Hawaiian Airlines is looking to curb its soaring fuel costs by putting its wide-body jets on a weight-loss program.

The state's largest carrier is also power washing its jet engines more frequently, reducing the cruising speed on its long-haul flights and towing its planes to the airport runways instead of using the jet engines.

Hawaiian said the fuel conservation efforts are expected to save about $4 million this year.

"We're doing everything we can to save on fuel, and we're exploring other ways to see how we can save," said Charles Nardello, Hawaiian's senior vice president of operations.

In recent years, fuel has replaced labor as the No. 1 cost driver, as the price for a gallon of jet fuel has nearly tripled from about $1.40 a gallon in 2005 to about $4 today.

Last year, Hawaiian spent $291.6 million on fuel, which was an increase of nearly $50 million, or 21 percent, from 2006's $241.7 million.

For consumers, the conservation efforts are a welcome alternative to the airlines' traditional way of dealing with rising fuel costs: Higher ticket prices and new fees.

The cost to fly to and from the West Coast has risen dramatically during the past year, especially after the twin failures of Aloha Airlines and ATA Airlines in the spring.

At the same time, the carriers have added new fees for food, checked-in bags and other services, adding to consumers' growing dissatisfaction with the nation's airline industry.

To be sure, Hawaiian is hardly alone when it comes to airlines cutting their fuel costs.

For instance, Northwest and American airlines are parking their older, less-efficient aircraft. And Delta, like Hawaiian, is reducing its cruising speed on long-distance flights.

But Hawaiian is aiming to become one of the first in the industry to install advanced-technology winglets on its Boeing 767-300 jets.

The airline announced two weeks ago that it plans to invest $10 million to purchase eight winglets for its long-haul aircraft, in a move that will save more than 2 million gallons of jet fuel each year. The 11-foot-tall fin-like attachments, which could be installed by September 2009, will pay for themselves in four years, the airline said.

Nardello said the payoff for many of the smaller fuel-conservation efforts are more immediate.

For instance, the airline is cutting the weight on each of its Boeing 767-300 jets by 3,000 pounds, replacing its passenger seats with lighter seats and by using smaller in-flight service carts. A 767-300s, when filled with passengers, weighs about 360,000 pounds for West Coast flights and 408,000 pounds for flights to Sydney and Manila.

Nardello said lighter seats, which will cost the airline about $1.5 million, will pay for themselves in less than two years.

The airline also has purchased portable air-conditioning units for its Honolulu interisland gates to cool the interiors of Hawaiian's Boeing 717 aircraft in between flights. The portable air conditioners will be used in place of an internal AC system, which are powered by the aircraft's engines.

Nardello said the investment in the portable units will pay for themselves in six months.

"Our No. 1 job is to get you there safely and on time," Nardello said.

"Our No. 2 priority is to get you there as efficiently as possible and to keep prices stable."