Efficient impeller or propeller wherein at least one blade in a set of blades on a hub of said impeller is oriented with respect to the tilted plane rotated clockwise or counter clockwise in an axis perpendicular to the longitudinal axis of said impeller. At least one blade in a set of blades of the multi-set impeller may have the same or different sizes or the same or different tilted plane angle compared to at least one blade of the adjacent set or the blade of one set may have the same or different angle as viewed from the second end of the impeller from a reference plane along the longitudinal axis of the impeller compared to the angle of at least one blade of the adjacent set. The invention also includes: blade arrangement for multi-set impeller, inner hub length variations, and hub shapes for better efficiency and utility.