Fuel consumption data - looking at 787

[JumboShrimp]

I know that these figures are extremely hard to track down, and I personally did not have much luck finding anything.  The reason I was looking was that 787 almost went out of production in ATB, and looking at the comparative advantage, it does not look great.

According to various press releases and inpresize online chat, 787 is supposed to be 17, 20 or 22 percent more fuel efficient vs. previous generation aircraft (A330, 767).

While in AWS, 787 is more efficient than A330, but less fuel efficient than 767-300 and 300ER.

Also, comparing it with A350, 787 has higher fuel consumption, while it has smaller cross-section diameter, lower MTOW.  While the engines are pretty much the same generation.  All this combined makes 787 a tough sell in AWS.

One thing that complicates things is that 787 has more cargo space vs. 767, which does nothing  for us in AWS...

[Sigma]

Read here the exact same question:

https://www.airwaysim.com/forum/index.php/topic,17064.0.html

In particular my post about 4 down.

Or, rather, I can repost it here:

Has Boeing actually explictly mentioned the models it's comparing to when it says "20% better"?  All I can recall reading (or find on a quick search just now) is a Boeing statement in regards to "comparably-sized aircraft" which is a hazy statement at best.  The 787 is, oddly, a very heavy aircraft even empty and, with a much higher fuel capacity can weigh as much as 20% more on takeoff than a 767 or A330; so measured on a number of pounds moved to gallon, the 787 is technically more fuel-efficient even if it consumes the same amount of fuel as a much lighter plane (like the 767 or A330).

You can look at other official Boeing figures to get a rough idea of fuel economy and can see that the "20% figure" that PR throws around just doesn't jive up.  Carrying roughly (give or take a few) pax, the 787 has a fuel tank about 38% larger than a 764ER; and a range of about 44% more.  If indeed the 787 got "20% better fuel economy" it should be able to get a LOT further given it's fuel tank is so much larger.  It should easily go 9100+NM if it was indeed burning 20% less fuel for every pax onboard with as much fuel as it's got, but it can't even come close to that.

Given other Boeing information, I would say that the real-life (rather than PR-speak) fuel economy difference between the 787-8 and the 767-400ER is probably in the 5-10% range on the per-passenger level, and that's at best.

EDIT:  Found a site (  http://www.lissys.demon.co.uk/samp1/index.html  ) that did full modeling of the 787-8 using Piano-X, a tool used by airframe and engine manufacturers including Boeing, and they came up with an estimated fuel economy of 11402 lb/hr at cruise with the GEnx -- almost spot-on what Sami's got here.

[JumboShrimp]

Good thread, thanks Sigma.

What I am wondering is that if the biggest difference (that accounts for extra weight vs. 767) is ability to carry more cargo, which we are not doing in AWS (and not receiving extra revenue from it),  I wonder if it would not make sense to estimate what the fuel consumption would be without cargo.  Maybe it might make sense to tweak the fuel consumption in AWS to be somewhat below 767.

It should also be below A350.  A350 has wider body (more drag), hgher weight - in comparable configuration 787-9 vs. A350-800