At some gas stations, you may find signs advertising ethanol-free gas. And, if you're like many people, you may have wondered what makes this gas so different. Is it worth buying over your usual gas? While people have differing opinions on this matter, many swear by non-ethanol gas, and for good reason. This gasoline offers some unique advantages that you won't find with other types of fuel. Fuel Efficiency One reason people prefer ethanol-free gas is because of its increased fuel efficiency.