Extending EPA range by 3% could easily extend real highway range by more. EPA range is city/highway combined. City range is meaningless. Real highway range is mostly about aerodynamics. Throwing out the city start/stop component could bump the boost from the aero wheels higher than 3%, lets say 4% or 5%. But that's still mostly at 55mph. At 80mph the aerodynamic component is much more important - at 80mph the difference might be 6% or 7%
Now you have a difference that matters. Only testing will tell. Testing at 80mph - the speed people really want to drive.
The purpose of the aerodynamic wheels isn't to save money - it is to save time. Better efficiency/more range means fewer stops, less time stopped on a long trip.
If you are going somewhere without superchargers it matters a lot.
I agree the price is steep and I don't like the way they look.
[Source:
Why the 19 Aero Rims will Never Sell]