Most automotive oil coolers pass heated oil through a radiator-type device equipped with a fan that forces air through coils to dissipate heat, explains About.com. Some systems prevent oil overheating by constantly forcing water or liquid coolant through a maze of tubes. Viscosity is drastically reduced in overheated oil, reducing lubricating efficiency and engine performance.
Oil in an automobile lubricates and helps regulate temperatures of moving metallic components of an engine or transmission. The surfaces of these components cause friction, which generates heat; without a cooler, oil can prematurely break down, eventually resulting in engine wear and failure.
There are two types of oil coolers, the tube and fin system, and the shell and tube system. The tube and fin system is normally located in front of the radiator, and oil passing through copper tubes is cooled by air through the system's fins. The shell and tube system circulates water or liquid coolant around a series of tubes to cool heated oil.
Standard vehicles generally have no need for oil coolers because their radiators are adequate to provide the cooling requirements of engines. Oil coolers are typically installed on specialized vehicles, such as high-performance cars, racing cars, towing trucks and oversized vehicles that haul heavy loads.