Soulsea, I have to disagree with your article. If all the gas comes from the same place, then why do all the trucks look different and come from different refineries? I'm going to use Salt Lake City as an example because that is where I'm from. In North Salt Lake there are a few refineries, and each of them have their own companies logo that is visible to the public from a good distance away. These refineries are where the fuel that goes to gas stations is sourced from. If the gas is all the same, and comes from one source, why are there all these different refineries? Why did GM conduct its own testing and determiner who was Top Tier, and write a TSB on it? GM wasn't the only one. Mercedes and a few others did this too. It's just like the oil debate, are all oils the same? The answer is no. Ashland bottles Valvoline and Parts Master oil. Parts Master is cheaper. Why? It lacks some of the protective qualities as Valvoline, thus I would never recommend using Parts Master ATF type VI synthetic transmission fluid which is used in GM vehicles. Even if the gas did come from the same place, I would wonder why each refinery has a different holding unit for each type of gas.