Q: It is advisable to add engine antifreeze to a car’s windshield washer water supply tank to keep it from freezing in very cold weather?
A: Do not add engine antifreeze to the windshield washer supply tank. Engine antifreeze will harm your car’s finish and will not work well in cleaning the windshield. Use a product that is specifically designed as a washer fluid and protects against freezing. Buy an all season washer fluid that protects down to -25 degrees F.