"Blueskies" wrote

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?

Folks have said that the various sellers have their own additive packages,
and others have said that the ethanol is added near the point of use, and
still others have indicated the ethanol is added to increase the octane
rating. If all this is true, then the gas in hte pipes could be some low
octane rating which is then boosted with ethanol to 87 octane for the
pumps. That infers to me that even if you bought gas straight from the
pipe it would not be 87 octane. Not good for STC holders...

Not to worry.

The pipeline people send many various grades of gas, all through the same
pipeline. They may send 95 octane straight gas for 4 hours, then switch to
82 octane for 2 hours, and so on, with the right storage facilities along
the way intercepting it, and putting it into separate tanks. I believe how
they know how to switch over, is to first know how long the switch in types
to get to them, then the senders put a dye package into the fuel to alert
the storage and distribution people that it is time to switch some valves,
and send the next fuel into a different tank.

When the tanker comes to deliver the fuel to the gas station, they blend the
correct amounts of each into the tank, and you get what you ordered.

Specialty fuels may not travel the pipeline, but be shipped some distances
by tanker truck, or barge.
--
Jim in NC