U.S. domestic airline fuel efficiency ranking, 2010

Aviation plays a vital role in the modern global economy, but it is a significant and growing source of greenhouse gas emissions, and of oil demand. GHG emissions from aviation are projected to increase by 4 percent annually through 2050, by which time they might contribute as much as 15 percent of anthropogenic CO2 emissions. And aviation is currently responsible for about 10 percent of global transportation-related oil use, amounting to around 4.5 million barrels per day—a level of consumption that is expected to at least double by 2030.

But surprisingly little public information is available to policymakers, investors, and consumers about airline fuel efficiency and CO2 emissions. This report is a step toward filling that information gap. It ranks the 15 mainline domestic carriers operating in the U.S. in 2010 in terms of their overall in-service fuel efficiency. This is the first such analysis done using publicly available data and adjusting for variations among airlines in business operations, networks, and scale to provide an apples-to-apples comparison.

The analysis is based on fuel-consumption data reported annually by the airlines to the U.S. Bureau of Transportation Statistics. It employs a new methodology, developed by a team of researchers at Federal Aviation Administration’s National Center of Excellence for Aviation Operations Research (NEXTOR) at the University of California, Berkeley, to evaluate an airline’s fuel efficiency relative to both the mobility (straight-line passenger miles between origin and destination) and access (airports served and/or flight frequency) it provides. This approach permits a precise distinction between fuel burned to provide a given level of service and fuel burned as a result of inefficiencies, such as the use of older technology, circuitous routing, or taxiing with two engines instead of one.

The study also includes an analysis of the ten most important city-to-city routes in the continental U.S., to show which carriers were most fuel-efficient on those routes.


  • 26 percent difference between the most-efficient airline (Alaska) and the least-efficient (Allegiant) overall
  • About a third of the variation in fuel efficiency is attributable to aircraft technology, with the remainder due to factors like seating density, percent occupancy, ground operations practices, etc.
  • Weak correlation between fuel-efficiency and profitability
  • On city-city routes, the difference between the most- and least-efficient carriers ranged from 9 percent to 87 percent
  • Route-specific performance tracks overall efficiency poorly; in a number of cases, the most efficient carriers between cities were below average overall.