How Much Money/Fuel is Saved ?

[Speedbird1]

Regarding all those long-haul 744 flights being replaced by 773 service. I am curious how much fuel and expense is saved by flying let's say a 773 from JFK to Japan or Korea. I guess that 2 engines are cheaper than 4.

[Delta777LR]

Pretty much true, 2 engines save alot of fuel than 4 engines probably by 10% if im not mistaking. Thats pretty much why the 77Ws have been replacing the 747s, im starting to see the same thing with the Airbus A340s too. A number of airlines have been switching from A340s to 777s. But yes the 777s are more fuel efficient than the A340s/747s.

[cancidas]

someone once told me that a 777 burns a little more than half the fuel a 747 does.

[lijk604]

When I was at UAL and was working the JFK-NRT flights, the B744's at that time would routinely depart with 350,000 - 375,000 lbs of fuel. Depending on payload & winds of course. I do remember a few times it was topped off...383,500lbs of Jet-A. If someone who works with a trip-7 now can compare numbers we can get a good idea of the savings, just in fuel alone.

[AA 777]

I'd say in the ballpark of 230.0 for the 777 to NRT....

[lijk604]

Ok, let say we use 350,000 for the 744, and 230,000 for the trip 7.
Your saving 120,000 pounds of fuel. At 6.75#/gal that's 17,777 gallons of Jet-A.
Let's use a $2.50/gal airline Jet-A price. That means by switching to the B777 an airline can save over $44,000 per FLIGHT.
Remember, that is a low number too, because they are also only putting wear and tear on two engines vs. four. The B747 has 18 tires, the B777 has 14, so you are saving on tire wear on 4 tires per flight. Etc...etc...etc.

[Idlewild]

How about fuel used vs loads carried? Isn't the 744 able to carry more loads?

[Mateo]

The 747 can carry more load, but even if you figure 1000/pax for a standard international fare, that means you have to scrape up 44 more people (also extra cabin crew, so reduce the margin a little). Airlines will choose the aircraft that's optimum for the route pairing. Sometimes you want frequency (BA or AF downgrading from 747s to 777s and the Airbus), sometimes you have to go for efficiency (KE or JL going to the 777s), and sometimes you just have to haul the bodies (LY mostly keeping the 744 on JFK).