Can You Use Plain Water Instead of Coolant? 10 Facts Every Car Owner Should Know
Can You Use Plain Water Instead of Coolant? 10 Facts Every Car Owner Should Know One of the most common questions we hear at the workshop is: "Can I just top up the radiator with plain water?" The short answer? Only in an emergency. For long-term engine protection, manufacturers recommend using the correct coolant—not plain water. Let's understand why. 1. Coolant Does More Than Prevent Overheating Many people think coolant only keeps the engine cool. In reality, it also: Raises the boiling point Lowers the freezing point Prevents corrosion Lubricates the water pump Protects aluminium engine components It's designed to protect the entire cooling system. 2. Plain Water Can Cause Rust Tap water contains minerals and impurities. Over time these can cause: Rust Corrosion Scale build-up These deposits reduce cooling efficiency and shorten the lifespan of the radiator and engine components. 3. Coolant Protects Aluminium Engines Most modern engines use aluminium cylinder head...