2011 Subaru Impreza Owner's Manual - Page 391

11-40 Maintenance and service Washer fluid level gauge level gauge or the "FULL" mark on the tank. Use windshield washer fluid. If windshield washer fluid is unavailable use clean water. In areas where water freezes in winter, use an anti-freeze type windshield washer fluid. SUBARU Windshield Washer Fluid contains 58.5% methyl alcohol and 41.5% surfactant, by volume. Its freezing temperature varies according to how much it is diluted, as indicated in the following table. Washer Fluid Concentration 30% 50% 100% Freezing Temperature 10.48F (−128C) −48F (−208C) −498F (−458C) a different concentration from the one used previously, purge the old fluid from the piping between the reservoir tank and washer nozzles by operating the washer for a certain period of time. Otherwise, if the concentration of the fluid remaining in the piping is too low for the outside temperature, it may freeze and block the nozzles. CAUTION . Adjust the washer fluid concentration appropriately for the outside temperature. If the concentration is inappropriate, sprayed washer fluid may freeze on the windshield and obstruct your view, and the fluid may freeze in the reservoir tank. . State or local regulations on volatile organic compounds may restrict the use of methanol, a common windshield washer antifreeze additive. Washer fluids containing non-methanol antifreeze agents should be used only if they provide cold weather protection without damaging your vehicle's paint, wiper blades or washer system. CAUTION Never use engine coolant as washer fluid because it could cause paint damage. Remove the washer tank filler cap, then check the fluid level indicated by the level gauge (attached to the inside of the cap). If the level is near the "Low" mark, add fluid until it reaches the "Hi" level on the In order to prevent freezing of washer fluid, check the freezing temperatures in the table above when adjusting the fluid concentration to the outside temperature. If you fill the reservoir tank with a fluid with