As the aviation industry continues to prioritize sustainability, questions about fuel efficiency between two iconic aircraft—the Airbus A380 and Boeing 747—are gaining attention. These aircraft have been pivotal in shaping commercial air travel, but their fuel efficiency has become a critical factor in today's environmentally conscious landscape.

The Airbus A380 generally surpasses the Boeing 747 in fuel efficiency per seat mile. This is attributed to its modern engines and larger passenger capacity, which distribute fuel consumption more effectively on a per-passenger basis. However, the Boeing 747-8 Intercontinental narrows this gap with its updated engines and aerodynamics.

According to data from Airbus, the A380 achieves approximately 0.1 miles per gallon (mpg), whereas the older Boeing 747-400 is around 0.2 mpg. Despite appearing less efficient at first glance, the A380's higher passenger capacity improves its mpg per seat on long-haul flights.

Fuel efficiency in these large aircraft is influenced by several factors including design, engine performance, passenger load, and flight length. The A380 benefits from advanced wing profiles and composite materials that enhance aerodynamics compared to older models like the 747-400.

Airlines have mixed opinions regarding these quadjets' operational costs and efficiency. Qatar Airways CEO Akbar Al Baker labeled the A380 as “the biggest mistake we ever made,” due to high maintenance and fuel costs. Conversely, Lufthansa supports the Boeing 747-8 for its range and cargo capacity.

Newer twin-engine aircraft like the Airbus A350 and Boeing 787 offer better fuel efficiency than both jumbo jets. These modern planes are increasingly favored by airlines seeking sustainable operations with lower emissions.

In conclusion, while the Airbus A380 slightly edges out its rival in terms of fuel economy per seat mile, both are being overshadowed by newer twinjets that promise greater efficiency and flexibility.