Water system

Engine water temperature typically runs around 90 degrees, but can vary depending on the pressure rating of the cooling system's lid. A higher pressure rating can handle higher temperatures before the water boils.

The radiator cap pressure typically falls in the range of 0.9 bar (13 psi), 1.1 bar (16 psi), and 1.38 bar (20 psi). These values are the most commonly observed ones.

Water boils at approximately 100 degrees Celsius. When pressure is increased, the boiling point of water also increases. Conversely, when pressure is reduced, the boiling point decreases. In order to ensure effective cooling, a cooling system is pressurized. Additionally, a hotter engine requires a higher pressure which puts more demands on the cooling system. Glycol is also added to the cooling system to increase the boiling point of the coolant (and decrease its freezing point).