Airliners flying slower to save fuel?

[CockpitCat]

Apparently airliners will now cruise at lower altitudes to save fuel. Surely this would mean that, at lower altitudes, more lift (and drag?) will be experienced due to denser atmosphere? Which in turn would mean that the flight duration for the same leg would lengthen?

What are the real pros & cons of flying slower to conserve fuel, given the aerodynamics & physics involved?

[T.O.G.A.]

Slower, I can understand but lower? It takes fuel to get to altitude but jets burn more efficiently at higher altitudes.

Perhaps lower for short distance flights and slower on all flights.

[QFCPT747]

where are your sources from? Because logically air is thinner at higher altitude meaning the plane uses less fuel to fly, though it also goes slower.

[MCM]

Have a quick search through some of the recent threads on this site and you'll see that this topic has been done to death already.

Quick summary... Flying slower to a point fuel burn decreases, but will then increase again... so there is an optimum speed to fly for lowest burn... any faster or slower than that increses the burn.

As to lower... Usually airlines fly low if they want to SPEED UP and are happy to burn the fuel... depending on winds of course!

You have to consider many other factors... fuel isn't the only cost an airline has... crew costs, and the scheduling of flights to fit in with curfews etc all mean that there is a "happy medium" in there somewhere.

[DAL767-400ER]

Have a quick search through some of the recent threads on this site and you'll see that this topic has been done to death already.

Indeed:

http://forums.jetphotos.net/showthread.php?t=43505