Downunder, I still beleive you are incorrect.If you are correct , then there would be only 100 % nitro fuels.they would all be the same nitro content.Explain why a fuel that has 10% nitro , and another that has 15% nitro..If oil doesn't lower the nitro content then what does? Nitro is nitro.I don't beleive there is different octane levels.If there is then that would explain it to me.

<ul>[*]<font face="verdana,arial,helvetica,swiss" size="2">Adding any component to fuel will automatically decrease the percentage of other components already in fuel. If you have 10 ounces of Substance A and 10 ounces of Substance B in a glass, for example, you have a 50/50 mixture. Let's say you then go and add 10 more ounces of Substance B. You've increased you percentage of Substance B, right? Well, yes, but you've also decreased your percentage of Substance A. You still only have 10 ounces of Substance A, but you have a total of 30 ounces of mixture, and only 1/3 of it is now Substance A. You've decreased Substance A's percentage from 50% to 33% and increased Substance B's from 50% to 66%. Sound complicated? Well, not really, that's why we're here to calculate this for you.</font>[/list]
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Also tunning the needle valveand nitro % is two different things..
Jim</p>