How is oil cooled in a Cessna 172?

In the Cessna 172, oil is cooled through an oil cooler. The oil cooler is an essential component that helps maintain the engine's optimal operating temperature by dissipating heat from the oil. As the engine runs, the oil absorbs heat from the engine components. This heated oil is then routed through the oil cooler, which typically uses airflow to lower the temperature of the oil before it returns to the engine.

The efficiency of the oil cooler is critical because it prevents the oil from overheating, which can lead to reduced lubrication properties and potential engine damage. Proper oil temperature is crucial for maintaining engine efficiency, performance, and longevity.

Other methods mentioned in the options, such as mixing oil with fuel or using a water-cooling system, are not applicable to the Cessna 172 as it relies on an air-cooled engine system. Additionally, while air exposure at high speeds can contribute to some degree of cooling, it is not the primary method used in the Cessna 172. Thus, the oil cooler serves as the dedicated and most effective mechanism for cooling the engine oil in this aircraft.