Oil cooling

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For the cooling of lubricating oil, see oil cooler.

Oil cooling refers to a process in which oil is used as a coolant. The oil is heated by the object it cools and then usually passes through a cooling unit such as an oil cooler, typically a type of radiator, or less commonly a gas decompresser. The cooled oil flows back into the hot object to cool it continuously.

Oil cooling is most commonly used to cool high-performance motorcycle engines that are not water-cooled. The cylinder barrel is air-cooled, as is commonly used for motorcycles, but the cylinder head may require additional cooling. As there is already an oil circulation system available for lubrication, this oil is also piped to the cylinder head and used as a liquid coolant. Compared to an oil system used solely for lubrication, oil cooling requires additional oil capacity, a greater flow rate through the oil pump and also an oil-air oil cooler, or a larger oil cooler if one is already present.

Advantages and disadvantages[edit]


  • Oil has a higher boiling point than water, so it can be used to cool items at a temperature of 100°C or higher. However, pressurised water-cooling may also exceed 100°C.
  • Oil is an electrical insulator, thus it can be used inside of or in direct contact with electrical components.
  • Oil is already used as a lubricant, therefore it may serve in a double use arrangement.


  • Coolant oil may be limited to cooling objects under approximately 200°C - 300°C.
  • Parts are hard to take out and put in after the oil is put in.
  • Water is almost universally available in case coolant needs to be added to the system, but oil is not.
  • Unlike water, oil may be flammable.

Gas cooling[edit]

If the object requiring cooling is hot enough to degrade the cooling oil, a compressed cooled gas would be used. As compressed gas is decompressed, heat is absorbed from surroundings of the gas, in particular, the hot object.

See also[edit]