What is car coolant and how does it work in UK vehicles?

Car coolant is a liquid that regulates engine temperature by circulating through the cooling system to prevent overheating in UK vehicles like the Nissan Qashqai or Ford Focus. In the UK, coolant is typically a mixture of water and antifreeze (usually ethylene glycol) that prevents freezing in winter while also raising the boiling point. The standard 50/50 mix protects engines down to -35°C and contains corrosion inhibitors to protect components in popular UK models such as the Vauxhall Corsa and MINI hatchback. Coolant appears blue/green or yellow for easy identification and requires regular replacement as additives deplete over time.

Car coolant, also known as antifreeze, is a liquid mixture that regulates engine temperature by absorbing and dissipating heat. In UK vehicles, it typically consists of a 50/50 blend of ethylene or propylene glycol and water. The coolant circulates through the engine block and radiator, preventing overheating in summer and freezing in winter.

Modern coolants also contain additives to prevent corrosion and lubricate the water pump. The system works as follows:

1. The coolant absorbs heat from the engine.
2. It flows to the radiator, where air cools it.
3. A thermostat controls the flow to maintain optimal temperature (usually 90°C).

In the UK, coolants must meet BS 6580 standards. Silicate-free formulations (like OAT) are common in newer cars like the Vauxhall Corsa or Ford Focus. Always check your vehicle handbook for the correct type – mixing incompatible coolants can cause damage.