Which of the following statements about oil coolers is true?

Oil coolers play a crucial role in maintaining the proper operating temperature of engine oil. When engine oil heats up excessively, it can lose its lubricating properties, which can lead to increased wear and tear on engine components. By regulating the oil temperature through an oil cooler, the oil remains within its optimal operating range, ensuring efficient lubrication and preventing overheating.

While some engines may operate adequately without oil coolers, especially standard vehicles with lower performance demands, the benefits of maintaining oil temperature can lead to enhanced engine longevity and performance. Therefore, it is not accurate to claim they are unnecessary in standard vehicles. Similarly, oil coolers are utilized in various types of engines, not just diesel engines, and they do not directly change the viscosity of the oil; rather, they maintain the oil at temperatures where it retains the proper viscosity characteristics.

By ensuring the oil remains at an ideal temperature, oil coolers contribute significantly to engine health and performance, making the statement about their function in maintaining proper oil temperature the most accurate.