For regular cars, it is recommended to replace and refill the antifreeze every 2 years or 40,000 kilometers. Commercial vehicles may require more frequent antifreeze refills. Below is a detailed introduction about antifreeze addition: 1. During car maintenance, pay attention to the antifreeze level. When the antifreeze level drops below the minimum mark, it should be replenished promptly. Note that antifreeze has an expiration period, typically around 2 years, while high-quality antifreeze can last up to 5 years. Using expired antifreeze can cause rust in the engine's water passages, leading to blockages and resulting in engine overheating or even 'boiling over.' 2. When adding antifreeze, keep the following in mind: First, identify the antifreeze filler port, which is usually marked with a thermometer-like triangular symbol on the cap. Second, do not mix different brands or colors of antifreeze, as they may have different compositions and formulas, leading to chemical reactions that can impair the antifreeze's performance. Third, choose a high-quality product of the same brand and model as the original antifreeze. Fourth, antifreeze is somewhat corrosive, so avoid contact with skin and other rubber components. If spilled, rinse immediately with water. Fifth, always add antifreeze when the vehicle is turned off and cooled down to prevent the pressurized hot antifreeze from spraying out and causing burns.
