I recently switched from less expensive Valero to higher price-point Chevron. First full fill with Chevron and I swore I noticed more responsive acceleration. It may very well be all in my head. It probably is in my head because (according to my wife) my head has a lot of empty space dedicated to thinking about performance vehicles.... Anyway, for me, when I'm ripping down a country road, fresh air coming in through the open windows, Sport exhaust mode engaged and roaring like an angry beast, and I'm feeling like my Mach 1 simply OWNS said road, I don't care about the gas marketing, fuel technology etc. All I know is that I paid $80.00 for Chevron gas, and I am having a blast with the perceived increased performance. Even if it is all in my head.