What device is used to reduce oil temperature by passing it near streams of air or fuel?

The device that is specifically designed to reduce oil temperature by passing it near streams of air or fuel is the oil cooler. Oil coolers function by transferring heat from the oil to the surrounding air or fuel, allowing the oil temperature to drop before it circulates back to the engine components. This temperature regulation is vital in maintaining optimal engine performance and preventing overheating, which can lead to damage or reduced efficiency.

Heat exchangers also play a role in transferring heat between fluids, but they are broader in application and may not specifically address oil cooling in the context presented. Oil filters and thermostats focus on filtration and maintaining fluid temperature regulation, respectively, without the primary function of directly cooling the oil through airflow or fuel streams. Thus, the oil cooler is uniquely suited to fulfill the requirement of reducing oil temperatures in the scenario described.