Originally Posted by False Capture
It's a bit unfair comparing the fuel burn of a B747-400 with that of a B777-200. The B777 engines (being more modern in design) are far more efficient than the comparatively older engines on a B747. Therefore, the difference in fuel burn is largely down to technology and not the "2 engines vs 4 engines" topic of this thread.
Correct,
That is why the 748i is more efficient than the 777-300ER, and maybe why Boeing has not sold a 777 this year. The GEnx/Trent 1000 family on the new aircraft either on a twin or a quad are far more efficient than the equivalent current models.
The 787-10 is better than the 777-200, 747-800 better than the 777-300ER, nothing to do with the number of engines, just the type.