At this point the 737 Max 8 and A320 both are sitting around an 18:1 L/D. You can't really go a whole lot higher than that without affecting controllability. Things like winglets give you incremental improvements on the order of single digit percentages.
But weight savings... that's huge. For every pound you shave off, all other things equal, means the engine needs to make less thrust and the aircraft itself needs to carry less fuel.
At this point the 737 Max 8 and A320 both are sitting around an 18:1 L/D. You can't really go a whole lot higher than that without affecting controllability. Things like winglets give you incremental improvements on the order of single digit percentages.
But weight savings... that's huge. For every pound you shave off, all other things equal, means the engine needs to make less thrust and the aircraft itself needs to carry less fuel.