The Slatest

Which Airlines Are Most Fuel Efficient? A New Study Helps You Fly Green.

The first plane of the new Hungarian airline ‘Solyom’ flies over the Budapest Liszt Ferenc International Airport on August 18, 2013.

Photo by FERENC ISZA/AFP/Getty Images

Your life may be getting greener by the minute, but when it comes to going on quick weekend getaway or a European vacation, you can’t exactly load up the Prius and set off. You have to fly. The most diligent fliers among us can, of course, tack on their own personal carbon offset tax on a flight so they can sleep better onboard.

But, if you’re still one of those fliers looking for the best deal, and thought all airlines are about the same when it comes to environmental impact, you’d be wrong. That’s according to a new study that ranks the fuel efficiency of U.S carriers, courtesy of the International Council on Clear Transportation.

The study analyzed the fuel efficiency of major U.S. airlines and anointed Alaska Airlines the most fuel-efficient. Rounding out the top five are: Spirit, Hawaiian Airlines, Continental, and Southwest. Delta, US Airways, AirTran, and American Airways brought up the rear, faring below the industry average.

One of the biggest factors in fuel efficiency was the technology of the aircraft, as well as the age of the fleet. The study found that fuel efficiency ranged by 26% from airline to airline. When it came to specific routes that airlines fly, the range is even more striking, as “researchers uncovered an 87% difference in fuel efficiency between Southwest, the most efficient carrier, and Delta, the least, on the Chicago-New York route,” the Guardian reports.

 “Fuel costs are a big concern for airlines now, but these numbers raise real questions about the conventional wisdom that fuel costs by themselves act as a sufficient incentive to drive efficiency in this sector,” one of the report’s authors told Businessweek. The airline industry is the fastest growing source of the greenhouse gas emissions that cause climate change, according to the Guardian, with the United Nations set to meet this month to try to broker a carbon-cutting deal with the airline industry.