CSF vs OEM: The new 964/993 Condenser utilizes a modern parallel-flow core design. parallel-flow condensers are far more efficient than old serpentine style designs like the OEM unit for the 964/993. Key Differences and Improvements: Increased performance: Approximately 5% better performance than a brand-new OEM condenser and much larger improvement over a clogged or dirty unit that has been installed for some time. Optimized for R134a: Helps recover some of the cooling power lost in a refrigerant conversion. Improved Durability: More robust design and construction materials. Less Expensive: Around half the price of a new Genuine Porsche unit.