A liquid which flows through a device to prevent the overheating of this device is called as coolant. It is commonly used in automotive and temperature control applications
Coolant in engine is used to absorb the heat of the engine. It is used in radiator and circulated outside the engine. Water is used as coolant but now a days chemicals are used along with water. They prevent the rusting, cool engine fast and doesn’t freeze. Lubricants are used inside the engine. They are hydrocarbons made up of base oil and additives. Base oil is the product of refining of crude like diesel and petrol and additives are chemicals mixed with base oil for specific purposes. They reduce friction, seals the engines, indicates service life, clean the carbon, cool the engines, preventing breaking of parts and distributes the pressure. Lubricants outside the engine are used as greases and gear oil.