What's the most fuel efficient airline in America?

Dylan Stableford
ÖLOS ANGELES, CA - APRIL 22: An Alaska Airlines jet passes the air traffic control tower at Los Angles International Airport (LAX) during take-off on April 22, 2013 in Los Angeles, California. Delays have been reported throughout the nation because of the furloughing of air traffic controllers under sequestration. The average delay overnight in the Southern California Terminal Radius Approach Control (TRACON) was was three hours. (Photo by David McNew/Getty Images)

What's the "greenest" airline in America?

In terms of fuel efficiency, it's Alaska Airlines, according to a new report by the International Council on Clean Transportation, which ranked the 15 major domestic carriers operating in the U.S. in 2010.

The rankings, released last week, are based on fuel consumption data provided by Bureau of Transportation Statistics and adjusted for things like number of airports served and frequency of flights.

Alaska Airlines was 11 percent more efficient than the average U.S. carrier, in part because it flies mostly newer Boeing 737 jets and Bombardier turboprops to and from hubs in Seattle and Portland, Ore., limiting the "circuity" of its flying, AviationPros.com noted.

The airline also operates solar-powered boarding ramps and gives passengers "biodegradable forks, knives and spoons and napkins made of corn starch," the Los Angeles Times said. (In 2011, Alaska Airlines conducted weeks of testing using fuel made from cooking oil on regularly scheduled flights.)

Spirit Airlines, 2 percent less efficient than Alaska Air, came in second, followed by Hawaiian Airlines at No. 3.

Allegiant Air, the ultra-low-cost airline, came in last in terms of fuel efficiency in 2010. Allegiant was also the most profitable.

"Profitability and in-service fuel efficiency were not well correlated," the report said.

The ICCT added that some common-sense fuel-saving tips on the ground — like taxiing with one engine instead of two — contributes to airline fuel efficiency.

Below, the full list of U.S. airlines ranked in terms of fuel efficiency.

1. Alaska Airlines
2. Spirit Airlines
2. Hawaiian Airlines
4. Continental Airlines
5. Southwest Airlines
6. Frontier Airlines
7. JetBlue Airways
8. United Airlines
9. Virgin America
10. Sun Country Airlines
11. Delta Airlines
12. US Airways
13. AirTran Airways
14. American Airlines
15. Allegiant Air

Source: International Council on Clean Transportation