Press release

A 52% gap in carbon intensity of airlines flying between the U.S. and South America

Azul, Frontier, and Volaris operated the most fuel-efficient direct flights between the United States and Latin America in 2018

A new ICCT study compares the fuel efficiency of major airlines operating between the United States and Latin America. Brazilian airline Azul, at 44 passenger-kilometers per liter of fuel (pax-km/L), was the most fuel-efficient airline on direct flights between the United States and South America (SA) in 2018. The least fuel-efficient carrier, TAME, burned 52% more fuel per passenger kilometer than Azul, which operated the fullest planes, in terms of passenger and freight load factors, in the SA market.

U.S. carrier Frontier and Mexican carrier Volaris tied as the most fuel-efficient airlines on nonstop flights in 2018 between the United States and Mexico, Central America, and the Caribbean (MCC operations). Each had an average fuel efficiency of 37 pax-km/L, or 16% better than the industry average. Volaris improved its average fuel efficiency significantly by 9% from 2017 to 2018, mainly by modernizing its fleet with new, highly fuel-efficient Airbus A320neo aircraft.

The belly freight share of total mass carried was the most influential driver of airline fuel efficiency in the U.S.¬–Latin America market, and it explained almost half of the quantifiable variance between the best and worst performers. Other significant operational factors are aircraft fuel burn, which accounted for 19% of the variation, seating density (17%), and passenger load factor, or the amount of passenger carrying capacity used (15%).

“This study shows that operational strategies such as carrying more belly freight can really boost an airline’s fuel efficiency,” said Sola Zheng, the paper’s lead author. “Improving fleet fuel efficiency by 2% annually is crucial to meeting the UN’s climate goals.”

“Consumers still don’t know that which airline you fly makes a big difference in terms of carbon emissions,” said Dan Rutherford, the ICCT’s aviation program director and a co-author of the study. “Airlines should disclose more emissions data to help travelers reduce their environmental footprints.”

The work builds on ICCT’s previous fuel efficiency rankings of U.S. domestic, transpacific, and transatlantic operations by analyzing the fast-growing U.S.–Latin America market. At 42% of the flights, this is the largest international market for the United States. Total revenue passenger kilometers of flights between North America and Latin America are expected to double from 2015 to 2035.

Aviation presently accounts for about 2.4% of global CO2 emissions, but under a business-as- usual scenario, its share could increase to 25% of the 1.5°C global carbon budget by 2050. While the International Civil Aviation Organization (ICAO) is formally committed to pursuing carbon-neutral growth after 2020, achieving this amidst the rapid expansion of passenger air travel and air freight operations requires further action within the sector.

Publication details

U.S.–Latin America airline fuel efficiency ranking, 2017–2018

Authors: Xinyi Sola Zheng and Dan Rutherford


Contact: Sola Zheng, +1 415.818.0206 ext. 1145,, Dan Rutherford, +1 650.336.3536,

Tracking progress