Drawbacks of using water as a coolant:
1. Freezing Point: Water freezes at 0 degrees Celsius (32 degrees Fahrenheit). In cold climates, this means that water-based coolants can freeze and expand, potentially damaging the engine block, cylinder head, and other components.
2. Boiling Point: Water boils at 100 degrees Celsius (212 degrees Fahrenheit) at sea level. This relatively low boiling point can cause the coolant to boil and form steam bubbles in the cooling system, leading to overheating and potential engine damage.
3. Corrosion: Water can cause corrosion of metal components within the cooling system, such as the radiator, water pump, and cylinder head. Corrosion can lead to leaks, blockages, and reduced cooling efficiency.
4. Mineral Deposits: Water can contain dissolved minerals, such as calcium and magnesium, which can form scale and deposits within the cooling system. These deposits can restrict coolant flow, reduce heat transfer, and eventually cause blockages.
5. Lubrication: Water does not provide any lubricating properties, which can increase wear and tear on the water pump and other moving parts of the cooling system.
Usage of Coolants in Modern Cars:
Given these drawbacks, modern vehicles typically use a mixture of water and ethylene glycol or propylene glycol as a coolant. These coolants address the disadvantages of water by providing lower freezing points, higher boiling points, corrosion protection, and lubrication for the cooling system.
Properties of Coolants:
1. Freezing Point: Coolants typically have a freezing point below -35 degrees Celsius (-31 degrees Fahrenheit), ensuring that they remain liquid even in cold weather.
2. Boiling Point: Coolants have a higher boiling point than water, typically around 120-130 degrees Celsius (248-266 degrees Fahrenheit), preventing overheating.
3. Additives: Coolants contain various additives, such as corrosion inhibitors, lubricants, and surfactants, which protect metal components from corrosion, reduce wear, and prevent scale formation.
Changing Coolant:
It's important to follow the vehicle manufacturer's recommendations for coolant maintenance. Coolants do not last indefinitely and should be replaced periodically, usually every 2-3 years or as specified in the owner's manual, to maintain their effectiveness and prevent cooling system issues.
