The performance of a parallel flow condenser of a domestic vehicle was simulated by using the computer program developed earlier by the author (Mathur, 1997). None of the original correlations for predicting heat transfer, pressure drop, void fraction were changed. The working fluid used in this investigation was R-134a. The simulated performance was compared with the experimentally obtained data from the calorimeter tests. The simulated thermal and hydrodynamic performance was within ±6% of the experimental data. Detailed performance data has been presented in this paper.The performance of the same condenser was optimized by varying the number of tubes in a given pass by fixing all other variables, e.g., tube and fin pitch; tube geometry; height, length, and depth of the condenser; number of passes; and location of the inlet and outlet connections. The investigation revealed that the performance can be improved by 4% in comparison to the base case by changing the number of tubes in the flow pass.