The PFR (parallel flow) condenser possesses numerous advantages for the automotive designer. Light weight, compact dimensions, low refrigerant charge and high performance are well documented features. In addition, the PF condenser offers a corrosion resistant materials package. This helps to assure a long life in a vehicular application where a corrosive environment is present.The corrosion resistance of the PFR condenser is documented and explained in this paper. Laboratory accelerated corrosion tests (CASS) and field testing in the harsh climate of Montreal gave evidence of the effectiveness of cathodic protection by zinc. Observed (SEM-EDS) zinc diffusion profiles at the critical areas of the condenser characterize the diffusion layers. It is clear that these zinc concentration profiles are responsible for the excellent corrosion resistance.