Winter weather is extremely harsh on vehicles, with intense snowfalls, sleet, freezing rain and ice. Drivers need to ensure that their vehicle’s windshield wipers are working properly and that they’re fully stocked with plenty of non-freezing windshield washer fluid. You can often save money by making your own windshield washer fluid.
Ammonia and Water - One option is mixing 70 percent water (distilled, preferably) and 30 percent non-sudsing ammonia in a large plastic container fitted with a tight lid. According to ThriftyFun.com, non-sudsing ammonia doesn't freeze and "leaves no residue or detergents on your windshield." You can also add a splash of vinegar to this mixture to help break down grime.
Rubbing Alcohol - Another recipe for homemade windshield washer fluid is combining an ounce of dishwashing liquid (Dawn, Joy, Sunlight) with one-third of a bottle of 70 percent isopropyl rubbing alcohol (or a quarter-bottle of 90 percent isopropyl alcohol), the filling the rest of a large container with distilled water.
Methanol and Water - A third recipe for homemade windshield washer fluid involves combining 10 percent methanol with 90 percent water. You can purchase methanol at industrial supply warehouses and home improvement stores. Some drivers choose to add a few drops of blue food coloring to the mixture.
Considerations and Warnings - Always make sure your homemade windshield washer fluid is contained in a sturdy container with a tightly-fitting lid and is labeled completely on the front to avoid accidental ingestion (keep out of reach of children). Also, consult your vehicle manufacturer if you're concerned about any homemade mixtures possibly damaging the vehicle's hoses or other internal parts. Use caution when combining chemicals; use safety glasses and gloves and wipe up any spills immediately.