Most assuredly
Winglets convert Drag associated with tip vortices to a small amount of lift. The aerodynamics are complicated and the fixture is expensive, but in directing some of the turbulence to the outboard portion of the winglet, a small amount of otherwise wasted burble "pushes up" the canted underside and can save as much as three percent in Fuel costs. For you Nascar fans, it is similar to "drafting" only it is drafting itself instead of another vehicle.