"Blueskies" wrote in message
t...
How can "pure gasoline" coming out of a 'supply depot' have the same 87
octane as the same "pure gasoline" mixed with 10% ethanol? Since all auto
gasoline is coming from the same distribution pipes, what is the octane in
those pipes?

IIRC, the octane rating is what it is measured at DELIVERY, not in the
pipeline.

Think (I think): Adjustments in the chemical composition at various points
in the delivery system.