octane gasoline does improve mileage, you might find that your engine, or its
    control systems, need repair.



    • High octane gasoline gives quicker starting.
    No, it doesn’t. Not necessarily true, it depends on the season. In winter the volatility requirement of the fuel is higher so more butane goes into the fuel. Butane vapourises quicker and that results in quicker start. Generally higher octane fuels will have a percent more butane than a lower octane fuel but still remain within the volatility range.



    • High octane gasoline increases power.
    If your car is designed to run on 87 octane gasoline, you shouldn’t notice any more power on high octane
    gasoline. Again, if it does make a noticeable difference, your engine, or the engine’s electronic control
    systems, may need repair. Not necessarily true. If the engine is designed to run on higher octane, a lower octane fuel will result in the ECU changing the engine settings to a more conservative map meaning the engine runs in a lower power mode.



    • High octane gasoline has been refined more – it is just a better product.
    Additional refining steps are used to increase the octane; however, these additional steps do not necessarily
    make the gasoline a “better” product for all engines. They just yield a different blend of hydrocarbons that
    burn more slowly. The additional steps also increase the price.
    Again, not necessarily true. Its only true if more benzine structures are present to recover the octane lost due to removing TEL. If Alkylate is used then the fuel actually burns faster. This stuff is 20 years out of date!


  7. #7

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    RE: Super Unleaded Gas = Loss of Performance?


    .
    Pe, (www.mvvs.nl), MVVS, MOKImotor, RCexl, MTW, Xoar, Mejzlik.
    Blessing in ignorance? There is sanctuary in analysis.

  8. #8

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    RE: Super Unleaded Gas = Loss of Performance?


    ORIGINAL: pe reivers

    [img][/img]
    .

    [] No PE , not Thumbs up at all !

    The Tim guy really ought to apologize to Earl for his nasty response to the post . Ok , so maybe not all of Earl's facts are correct , that's no reason to throw around trollbait like "Rubbish !" and "Utter nonsense !"

    I'd like to think that were all above insulting someone we disagree with here , and can stick to the facts of small gasoline engine operating conditions without the need to berate others in the mocking , taunting way Tim has done here .

    If there were any way to assign "negative points" to a post , I'd give Tim's post a -3 []

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    RE: Super Unleaded Gas = Loss of Performance?

    While I agree, TimBle could have left off the little snipit personal remarks, overall I thought his coments and content was refreshing. I get tired of people tip toeing around issues when facts are required. I welcome his no nonsense engineer's perspective just as I welcome some other people's technical, down in the dirt real world experiences.

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    RE: Super Unleaded Gas = Loss of Performance?

    I did not think the response as nasty, nor insulting. When I write up something, and part of it is rubbish on nonsense, I would appreciate someone telling me. Nobody is perfect.
    Pe, (www.mvvs.nl), MVVS, MOKImotor, RCexl, MTW, Xoar, Mejzlik.
    Blessing in ignorance? There is sanctuary in analysis.

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    RE: Super Unleaded Gas = Loss of Performance?

    The reason I am using the premium unleaded is that is the only way I can buy ethanol free gasoline. I use ethanol free gas in my lawn mower, my garden tractor, my chain saw, my string trimmer and my model airplane engines.
    AMA 16066

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    RE: Super Unleaded Gas = Loss of Performance?


    ORIGINAL: Truckracer

    In our state regular unleaded is 87 octane, Super Unleaded is usually 89, Premium is 91 and up to 93 depending on station. I've tried all of these fuels at one time or another and can't see much if any difference .... kinda like different oils. Yup .... I mentioned the "oil" word. Sorry!
    Thats strange, in Australia we have 91 as standard then 95 and 98, ethanol blends are not common and have to be labelled as such by law.
    Cub brother #206

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    RE: Super Unleaded Gas = Loss of Performance?

    God I wish we could buy 95 or 98 octane fuel!! Then I could build some decent hot rod engines again with some high compression.

    But how are your octane numbers calculated? Ours (in the USA) are calculated by adding the Research Octane number to the Motor Octane number and then dividing by two.

    AV8TOR
    If it is not SCARY, it is NO WHERE NEAR powerful enough!!
    All R/C planes have expiration dates---> It's just not printed on them anywhere!

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    RE: Super Unleaded Gas = Loss of Performance?


    ORIGINAL: init4fun


    ORIGINAL: pe reivers

    [img][/img]
    .

    [] No PE , not Thumbs up at all !

    The Tim guy really ought to apologize to Earl for his nasty response to the post . Ok , so maybe not all of Earl's facts are correct , that's no reason to throw around trollbait like "Rubbish !" and "Utter nonsense !"

    I'd like to think that were all above insulting someone we disagree with here , and can stick to the facts of small gasoline engine operating conditions without the need to berate others in the mocking , taunting way Tim has done here .

    If there were any way to assign "negative points" to a post , I'd give Tim's post a -3 []
    How was I nasty?
    The information provided in Earl's post is non sense. Whether its his personal view or not it is still non sense and I would expect someone who desires to answer these technical questions to have an understanding of the subject at hand and not post someones elses mistakes as their own.


    The short answer to the original post is that Super Unleaded with high octane DOES NOT EQUAL A LOSS IN PERFORMANCE. Octane is expensive to manufacture (no matter how its derived) and overbuying on octane is really wasted energy if its not being used to extract performance.. The nergy I refer to here is not the BTU's you get into your engine but rather the BTU's and KW/hr's at the refineries that make high octane unleaded. You pay a premium for it as well.

    as for fuel economy, theres much more to be gained through good engine maintenance and throttle management than any thing else. There is no fuel economy effect that relates to octane if you are driving or flying with fuel economy in mind.

    Octane is purely the fuel's resistance to knock. How well it burns is related to how well your engine is tuned and the load demand on the engine at that state of tune.


    Our octanes in the rest of the world is Research Octane Number which is derived via ASTM D2699 or IP237 methods.
    To obtain AKI you need to run RON (ASTM D2699 ) and MON(ASTM D2700 or IP236) and use the formula AKI = (RON+MON)/2

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    RE: Super Unleaded Gas = Loss of Performance?


    ORIGINAL: 3136


    ORIGINAL: Truckracer

    *In our state regular unleaded is 87 octane, Super Unleaded is usually 89, Premium is 91 and up to 93 depending on station. I've tried all of these fuels at one time or another and can't see much if any difference .... kinda like different oils. Yup .... I mentioned the ''oil'' word. Sorry!
    Thats strange, in Australia we have 91 as standard then 95 and 98, ethanol blends are not common and have to be labelled as such by law.
    ORIGNAL: av8tor1977

    God I wish we could buy 95 or 98 octane fuel!! Then I could build some decent hot rod engines again with some high compression.
    I use 98 so I can get consistant runs out of the engines as there is that much difference in the fuel quality here, our regular unleaded is 87 octane is 10% ethanol and the fuel systems in cars are labled to take it. There is a major change in the rubber components in the EFI system to take the ethanol fuel(retired mechanic) and I had to do a course on the modifications in the fuel systems for the company I was working for when it came out.

    Cheers
    Remember, Always look after the ORGANIC part of the model

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    RE: Super Unleaded Gas = Loss of Performance?

    ORIGINAL: TimBle How was I nasty?
    Had you said something polite , such as ;

    "I believe your mistaken , Earl"

    We wouldn't be having this conversation .

    BUT !

    To come out "guns blazin" with "NONSENSE !" , , "RUBBISH !" , , and "DRIVEL !"

    Is not giving the man the respect he DESERVES as a frequent poster here who has as much "engine cred" as any of the rest of you .

    Yes , I have no argument that some of Earl's statements were not correct , but a polite man surely could have found a far less Boorish approach to advise Earl of the mistakes in his post .

    If the two of you were standing face to face having a conversation of engines , would you REALLY yell "RUBBISH !" to the man's face in the instance of an inaccurate statement ?

    I think NOT !

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    RE: Super Unleaded Gas = Loss of Performance?


    ORIGINAL: The Ghost



    I use 98 so I can get consistant runs out of the engines as there is that much difference in the fuel quality here, our regular unleaded is 87 octane is 10% ethanol and the fuel systems in cars are labled to take it. There is a major change in the rubber components in the EFI system to take the ethanol fuel(retired mechanic) and I had to do a course on the modifications in the fuel systems for the company I was working for when it came out.

    Cheers
    Hi there Ghost, I haven't seen 87 in Victoria, we only have 91,95,98.
    Just wondering are the laws the same in NSW, do they have to label ethanol blends on the pumps there?
    Cub brother #206

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    RE: Super Unleaded Gas = Loss of Performance?

    If it is a high performance auto, and you run it on regular instead of premium, you will definitely experience a loss of power and gas mileage. My Corvette gets 22 mpg on the highway with regular, and is down on power. On premium, it gets 26 mpg and has very noticeably more power. My brother's Z-28 Camaro is the same, as are many other performance oriented cars.

    The high performance cars have higher compression and need premium fuel to function as designed. If not, the knock sensor in the computer controlled ignition system will retard the timing to prevent detonation and/or preignition and cause a loss of fuel mileage and performance. Under certain circumstances it may enrichen the fuel mixture as well, adding to the problem.

    AV8TOR
    If it is not SCARY, it is NO WHERE NEAR powerful enough!!
    All R/C planes have expiration dates---> It's just not printed on them anywhere!

  19. #19
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    RE: Super Unleaded Gas = Loss of Performance?


    ORIGINAL: av8tor1977


    But how are your octane numbers calculated? Ours (in the USA) are calculated by adding the Research Octane number to the Motor Octane number and then dividing by two.

    AV8TOR
    Hi Av8tor, they measure it with the ASTM D2699 test (sounds like what you guys do ) http://www.astm.org/Standards/D2699.htm

    Here is shell fuels Australia data page http://www.shell.com.au/products-ser...s-msdspds.html

    I'm amazed in this little backwater we have better fuels than you guys do
    Cub brother #206

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    RE: Super Unleaded Gas = Loss of Performance?


    ORIGINAL: init4fun

    ORIGINAL: TimBle How was I nasty?
    Had you said something polite , such as ;

    "I believe your mistaken , Earl"

    We wouldn't be having this conversation .

    BUT !

    To come out "guns blazin" with "NONSENSE !" , , "RUBBISH !" , , and "DRIVEL !"

    Is not giving the man the respect he DESERVES as a frequent poster here who has as much "engine cred" as any of the rest of you .

    Yes , I have no argument that some of Earl's statements were not correct , but a polite man surely could have found a far less Boorish approach to advise Earl of the mistakes in his post .

    If the two of you were standing face to face having a conversation of engines , would you REALLY yell "RUBBISH !" to the man's face in the instance of an inaccurate statement ?

    I think NOT !


    Believe me, the response I gave here will exactly the response I will give face to face at the Rc flying field. I have called out rubbish information before, even laughed it off when people refuse to learn the facts and choose to believe in dogma gleened from the internet fora on motor vehicles or Rc.
    I'm gentle the first time, and progressively less gentle thereafter. I dislike repeating myself and I've repeated myself on this matter several times over.
    You can do a search to find the more gentle responses to these matters but it seems gentle does not sink in.




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    RE: Super Unleaded Gas = Loss of Performance?

    The only thing the higher octane fuel will hurt is your wallet if your engine only requires 87. There's no benefit in running a engine on a fuel with a higher octane rating than what it was designed for.

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    RE: Super Unleaded Gas = Loss of Performance?

    After it is all said n done - the gasoline needed for these small two strokers can have a very low octane rating with no loss in performance
    using higher ratings up to and including 115 race gas offeres nothing -
    adding alky (ethyl alky) further reduces power in MOST situations.
    Cars are a different bag- My old small chamber race Chev heads were really fussy at 11-1 compression ratio.
    but my Honda Odyssey will run on anything you put in the tank- like all modern stuf - the mix just changes as does the timing - to get a usable burn.
    I did a lot of tuned pipe stuf on ZDZ engines - and when tuned for max power - the gas used made a minor but measurable difference.

    For the run of the mill model engines on the market - if we could change compression easily on these little buggers the gasoline used would show some changes -as it is - the cheapest pump gas will give as much reliable power as the most expensive gas you can find.
    Libby is still watching you

  23. #23

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    RE: Super Unleaded Gas = Loss of Performance?


    ORIGINAL: 3136


    ORIGINAL: av8tor1977


    But how are your octane numbers calculated? Ours (in the USA) are calculated by adding the Research Octane number to the Motor Octane number and then dividing by two.

    AV8TOR
    Hi Av8tor, they measure it with the ASTM D2699 test (sounds like what you guys do ) http://www.astm.org/Standards/D2699.htm

    Here is shell fuels Australia data page http://www.shell.com.au/products-ser...s-msdspds.html

    I'm amazed in this little backwater we have better fuels than you guys do
    Down under, like Europe uses RON (ASTM standard D2600-82). Research octane number, obtained in a variable compression engine, whereas USA uses PON (pump octane number), which is calculated from RON and MON (Motor octane number according to ASTM standard D2700-82 )
    PON=(RON+MON)/2 ; this is also known as the Anti-knock rating.
    To confuse matters further, USA also has ROAD octane number
    PON is a typical 5 points lower than RON. However, the more refined the fuel, the less the difference with RON

    Where I live I can buy 95, 98, 100, 101 RON straight from the pump. 100 is Shell V-power (Germany) 101 is ARALwithout ethanol (Germany as well). I live 1000m from the German border.

    If anyone states Octane requirements for an engine, they should state the octane designation as well. Like said before, European manufacturers will use RON, with general reqiorement being 95octane fuel. USA regular will harm those engines, unless the pilot (Like Dick Hansson (RMH)) is at some altitude which lowers the effective compression ratio.


    Pe, (www.mvvs.nl), MVVS, MOKImotor, RCexl, MTW, Xoar, Mejzlik.
    Blessing in ignorance? There is sanctuary in analysis.

  24. #24
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    RE: Super Unleaded Gas = Loss of Performance?

    Even at sea level -_Los Angeles- What you can buy at the pump the cheapest crap possible - will work in our engines
    stir it up with 32-1 and go fly.
    Biggest problem? trying to lean it out for "more power".
    One of my friends here uses Coleman in his little industrial conversions - works like a charm- tho I won't use it.
    Listen to your engine - it will tell you if it is too lean or heating up.
    Libby is still watching you

  25. #25
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    RE: Super Unleaded Gas = Loss of Performance?


    ORIGINAL: 3136


    ORIGINAL: The Ghost



    I use 98 so I can get consistant runs out of the engines as there is that much difference in the fuel quality here, our regular unleaded is 87 octane is 10% ethanol and the fuel systems in cars are labled to take it. There is a major change in the rubber components in the EFI system to take the ethanol fuel(retired mechanic) and I had to do a course on the modifications in the fuel systems for the company I was working for when it came out.

    Cheers
    Hi there Ghost, I haven't seen 87 in Victoria, we only have 91,95,98.
    Just wondering are the laws the same in NSW, do they have to label ethanol blends on the pumps there?
    3136,
    Yes the pumps here have to be labled. We have 87 with 10%ethanol standard fuel, 91 premium, and 95 ultra, 98 is getting very hard to get here as only one servo here still has it.

    Cheers
    Remember, Always look after the ORGANIC part of the model


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