Have you ever noticed one brand of gasoline tanker filling the tanks of an altogether different brand gas station? This kind of occurrence is much more common than most people expect.
The truth of the matter is that a gas company that owns and operates a particular refinery or distribution center will likely supply gasoline to many different retailers representing many different brands of gasoline in the area. This is done in cooperation with other companies as a way of reducing the cost of shipping.
All of the gasoline coming from refineries or distribution centers meets government standards. Before it is distributed to specific branded stations the base stock is combined with a package of additives designed to perform different functions. The additives are generally what distinguish one product from another and accounts for the claims made by various brands.
Common gasoline additives include oxygenated compounds designed to reduce carbon monoxide while gasoline burns. Antioxidants prevent the formation of engine fouling residue.