The problem with this analysis is that it doesn't take into account the fact that better wing profiles also improve performance by reducing drag, as we have seen with sailplanes in the last thirty years.
A modern sailplane can fly at higher speeds than those with thicker wing profiles with less drag, optimizing the lift. This is an approach that modern airliners could follow, optimizing the lift and reduce the drag, to save on fuel, not reducing the speed.
The engine is not the only thing that can be optimized.
A modern sailplane can fly at higher speeds than those with thicker wing profiles with less drag, optimizing the lift. This is an approach that modern airliners could follow, optimizing the lift and reduce the drag, to save on fuel, not reducing the speed.
The engine is not the only thing that can be optimized.
http://soaringcafe.com/2011/01/concordia-supersegler/