California has a state mandate to blend ethanol with all the gas sold in the state. If the pumps are labeled, not all are, they say up to 10% may be blended. When I asked the station manager just how much ethanol was in the fuel, he didn't know, and wouldn't find out. Three different stations behaved this way. Basically, you buy whatever they offer, whatever it is. Customer satisfaction has absolutely no meaning to the gas distribution industry. Instead consumers are treated like addicts seeking a desparate fix. (Which isn't too far from the truth.) The drug can be "cut" with whatever, and however the dealer sees fit. The consumer generally has no concept of quality product.