Try do do such bumpy details on a NURBS wheel. At this image resolution, there's practically no difference in the amount of CVs needed for a NURBS model and the amount of polygons for a poly model. It wouldn't save you much (if any) on transformation calculations and memory bandwith, but it'd introduce consideralbe calculation overhead on tesselation.
Actually try to model anything with NURBS... there's a reason the CGI industry jumped to subdivision surfaces.
Actually try to model anything with NURBS... there's a reason the CGI industry jumped to subdivision surfaces.