By contrast, straight antifreeze will freeze at about 0 to minus 20 degrees.

Furthermore, antifreeze doesn’t absorb heat from your engine as well as water does.Īlthough the specifics vary somewhat, the widely recommended solution of a 50/50 mix of antifreeze and water will freeze at about minus 35 degrees Fahrenheit. Why should you always mix antifreeze and water? Because - against all logic - straight antifreeze will freeze at a higher temperature than the usual 50/50 mix of antifreeze and water. Related: Why Is My Car Leaking Coolant? Useful Coolant Terminology and FactsĪntifreeze is mostly straight ethylene glycol or propylene glycol, which is very poisonous, while coolant is the result of mixing antifreeze with water, which you should always do. If you want to skip right to checking whether you have enough, you can scroll down to “Checking Your Coolant Level.” If you want to skip to testing your level of protection, you can scroll down to “Checking the Freezing Point.” There are two checks you can easily do on your coolant, or the mixture of antifreeze and water: whether you have enough of it and if it’s still protecting your engine in cold temperatures. If a vehicle’s cooling system only used water, the engine would freeze in cold temperatures, leading to cracking and failure. It also adds antifreeze protection and acts as a lubricant for some of the engine’s components. As engines get very hot, coolant helps distribute heat to help prevent overheating and engine damage.

Radiator coolant level