Posted on 1/29/2026

It might seem harmless to top off your windshield washer reservoir with plain water—but doing so can actually create bigger problems for your vehicle, especially during colder months. Here’s why it matters more than most drivers realize. First, water freezes, and that’s a major issue. When water freezes inside your washer reservoir, pump, or lines, it can crack components, clog the system, or completely disable your washer sprayers right when you need them the most. Windshield washer fluid is specially formulated with antifreeze properties, allowing it to function in cold weather while protecting the system from damage. Second, water doesn’t clean as effectively as washer fluid. Road grime, salt, bugs, oil film, and windshield haze won’t break down with plain water alone. Washer fluid contains detergents designed to cut through debris quickly, improving visibility and keeping your windshield clear. Clear visibility ... read more