Actually, adding oil to a fuel doesn't really "dilute" the methanol/nitro content. Consider the simplest possible fuel with 80% methanol and 20% oil (which just happens to be my standard fuel
) and then add oil to bring it up to 25% oil. As far as the
container is concerned there seems to be less methanol but as far as the
engine is concerned there's still the same amount of
methanol going through the carb once the needle is opened a fraction more to get the right tune. Same thing applies when there's nitro in the blend. No matter how much oil is added the proportion of methanol/nitro always remains the same which is all the engine cares about.