This article presents a detailed examination of the performance characteristics of a high-viscosity spray oil cooling system, utilizing various commercial nozzles. These include one spiral hollow cone nozzle, three full cone nozzles, and three flat fan nozzles, all of which were subjected to experimental investigation. Parameters such as temperature, temperature uniformity, injection pressure, spray coverage, spray patterns, spray angles, spray capacitance, heat transfer coefficient, and spray power consumption were assessed to gauge the system's effectiveness. To conduct these experiments, a dedicated test bench was constructed, and a range of commercial nozzles with different spray patterns (full cone, hollow cone, and flat fan) and spray angles (narrow, medium, and wide) were selected. Through a series of experiments, the influence of various nozzle input parameters was scrutinized, with a focus on heat transfer capabilities, temperature uniformity, and cooling efficiency. The results revealed that increasing the nozzle's inlet pressure significantly improves its performance. Moreover, nozzles with medium to wide spray angles demonstrated the best cooling performance, particularly flat fan nozzles in this category. Based on these findings, the article offers recommendations to enhance temperature regulation and cooling efficiency for improved overall system performance. © 2024