This paper describes improvements in the design of conventional copper-brass radiators that should provide increased thermal performance, durability, and reduced material cost. A 1-row, and an improved 2-row design is described that has lower air and coolant pressure drop, and lower material costs than a conventional multi-row design. A parametric study describes how changes in core geometry affect thermal and pressure drop performance, and core weight. Several mechanical design improvements are identified, which reduce stress in the radiator tube-header joint. Design equations supporting the design recommendations are also given or referenced. Work in progress leading to reduced fin corrosion is also reviewed.