Selecting the appropriate hydraulic oil is essential for forklift performance. New forklifts typically need a viscosity of 32 Cst or 48 Cst, whereas older models perform better with higher viscosity oils. Viscosity affects fluid flow and lubrication, impacting energy transfer and wear reduction. Regular maintenance checks are vital to identify issues like leaks or contamination early on. Understanding manufacturer recommendations regarding temperature ranges and additives can enhance machinery longevity. For second-hand forklifts, thicker oils provide better lubrication and sealing due to larger clearances from wear. This guide offers insights into choosing the right hydraulic oil based on age, condition, and environmental factors to ensure efficient operation and prevent costly repairs.