Two aircraft in particular, the Airbus A220 and Embraer E195-E2 are frequently described as the world's most efficient small single-aisle passenger airliners. Several industry analyses estimate its per-seat fuel efficiency advantage at roughly 11% compared with the E195-E2 on longer sectors. What Makes The Airbus A220 And Embraer E195-E2 So Fuel Efficient? Credit: ShutterstockComparing aircraft fuel efficiency is considerably more complicated than simply looking at how many gallons of fuel an airplane burns per hour. Credit: ShutterstockThe Airbus A220-300 and Embraer E195-E2 represent the current state of the art in small narrowbody efficiency.