Originally Posted by
EMIT
Real figures are 8 to 10 percent lower fuel consumption per distance, at least that is my experience.
I see that SR-22 sort of beat me to the punch, but 8-10 percent is way more than Aviation Partners is claiming. I have a buddy who works there (and worked on the 767 winglets) and he says 4-5% is typical.
Note also there is a significant weight impact - over a ton - to add winglets. Obviously the fuel burn more than makes up for it on a long flight, but they're not well suited to short hop.