Air New Zealand ranks high in fuel efficiency report across Asia's airlines

Air New Zealand ranked third in fuel efficiency among major airlines to fly across the Pacific Ocean, according to a report by the International Council on Clean Transportation.

The report, conducted by the researcher that exposed Volkswagen AG's emissions cheating, showed that Air New Zealand burns an average of one litre of aviation fuel per 35 kilometers.

The ICCT looked at 20 airlines that operate flights from mainland United States to East Asia and Oceania in 2016.

Air New Zealand was narrowly behind private mainland carrier Hainan Airlines and Japan's All Nippon Airways which were tied for the greenest flights - burning average of one litre of aviation fuel per 36km.

Other major findings in the study stated the four-engine Airbus A380 was not fuel-efficient over long distances, while low oil prices had a detrimental impact on airlines investing in new planes, as well as on manufacturers producing a new generation of aircraft.

Airlines flying the double-decker "superjumbo" that is seen as a good replacement for the Boeing 747 - which are being phased out - were found to be just as inefficient, compared with those flying twin-engined planes.

"There's a large gap in fuel efficiency on trans-Pacific flights, leading to excess carbon emissions," study co-author Brandon Graver said.

"A lot of people tend to think that airlines do everything they can to reduce fuel usage because it's good for the bottom line. It turns out that's not the case, especially [now] when fuel is cheap," Graver said.

"It's clear from this study that very large aircraft are bad for airlines and the environment. You tend to think that the larger the plane, the more fuel-efficient it is per passenger, but conventional wisdom turns out to be wrong here."

"For years, Airbus tried to market the A380 as the green giant. This study shows that's just not the case," he said.

The report analysing the environmental friendliness of Asia's airlines found that Australian carrier Qantas was ranked the worst in fuel efficiency.

Qantas was found to burn an average of one litre of aviation fuel per 22km it flew, 64 per cent more than top-ranked Hainan and All Nippon Airways.

"The reason Qantas ranks low in this study is chiefly because we use larger aircraft, fly very long distances and have premium cabins that naturally have fewer people on board," Alan Milne, Qantas head of fuel and environment said in an emailed statement.

The data from the study was compiled from flights in 2016, the most recent period with a full year of data to compare and analyse. Since then, all airlines have taken deliveries of newer generations of green planes and more are flying transpacific routes.

The full report can be read here.

- Additional reporting from the South China Morning Post and Bloomberg