Brand name gas no longer exists due to the way the gas is shipped by pipe to the tank farms from the ports. They no longer use a pig to seperate the different brands, wow saved us some money that they forgot to pass onto to us. They will even flow diesel after gas, then gas again, and the muck that mixes in the pipe is sold off to be used as fuel for ships. The only difference today is once the gas, it could shell pumped from the ground gas, reaches the chevron tank farm the mojo takes place, the additives, this is what seperates to good gas from gas like arco from my own experience that leaves huge carbon deposits in your combustion chamber steadlily increasing your compression ratio over time. Chevron has techron, many studies have shown it to be the best at reducing carbon deposits over the long term. It doesnt matter the grade either all the grades of any spicific brand use the same additive.