As has been pointed out in a couple of these posts. The gas comes into the tank farm and is distributed to various tankers from various companies with each companies additive package added at the truck. Because of federal control that keeps companies from advertising they have better gas, they all use whatever it takes to make the standard in the area the fuel is blended for.
Not only does the additive package change by what you buy, but the relative closeness the fuel ran in the pipeline to the diesel that preceded or the motor oil that follows also determines the price of the bulk.
Bosch Master, ASE Master, L1
33 years MB technician