At 04:26 PM 15/09/98 PDT, you wrote:
>>I don't know, guys.  I talked to a gas broker, and he says gas is a
>>commodity only.  It is all the same.  Right down to the additives.  No
>>one even asks who refined it anymore.
>>
>>
>Here's something to ponder:
>
>Here in Fairfax on Pickett St. there is a Texaco tank farm.  I see
>Sheetz and Flying J trucks go in and out of there all the time, as well
>as a number of unmarked tanker trucks.  FWIW.
>
>
The basic gasoline is usually the same because there are a limited number of
refineries and distribution stations in one given area. However, at the
filling stations they have different lines for the additives, which are
added right when the trucks are being filled. 
Some oil companies have contracted out the transportation of fuels. That's
why you see some trucks with strange or no markings.
This is refering to the Canadian situation, but I expect it is the same in
the USA. As a firefighter I got several tours of the local refilling station
and could ask all these interesting questions.
However, I am not sure how accurate these processes really are and what the
secret formulas actually contain.

Bj�rn