At what temperature does windshield washer fluid freeze in a car?

[LeJoshua]

In summer, windshield washer fluid will freeze at around 0 degrees Celsius because it does not contain antifreeze substances. Antifreeze windshield washer fluid contains antifreeze agents and will not freeze even when the external temperature drops to approximately -20 degrees Celsius. Cooling function: Cooling is the basic function of coolant. When the engine is running, it generates a large amount of heat, with about 60% of this heat being dissipated into the surrounding space through the cooling system. Water and methanol-based coolants have low boiling points and are prone to boiling. If the vehicle operates under conditions where the coolant is boiling, even for a short period, it can cause engine damage or even complete failure. Anti-corrosion function: Components in the cooling system, such as the radiator, water pump, cylinder block, cylinder head, and water distribution pipes, are made of metals like steel, cast iron, brass, copper, aluminum, and tin. Due to the different electrode potentials of these metals, electrochemical corrosion can easily occur in the presence of an electrolyte. Additionally, acidic byproducts formed from the decomposition of glycol-based substances in the coolant and acidic exhaust gases from fuel combustion may infiltrate the cooling system, accelerating corrosion. Anti-scaling function: Scale in the cooling system originates from cations such as calcium and magnesium ions in the water. Under thermal load conditions, these alkaline earth metal cations readily react with anions in the water to form scale. Scale can wear out the seals of the water pump and accumulate on the outer walls of the cylinder block water jackets, reducing thermal conductivity. This can cause a sharp increase in temperature in high-temperature zones of the cylinder head, leading to cylinder cracking.

[McMaria]

The freezing temperature of windshield washer fluid mainly depends on its formula parameters. Common supermarket varieties are mostly rated for -15°C, meaning they won't freeze above -15°C. For northern regions, it's recommended to choose anti-freeze types rated for -25°C or -30°C. I once used regular washer fluid in Harbin and it froze solid at just -10°C. Remember to check the freezing point marked on the bottle - northern car owners are better off using -30°C fluid. Don't try to save money by diluting it with water, as this raises the freezing temperature and may cause pipes to freeze and crack. Before winter temperatures drop below the fluid's rating, be sure to switch to a higher-grade fluid. Otherwise, the washer pump may burn out when frozen, and repairing the entire cleaning system can be particularly troublesome.

[WestonRose]

I live in Shenyang, and last winter we experienced temperatures as low as -22°C, which completely froze regular windshield washer fluid. Actually, the freezing point of washer fluid entirely depends on its formulation. The basic version usually has an ethanol-based formula, resistant to about -15°C. Those with silicone components can withstand -40°C. When choosing washer fluid, refer to the lowest winter temperature in your area. For example, the Yangtze River region can use -15°C fluid, while northeastern China requires -30°C or lower. Avoid mixing different brands, as some formulations may cause chemical reactions and freeze. If the reservoir freezes, don’t force the washer system to operate—wait until midday when temperatures rise to handle it, otherwise you risk damaging the motor. In an emergency, you can use medical alcohol in a 1:3 ratio to quickly thaw the frozen fluid.

[ValentinaDella]

The freezing point of windshield washer fluid depends on the product specification. Standard fluids typically freeze around -10°C, while antifreeze versions are usually labeled with freezing points of -25°C or -40°C. Northern car owners should choose a product with a freezing point at least 10°C below the local minimum temperature for safety. I once mixed brands, and it froze at -12°C—the repair shop said conflicting formulations raised the freezing point. Avoid buying unlabeled bottles as they might be substandard. When replacing, drain the old fluid completely to prevent mixing, which reduces antifreeze effectiveness. Never force the spray if frozen to avoid motor damage. A hot towel on the nozzle can provide temporary thawing.