I remember making that mistake. At an old gas station along the freeway. The batch of fuel stirred up all the water and garbage, and the car would barely run to the next gas station to add better fuel. I wasn't alone, the clue was stalled cars all over the freeway. It made the news and the city closed it down to get the tanks cleaned out. I wouldn't be surprised if the tanker was selling the station a load of water either. I will admit I don't like BP either. It's the only station that has short changed me on fuel with bad pump meters. Happening more than once is deliberate in my opinion. It was probably only that one station's owner. My Dad always said Shell was the best, because they supply all the fuel for aviation. But I tend to go for something cheaper, and I use UDF and Speedway. Both are generally newer stations with clean tanks. I think UDF fuel is supplied by Mobil, and Speedway fuel is supplied by Marathon. But like I said, it's all the same fuel anyway. The percent of alcohol in fuel used to be variable, but it appears to also be all the same now. It's now regulated to not be more than a certain maximum mixed in the fuel. It will vary from state to state per each state's regulations. Gasohol was cool, and ran great in inline fours. And smelled like whiskey to everyone behind you. Gasohol was high percentages of ethanol (grain alcohol) instead of methanol. As high as it could go and still run ok. My I-4 motorcycle got great gas mileage on it, but the V-8 car got terrible mileage using it. Both types of alcohol can cause problems with seals and gaskets and plastic parts on older vehicles from back in the day before alcohol was added to the fuel. Which means anything old enough to run leaded fuel, and a few years past that. The exact year that manufacturers switched over to better parts escapes me. Opinion: Gas stations do not make any money from selling gasoline. They make money from selling all that stuff inside the store. The store that gas stations never used to have. This means that all gas stations are selling the cheapest fuel that they can possibly buy. So it's a good thing actually, that all fuel is the same. And regulated and inspected by the state to be that way.