Requirements for fuel economy improvement and reduction in the vehicles engine compartment have increased significantly in the pass years. Performances in radiators have driven changes in terms of compactness and weight reductions. By focusing on the air flow we have optimized the radiator fin and developed a high performance radiator. A similar performance was achieved using an 11mm core depth which has 30% weight reduction compared to a 16mm core depth. The purpose of this paper is to present a technical outline about fin optimization.