Will using summer windshield fluid in winter damage the car?

[LeahAnn]

Yes. Summer windshield fluid is prone to freezing, which can cause the washer fluid reservoir to malfunction. When selecting windshield fluid, it should be chosen according to the season: In winter, the antifreeze performance should be the selection criterion. Choose a windshield fluid with a freezing point at least 10°C below the local minimum temperature. Otherwise, when the temperature drops in winter, the windshield fluid will freeze and become unusable, leading to issues such as malfunctioning of the washer fluid pump. Use antifreeze windshield washer fluid in winter: It ensures that the car's facilities will not freeze even when the outside temperature is below -20°C; there is also a special antifreeze type that remains unfrozen at -40°C, suitable for use in the extremely cold regions of northern China.

[HarleyFitz]

Actually, the key to this issue depends on the weather in your location. Having lived in the south for over a decade, winter temperatures here mostly stay above freezing, so using summer windshield washer fluid is completely fine. However, friends in the north need to be more cautious. Last year, my cousin in Harbin didn't switch to winter fluid, and when temperatures dropped to -20°C, the reservoir froze and cracked. Summer washer fluid is mainly water and cleaning agents, with no antifreeze properties at all. When it freezes, the expansion can crack plastic reservoirs, not to mention the hoses and pump. The repair cost over 800 yuan, whereas spending just a few dozen yuan on antifreeze washer fluid would have prevented it. Now, every year before winter, I remind my friends to check their washer fluid—it's a crucial habit.

[EmilyRose]

I had a personal experience that really drove the point home. One winter, I was driving back to my hometown when it started snowing, and I couldn't spray any windshield washer fluid. It turned out that the leftover summer fluid had frozen and blocked the system. At that time, the wipers were scraping dry, which was really damaging to the windshield. The mechanic later found that the water pump had burned out because the ice had jammed the impeller, causing the motor to overload. The worst part was that the entire piping system could have frozen and cracked. The difference in price between antifreeze washer fluids with different freezing points is only about ten yuan. I learned my lesson and now make sure to switch to winter fluid every November. If your washer fluid won't spray, it's really dangerous when visibility is already poor due to rain or snow.

[LeBrianna]

Simply put, different freezing points can cause trouble. Summer windshield washer fluid is primarily formulated for cleaning and has poor antifreeze performance. Winter windshield washer fluid contains methanol or ethylene glycol, which lowers the freezing temperature. When the temperature drops below the freezing point, regular washer fluid freezes and expands first, potentially clogging the nozzles or even cracking the reservoir. My neighbor learned this the hard way and spent over 600 yuan on repairs. Now I always check the product's freezing point index when buying washer fluid—choosing -25°C for northern regions and -10°C for southern areas, which is sufficient. Don't underestimate this small detail; it's crucial for driving safety.