You're right, it's going to depend on multiple factors, wheel and tire width, offset, weight, and construction. Suspension lowering and wheel design that affect aero resistance. Even how much weight with passengers+cargo, head vs tail winds, rain, etc. Just to say, difficult to quantify unless comparing on a track same day. As I recall, even the out of spec guy mentioned how the ambient temperature and state of charge was different at different times of their track testing day. More aerodynamic wheels help at highway speeds, and lighter wheels help at city (stop and go) speeds, but may hurt at highway speeds if they have an open design that's less aerodynamic.