How does it get into my car's tank?

After crude oil is refined into gasoline and other petroleum products, the products must be distributed to consumers. The majority of gasoline is shipped first by pipeline to storage terminals near consuming areas and then loaded into trucks for delivery to individual gas stations. Gasoline and other products are sent through shared pipelines in “batches.”

Since these batches are not physically separated in the pipeline, some mixing or “commingling” of products occurs. This is why the quality of the gasoline and other products must be tested as they enter and leave the pipeline to make sure they meet appropriate specif-ications. Whenever the product fails to meet local, State, or Federal product specifications, it must be removed and trucked back to a refinery for further processing.

After shipment through the pipeline, gasoline is typically held in bulk storage terminals that often service many companies. At these terminals, the gasoline is loaded into tanker trucks destined for various retail gas stations. The tanks in these trucks, which can typically hold up to 10,000 gallons, usually have several compartments, enabling them to transport different grades of gasoline or petroleum products. The truck tank is where the special additive packages of gasoline retailers get blended into the gasoline to differentiate one blend from another. In some areas, ethanol may be “splash blended” in the tanker to meet environmental requirements. When the tanker truck reaches a gas station, the truck operator unloads each grade of gasoline into the appropriate underground tanks at the station.