I make gasoline, and I make A LOT of it. All gasoline starts it’s life as the same thing - RBOB. RBOB is a commodity and every refinery makes RBOB blends to the federal set specifications. What makes Exxon different from Shell is that when they buy the RBOB, they mix in their own lubricants and extras that they believe makes their final blend superior. This is what you are paying for. When you buy from a sketchy looking brand, they may be buying RBOB straight and adding nothing to it. This is NOT good for your engine. Save now and pay later (when your engine fails).