Originally Posted by relient3074

My grandpa was the operations manager for the Flying J refinery(Big West Oil) here in Utah. He worked there for over 40 years before he retired, so he knows a bit about the production of automotive grade fuel. We have had multiple discussions about this issue. All of these "special, proprietary additives" that companies market are either EXACTLY the same or vary very little. There are specific guidelines that they must follow regarding these additives and they must not deviate from these guidelines. Chemically, the gasolines that are supplied to these stations are nearly identical. The minor differences can be attributed to temperature, humidity, etc. Unlike we are led to believe, there are NOT any "special" trade-secret recipes out there because of the strict regulations put on ALL refineries regarding the production of gasoline.

What your Grandpa is referring to is raw gasoline. It is refined to certain specs., but it isn't finished yet. Refineries cannot refine gas for each brand of fuel. It would take enormous storage facilities and planning to do it for each individual brand. Yes, there are trade secrets for brands of gas, they are added at the distribution terminal not the refinery. Refineries not only refine gas for their own brand but for others also. By producing raw gas it can be sent down the pipeline to the customer where additives can be added to it by the customer, to fit the customers needs.

If some of you are old enough to remember, Shell is one of the leaders in additives. One additive they touted was "platformate" back in the 60s. Supposedly you got better gas mileage.
Oil and Petroleum Commercials: Super Shell

Of course a Shell station will distribute Shell, Chevron sells Chevron, Tesoro sells Tesoro, etc.

Not so. You have no idea what is in the stations tanks. We just take it for granted that they are honest to do the right thing. But money talks,LOUDLY in the gas business. If a station owner has a chance to put the cheaper gas in the tanks, money wise, he will do so, regardless of contract. When I was in the business I started my day by checking the wholesale prices of 7 terminals in a 100 mile radius. I would find the cheapest price and the closest distance to the station. Sometimes it was Marathon, sometimes Shell but we were under contract with Shell. That is the way the owner wanted it and they "juggled" the books in case we got audited. Never happened but that is water under the bridge as the company is out of business. I am sure it still happens today.

Also, the tanks the gasoline is stored in can influence differences as well. This can be caused by excess sediment in older tanks as well as degradation of the tank itself. Older stations, unless recently upgraded, could be using tanks older than your car. All tanks storing gasoline, over time, will degrade. The alloys used in newer tanks are much more resistant to this.

This also is incorrect. In the early 90s the EPA mandated upgrading gas station underground storage tanks. There were 2 options for tanks in service or out of service. For tanks out of service: 1. Remove the tank from the ground. 2. If removal would damage or is too close to a structure, fill it with a mixture of sand and concrete. For tanks in service: 1. Remove the steel tank and replace with a fiberglass tank. This option was used for tanks in the ground for 30 years or more. 2. Leave the steel tank in place and line it with fiberglass. This option was for tanks in the ground 20 years or less. It made economic sense with this option instead of removing the tank if it was still usable. With these options there are virtually no tanks with sediment in the bottom as all tanks have been upgraded or replaced. The gas no longer comes in contact with steel except in the pump itself.

If none of this was enough, last year one of the local stations took unlabeled gasoline to an independant laboratory and had them tested. None of them varied greatly from one another.