It is not recommended to add pure antifreeze (undiluted concentrate) directly to the vehicle's cooling system, as antifreeze needs to be mixed with distilled water or deionized water in a specific ratio to achieve optimal performance. Most commercially available antifreeze concentrates suggest a 1:1 dilution ratio (e.g., mixed with an equal amount of water), which balances anti-boiling, anti-freezing, and anti-corrosion properties. If pure antifreeze is used directly, its excessively high viscosity may reduce heat dissipation efficiency, and the high concentration of ethylene glycol may corrode rubber hoses. When adding antifreeze, you should first check the vehicle manual for requirements, as some models may specify a particular mixing ratio (such as 40% antifreeze + 60% water). The operation should be performed after the engine has completely cooled down. Locate the expansion tank marked with "COOLANT" or a thermometer icon (usually a translucent container with MIN/MAX scale lines), and the liquid level should be maintained between the scale lines. The standard replacement interval is 40,000 to 60,000 kilometres. It is best to use products that meet the same specifications as the original equipment. For example, Toyota models typically use red long-life organic acid technology (OAT) antifreeze.
