Originally Posted by
EmailKid
From what I read, 764 wing is designed differently from 763, and not really made for a winglet. My guess the same applies to 777s, otherwise they would be getting them.
764 wing is essentially the same as a 763, with the addition of a raked wingtip device, which serves the same function as a winglet. The same design as the 77W wingtip.
The 777 wing is a more modern, higher-speed design than the 767 and generates significantly less drag to begin with. I believe the issue with the 777 wing is that a blended winglet or raked wingtip would be large and require structural modifications, and the device even then would not deliver the same fuel burn benefits as the 757/767 blended winglet.